Brandywine Operating Partnership 10-K21 Feb 232022 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($)	12 Months Ended
Cover Page - USD ($)	Dec. 31, 2022	Feb. 14, 2023	Jun. 30, 2022
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity Registrant Name	Brandywine Realty Trust
Entity Incorporation, State or Country Code	MD
Entity File Number	001-9106
Entity Tax Identification Number	23-2413352
Entity Address, Address Line One	2929 Arch Street
Entity Address, Address Line Two	Suite 1800
Entity Address, City or Town	Philadelphia
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19104
City Area Code	610
Local Phone Number	325-5600
Title of 12(b) Security	Common Shares of Beneficial Interest
Trading Symbol	BDN
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,608,700,263
Entity Common Stock, Shares Outstanding		171,727,703
Documents Incorporated by Reference	Portions of the proxy statement for the 2023 Annual Meeting of Shareholders of Brandywine Realty Trust are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000790816
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Document Information [Line Items]
Entity Registrant Name	Brandywine Operating Partnership, L.P.
Entity Incorporation, State or Country Code	DE
Entity File Number	000-24407
Entity Tax Identification Number	23-2862640
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Central Index Key	0001060386

Audit Information

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Auditor Information [Abstract]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Philadelphia, Pennsylvania
Auditor Firm ID	238

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Real estate investments:
Operating properties	$ 3,617,240	$ 3,472,602
Accumulated depreciation	(1,063,060)	(957,450)
Right of use asset - operating leases, net	19,664	20,313
Operating real estate investments, net	2,573,844	2,535,465
Construction-in-progress	218,869	277,237
Land held for development	76,499	114,604
Prepaid leasehold interests in land held for development, net	35,576	27,762
Total real estate investments, net	2,904,788	2,955,068
Assets held for sale, net	0	562
Cash and cash equivalents	17,551	27,463
Accounts receivable	11,003	11,875
Accrued rent receivable, net of allowance of $3,947 and $4,133 as of December 31, 2022 and December 31, 2021, respectively	179,771	167,210
Investment in unconsolidated real estate ventures	567,635	435,506
Deferred costs, net	96,639	86,862
Intangible assets, net	18,451	28,556
Other assets	78,667	133,094
Total assets	3,874,505	3,846,196
LIABILITIES AND BENEFICIARIES' EQUITY
Unsecured credit facility	88,500	23,000
Unsecured term loan, net	248,168	249,608
Unsecured senior notes, net	1,628,370	1,580,978
Accounts payable and accrued expenses	132,440	150,151
Distributions payable	32,792	32,765
Deferred income, gains and rent	25,082	23,849
Intangible liabilities, net	10,322	12,981
Lease liability - operating leases	23,166	22,962
Other liabilities	52,331	48,683
Total liabilities	2,241,171	2,144,977
Commitments and contingencies (See Note 20)
Brandywine Realty Trust's Equity:
Common Shares of Brandywine Realty Trust's beneficial interest, $0.01 par value; shares authorized 400,000,000; 171,569,807 and 171,126,257 issued and outstanding as of December 31, 2022 and December 31, 2021, respectively	1,716	1,712
Additional paid-in-capital	3,153,229	3,146,786
Deferred compensation payable in common shares	19,601	18,491
Common shares in grantor trust, 1,179,643 and 1,169,703 issued and outstanding as of December 31, 2022 and December 31, 2021, respectively	(19,601)	(18,491)
Cumulative earnings	1,176,195	1,122,372
Accumulated other comprehensive income (loss)	3,897	(2,020)
Cumulative distributions	(2,709,405)	(2,578,583)
Total Brandywine Realty Trust's equity	1,625,632	1,690,267
Noncontrolling interests	7,702	10,952
Total beneficiaries' equity	1,633,334	1,701,219
Total liabilities and partners' equity	$ 3,874,505	$ 3,846,196

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Accrued rent receivable, allowance	$ 3,947	$ 4,133
Common stock, par or stated value per share (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common shares in grantor trust, issued and outstanding (in shares)	1,179,643	1,169,703

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue
Total revenue	$ 506,100	$ 486,819	$ 534,852
Operating expenses
Property operating expenses	130,209	121,890	132,172
Real estate taxes	53,645	53,621	63,032
Third party management expenses	10,547	12,800	10,252
Depreciation and amortization	177,984	178,105	188,283
General and administrative expenses	35,006	30,153	30,288
Provision for impairment	4,663	0	0
Total operating expenses	412,054	396,569	424,027
Gain on sale of real estate
Net gain on disposition of real estate	17,677	142	289,461
Net gain on sale of undepreciated real estate	8,007	2,903	201
Total gain on sale of real estate	25,684	3,045	289,662
Operating income	119,730	93,295	400,487
Other income (expense):
Interest and investment income	1,905	8,295	1,939
Interest expense	(68,764)	(62,617)	(73,911)
Interest expense - amortization of deferred financing costs	(3,091)	(2,836)	(2,904)
Equity in loss of unconsolidated real estate ventures	(22,016)	(26,697)	(18,584)
Net gain on real estate venture transactions	26,718	2,973	75
Loss on early extinguishment of debt	(435)	0	0
Net income before income taxes	54,047	12,413	307,102
Income tax (provision) benefit	(55)	(47)	224
Net income	53,992	12,366	307,326
Net income attributable to noncontrolling interests	(168)	(77)	(1,799)
Net income attributable to Brandywine Realty Trust	53,824	12,289	305,527
Nonforfeitable dividends allocated to unvested restricted shareholders	(456)	(421)	(410)
Net income attributable to Common Shareholders, Basic	$ 53,368	$ 11,868	$ 305,117
Basic income per Common Share (in dollars per shares)	$ 0.31	$ 0.07	$ 1.77
Diluted income per Common Share (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Basic weighted average shares outstanding (in shares)	171,491,369	170,878,185	171,926,079
Diluted weighted average shares outstanding (in shares)	172,325,646	172,273,240	172,317,076
Rents
Revenue
Total revenue	$ 470,851	$ 451,519	$ 513,504
Third party management fees, labor reimbursement and leasing
Revenue
Total revenue	24,132	26,444	18,580
Other
Revenue
Total revenue	$ 11,117	$ 8,856	$ 2,768

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income		$ 53,992	$ 12,366	$ 307,326
Comprehensive income (loss):
Unrealized gain (loss) on derivative financial instruments		5,371	4,817	(5,972)
Amortization of interest rate contracts	[1]	564	752	752
Total comprehensive income (loss)		5,935	5,569	(5,220)
Comprehensive income		59,927	17,935	302,106
Comprehensive income attributable to noncontrolling interest		(186)	(105)	(1,770)
Comprehensive income attributable to Brandywine Realty Trust		$ 59,741	$ 17,830	$ 300,336

[1]Amounts reclassified from comprehensive income to interest expense within the Consolidated Statements of Operations.

CONSOLIDATED STATEMENTS OF BENE

CONSOLIDATED STATEMENTS OF BENEFICIARIES’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Deferred Compensation Payable in Common Shares	Additional Paid-in Capital	Common Shares in Grantor Trust	Cumulative Earnings	Accumulated Other Comprehensive Income (Loss)	Cumulative Distributions	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2019		176,480,095	1,105,542
Beneficiaries' Equity, beginning balance at Dec. 31, 2019	$ 1,688,303	$ 1,766	$ 16,216	$ 3,192,158	$ (16,216)	$ 804,556	$ (2,370)	$ (2,318,233)	$ 10,426
Parent Company
Net income	307,326					305,527			1,799
Other comprehensive income (loss)	$ (5,220)						(5,191)		(29)
Repurchase and retirement of Common Shares of Beneficial Interest (in shares)	(6,248,483)	(6,248,483)
Repurchase and retirement of Common Shares of Beneficial Interest	$ (59,999)	$ (62)		(59,937)
Sale of partnership interest to consolidated real estate venture	(1,017)								(1,017)
Distributions from consolidated real estate venture	(22)								(22)
Share-based compensation activity (in shares)		309,096	50,967
Share-based compensation activity	6,236	$ 3		6,233
Share Issuance from/(to) Deferred Compensation Plan (in shares)		32,256	3,985
Share Issuance from/(to) Deferred Compensation Plan	(206)		$ 1,300	(206)	(1,300)
Reallocation of Noncontrolling Interest	0			(96)					96
Distributions declared	(130,753)							(130,005)	(748)
Ending balance (in shares) at Dec. 31, 2020		170,572,964	1,160,494
Beneficiaries' Equity, ending balance at Dec. 31, 2020	1,804,648	$ 1,707	$ 17,516	3,138,152	(17,516)	1,110,083	(7,561)	(2,448,238)	10,505
Parent Company
Net income	12,366					12,289			77
Other comprehensive income (loss)	5,569						5,541		28
Issuance of Common Shares of Beneficial Interest (in shares)		226,695
Issuance of Common Shares of Beneficial Interest	$ 3,052	$ 3		3,049
Repurchase and retirement of Common Shares of Beneficial Interest (in shares)	0
Issuance of partnership interest in consolidated real estate venture	$ 2,765								2,765
Redemption of LP Units	(2,334)								(2,334)
Share-based compensation activity (in shares)		344,656	70,645
Share-based compensation activity	6,354	$ 2		6,352
Share Issuance from/(to) Deferred Compensation Plan (in shares)		(18,058)	(61,436)
Share Issuance from/(to) Deferred Compensation Plan	(198)		$ 975	(198)	(975)
Reallocation of Noncontrolling Interest	0			(569)					569
Distributions declared	(131,003)							(130,345)	(658)
Ending balance (in shares) at Dec. 31, 2021		171,126,257	1,169,703
Beneficiaries' Equity, ending balance at Dec. 31, 2021	1,701,219	$ 1,712	$ 18,491	3,146,786	(18,491)	1,122,372	(2,020)	(2,578,583)	10,952
Parent Company
Net income	53,992					53,824			168
Other comprehensive income (loss)	$ 5,935						5,917		18
Repurchase and retirement of Common Shares of Beneficial Interest (in shares)	0
Redemption of LP Units	$ (4,006)								(4,006)
Share-based compensation activity (in shares)		469,529	85,384
Share-based compensation activity	7,718	$ 4		7,714
Share Issuance from/(to) Deferred Compensation Plan (in shares)		(25,979)	(75,444)
Share Issuance from/(to) Deferred Compensation Plan	(312)		$ 1,110	(312)	(1,110)
Reallocation of Noncontrolling Interest	(1)			(959)		(1)			959
Distributions declared	(131,211)							(130,822)	(389)
Ending balance (in shares) at Dec. 31, 2022		171,569,807	1,179,643
Beneficiaries' Equity, ending balance at Dec. 31, 2022	$ 1,633,334	$ 1,716	$ 19,601	$ 3,153,229	$ (19,601)	$ 1,176,195	$ 3,897	$ (2,709,405)	$ 7,702

CONSOLIDATED STATEMENTS OF BE_2

CONSOLIDATED STATEMENTS OF BENEFICIARIES’ EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Stockholders' Equity [Abstract]
Distributions declared per Common Share (in dollars per share)	$ 0.76	$ 0.76	$ 0.76

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 53,992	$ 12,366	$ 307,326
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	177,984	178,105	188,283
Amortization of deferred financing costs	3,091	2,836	2,904
Amortization of debt discount/(premium), net	(5,254)	(1,951)	(568)
Amortization of stock compensation costs	8,939	7,130	6,627
Straight-line rent income	(13,631)	(13,485)	(14,743)
Amortization of acquired above (below) market leases, net	(2,581)	(5,377)	(4,867)
Straight-line ground rent expense	814	918	1,455
Provision for doubtful accounts	0	0	1,049
Net gain on real estate venture transactions	(26,718)	(2,973)	(75)
Total gain on sale of real estate	(25,684)	(3,045)	(289,662)
Loss on early extinguishment of debt	435	0	0
Provision for impairment	4,663	0	0
Loss from unconsolidated real estate ventures, including income distributions	23,522	26,697	18,584
Income tax provision (benefit)	55	47	(224)
Changes in assets and liabilities:
Accounts receivable	1,328	2,506	(2,031)
Other assets	(1,120)	(19,325)	(5,034)
Accounts payable and accrued expenses	5,405	2,974	14,374
Deferred income, gains and rent	1,567	2,986	(12,149)
Other liabilities	2,500	465	14,557
Net cash provided by operating activities	209,307	190,874	225,806
Cash flows from investing activities:
Acquisition of properties	(3,446)	0	(41,950)
Proceeds from the sale of properties	64,210	10,303	278,114
Proceeds from insurance	0	1,250	0
Proceeds from note receivable	44,300	50,000	0
Issuance of note receivable	0	0	(50,000)
Capital expenditures for tenant improvements	(86,774)	(56,830)	(73,166)
Capital expenditures for redevelopments	(87,223)	(48,022)	(21,664)
Capital expenditures for developments	(89,017)	(30,269)	(65,420)
Advances for the purchase of tenant assets, net of repayments	(447)	270	1,488
Investment in unconsolidated real estate ventures	(47,428)	(31,643)	(719)
Deposits for real estate	(4,900)	(2,550)	0
Capital distributions from unconsolidated real estate ventures	46,898	27,028	9,001
Leasing costs paid	(26,762)	(19,852)	(17,394)
Net cash provided by (used in) investing activities	(190,589)	(100,315)	18,290
Cash flows from financing activities:
Repayments of mortgage notes payable	0	0	(94,993)
Proceeds from credit facility borrowings	478,000	154,000	318,000
Repayments of credit facility borrowings	(412,500)	(131,000)	(318,000)
Proceeds from unsecured notes	350,000	0	0
Repayments of unsecured notes	(296,134)	0	0
Debt financing costs paid	(9,875)	0	0
Exercise of stock options, net	0	(63)	47
Shares used for employee taxes upon vesting of share awards	(2,941)	(1,762)	(1,346)
Partner contributions to consolidated real estate venture	0	2,765	0
Repurchase and retirement of common shares	0	0	(60,000)
Redemption of limited partnership units	(4,006)	(2,334)	0
Distributions paid to shareholders	(130,724)	(130,255)	(131,150)
Distributions to noncontrolling interest	(451)	(687)	(747)
Net cash used in financing activities	(28,631)	(109,336)	(288,189)
Decrease in cash and cash equivalents and restricted cash	(9,913)	(18,777)	(44,093)
Cash and cash equivalents and restricted cash at beginning of year	28,300	47,077	91,170
Cash and cash equivalents and restricted cash at end of period	18,387	28,300	47,077
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents, beginning of period	27,463	46,344	90,499
Restricted cash, beginning of period	837	733	671
Cash and cash equivalents, end of period	17,551	27,463	46,344
Restricted cash, end of period	836	837	733
Cash and cash equivalents and restricted cash	18,387	28,300	47,077
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2022, 2021 and 2020 of $10,517, $8,689 and $4,650 respectively	85,761	72,391	79,498
Cash paid for income taxes	902	785	688
Supplemental disclosure of non-cash activity:
Dividends and distributions declared but not paid	32,792	32,765	32,706
Extinguishment of debt costs accrued in financing activities	393	0	0
Change in investment in real estate ventures as a result of deconsolidation	107,057	32,761	0
Change in operating real estate from deconsolidation of operating properties	(92,009)	(30,073)	427,710
Change in investment in real estate ventures from deconsolidation of operating properties	0	0	(296,262)
Change in mortgage notes payable from deconsolidation of operating properties	0	0	(220,271)
Change in other assets as a result of deconsolidation of operating properties	(15,048)	(2,688)	1,471
Change in capital expenditures financed through accounts payable at period end	(6,135)	22,744	(9,949)
Change in capital expenditures financed through retention payable at period end	$ (7,165)	$ (613)	$ 284

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Supplemental disclosure:
Capitalized interest	$ 10,517	$ 8,689	$ 4,650

CONSOLIDATED BALANCE SHEETS - B

CONSOLIDATED BALANCE SHEETS - BRANDYWINE OPERATING PARTNERSHIP, L.P. - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Real estate investments:
Operating properties	$ 3,617,240	$ 3,472,602
Accumulated depreciation	(1,063,060)	(957,450)
Right of use asset - operating leases, net	19,664	20,313
Operating real estate investments, net	2,573,844	2,535,465
Construction-in-progress	218,869	277,237
Land held for development	76,499	114,604
Prepaid leasehold interests in land held for development, net	35,576	27,762
Total real estate investments, net	2,904,788	2,955,068
Assets held for sale, net	0	562
Cash and cash equivalents	17,551	27,463
Accounts receivable	11,003	11,875
Accrued rent receivable, net of allowance of $3,947 and $4,133 as of December 31, 2022 and December 31, 2021, respectively	179,771	167,210
Investment in unconsolidated real estate ventures	567,635	435,506
Deferred costs, net	96,639	86,862
Intangible assets, net	18,451	28,556
Other assets	78,667	133,094
Total assets	3,874,505	3,846,196
LIABILITIES AND BENEFICIARIES' EQUITY
Unsecured credit facility	88,500	23,000
Unsecured term loan, net	248,168	249,608
Unsecured senior notes, net	1,628,370	1,580,978
Accounts payable and accrued expenses	132,440	150,151
Distributions payable	32,792	32,765
Deferred income, gains and rent	25,082	23,849
Intangible liabilities, net	10,322	12,981
Lease liability - operating leases	23,166	22,962
Other liabilities	52,331	48,683
Total liabilities	2,241,171	2,144,977
Commitments and contingencies (See Note 20)
Brandywine Operating Partnership, L.P.'s equity:
Accumulated other comprehensive income (loss)	3,897	(2,020)
Total liabilities and partners' equity	3,874,505	3,846,196
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Real estate investments:
Operating properties	3,617,240	3,472,602
Accumulated depreciation	(1,063,060)	(957,450)
Right of use asset - operating leases, net	19,664	20,313
Operating real estate investments, net	2,573,844	2,535,465
Construction-in-progress	218,869	277,237
Land held for development	76,499	114,604
Prepaid leasehold interests in land held for development, net	35,576	27,762
Total real estate investments, net	2,904,788	2,955,068
Assets held for sale, net	0	562
Cash and cash equivalents	17,551	27,463
Accounts receivable	11,003	11,875
Accrued rent receivable, net of allowance of $3,947 and $4,133 as of December 31, 2022 and December 31, 2021, respectively	179,771	167,210
Investment in unconsolidated real estate ventures	567,635	435,506
Deferred costs, net	96,639	86,862
Intangible assets, net	18,451	28,556
Other assets	78,667	133,094
Total assets	3,874,505	3,846,196
LIABILITIES AND BENEFICIARIES' EQUITY
Unsecured credit facility	88,500	23,000
Unsecured term loan, net	248,168	249,608
Unsecured senior notes, net	1,628,370	1,580,978
Accounts payable and accrued expenses	132,440	150,151
Distributions payable	32,792	32,765
Deferred income, gains and rent	25,082	23,849
Intangible liabilities, net	10,322	12,981
Lease liability - operating leases	23,166	22,962
Other liabilities	52,331	48,683
Total liabilities	2,241,171	2,144,977
Commitments and contingencies (See Note 20)
Redeemable limited partnership units at redemption value; 516,467 and 823,983 issued and outstanding as of December 31, 2022 and December 31, 2021, respectively	3,195	11,140
Brandywine Operating Partnership, L.P.'s equity:
General Partnership Capital; 171,569,807 and 171,126,257 units issued and outstanding as of December 31, 2022 and December 31, 2021, respectively	1,623,738	1,689,611
Accumulated other comprehensive income (loss)	3,569	(2,366)
Total Brandywine Operating Partnership, L.P.'s equity	1,627,307	1,687,245
Noncontrolling interest - consolidated real estate ventures	2,832	2,834
Total partners' equity	1,630,139	1,690,079
Total liabilities and partners' equity	$ 3,874,505	$ 3,846,196

CONSOLIDATED BALANCE SHEETS -_2

CONSOLIDATED BALANCE SHEETS - BRANDYWINE OPERATING PARTNERSHIP, L.P. (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accrued rent receivable, allowance	$ 3,947	$ 4,133
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Accrued rent receivable, allowance	$ 3,947	$ 4,133
Common stock, shares, issued (in shares)	171,569,807	171,126,257
Common stock, shares, outstanding (in shares)	171,569,807	171,126,257
BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Class A Units
Redeemable limited partnership units issued (in units)	516,467	823,983
Redeemable limited partnership units outstanding (in units)	516,467	823,983

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS - BRANDYWINE OPERATING PARTNERSHIP, L.P. - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue
Total revenue	$ 506,100	$ 486,819	$ 534,852
Operating expenses
Property operating expenses	130,209	121,890	132,172
Real estate taxes	53,645	53,621	63,032
Third party management expenses	10,547	12,800	10,252
Depreciation and amortization	177,984	178,105	188,283
General and administrative expenses	35,006	30,153	30,288
Provision for impairment	4,663	0	0
Total operating expenses	412,054	396,569	424,027
Gain on sale of real estate
Net gain on disposition of real estate	17,677	142	289,461
Net gain on sale of undepreciated real estate	8,007	2,903	201
Total gain on sale of real estate	25,684	3,045	289,662
Operating income	119,730	93,295	400,487
Other income (expense):
Interest and investment income	1,905	8,295	1,939
Interest expense	(68,764)	(62,617)	(73,911)
Interest expense - amortization of deferred financing costs	(3,091)	(2,836)	(2,904)
Equity in loss of unconsolidated real estate ventures	(22,016)	(26,697)	(18,584)
Net gain on real estate venture transactions	26,718	2,973	75
Loss on early extinguishment of debt	(435)	0	0
Net income before income taxes	54,047	12,413	307,102
Income tax (provision) benefit	(55)	(47)	224
Net income	53,992	12,366	307,326
Nonforfeitable dividends allocated to unvested restricted shareholders	(456)	(421)	(410)
Net income attributable to Common Shareholders, Basic	$ 53,368	$ 11,868	$ 305,117
Basic income per Common Partnership Unit (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Diluted income per Common Partnership Unit (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Basic weighted average common partnership units outstanding (in shares)	171,491,369	170,878,185	171,926,079
Diluted weighted average common partnership units outstanding (in shares)	172,325,646	172,273,240	172,317,076
Rents
Revenue
Total revenue	$ 470,851	$ 451,519	$ 513,504
Third party management fees, labor reimbursement and leasing
Revenue
Total revenue	24,132	26,444	18,580
Other
Revenue
Total revenue	11,117	8,856	2,768
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Total revenue	506,100	486,819	534,852
Operating expenses
Property operating expenses	130,209	121,890	132,172
Real estate taxes	53,645	53,621	63,032
Third party management expenses	10,547	12,800	10,252
Depreciation and amortization	177,984	178,105	188,283
General and administrative expenses	35,006	30,153	30,288
Provision for impairment	4,663	0	0
Total operating expenses	412,054	396,569	424,027
Gain on sale of real estate
Net gain on disposition of real estate	17,677	142	289,461
Net gain on sale of undepreciated real estate	8,007	2,903	201
Total gain on sale of real estate	25,684	3,045	289,662
Operating income	119,730	93,295	400,487
Other income (expense):
Interest and investment income	1,905	8,295	1,939
Interest expense	(68,764)	(62,617)	(73,911)
Interest expense - amortization of deferred financing costs	(3,091)	(2,836)	(2,904)
Equity in loss of unconsolidated real estate ventures	(22,016)	(26,697)	(18,584)
Net gain on real estate venture transactions	26,718	2,973	75
Loss on early extinguishment of debt	(435)	0	0
Net income before income taxes	54,047	12,413	307,102
Income tax (provision) benefit	(55)	(47)	224
Net income	53,992	12,366	307,326
Net (income) loss attributable to noncontrolling interests - consolidated real estate ventures	2	3	(20)
Net income attributable to Brandywine Operating Partnership	53,994	12,369	307,306
Nonforfeitable dividends allocated to unvested restricted shareholders	(456)	(421)	(410)
Net income attributable to Common Shareholders, Basic	$ 53,538	$ 11,948	$ 306,896
Basic income per Common Partnership Unit (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Diluted income per Common Partnership Unit (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Basic weighted average common partnership units outstanding (in shares)	172,036,481	171,770,843	172,907,713
Diluted weighted average common partnership units outstanding (in shares)	172,870,758	173,165,898	173,298,710
BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Rents
Revenue
Total revenue	$ 470,851	$ 451,519	$ 513,504
BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Third party management fees, labor reimbursement and leasing
Revenue
Total revenue	24,132	26,444	18,580
BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Other
Revenue
Total revenue	$ 11,117	$ 8,856	$ 2,768

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - BRANDYWINE OPERATING PARTNERSHIP, L.P. - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income		$ 53,992	$ 12,366	$ 307,326
Comprehensive income (loss):
Unrealized gain (loss) on derivative financial instruments		5,371	4,817	(5,972)
Amortization of interest rate contracts	[1]	564	752	752
Total comprehensive income (loss)		5,935	5,569	(5,220)
Comprehensive income		59,927	17,935	302,106
Comprehensive (income) loss attributable to noncontrolling interest - consolidated real estate ventures		(186)	(105)	(1,770)
Comprehensive income attributable to Brandywine Realty Trust		59,741	17,830	300,336
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Net income		53,992	12,366	307,326
Comprehensive income (loss):
Unrealized gain (loss) on derivative financial instruments		5,371	4,817	(5,972)
Amortization of interest rate contracts	[1]	564	752	752
Total comprehensive income (loss)		5,935	5,569	(5,220)
Comprehensive income		59,927	17,935	302,106
Comprehensive (income) loss attributable to noncontrolling interest - consolidated real estate ventures		2	3	(20)
Comprehensive income attributable to Brandywine Realty Trust		$ 59,929	$ 17,938	$ 302,086

[1]Amounts reclassified from comprehensive income to interest expense within the Consolidated Statements of Operations.

CONSOLIDATED STATEMENTS OF PART

CONSOLIDATED STATEMENTS OF PARTNERS’ EQUITY - USD ($) $ in Thousands	Total	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest - Consolidated Real Estate Ventures	BRANDYWINE OPERATING PARTNERSHIP, L.P.	BRANDYWINE OPERATING PARTNERSHIP, L.P. Accumulated Other Comprehensive Income (Loss)	BRANDYWINE OPERATING PARTNERSHIP, L.P. Noncontrolling Interest - Consolidated Real Estate Ventures	BRANDYWINE OPERATING PARTNERSHIP, L.P. General Partner Capital
Beginning balance (in shares) at Dec. 31, 2019							176,480,095
Partners' Equity, beginning balance at Dec. 31, 2019				$ 1,672,915	$ (2,715)	$ 1,091	$ 1,674,539
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 307,326		$ 1,799	307,326		20	$ 307,306
Other comprehensive income (loss)	(5,220)	$ (5,191)	(29)	(5,220)	(5,220)
Deferred compensation obligation (in shares)							32,256
Deferred compensation obligation	(206)			(206)			$ (206)
Repurchase and retirement of LP units (in shares)							(6,248,483)
Repurchase and retirement of LP units				(59,999)			$ (59,999)
Distributions from consolidated real estate venture	(22)		(22)	(22)		(22)
Share-based compensation activity (in shares)							309,096
Share-based compensation activity	6,236			6,236			$ 6,236
Sale of partnership interest to consolidated real estate venture	(1,017)		(1,017)	(1,017)		(1,017)
Adjustment of redeemable partnership units to liquidation value at period end				3,074			3,074
Distributions declared to general partnership unitholders				(130,005)			$ (130,005)
Ending balance (in shares) at Dec. 31, 2020							170,572,964
Partners' Equity, ending balance at Dec. 31, 2020				1,793,082	(7,935)	72	$ 1,800,945
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	12,366		77	12,366		(3)	$ 12,369
Other comprehensive income (loss)	5,569	5,541	28	5,569	5,569
Deferred compensation obligation (in shares)							(18,058)
Deferred compensation obligation	(198)			(198)			$ (198)
Issuance of LP Units (in shares)							226,695
Issuance of LP Units				3,052			$ 3,052
Repurchase and retirement of LP units				(2,334)			$ (2,334)
Issuance of partnership interest in consolidated real estate venture	2,765		2,765	2,765		2,765
Share-based compensation activity (in shares)							344,656
Share-based compensation activity	6,354			6,354			$ 6,354
Adjustment of redeemable partnership units to liquidation value at period end				(232)			(232)
Distributions declared to general partnership unitholders				(130,345)			$ (130,345)
Ending balance (in shares) at Dec. 31, 2021							171,126,257
Partners' Equity, ending balance at Dec. 31, 2021				1,690,079	(2,366)	2,834	$ 1,689,611
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	53,992		168	53,992		(2)	$ 53,994
Other comprehensive income (loss)	5,935	$ 5,917	$ 18	5,935	5,935
Deferred compensation obligation (in shares)							(25,979)
Deferred compensation obligation	(312)			(312)			$ (312)
Repurchase and retirement of LP units				(4,006)			$ (4,006)
Share-based compensation activity (in shares)							469,529
Share-based compensation activity	$ 7,718			7,718			$ 7,718
Adjustment of redeemable partnership units to liquidation value at period end				7,555			7,555
Distributions declared to general partnership unitholders				(130,822)			$ (130,822)
Ending balance (in shares) at Dec. 31, 2022							171,569,807
Partners' Equity, ending balance at Dec. 31, 2022				$ 1,630,139	$ 3,569	$ 2,832	$ 1,623,738

CONSOLIDATED STATEMENTS OF PA_2

CONSOLIDATED STATEMENTS OF PARTNERS’ EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Distributions to general partnership unitholders (in dollars per share)	$ 0.76	$ 0.76	$ 0.76

CONSOLIDATED STATEMENTS OF CA_3

CONSOLIDATED STATEMENTS OF CASH FLOWS - BRANDYWINE OPERATING PARTNERSHIP L.P. - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 53,992	$ 12,366	$ 307,326
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	177,984	178,105	188,283
Amortization of deferred financing costs	3,091	2,836	2,904
Amortization of debt discount/(premium), net	(5,254)	(1,951)	(568)
Amortization of stock compensation costs	8,939	7,130	6,627
Straight-line rent income	(13,631)	(13,485)	(14,743)
Amortization of acquired above (below) market leases, net	(2,581)	(5,377)	(4,867)
Straight-line ground rent expense	814	918	1,455
Provision for doubtful accounts	0	0	1,049
Net gain on real estate venture transactions	(26,718)	(2,973)	(75)
Total gain on sale of real estate	(25,684)	(3,045)	(289,662)
Loss on early extinguishment of debt	435	0	0
Provision for impairment	4,663	0	0
Loss from unconsolidated real estate ventures, including income distributions	23,522	26,697	18,584
Income tax provision (benefit)	55	47	(224)
Changes in assets and liabilities:
Accounts receivable	1,328	2,506	(2,031)
Other assets	(1,120)	(19,325)	(5,034)
Accounts payable and accrued expenses	5,405	2,974	14,374
Deferred income, gains and rent	1,567	2,986	(12,149)
Other liabilities	2,500	465	14,557
Net cash provided by operating activities	209,307	190,874	225,806
Cash flows from investing activities:
Acquisition of properties	(3,446)	0	(41,950)
Proceeds from the sale of properties	64,210	10,303	278,114
Proceeds from insurance	0	1,250	0
Proceeds from note receivable	44,300	50,000	0
Issuance of note receivable	0	0	(50,000)
Capital expenditures for tenant improvements	(86,774)	(56,830)	(73,166)
Capital expenditures for redevelopments	(87,223)	(48,022)	(21,664)
Capital expenditures for developments	(89,017)	(30,269)	(65,420)
Advances for the purchase of tenant assets, net of repayments	(447)	270	1,488
Investment in unconsolidated real estate ventures	(47,428)	(31,643)	(719)
Deposits for real estate	(4,900)	(2,550)	0
Capital distributions from unconsolidated real estate ventures	46,898	27,028	9,001
Leasing costs paid	(26,762)	(19,852)	(17,394)
Net cash provided by (used in) investing activities	(190,589)	(100,315)	18,290
Cash flows from financing activities:
Repayments of mortgage notes payable	0	0	(94,993)
Proceeds from credit facility borrowings	478,000	154,000	318,000
Repayments of credit facility borrowings	(412,500)	(131,000)	(318,000)
Proceeds from unsecured notes	350,000	0	0
Repayments of unsecured notes	(296,134)	0	0
Debt financing costs paid	(9,875)	0	0
Exercise of stock options, net	0	(63)	47
Shares used for employee taxes upon vesting of share awards	(2,941)	(1,762)	(1,346)
Partner contributions to consolidated real estate venture	0	2,765	0
Repurchase and retirement of common shares	0	0	(60,000)
Redemption of limited partnership units	(4,006)	(2,334)	0
Distributions paid to preferred and common partnership units	(130,724)	(130,255)	(131,150)
Net cash used in financing activities	(28,631)	(109,336)	(288,189)
Decrease in cash and cash equivalents and restricted cash	(9,913)	(18,777)	(44,093)
Cash and cash equivalents and restricted cash at beginning of year	28,300	47,077	91,170
Cash and cash equivalents and restricted cash at end of period	18,387	28,300	47,077
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents, beginning of period	27,463	46,344	90,499
Restricted cash, beginning of period	837	733	671
Cash and cash equivalents, end of period	17,551	27,463	46,344
Restricted cash, end of period	836	837	733
Cash and cash equivalents and restricted cash	18,387	28,300	47,077
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2022, 2021 and 2020 of $10,517, $8,689 and $4,650 respectively	85,761	72,391	79,498
Cash paid for income taxes	902	785	688
Supplemental disclosure of non-cash activity:
Dividends and distributions declared but not paid	32,792	32,765	32,706
Extinguishment of debt costs accrued in financing activities	393	0	0
Change in investment in real estate ventures as a result of deconsolidation	107,057	32,761	0
Change in operating real estate from deconsolidation of operating properties	(92,009)	(30,073)	427,710
Change in investment in real estate ventures from deconsolidation of operating properties	0	0	(296,262)
Change in mortgage notes payable from deconsolidation of operating properties	0	0	(220,271)
Change in other assets as a result of deconsolidation of operating properties	(15,048)	(2,688)	1,471
Change in capital expenditures financed through accounts payable at period end	(6,135)	22,744	(9,949)
Change in capital expenditures financed through retention payable at period end	(7,165)	(613)	284
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Cash flows from operating activities:
Net income	53,992	12,366	307,326
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	177,984	178,105	188,283
Amortization of deferred financing costs	3,091	2,836	2,904
Amortization of debt discount/(premium), net	(5,254)	(1,951)	(568)
Amortization of stock compensation costs	8,939	7,130	6,627
Straight-line rent income	(13,631)	(13,485)	(14,743)
Amortization of acquired above (below) market leases, net	(2,581)	(5,377)	(4,867)
Straight-line ground rent expense	814	918	1,455
Provision for doubtful accounts	0	0	1,049
Net gain on real estate venture transactions	(26,718)	(2,973)	(75)
Loss on promoted interest in unconsolidated real estate venture	0	0	0
Total gain on sale of real estate	(25,684)	(3,045)	(289,662)
Loss on early extinguishment of debt	435	0	0
Provision for impairment	4,663	0	0
Loss from unconsolidated real estate ventures, including income distributions	23,522	26,697	18,584
Income tax provision (benefit)	55	47	(224)
Changes in assets and liabilities:
Accounts receivable	1,328	2,506	(2,031)
Other assets	(1,120)	(19,325)	(5,034)
Accounts payable and accrued expenses	5,405	2,974	14,374
Deferred income, gains and rent	1,567	2,986	(12,149)
Other liabilities	2,500	465	14,557
Net cash provided by operating activities	209,307	190,874	225,806
Cash flows from investing activities:
Acquisition of properties	(3,446)	0	(41,950)
Proceeds from the sale of properties	64,210	10,303	278,114
Proceeds from insurance	0	1,250	0
Proceeds from note receivable	44,300	50,000	0
Issuance of note receivable	0	0	(50,000)
Capital expenditures for tenant improvements	(86,774)	(56,830)	(73,166)
Capital expenditures for redevelopments	(87,223)	(48,022)	(21,664)
Capital expenditures for developments	(89,017)	(30,269)	(65,420)
Advances for the purchase of tenant assets, net of repayments	(447)	270	1,488
Investment in unconsolidated real estate ventures	(47,428)	(31,643)	(719)
Deposits for real estate	(4,900)	(2,550)	0
Capital distributions from unconsolidated real estate ventures	46,898	27,028	9,001
Leasing costs paid	(26,762)	(19,852)	(17,394)
Net cash provided by (used in) investing activities	(190,589)	(100,315)	18,290
Cash flows from financing activities:
Repayments of mortgage notes payable	0	0	(94,993)
Proceeds from credit facility borrowings	478,000	154,000	318,000
Repayments of credit facility borrowings	(412,500)	(131,000)	(318,000)
Proceeds from unsecured notes	350,000	0	0
Repayments of unsecured notes	(296,134)	0	0
Debt financing costs paid	(9,875)	0	0
Exercise of stock options, net	0	(63)	47
Shares used for employee taxes upon vesting of share awards	(2,941)	(1,762)	(1,346)
Partner contributions to consolidated real estate venture	0	2,765	0
Repurchase and retirement of common shares	0	0	(60,000)
Redemption of limited partnership units	(4,006)	(2,334)	0
Distributions paid to preferred and common partnership units	(131,175)	(130,942)	(131,897)
Net cash used in financing activities	(28,631)	(109,336)	(288,189)
Decrease in cash and cash equivalents and restricted cash	(9,913)	(18,777)	(44,093)
Cash and cash equivalents and restricted cash at beginning of year	28,300	47,077	91,170
Cash and cash equivalents and restricted cash at end of period	18,387	28,300	47,077
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents, beginning of period	27,463	46,344	90,499
Restricted cash, beginning of period	837	733	671
Cash and cash equivalents, end of period	17,551	27,463	46,344
Restricted cash, end of period	836	837	733
Cash and cash equivalents and restricted cash	18,387	28,300	47,077
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2022, 2021 and 2020 of $10,517, $8,689 and $4,650 respectively	85,761	72,391	79,498
Cash paid for income taxes	902	785	688
Supplemental disclosure of non-cash activity:
Dividends and distributions declared but not paid	32,792	32,765	32,706
Extinguishment of debt costs accrued in financing activities	393	0	0
Change in investment in real estate ventures as a result of deconsolidation	107,057	32,761	0
Change in operating real estate from deconsolidation of operating properties	(92,009)	(30,073)	427,710
Change in investment in real estate ventures from deconsolidation of operating properties	0	0	(296,262)
Change in mortgage notes payable from deconsolidation of operating properties	0	0	(220,271)
Change in other assets as a result of deconsolidation of operating properties	(15,048)	(2,688)	1,471
Change in capital expenditures financed through accounts payable at period end	(6,135)	22,744	(9,949)
Change in capital expenditures financed through retention payable at period end	$ (7,165)	$ (613)	$ 284

CONSOLIDATED STATEMENTS OF CA_4

CONSOLIDATED STATEMENTS OF CASH FLOWS - BRANDYWINE OPERATING PARTNERSHIP L.P. (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Capitalized interest	$ 10,517	$ 8,689	$ 4,650
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Capitalized interest	$ 10,517	$ 8,689	$ 4,650

ORGANIZATION OF THE PARENT COMP

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP	1. ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP Brandywine Realty Trust (the Parent “Company”) is a self-administered and self-managed real estate investment trust (“REIT”) engaged in the acquisition, development, redevelopment, ownership, management, and operation of a portfolio of office and mixed-use properties. The Parent Company owns its assets and conducts its operations through Brandywine Operating Partnership, L.P. (the “Operating Partnership”) and subsidiaries of the Operating Partnership. The Parent Company is the sole general partner of the Operating Partnership and, as of December 31, 2022, owned a 99.7% interest in the Operating Partnership. The Parent Company’s common shares of beneficial interest are publicly traded on the New York Stock Exchange under the ticker symbol “BDN.” The Parent Company, the Operating Partnership, and their consolidated subsidiaries are collectively referred to as the “Company.” As of December 31, 2022, the Company owned 77 properties that contained an aggregate of approximately 13.6 million net rentable square feet (collectively, the “Properties”). The Company’s core portfolio of operating properties (the “Core Properties”) excludes development properties, redevelopment properties, and properties held for sale. The Properties were comprised of the following as of December 31, 2022: Number of Properties Rentable Square Feet Office properties 67 11,848,707 Mixed-use properties 5 942,334 Core Properties 72 12,791,041 Development property 2 350,488 Redevelopment properties 3 436,659 The Properties 77 13,578,188 In addition to the Properties, as of December 31, 2022, the Company owned 159.9 acres of land held for development. The Company also held a leasehold interest in one land parcel totaling 0.8 acres, acquired through a prepaid 99-year ground lease, and held options to purchase approximately 55.1 additional acres of undeveloped land. As of December 31, 2022, the total potential development that this inventory of land could support under current zoning and entitlements, including the parcels under option, amounted to an estimated 11.9 million square feet. As of December 31, 2022, the Company also owned economic interests in twelve unconsolidated real estate ventures (see Note 4 “Investment in Unconsolidated Real Estate Ventures” for further information). The Properties and the properties owned by the unconsolidated real estate ventures are primarily located in or near Philadelphia, Pennsylvania; Austin, Texas; Metropolitan Washington, D.C.; Southern New Jersey; and Wilmington, Delaware. All references to building square footage, rentable square feet, acres, occupancy percentage, the number of buildings, and tax basis are unaudited. The Company conducts its third-party real estate management services business primarily through seven management companies (collectively, the “Management Companies”): Brandywine Realty Services Corporation (“BRSCO”), BDN Management Inc. (“BMI”), Brandywine Properties I Limited, Inc. (“BPI”), BDN Brokerage, LLC (“BBL”), Brandywine Properties Management, L.P. (“BPM”), Brandywine Brokerage Services, LLC (“BBS”), and BDN GC Services LLC (“BGCS”). Each of BRSCO, BMI and BPI is a taxable REIT subsidiary. BBS, BBL, BPM, and BGCS are tax disregarded entities wholly owned by the taxable REIT subsidiary entities. As of December 31, 2022, the Operating Partnership owned, directly and indirectly, 100% of each of BRSCO, BMI, BPI, BBL, BPM, BBS, and BGCS. As of December 31, 2022, the Management Company subsidiaries were managing properties containing an aggregate of approximately 23.0 million net rentable square feet, of which approximately 13.6 million net rentable square feet related to Properties owned by the Company and approximately 9.4 million net rentable square feet related to properties owned by third parties and unconsolidated real estate ventures.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Dec. 31, 2022
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Change in Depreciable Lives of Real Estate Investments In accordance with its policy, the Company reviews the estimated useful lives of its real estate investments on an ongoing basis. The estimated useful lives of seven operating properties in Austin, Texas were modified to reflect the estimated periods during which these assets will remain in service pursuant to the Company's Uptown ATX master development plans. The estimated useful lives of these properties were decreased from approximately 35 to approximately 12 coinciding with the remaining terms of in-place leases. The effect of this change in estimate was a $9.8 million and $14.6 million increase in depreciation expense during the years ended December 31, 2021 and 2022, respectively. Principles of Consolidation The Company consolidates variable interest entities (“VIEs”) in which it is considered to be the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or that the holders of the equity investment at risk do not have a controlling financial interest. The primary beneficiary is defined by the entity having both of the following characteristics: (i) the power to direct those matters that most significantly impact the activities of the VIE and (ii) the obligation to absorb losses or the right to receive benefits of the VIE that could potentially be significant to the VIE. For entities that the Company has the obligations to fund losses, its maximum exposure to loss is not limited to the carrying amount of its investments. The Company continuously assesses its determination of the primary beneficiary for each entity and assesses reconsideration events that may cause a change in the original determinations. As of December 31, 2022 and 2021, the Company included in its consolidated balance sheets consolidated VIEs having total assets of $47.3 million and $46.5 million, respectively, and total liabilities of $21.0 million, respectively. When an entity is not deemed to be a VIE, the Company consolidates entities for which it has significant decision making control over the entity’s operations. The Company’s judgment with respect to its level of influence or control of an entity involves consideration of various factors including the form of the Company’s ownership interest, its representation in the entity’s governance, the size of its investment (including loans), estimates of future cash flows, its ability to participate in policy making decisions and the rights of the other investors to participate in the decision making process and to replace the Company as manager and/or liquidate the venture, if applicable. The Company’s assessment of its influence or control over an entity affects the presentation of these investments in the Company’s consolidated financial statements. In addition to evaluating control rights, the Company consolidates entities in which the outside partner has no substantive kick-out rights to remove the Company as managing member. The portion of the consolidated entities that are not owned by the Company is presented as noncontrolling interest as of and during the periods consolidated. All intercompany transactions have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Operating Properties Operating properties are carried at historical cost less accumulated depreciation and impairment losses. The value of operating properties reflects their purchase price or development cost. Acquisition costs related to business combinations are expensed as incurred, whereas the costs related to asset acquisitions are capitalized as incurred. Costs incurred for the renovation and betterment of an operating property are capitalized to the Company’s investment in that property. Ordinary repairs and maintenance are expensed as incurred. Purchase Price Allocation For acquisitions of real estate or in-substance real estate that are accounted for as business combinations, we recognize the assets acquired (including the intangible value of acquired above- or below-market leases, acquired in-place leases and tenant relationship values), liabilities assumed, noncontrolling interests, and previously existing ownership interests at fair value as of the acquisition date. Any excess (deficit) of the consideration transferred relative to the fair value of the net assets acquired is accounted for as goodwill (bargain purchase gain). Acquisition costs related to business combinations are expensed as incurred. Acquisitions of real estate and in-substance real estate that do not meet the definition of a business are accounted for as asset acquisitions. The Company generally expects that acquisitions of real estate or in-substance real estate will not meet the definition of business and therefore are accounted for as asset acquisitions, unless specifically noted otherwise. The accounting model for asset acquisitions is similar to the accounting model for business combinations except that the acquisition consideration (including acquisition costs) is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. As a result, asset acquisitions do not result in recognition of goodwill or a bargain purchase gain. Additionally, because the accounting model for asset acquisitions is a cost accumulation model, preexisting interests in the acquired assets, if any, are not remeasured to fair value but continue to be accounted for at their historical cost. Direct acquisition costs are capitalized if an asset acquisition is probable. If we determine that an asset acquisition is no longer probable, no new costs are capitalized and all capitalized costs that are not recoverable are written off. The purchase price is allocated to the acquired assets and assumed liabilities, including land and buildings, as if vacant based on highest and best use for the acquired assets. The Company assesses and considers fair value of the operating properties based on estimated cash flow projections that utilize discount and/or capitalization rates that it deems appropriate, as well as available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known and anticipated trends, and market and economic conditions. The Company allocates the purchase price of properties considered to be business combinations and asset acquisitions to net tangible and identified intangible assets acquired based on fair values. Above-market and below-market in-place lease values for acquired properties are recorded based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) the Company’s estimate of the fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining noncancellable term of the lease (including the below market fixed renewal periods that are considered probable, if applicable). Capitalized above-market lease values are amortized as a reduction of rental income over the remaining noncancellable terms of the respective leases. Capitalized below-market lease values are amortized as an increase to rental income over the remaining noncancellable terms of the respective leases, including any below market fixed-rate renewal option periods that are considered probable. Other intangible assets also include in-place leases based on the Company’s evaluation of the specific characteristics of each tenant’s lease and the Company’s overall relationship with the respective tenant. The Company estimates the cost to execute leases with terms similar to the remaining lease terms of the in-place leases, including leasing commissions, legal and other related expenses. This intangible asset is amortized to expense over the remaining term of the respective leases and any fixed-rate bargain renewal periods. Factors considered by the Company in this analysis include an estimate of the carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases. In estimating carrying costs, the Company includes real estate taxes, insurance, and other operating expenses, and estimates of lost rents at market rates during the expected lease-up periods, which primarily range from four In the event that a tenant terminates its lease, the unamortized portion of each intangible, including in-place lease values and tenant relationship values, is charged to expense and market rate adjustments (above or below) are recorded to revenue. Depreciation and Amortization The costs of buildings and improvements are depreciated using the straight-line method based on the following useful lives: buildings and improvements (5 to 55 years) and tenant improvements (the shorter of (i) the life of the asset (1 to 16 years) or (ii) the lease term). Construction-in-Progress Project costs directly associated with the development or redevelopment and construction of a real estate project are capitalized as construction-in-progress. Construction-in-progress also includes costs related to ongoing tenant improvement projects. In addition, interest, real estate taxes, and other expenses that are directly associated with the Company’s development or redevelopment activities are capitalized beginning when activities necessary to ready the asset for its intended use are in progress and capital expenditures have been made and ending when the property is placed in service. Interest expense is capitalized using the Company’s weighted average interest rate. Internal direct costs are capitalized to projects in which qualifying expenditures are being incurred. See Note 3 “Real Estate Investments,” for more information related to the capitalization of project costs. Ground Leases The Company is the lessee under long-term ground leases classified as operating leases. The Company makes significant assumptions and judgments when determining the discount rate for the lease to calculate the present value of the lease payments. As the rate implicit in the lease is not readily determinable, the Company estimates the incremental borrowing rate (“IBR”) that it would need to pay to borrow, on a collateralized basis, an amount equal to the lease payments in a similar economic environment, over a similar lease term. The Company utilizes a market-based approach to estimate the IBR for each individual lease. The base IBR is estimated utilizing observable mortgage and corporate bond rates, which are then adjusted to account for considerations related to the Company’s credit rating and the lease term to select an incremental borrowing rate for each lease. The right of use assets and lease liabilities are presented as “Right of use asset - operating leases, net” and “Lease liability - operating leases”, respectively, on the consolidated balance sheet as of December 31, 2022 and 2021, respectively. The lease liabilities and right of use assets are amortized on a straight-line basis over the lease term with the corresponding expense classified in “Property operating expenses” on the consolidated statements of operations. The most recent CPI adjustment is used to determine the present value of the lease payments for an indexed lease and ultimately the right of use asset and corresponding lease liability. Rent payments for amounts in excess of this estimated growth rate will be expensed on a cash basis as incurred and are considered variable lease costs. Impairment of Real Estate Investments The Company reviews its real estate investments for impairment following the end of each quarter for each of its real estate investments where events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company updates leasing and other assumptions regularly, paying particular attention to real estate investments where there is an event or change in circumstances that indicates an impairment in value. Additionally, the Company considers strategic decisions regarding the future development plans for real estate investment under development and other market factors. For real estate investments to be held and used, the Company analyzes recoverability based on the estimated undiscounted future cash flows expected to be generated from the operations and eventual disposition of the assets over, in most cases, a 10-year hold period. If there is significant possibility that the Company will dispose of assets earlier, it analyzes the recoverability using a probability weighted analysis of the undiscounted future cash flows expected to be generated from the operations and eventual disposition of each asset using various probable hold periods. If the recoverability analysis indicates that the carrying value of the tested real estate investment is not recoverable, the real estate investment is written down to its fair value and an impairment is recognized in the amount of the excess of the carrying amount of the asset over its fair value. If and when the Company’s plans change, it revises its recoverability analysis to use cash flows expected from operations and eventual disposition of each asset using hold periods that are consistent with its revised plans. Estimated future cash flows used in such analysis are based on the Company’s plans for the real estate investment and its views of market economic conditions. The estimates consider assumptions, including but not limited to market rental rates, capitalization rates, and recent sales data for comparable real estate investments. Future cash flows are discounted when determining fair value of an asset. Most of these assumptions are influenced by our direct experience with the real estate investments and their markets as well as market data obtained from real estate leasing and brokerage firms. Assets Held for Sale The Company generally reclassifies assets to held for sale when the transaction has been approved by its Board of Trustees, or by officers vested with authority to approve the transaction, and there are no known significant contingencies relating to the sale of the real estate investment within one year of the consideration date and the consummation of the transaction is otherwise considered probable. When a real estate investment is designated as held for sale, the Company stops depreciating the real estate investment and estimates the real estate investment’s fair value, net of selling costs. If the determination is made that the estimated fair value, net of selling costs, is less than the net carrying value of the real estate investment, an impairment is recognized, reducing the net carrying value of the real estate investment to estimated fair value less selling costs. For periods in which a real estate investment is classified as held for sale, the Company classifies the assets and liabilities, as applicable, of the real estate investment as held for sale on the consolidated balance sheet for such periods. Impairment of Land Held for Development When demand for build-to-suit properties declines and the ability to sell land held for development deteriorates, or other market factors indicate possible impairment in the recoverability of land held for development, it is reviewed for impairment by comparing its fair value to its carrying value. If the estimated sales value is less than the carrying value, the carrying value is written down to its estimated fair value. Estimated fair value is generally determined using a market valuation approach, comparing the subject property to recent comparable market transactions in a similar location; or using estimated cash flows. Cash and Cash Equivalents Cash and cash equivalents are highly-liquid investments with original maturities of three months or less. The Company maintains cash equivalents in money market accounts with financial institutions in excess of insured limits, but believes this risk is mitigated by only investing in or through major financial institutions. The Company does not invest its available cash balances in money market funds. As such, available cash balances are appropriately reflected as cash and cash equivalents on the consolidated balance sheets. Restricted Cash Restricted cash consists of cash held as collateral to provide credit enhancement for the Company’s mortgage debt, cash for property taxes, capital expenditures and tenant improvements. Restricted cash also includes cash held by qualified intermediaries for possible investments in like-kind exchanges in accordance with Section 1031 of the Internal Revenue Code in connection with sales of the Company’s properties. Restricted cash is included in “Other assets” in the consolidated balance sheets. Accounts Receivable and Accrued Rent Receivable Generally, leases with tenants are accounted for as operating leases. Minimum lease payments under tenant leases are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payment terms are recorded as “Accrued rent receivable, net” on the consolidated balance sheets. Included in current tenant receivables are tenant reimbursements which are comprised of amounts recoverable from tenants for common area maintenance expenses and certain other recoverable expenses that are recognized as revenue in the period in which the related expenses are incurred. Accrued rent receivables are carried net of the allowances for doubtful accounts. The allowance for doubtful accounts is an estimate based on the Company's experience of the probability of future events confirming a loss and represents the estimated probable losses. The allowance is generally calculated by assigning risk factors by industry which are primarily based on the Company's historical collection and charge-off experience adjusted for current market conditions, which requires management's judgment. Investments in Unconsolidated Real Estate Ventures Under the equity method, investments in real estate ventures are recorded initially at cost and subsequently adjusted for equity in earnings, contributions, distributions, and impairments. The Company generally allocates income and losses from the unconsolidated real estate ventures based on the venture's distribution priorities, which may be different from its stated ownership percentage. For real estate ventures that are constructing assets to commence planned principal operations, the Company capitalizes interest expense to the extent that it is recoverable using the Company’s weighted average interest rate of consolidated debt and its investment balance as a basis. Planned principal operations commence when a property is available to lease and at that point in time, the Company ceases capitalizing interest to its investment basis. At least quarterly, management assesses whether there are any other than temporary impairment indicators of the Company’s investments in real estate ventures. If any indicators of impairment are present, we calculate the fair value of the investment in the unconsolidated real estate venture. An investment is other than temporarily impaired only if the fair value of the investment in a real estate venture, as estimated by management, is less than the carrying value and the decline is other than temporary. To the extent that an other than temporary impairment has occurred, an impairment charge is recorded in the amount of the excess of the carrying amount of the investment over the estimated fair value. Management is required to make significant judgments about the estimated fair value of its investments to determine if an impairment exists. Fair value is generally determined through income valuation approaches, including discounted cash flows and direct capitalization models. When the Company acquires an interest in or contributes assets to a real estate venture project, the difference between the Company’s cost basis in the investment and the value of the real estate venture or asset contributed is amortized over the life of the related assets, intangibles, and liabilities and such adjustment is included in the Company’s share of equity in income of unconsolidated real estate ventures. Deferred Costs Certain costs incurred in connection with property leasing are capitalized as deferred leasing costs. Deferred leasing costs consist primarily of third-party and internal leasing commissions that are amortized using the straight-line method over the life of the respective lease which generally ranges from 1 to 16 years. Management re-evaluates the remaining useful lives of leasing costs in conjunction with changes in the respective lease term. Notes Receivable The Company accounts for notes receivable on its balance sheet at amortized cost, net of allowance for loan losses. Interest income is recognized over the term of the notes receivable and is calculated based on the contractual terms of each note agreement. At inception and on a quarterly basis, the Company evaluates notes receivable for the current estimate of expected credit losses over the contractual term using a probability-of-default method and reports in net income (as a credit loss expense) the amount necessary to adjust the allowance for credit losses to reflect management's current estimate. Management considers performance and/or value of the underlying collateral property as well as the financial and operating capability of the borrower/sponsor in its evaluation. Notes receivable are placed on nonaccrual status when management determines, after considering economic and business conditions and collection efforts, that the loans are impaired, or collection of interest is doubtful. Uncollectible interest previously accrued is recognized as bad debt expense. Interest income on nonaccrual loans is recognized only to the extent that cash payments are received. Deferred Financing Costs Costs incurred in connection with debt financing are capitalized as a direct deduction from the carrying value of the debt, except for costs capitalized related to the Company’s unsecured credit facility, which are capitalized within the “Deferred costs, net” caption on the accompanying consolidated balance sheets. Deferred financing costs are charged to interest expense over the terms of the related debt agreements. Deferred financing costs consist primarily of loan fees which are amortized over the related loan term on a basis that approximates the effective interest method. Deferred financing costs are accelerated, when debt is extinguished, as part of the “Interest expense-amortization of deferred financing costs” caption within the Company’s consolidated statements of operations. Original issue discounts are recognized as part of the gain or loss on extinguishment of debt, as appropriate. Revenue Recognition Rental Revenue The Company generates revenue under leases with tenants occupying the Properties. Generally, leases with tenants are accounted for as operating leases. The operating leases have various expiration dates. As of December 31, 2022 and 2021, the Company did not have any leases classified as direct-financing or sales-type leases. Fixed lease payments under tenant leases, determined to be collectible, are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payments are recorded as “Accrued rent receivable” on the consolidated balance sheets. Variable lease payments are recognized as lease revenue in the period in which changes occur in facts and circumstances on which the variable lease payments are based. Topic 842 requires a binary approach to evaluating leases for collectability. Lessors are required to determine if it is probable that substantially all of the lease payments will be collected from the tenant over the lease term. Should the lessor determine that it is not probable that substantially all of the lease payments will be collected, the standard requires that the lessor write off any accrued rent receivable and begin recognizing lease payments on a cash basis. The Company’s lease revenue is impacted by the Company’s determination of whether improvements to the property, whether made by the Company or by the tenant, are landlord assets. The determination of whether an improvement is a landlord asset requires judgment. In making this judgment, the Company’s primary consideration is whether an improvement would be utilizable by another tenant upon the then-existing tenant vacating the improved space. If the Company has funded an improvement that it determines not to be landlord assets, then it treats the cost of the improvement as a lease incentive. If the tenant has funded an improvement that the Company determines to be landlord assets, then the Company treats the costs of the improvement as deferred revenue and amortizes these costs into revenue over the lease term. For certain leases, the Company also makes significant assumptions and judgments in determining the lease term, including assumptions when the lease provides the tenant with an early termination option or purchase option. The lease term impacts the period over which the Company determines and records lease payments and also impacts the period over which it amortizes lease-related costs. The Company considers all relevant factors that create an economic incentive for the lessee and uses judgment to determine if those factors, considered together, signify that the lessee is reasonably certain to exercise the option. For leases where a tenant executes a lease termination, termination fees are generally recognized over the modified term of the lease as rental income. Additionally, any deferred rents receivable are accelerated over the modified lease term. The Company’s leases also typically provide for tenant reimbursement of a portion of common area maintenance expenses and other operating expenses to the extent that a tenant’s pro rata share of expenses exceeds a base year level set in the lease or to the extent that the tenant has a lease on a triple net basis. As the timing and pattern of revenue recognition is the same, rents and tenant reimbursements are treated as a combined lease component and included in the “Rents” caption within the Company's consolidated statements of operations. Fixed lease payments include contractual rents under lease agreements with tenants recognized on a straight-line basis over the lease term, including amortization of lease incentives and above or below market rent intangibles, and parking income that is fixed under a long-term contract. Variable lease payments include reimbursements billed to tenants, termination fees, bad debt expense, and parking income that is not fixed under a long-term contract. Point of Sale Revenue Point of sale revenue consists of parking, restaurant, and flexible stay revenue from the Company’s hotel operations. Point of sale service obligations are performed daily, and the customer obtains control of those services simultaneously as they are performed. Accordingly, revenue is recorded on an accrual basis as it is earned, coinciding with the services that are provided to the Company’s customers. Parking and flexible stay revenue is recognized within rents and restaurant income is recognized within other income on the consolidated statements of operations. Third party management fees, labor reimbursement, and leasing The Company performs property management services for its managed real estate ventures and third-party property owners of real estate that consist of: (i) providing leasing services, (ii) property inspections, (iii) repairs and maintenance monitoring, and (iv) financial and accounting oversight. For these services, the Company earns management fees monthly, which are based on a fixed percentage of each managed property’s financial results, and is reimbursed for the labor costs incurred by its property management employees as services are rendered to the property owners. The Company determined that control over the services is passed to its customers simultaneously as performance occurs. Accordingly, management fee revenue is earned as the services are provided to the Company’s customers. Lease commissions are earned when the Company, as a broker for the third party property owner, executes a lease agreement with a tenant. Based on the terms of the Company’s lease commission contracts, the Company's performance obligation to the customer has been completed upon execution of each lease agreement. The Company’s lease commissions are earned based on a fixed percentage of rental income generated for each executed lease agreement and there is no variable income component. Development fee revenue is earned through two different sources: (i) the Company performs development services for third parties as an agent and earns fixed development fees based on a percentage of construction costs incurred over the construction period, and (ii) the Company acts as a general contractor on behalf of one of its managed real estate ventures. The Company acts as the principal construction company for the real estate ventures and records gross revenue as it provides construction services based on the quantifiable construction outputs. In applying the cost based output method of revenue recognition, the Company uses the actual costs incurred relative to the total estimated costs to determine its progress towards contract completion and to calculate the corresponding gross revenue and gross profit to recognize. For any costs that do not contribute to satisfying the Company’s performance obligations, it excludes such costs from its output methods of revenue recognition as the amounts are not reflective of transferring control of the outputs to the customer. The use of estimates in this calculation involves significant judgment. Common Development Cost Estimates for Contributions to Development Joint Ventures When land is contributed to a development joint venture, estimated common development costs include actual costs incurred and estimates of future common development costs benefiting the property sold. When land is sold, common development costs, if they cannot be specifically identified, are allocated to each sold parcel based upon its relative sales value. For purposes of allocating common development costs, estimates of future sales proceeds and common development costs are re-evaluated throughout the year, with adjustments being allocated prospectively to the remaining land parcels available for sale. The common development cost estimates for development joint ventures are highly judgmental as they are sensitive to cost escalation, sales price escalation and pace of absorption, which are subject to judgment and are affected by expectations about future market or economic conditions. Changes in the assumptions used to estimate future common development costs could result in a significant impact on the amounts recorded as net gain on disposition of real estate or net gain on sale of undepreciated real estate. The following is a summary of revenue earned by the Company’s reportable segments (see Note 19 “Segment Information,” for further information) during the year ended December 31, 2022 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 151,034 $ 116,926 $ 60,831 $ 16,686 $ 9,805 $ (1,895) $ 353,387 Variable rent 51,346 11,615 32,958 1,283 2,644 (35) 99,811 Total lease revenue 202,380 128,541 93,789 17,969 12,449 (1,930) 453,198 Amortization of deferred market rents 1,308 10 1,264 — — — 2,582 Daily parking & hotel flexible stay 14,390 — 361 84 236 — 15,071 Total rents 218,078 128,551 95,414 18,053 12,685 (1,930) 470,851 Third party management fees, labor reimbursement and leasing 287 35 486 3,723 1,988 17,613 24,132 Other income 2,510 354 42

REAL ESTATE INVESTMENTS

REAL ESTATE INVESTMENTS	12 Months Ended
REAL ESTATE INVESTMENTS	Dec. 31, 2022
Real Estate [Abstract]
REAL ESTATE INVESTMENTS	3. REAL ESTATE INVESTMENTS As of December 31, 2022 and 2021, the gross carrying value of the operating properties was as follows (in thousands): December 31, 2022 December 31, 2021 Land $ 403,998 $ 410,144 Building and improvements 2,760,357 2,653,492 Tenant improvements 452,885 408,966 Total $ 3,617,240 $ 3,472,602 Construction-in-Progress Internal direct construction costs totaling $9.3 million in 2022, $7.9 million in 2021, and $8.4 million in 2020 and interest totaling $4.7 million in 2022, $7.0 million in 2021, and $4.6 million in 2020 were capitalized related to the development, redevelopment and construction of tenant improvements of certain properties and land holdings. During the years ended December 31, 2022, 2021 and 2020, the Company’s internal direct construction costs are comprised of capitalized salaries. The following table shows the amount of compensation costs (including bonuses and benefits) capitalized for the years presented (in thousands): December 31, 2022 2021 2020 Development $ 5,343 $ 4,815 $ 4,802 Redevelopment 1,484 1,170 543 Tenant Improvements 2,505 1,917 3,021 Total $ 9,332 $ 7,902 $ 8,366 2022 Acquisitions Property/Portfolio Name Acquisition Date Location Property Type Rentable Square Feet/Acres Purchase Price 631 Park Avenue January 21, 2022 King of Prussia, PA Land 3.3 acres $ 3,650 3151 Market Street (a) April 29, 2022 Philadelphia, PA Leasehold Interest 0.8 acres $ 27,349 (a) On April 29, 2022, the Company acquired, through a 99-year ground lease, the leasehold interest in a 0.8-acre land parcel, located at 3151 Market Street, in Philadelphia, Pennsylvania. The Company prepaid $19.5 million of the ground lease, representing 500,000 square feet of buildable floor to area ratio (“FAR”) to be used for the development of 3151 Market Street, and paid $7.8 million for 200,000 square feet of FAR density usable pursuant to the Schuylkill Yards Project master development agreement. The additional density is included in prepaid leasehold interests in land held for development in the consolidated balance sheets. See below regarding disposition of 500,000 square feet of FAR. 2021 Acquisitions During the year ended December 31, 2021, the Company did not acquire any properties from a third party. 2020 Acquisitions The following table summarizes the property acquisitions during the year ended December 31, 2020 (dollars in thousands): Property/Portfolio Name Acquisition Date Location Property Type Rentable Square Feet/Acres Purchase Price (a) 155 King of Prussia Road February 27, 2020 Radnor, PA Land 7.75 acres $ 11,250 1505-11 Race Street November 5, 2020 Philadelphia, PA Office 119,763 $ 9,700 250 King of Prussia Road (b) November 30, 2020 Radnor, PA Office 169,843 $ 20,250 (a) Exclusive of transaction costs and price adjustments. See purchase price allocation table below for a breakout of the net purchase price for wholly owned properties. (b) This property was placed into redevelopment and is therefore included within Construction-in-progress on the consolidated balance sheets. The Company accounted for the acquisition of 1501-11 Race Street as an asset acquisition and therefore capitalized $0.3 million of acquisition related costs. The Company utilized a number of sources in making estimates of fair value (including comparative sales transactions and market leasing assumptions) for purposes of allocating the purchase price to tangible and intangible assets acquired The acquisition values have been allocated as follows (in thousands): 1505-11 Race Street Building, land and improvements $ 9,723 Intangible assets acquired 2,422 Below market lease liabilities assumed (2,193) Total unencumbered acquisition value 9,952 Amortization period of intangible assets 1.5 years Amortization period of below market liabilities assumed 1.5 years Dispositions The following table summarizes the property dispositions during the years ended December 31, 2022, 2021 and 2020 (dollars in thousands): Property/Portfolio Name Disposition Date Location Property Type Rentable Square Feet/Acres Sales Price Gain/(Loss) on Sale (a) 200 Barr Harbor Drive November 22, 2022 West Conshohocken, PA Office 86,000 $ 30,500 $ 8,740 11501 Burnett Road (h) July 29, 2022 Austin, TX Land 4.7 acres $ 32,513 $ 8,340 3151 Market Street (g) July 14, 2022 Philadelphia, PA Leasehold Interest 0.8 acres $ 30,394 $ 2,583 Gibbsboro Portfolio (f) June 28, 2022 Gibbsboro, NJ Office/Land 42,809/4.0 acres $ 4,100 $ 831 25 M Street (e) April 14, 2022 Washington, D.C. Land 0.8 acres $ 29,675 $ 3,836 Gateway G & H January 20, 2022 Richmond, VA Land 10.0 acres $ 1,600 $ 897 1100 Lenox Drive September 8, 2021 Lawrenceville, NJ Land 5.0 acres $ 2,575 $ 68 2100-2200 Lenox Drive July 6, 2021 Lawrenceville, NJ Land 35.2 acres $ 8,900 $ 842 3025 JFK Boulevard February 2, 2021 Philadelphia, PA Leasehold Interest 1.0 acre $ 34,800 $ 2,000 Mid-Atlantic Office Portfolio (b) (d) December 21, 2020 Various Office 1,128,645 $ 192,943 $ 15,164 One and Two Commerce Square (c) July 21, 2020 Philadelphia, PA Office 1,896,142 $ 115,000 $ 271,905 Keith Valley June 15, 2020 Horsham, PA Land 14.0 Acres $ 4,000 $ 201 52 East Swedesford Road March 19, 2020 Malvern, PA Office 131,077 $ 18,000 $ 2,336 (a) Gain/(Loss) on Sale is net of closing and other transaction related costs. (b) The Company sold a 60% equity interest in a portfolio of twelve suburban office properties containing an aggregate of 1.1 million square feet (“Mid-Atlantic Office Portfolio”), nine of which are located in the Pennsylvania suburbs and three of which are located in Maryland, to an unrelated third party for a gross sales price of $192.9 million. The transaction resulted in deconsolidation of the properties and formation of PA/MD NNN Office JV, LLC (“Mid-Atlantic Office JV”). The Company recorded its investment at fair value and recognized a gain of $15.2 million in “Net gain on disposition of real estate” on the consolidated statements of operations. See Note 4 “Investment in Unconsolidated Real Estate Ventures,” for further information. (c) The Company sold a 30% preferred equity interest in two office buildings located in Philadelphia, Pennsylvania, to an unrelated third party for $115.0 million (the “Commerce Square Venture Transaction”), which resulted in deconsolidation of the properties and formation of Brandywine Commerce I LP and Brandywine Commerce II LP (collectively, the “Commerce Square Venture”). The transaction valued the properties at $600.0 million. The Company recorded its investment at fair value and recognized a gain of $271.9 million in “Net gain on disposition of real estate” on the consolidated statements of operations. See Note 4 “Investment in Unconsolidated Real Estate Ventures,” for further information. (d) The sales price includes $4.1 million of variable consideration held in escrow that will be released to the Company over a six (e) On September 30, 2022, the Company recognized $0.4 million of additional gain on disposition of real estate. (f) Includes $0.7 million of gain on sale of undepreciated real estate and $0.1 million of gain on disposition of real estate included within the consolidated statements of operations for the twelve months ended December 31, 2022. (g) On July 14, 2022, the Company contributed 500,000 square feet of FAR relating to its 99-year prepaid leasehold interest at 3151 Market Street in Philadelphia, Pennsylvania, acquired on April 29, 2022, to a newly formed joint venture with an unaffiliated third party. The Company's initial deemed contribution in the project was $30.4 million and the transaction resulted in deconsolidation of the property and conversion of Brandywine 3151 Market, LP, (formerly a wholly-owned subsidiary of the Operating Partnership) to a real estate venture (“3151 Market Street Venture”). The Company recorded its investment at fair value and recognized a gain, net of transaction costs, of $2.6 million, in “Net gain on sale of undepreciated real estate” on the consolidated statements of operations. See Note 4, “Investment in Unconsolidated Real Estate Ventures,” for further information. (h) On July 29, 2022, the Company contributed a 4.7 acre parcel of land held for development at 11501 Burnet Road in Austin, Texas to a newly formed joint venture with an unaffiliated third party. The project is part of the Uptown ATX master development. The Company's combined contributed initial land investment in the project was $32.5 million and the transaction resulted in the deconsolidation of the property and formation of Brandywine Uptown Office LLC and Brandywine One Uptown Multifamily LLC, (together, “One Uptown Ventures)”). The Company recorded its investment at fair value and recognized a gain of $8.3 million in “Net gain on disposition of real estate” on the consolidated statements of operations. Gain on sale of $8.3 million is calculated as the difference between the estimated relative sales value of the contributed land and the estimated total cost allocations per block. See Note 4, “Investment in Unconsolidated Real Estate Ventures,” for further information. 3025 JFK Venture In addition, on February 2, 2021, the Company contributed its investment in a 99-year prepaid leasehold interest in a one-acre land parcel held for development at 3025 JFK Boulevard in Philadelphia, Pennsylvania to a newly formed joint venture with an unaffiliated third party. The project is part of the Schuylkill Yards master development. The Company's investment in the project was valued at $34.8 million and the transaction resulted in deconsolidation of the property and conversion of Brandywine Opportunity Fund, L.P. (formerly a wholly-owned subsidiary of the Operating Partnership) to a real estate venture ( “ 3025 JFK Venture ” ). The Company recorded its investment at fair value and recognized a gain of $2.0 million in “ Net gain on sale of undepreciated real estate ” on the consolidated statements of operations. See Note 4, “ Investment in Unconsolidated Real Estate Ventures, ” for further information. 3151 Market Venture On July 14, 2022, the Company contributed 500,000 square feet of FAR relating to its 99-year prepaid leasehold interest at 3151 Market Street in Philadelphia, Pennsylvania, acquired on April 29, 2022, to a newly formed joint venture with an unaffiliated third party. The Company's initial deemed contribution in the project was $30.4 million and the transaction resulted in deconsolidation of the property and conversion of Brandywine 3151 Market, LP, (formerly a wholly-owned subsidiary of the Operating Partnership) to a real estate venture (“3151 Market Street Venture”). The Company recorded its investment at fair value and recognized a gain, net of transaction costs, of $2.6 million, in “Net gain on sale of undepreciated real estate” on the consolidated statements of operations. See Note 4, “Investment in Unconsolidated Real Estate Ventures,” for further information. Subsequent to December 31, 2022, the Company contributed an additional 200,000 square feet of FAR density, usable pursuant to the Schuylkill Yards Project master development agreement to the 3151 Market Street Venture pursuant to amendment to the partnership agreement. The Company deconsolidated the prepaid ground lease of $7.8M and recorded its investment in the 3151 Market Street Venture at fair value and recognized a gain, net of transaction costs, of $0.8 million. Held for Use Impairment During the year ended December 31, 2022, the Company recognized an impairment loss totaling approximately $4.7 million on a property located in the Metropolitan Washington, D.C. segment. The Company’s estimated fair value, is considered Level 3 in accordance with ASC 820, and was based on a pending offer form a third party to acquire the property and the subsequent execution of a purchase and sale agreement. Held for Sale As of December 31, 2022, the Company had no assets held for sale. As of December 31, 2021, the Company determined that the sale of two adjacent parcels of land within the Other segment totaling 10.0 acres was probable and classified these properties as held for sale. As such, $0.6 million was classified as Assets held for sale, net” on the consolidated balance sheets. The Company closed on the sale of the two parcels of land on January 20, 2022 for an aggregate sales price of $1.6 million.

INVESTMENT IN UNCONSOLIDATED RE

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES	12 Months Ended
INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES	Dec. 31, 2022
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES	4. INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES As of December 31, 2022, the Company held ownership interests in twelve unconsolidated real estate ventures for a net aggregate investment balance of $532.2 million, which includes a negative investment balance in one unconsolidated real estate venture of $35.4 million, reflected within “Other liabilities” on the consolidated balance sheets. As of December 31, 2022, five of the real estate ventures owned properties that contained an aggregate of approximately 9.1 million net rentable square feet of office space; two real estate ventures owned 1.4 acres of land held for development; four real estate venture owned 7.5 acres of land in active development; and one real estate venture owned a mixed used tower comprised of 250 apartment units and 0.2 million net rentable square feet of office/retail space. The Company accounts for its interests in the unconsolidated real estate ventures, which range from 15% to 70%, using the equity method. Certain of the unconsolidated real estate ventures are subject to specified priority allocations of distributable cash. The Company earned management fees from the unconsolidated real estate ventures of $8.2 million, $8.1 million and $4.7 million for the years ended December 31, 2022, 2021 and 2020, respectively. The Company earned leasing commissions from the unconsolidated real estate ventures of $2.5 million, $3.8 million and $1.1 million for the years ended December 31, 2022, 2021 and 2020, respectively. The Company had outstanding accounts receivable balances from the unconsolidated real estate ventures of $2.9 million and $2.5 million as of December 31, 2022 and 2021, respectively. The amounts reflected in the following tables (except for the Company’s share of equity in income) are based on the financial information of the individual unconsolidated real estate ventures. The Company records operating losses of a real estate venture in excess of its investment balance if the Company is liable for the obligations of the real estate venture or is otherwise committed to provide financial support to the real estate venture. The Company’s investment in the unconsolidated real estate ventures as of December 31, 2022 and 2021, and the Company’s share of the unconsolidated real estate ventures’ income (loss) for the years ended December 31, 2022, 2021, and 2020 was as follows (in thousands): Ownership Percentage Carrying Amount Company's Share of unconsolidated real estate venture Income (Loss) Unconsolidated Real Estate Venture Debt at 100%, gross 2022 2021 2022 2021 2020 2022 2021 Office Properties Commerce Square Venture 70% (a) $ 238,105 $ 247,798 $ (12,128) $ (15,501) $ (9,150) $ 206,737 $ 213,069 Mid-Atlantic Office Venture 40% (a) 31,005 31,680 412 932 96 128,904 123,015 Brandywine - AI Venture LLC 50% — — — (721) 185 — — Herndon Innovation Center Metro Portfolio Venture, LLC 15% 15,304 15,844 (536) (174) (358) 207,302 207,302 MAP Venture (b) 50% (35,411) (24,396) (8,340) (8,683) (6,570) 182,053 184,263 Cira Square 20% 27,815 — (985) — — 257,700 — Other 4040 Wilson Venture (c) 50% 29,633 31,059 (1,211) (2,258) (2,162) 145,070 145,000 1919 Venture (d) 50% — 13,791 1,392 427 59 — 88,860 Development Properties 3025 JFK Venture (c) 55% 57,630 56,370 (35) (118) — 60,118 — JBG - 51 N Street (c) 70% 21,208 21,213 (382) (402) (457) — — JBG - 1250 First Street Office (c) 70% 17,759 17,751 (195) (199) (227) — — 3151 Market Street Venture (c) 55% 63,751 — (8) — — — — One Uptown - Office (c) 50% 34,980 — — — — 16,895 — One Uptown - Multifamily (c) 50% 30,445 — — — — — — $ 532,224 $ 411,110 $ (22,016) $ (26,697) $ (18,584) $ 1,204,779 $ 961,509 (a) Ownership percentage represents the Company’s combined interest including preferred and common equity holdings. See “Commerce Square Venture” and “Mid-Atlantic Office JV” sections below for more information. (b) Included within “Other Liabilities” on the consolidated balance sheet. (c) This entity is a VIE. (d) On November 30, 2022, the Company sold its interest in 1919 Venture. See “1919 Venture” sections for more information on the disposal. The following is a summary of the financial position of the unconsolidated real estate ventures in which the Company held interests as of December 31, 2022 and December 31, 2021 (in thousands): December 31, 2022 December 31, 2021 Net property $ 2,117,226 $ 1,563,263 Other assets 506,213 434,687 Other liabilities 446,101 331,947 Debt, net 1,198,213 956,668 Equity (a) 979,125 709,335 (a) This amount does not include the effect of the basis difference between the Company's historical cost basis and the basis recorded at the real estate venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials occur from the impairment of investments, purchases of third party interests in existing real estate ventures and upon the transfer of assets that were previously owned by the Company into a real estate venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the real estate venture level. The following is a summary of results of operations of the unconsolidated real estate ventures in which the Company held interests during the twelve-month periods ended December 31, 2022, 2021 and 2020 (in thousands): Year Ended December 31, 2022 2021 2020 Revenue $ 244,981 $ 214,792 $ 150,276 Operating expenses (124,608) (117,273) (85,812) Interest expense, net (49,007) (30,569) (22,661) Depreciation and amortization (103,378) (97,147) (70,805) Provision for impairment — (1,393) — Net loss $ (32,012) $ (31,590) $ (29,002) Ownership interest % Various Various Various Company's share of net loss $ (21,594) $ (25,972) $ (18,540) Basis adjustments and other (422) (725) (44) Equity in loss of unconsolidated real estate ventures $ (22,016) $ (26,697) $ (18,584) As of December 31, 2022, the aggregate principal payments of the unconsolidated real estate ventures recourse and non-recourse debt payable to third-parties are as follows (in thousands): 2023 $ 388,789 2024 593,907 2025 60,118 2026 161,965 2027 — Thereafter — Total principal payments 1,204,779 Net deferred financing costs (6,837) Net original issue premium 271 Outstanding indebtedness $ 1,198,213 One Uptown Ventures On December 1, 2021, the Company established the One Uptown Ventures with affiliates of Canyon Partners Real Estate to commence development of One Uptown, a $335.6 million mixed-use project in Austin, Texas. One Uptown has been designed to deliver 348,000 square feet of Class-A workspace and 15,000 square feet of street-level retail space (through the “ office ” joint venture) and 341 apartment residences and a public park (through the “ multifamily ” joint venture) and a six- story parking garage to be shared by the two joint ventures. The Company's partner in each of the two joint ventures has agreed, subject to customary funding conditions, including closing of the applicable construction loan, to fund approximately $64.5 million of the combined project costs in exchange for a 50% preferred equity interest in each of the two joint ventures, with the Company retaining a 50% common equity interest in each. Under the terms of each of the joint venture agreements, the joint venture partner had no obligation to fund any portion of the applicable project costs until the closing of the applicable construction loan. The absence of this obligation prevented Company from meeting the sale recognition criteria of ASC 606 until the applicable closings of the construction loans. On July 29, 2022, the One Uptown Ventures closed on two separate construction loans. The office joint venture closed on a $121.7 million construction loan which bears interest at Secured Overnight Offering Rate ( “ SOFR ”) plus 3.00% and the multifamily joint venture closed on an $85.0 million construction loan which bears interest at SOFR plus 2.45%, plus, in each case, a daily SOFR adjustment of 10 basis points. Both loans mature in July 2026. The Company has also provided a carry guarantee and limited payment guarantee up to 30% and 15% of the principal balance of the $121.7 million and $85 million construction loan, respectively. The Company subsequently recognized the formation of the joint ventures and deconsolidated the projects upon the closing of the loans. The Company has determined that the each of the One Uptown Ventures is a VIE. As a result, the Company used the VIE model under the accounting standard for consolidation in order to determine whether to consolidate the One Uptown Ventures. Based upon each member's shared power over the activities of the One Uptown Ventures under the operating and related agreements, and the Company's lack of control over the development and construction phases of the project, the One Uptown Ventures are accounted for under the equity method of accounting. 3151 Market Street Venture On July 14, 2022, the Company formed a joint venture, with an unaffiliated third party, to develop a life science/office building containing approximately 417,000 rentable square feet under a long-term ground lease located at 3151 Market Street in Philadelphia, Pennsylvania. The estimated project cost is approximately $308 million, and the joint venture partner has agreed, subject to customary funding conditions, to fund up to approximately $55 million of the project costs in exchange for a 45% preferred equity interest in the venture. The Company has determined that the 3151 Market Street Venture is VIE. As a result, the Company used the VIE model under the accounting standard for consolidation in order to determine whether to consolidate the 3151 Market Street Venture. Based upon each member's shared power over the activities of the 3151 Market Street Venture under the operating and related agreements, and the Company's lack of control over the development and construction phases of the project, 3151 Market Street Venture is accounted for under the equity method of accounting. Cira Square On March 17, 2022, the Company formed a joint venture, Cira Square REIT, LLC (“Cira Square Venture”), for the purpose of acquiring Cira Square, an office property located at 2970 Market Street in Philadelphia, Pennsylvania containing 862,692 rentable square feet for a gross purchase price of $383.0 million. The Company owns a 20% common equity interest in Cira Square Venture and provided an initial capital contribution of $28.6 million on the closing date. On the closing date, Cira Square Venture obtained $257.7 million of third-party debt financing secured by the property. The loan bears interest at 3.50% over one-month term SOFR per annum capped at at total maximum interest rate of 6.75% per annum, and matures in March 2024. Based on the facts and circumstances at the formation of Cira Square Venture, the Company determined that the venture is not a VIE in accordance with the accounting standard for the consolidation of VIEs. As a result, the Company used the voting interest model under the accounting standard for consolidation in order to determine whether to consolidate Cira Square Venture. Based upon each member's substantive participating rights over the activities of Cira Square Venture under the operating and related agreements, it is not consolidated by the Company, and is accounted for under the equity method of accounting. 4040 Wilson Venture The 4040 Wilson LLC Venture (“4040 Wilson”) consists of one property containing an aggregate of 225,000 square feet of office/retail and 250 apartment units, located in the Metropolitan Washington, D.C. segment. The Company and its partner each own a 50% interest in 4040 Wilson. The residential component and office/retail portion of 4040 Wilson were substantially complete and placed into service during the first quarter of 2020 and the first quarter of 2021, respectively. During the fourth quarter of 2021, 4040 Wilson refinanced the $150.0 million secured construction loan into a $155.0 million mortgage loan secured by the property. The interest rate on this loan is 1.8% over term SOFR and matures in December 2026. Effective January 3, 2023, this debt is swapped to a fixed rate of 5.70% through the maturity of the loan. Brandywine - AI Venture During the year ended December 31, 2021, Brandywine - AI Venture, recorded a $1.4 million held for sale impairment charge related to 3141 Fairview Park Drive. The Company’s share of the impairment charge was $0.7 million, which is reflected in “Equity in loss of Real Estate Ventures” in the consolidated statements of operations for the year ended December 31, 2021. The impairment was measured based on an executed sale agreement with a third-party. The Company determined that its investment in the real estate venture is not impaired as the Company's share of the distributable cash is in excess of the Company's basis in the real estate venture. On November 9, 2021, BDN AI Venture sold 3141 Fairview Park Drive, the last remaining office property, totaling 183,618 rentable square feet in Falls Church, Virginia, at an aggregate sales price of $27.6 million. The Company received cash proceeds of $12.6 million after closing costs. The Company recorded an $3.0 million gain within the caption “Net gain on real estate venture transactions” within its consolidated statements of operations for the year ended December 31, 2021 upon liquidation of the venture. During 2019, BDN - AI Venture recorded a $5.6 million held for use impairment charge The Company determined that its investment in the real estate venture was not impaired as the Company's share of the distributable cash was in excess of the Company's basis in the real estate venture. During 2019, BDN - AI Venture transferred an office building located in Falls Church, Virginia containing 180,659 rentable square feet to the mortgage lender in full satisfaction of the lender’s outstanding $26.0 million mortgage loan. The mortgage loan was nonrecourse to the Company. The Company recognized its $2.2 million share of the gain on debt forgiveness in “Net gain on real estate venture transactions” in the consolidated statements of operations for the year ended December 31, 2019. 3025 JFK Venture On February 2, 2021, the Company contributed its investment in a 99-year prepaid leasehold interest in a one-acre land parcel held for development at 3025 JFK Boulevard in Philadelphia, Pennsylvania to the 3025 JFK Venture. The Company's initial investment in this real estate venture at February 2, 2021 was $34.8 million. The real estate venture was formed to develop a 570,000 square foot mixed-use building at property under the long-term ground lease. The estimated project cost is approximately $287.3 million, and the joint venture partner agreed, subject to customary funding conditions, to fund up to approximately $45.2 million of the project costs in exchange for a 45% preferred equity interest in the venture and the Company will retain a 55% preferred equity interest. On July 23, 2021, the 3025 JFK Venture closed on a $186.7 million construction loan, which bears interest at 3.50% plus LIBOR (subject to a LIBOR floor of 0.25%) per annum and matures in July 2025. In addition to its $34.8 million credit for contribution of the leasehold interest at 3025 JFK Venture, the Company has funded $20.5 million of project costs as of December 31, 2022. The remaining project costs will be funded by the joint venture partner and the construction loan. The Company has determined that the 3025 JFK Venture is a VIE. As a result, the Company used the VIE model under the accounting standard for consolidation in order to determine whether to consolidate the 3025 JFK Venture. Based upon each member’s shared power over the activities of 3025 JFK Venture under the operating and related agreements, and the Company’s lack of control over the development and construction phases of the project, 3025 JFK Venture is accounted for under the equity method of accounting. Mid-Atlantic Office JV On December 21, 2020, the Company contributed a portfolio of twelve properties containing an aggregate of 1,128,645 square feet, nine of which are located in the Pennsylvania suburbs segment and three located in the Metropolitan Washington, D.C segment, to the Mid-Atlantic Office JV, for a gross sales price of $192.9 million. After the transaction, the Company owns approximately 25% of the equity interest in the Mid-Atlantic Office JV through a $20.0 million preferred equity holding and approximately 15% of the equity interest through a common equity interest (representing 20% of the total common equity), for a combined approximately 40% equity interest in the venture. On the closing date, Mid-Atlantic Office JV also obtained $147.4 million of third-party debt financing secured by the twelve properties within the venture, with an initial advance of $120.8 million. The remaining funds available under the loan are $18.5 million. The loan bears interest at LIBOR + 3.15% capped at a total maximum interest rate of 5.7% and matures on January 9, 2024. Commerce Square Venture On July 21, 2020, the Company sold a 30% preferred equity interest in the entities that own One Commerce Square and Two Commerce Square, two office properties containing 1,896,142 square feet in Philadelphia, Pennsylvania. After the transaction, the Company owns approximately 32% of the equity interest in Commerce Square Venture through preferred equity interest holdings and approximately 38% of the equity interest in Commerce Square Venture as the sole common equity holder, for a combined approximately 70% equity interest in the venture. The properties held by the venture remain encumbered by the existing mortgages. Herndon Innovation Center Metro Portfolio Venture, LLC The Herndon Innovation Center Metro Portfolio Venture, LLC (“Herndon Innovation Center”) consists of eight properties containing an aggregate of 1,293,197 square feet, located in the Metropolitan Washington, D.C. segment. The Company and its partner own 15% and 85% interests in the Herndon Innovation Center, respectively. MAP Venture The MAP Venture owns 58 office properties that contain an aggregate of 3,924,783 square feet located in the Pennsylvania Suburbs, New Jersey/Delaware, Metropolitan Washington, D.C. and Richmond, Virginia (“MAP Venture”). The MAP Venture leases the land parcels under the 58 office properties through a ground lease that extends through February 2115. Annual payments by the MAP Venture, as tenant under the ground lease, initially total $11.9 million and increase 2.5% annually through November 2025. Thereafter, annual rental payments increase by 2.5% or CPI at the discretion of the lessor. 1919 Venture On November 30, 2022, the Company sold its 50% ownership interest in the 1919 Venture for a gross sales price of $83.2 million, a portion of which satisfied in full the $44.4 million outstanding loan between the Company and the venture. The Company recorded a gain on sale of $26.7 million with the caption “Net gain on real estate venture transactions” within its consolidated statement of operations for the year ended December 31, 2022. JBG Ventures JBG Ventures consists of 51 N 50 Patterson, Holdings, LLC Venture (“51 N Street”) and 1250 First Street Office, LLC Venture (“1250 First Street”), with the Company owning a 70.0% equity interest and JBG/DC Manager, LLC (“JBG”) owning a 30.0% equity interest in each of the two ventures. 51 N Street owns 0.9 acres of undeveloped land and 1250 First Street, owns 0.5 acres of undeveloped land.

DEBT AND PREFERRED EQUITY INVES

DEBT AND PREFERRED EQUITY INVESTMENTS	12 Months Ended
DEBT AND PREFERRED EQUITY INVESTMENTS	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
DEBT AND PREFERRED EQUITY INVESTMENTS	5. DEBT AND PREFERRED EQUITY INVESTMENTS Austin Preferred Equity Investment On December 31, 2020, the Company invested $50.0 million in exchange for a preferred equity interest in a single-purpose entity that owned two stabilized office buildings located in Austin, Texas. The Company accounted for this mandatorily redeemable investment as a note receivable, which was included within “Other assets” on the consolidated balance sheets.The preferred equity interest accrued a 9.0% annual return, compounded and paid monthly. The investment was required to be redeemed no later than December 31, 2023 (subject to a one-year extension option). On September 3, 2021, the $50.0 million investment was redeemed prior to maturity. As a result, the Company recognized an incremental $2.8 million of income on early redemption related to its accelerated minimum return and exit fees paid in cash on the redemption date during the three months ended September 30, 2021, which is included in “Interest and investment income” on the consolidated statements of operations.

LEASES

LEASES	12 Months Ended
LEASES	Dec. 31, 2022
Leases [Abstract]
LEASES	6. LEASES Lessor Accounting The Company leases properties to tenants under operating leases with various expiration dates. Future contractual lease payments under operating leases at December 31, 2022 are as follows (in thousands): Year 2023 $ 347,142 2024 344,641 2025 325,166 2026 304,102 2027 263,532 Thereafter 1,041,686 Lessee Accounting As of December 31, 2022, the Company is the lessee under six long-term ground leases classified as “operating leases” in the consolidated balance sheets. Certain of the Company’s ground leases contain extension options and the Company considered all relevant factors in determining if it was reasonably certain that it would exercise such extension options. The Company concluded that it was not reasonably certain that it would exercise the extension options and, therefore, has not included the extension period in the remaining lease terms. With the exception of certain ground leases that are subject to rent increases periodically based on the CPI index, all lease payments under the ground lease are fixed. The table below summarizes the Company’s operating lease cost (in thousands) recognized through “Property operating expenses” on the consolidated statements of operations (in thousands): Year Ended December 31, Lease Cost 2022 2021 Fixed lease cost $ 2,100 $ 2,100 Variable lease cost 67 43 Total $ 2,167 $ 2,143 Weighted-average remaining lease term (years) 54.6 55.2 Weighted-average discount rate 6.3 % 6.3 % Lease payments by the Company under the terms of all noncancellable ground leases of land are expensed on a straight-line basis regardless of when payments are due. The Company’s ground leases, excluding prepaid ground leases, have remaining lease terms ranging from 7 to 62 years. Lease payments on noncancellable leases at December 31, 2022 are as follows (in thousands): Year Minimum Rent 2023 $ 1,263 2024 1,305 2025 1,321 2026 1,338 2027 1,355 Thereafter 106,437 Total lease payments $ 113,019 Less: Imputed interest 89,853 Present value of operating lease liabilities $ 23,166 The Company obtained ground tenancy rights related to three properties in Philadelphia, Pennsylvania, which provide for contingent rent participation by the lessor in certain capital transactions and net operating cash flows of the properties after certain returns are achieved by the Company. Such amounts, if any, will be reflected as contingent rent when incurred. The ground leases also provide for payment by the Company of certain operating costs relating to the land, primarily real estate taxes. The above schedule of future minimum rental payments does not include any contingent rent amounts or any reimbursed expenses.
LEASES	6. LEASES Lessor Accounting The Company leases properties to tenants under operating leases with various expiration dates. Future contractual lease payments under operating leases at December 31, 2022 are as follows (in thousands): Year 2023 $ 347,142 2024 344,641 2025 325,166 2026 304,102 2027 263,532 Thereafter 1,041,686 Lessee Accounting As of December 31, 2022, the Company is the lessee under six long-term ground leases classified as “operating leases” in the consolidated balance sheets. Certain of the Company’s ground leases contain extension options and the Company considered all relevant factors in determining if it was reasonably certain that it would exercise such extension options. The Company concluded that it was not reasonably certain that it would exercise the extension options and, therefore, has not included the extension period in the remaining lease terms. With the exception of certain ground leases that are subject to rent increases periodically based on the CPI index, all lease payments under the ground lease are fixed. The table below summarizes the Company’s operating lease cost (in thousands) recognized through “Property operating expenses” on the consolidated statements of operations (in thousands): Year Ended December 31, Lease Cost 2022 2021 Fixed lease cost $ 2,100 $ 2,100 Variable lease cost 67 43 Total $ 2,167 $ 2,143 Weighted-average remaining lease term (years) 54.6 55.2 Weighted-average discount rate 6.3 % 6.3 % Lease payments by the Company under the terms of all noncancellable ground leases of land are expensed on a straight-line basis regardless of when payments are due. The Company’s ground leases, excluding prepaid ground leases, have remaining lease terms ranging from 7 to 62 years. Lease payments on noncancellable leases at December 31, 2022 are as follows (in thousands): Year Minimum Rent 2023 $ 1,263 2024 1,305 2025 1,321 2026 1,338 2027 1,355 Thereafter 106,437 Total lease payments $ 113,019 Less: Imputed interest 89,853 Present value of operating lease liabilities $ 23,166 The Company obtained ground tenancy rights related to three properties in Philadelphia, Pennsylvania, which provide for contingent rent participation by the lessor in certain capital transactions and net operating cash flows of the properties after certain returns are achieved by the Company. Such amounts, if any, will be reflected as contingent rent when incurred. The ground leases also provide for payment by the Company of certain operating costs relating to the land, primarily real estate taxes. The above schedule of future minimum rental payments does not include any contingent rent amounts or any reimbursed expenses.

DEFERRED COSTS

DEFERRED COSTS	12 Months Ended
DEFERRED COSTS	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
DEFERRED COSTS	7. DEFERRED COSTS As of December 31, 2022 and 2021, the Company’s deferred costs were comprised of the following (in thousands): December 31, 2022 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 155,457 $ (62,920) $ 92,537 Financing costs - Unsecured Credit Facility 4,688 (586) 4,102 Total $ 160,145 $ (63,506) $ 96,639 December 31, 2021 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 143,895 $ (57,445) $ 86,450 Financing costs - Unsecured Credit Facility 6,299 (5,887) 412 Total $ 150,194 $ (63,332) $ 86,862

INTANGIBLE ASSETS AND LIABILITI

INTANGIBLE ASSETS AND LIABILITIES	12 Months Ended
INTANGIBLE ASSETS AND LIABILITIES	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND LIABILITIES	8. INTANGIBLE ASSETS AND LIABILITIES As of December 31, 2022 and 2021, the Company’s intangible assets/liabilities were comprised of the following (in thousands): December 31, 2022 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 55,715 $ (37,437) $ 18,278 Tenant relationship value 167 (104) 63 Above market leases acquired 331 (221) 110 Total intangible assets, net $ 56,213 $ (37,762) $ 18,451 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 20,985 $ (10,663) $ 10,322 December 31, 2021 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 72,376 $ (44,066) $ 28,310 Tenant relationship value 167 (97) 70 Above market leases acquired 486 (310) 176 Total intangible assets, net $ 73,029 $ (44,473) $ 28,556 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 27,025 $ (14,044) $ 12,981 For the years ended December 31, 2022, 2021, and 2020, the Company accelerated the amortization of intangible assets by approximately $0.4 million, $3.6 million, and $0.3 million, respectively, as a result of tenant move-outs prior to the end of the associated lease term. For the years ended December 31, 2022, 2021, and 2020 the Company accelerated the amortization of approximately $0.1 million, $0.6 million, and $0.1 million of intangible liabilities as a result of tenant move-outs. As of December 31, 2022, the Company’s annual amortization for its intangible assets/liabilities, assuming no prospective early lease terminations, was as follows (dollars in thousands): Assets Liabilities 2023 $ 6,573 $ 1,516 2024 4,332 1,305 2025 3,154 1,029 2026 1,094 739 2027 809 623 Thereafter 2,489 5,110 Total $ 18,451 $ 10,322

DEBT OBLIGATIONS

DEBT OBLIGATIONS	12 Months Ended
DEBT OBLIGATIONS	Dec. 31, 2022
Debt Disclosure [Abstract]
DEBT OBLIGATIONS	9. DEBT OBLIGATIONS The following table sets forth information regarding the Company’s consolidated debt obligations outstanding as of December 31, 2022 and 2021 (in thousands): December 31, 2022 December 31, 2021 Effective Maturity UNSECURED DEBT $600 million Unsecured Credit Facility $ 88,500 $ 23,000 SOFR + 1.15% June 2026 Unsecured Term Loan 250,000 250,000 SOFR + 1.30% June 2027 (a) $350.0M 3.95% Guaranteed Notes due 2023 54,301 350,000 3.87% February 2023 (b) $350.0M 4.10% Guaranteed Notes due 2024 350,000 350,000 3.78% October 2024 $450.0M 3.95% Guaranteed Notes due 2027 450,000 450,000 4.03% November 2027 $350.0M 7.55% Guaranteed Notes due 2028 350,000 — 7.73% March 2028 $350.0M 4.55% Guaranteed Notes due 2029 350,000 350,000 4.30% October 2029 Indenture IA (Preferred Trust I) 27,062 27,062 LIBOR + 1.25% March 2035 Indenture IB (Preferred Trust I) 25,774 25,774 LIBOR + 1.25% April 2035 Indenture II (Preferred Trust II) 25,774 25,774 LIBOR + 1.25% July 2035 Principal balance outstanding 1,971,411 1,851,610 Plus: original issue premium (discount), net 2,934 8,187 Less: deferred financing costs (9,307) (6,211) Total unsecured indebtedness $ 1,965,038 $ 1,853,586 (a) On November 23, 2022, the unsecured term loan of $250.0 million was swapped to a fixed rate of 5.01% and matures on June 30, 2027. The effective date of the swap is January 31, 2023. (b) Remaining balance was redeemed on January 20, 2023. The Parent Company unconditionally guarantees the unsecured debt obligations of the Operating Partnership (or is a co-borrower with the Operating Partnership) but does not by itself incur unsecured indebtedness. The Parent Company has no material assets other than its investment in the Operating Partnership. Unsecured Credit Facility and Unsecured Term Loan On June 30, 2022, the Company entered into the Second Amended and Restated Credit Agreement (as amended and restated, the “2022 Credit Agreement”). The 2022 Credit Agreement among other things: (i) maintains the total commitment under the line credit of $600.0 million (the “Revolving Credit Facility”) and provides an unsecured term loan in the initial amount of $250.0 million (the “Term Loan”) with a scheduled maturity date of June 30, 2027; (ii) extended the maturity date of the Revolving Credit Facility from July 15, 2022 to June 30, 2026, with two six-month extensions at the Company’s election subject to specified conditions and subject to payment of an extension fee; (iii) reduced the interest rate margins applicable to SOFR revolving loans; and (iv) provides for an additional interest rate option based on a floating SOFR rate. In connection with the amendments, the Company capitalized $4.7 million and $2.0 million in financing costs, related to the Revolving Credit Facility and the Term Loan, respectively. The financing costs will be amortized through the maturity dates for each of the Revolving Credit Facility and the Term Loan. Upon closing of the 2022 Credit Agreement, the Term Loan was funded in full and the proceeds thereof, together with cash on hand, were used to prepay in full the Company’s unsecured term loan (“Term Loan C”) in the principal amount of $250.0 million, together with accrued and unpaid interest thereon. Term Loan C was scheduled to mature on October 8, 2022. Under the 2022 Credit Agreement, the Company may, subject to specified terms and conditions (including receipt of commitments from one or more lenders, whether or not currently parties to the 2022 Credit Agreement), elect to increase the amount of the Revolving Credit Facility and/or Term Loan or request one or more new pari passu tranches of unsecured term loans (each, an “Incremental Facility”), provided that the aggregate amount of all such increases is limited to $500.0 million. Up to $50.0 million of borrowing availability under the 2022 Credit Agreement is available for the issuance of letter of credits. Borrowings under the Revolving Credit Facility bear interest at a rate equal to either (i) the SOFR rate plus a margin of 72.5 to 140 basis points, or (ii) a base rate plus a margin of 0 to 40 basis points: and the Term Loan and borrowings under an Incremental Facility bear interest at a rate equal to either (i) the SOFR rate plus a margin of 80 to 160 basis points, or (ii) a base rate plus a margin of 0 to 60 basis points. The applicable margin will be determined based upon the unsecured senior debt rating of the Operating Partnership or the absence of such a rating. The Company also pays a quarterly facility fee on the total commitments under the Revolving Credit Facility. As of September 30, 2022, based on the Operating Partnership's unsecured senior debt rating, the applicable margin for SOFR revolving loans under the Revolving Credit Facility was 105 basis points (excluding the applicable facility fee rate of 25 basis points) and was 120.0 basis points for the Term Loan, plus, in each case, a daily SOFR adjustment of 10 basis points. The terms of the 2022 Credit Agreement require that the Company maintain customary financial and other covenants, including: (i) a fixed charge coverage ratio greater than or equal to 1.5 to 1.00; (ii) a leverage ratio less than or equal to 0.60 to 1.00, subject to specified exceptions; (iii) a ratio of unsecured indebtedness to unencumbered asset value less than or equal to 0.60 to 1.00, subject to specified exceptions; (iv) a ratio of secured indebtedness to total asset value less than or equal to 0.40 to 1.00; and (v) a ratio of unencumbered cash flow to interest expense on unsecured debt greater than 1.75 to 1.00. In addition, the 2022 Credit Agreement restricts payments of dividends and distributions on shares in excess of 95% of the Company's funds from operations (FFO) except to the extent necessary to enable the Company to continue to qualify as a REIT for federal income tax purposes. The Company had $88.5 million of borrowings under the Revolving Credit Facility as of December 31, 2022. During the twelve months ended December 31, 2022, the weighted-average interest rate on Revolving Credit Facility borrowings was 3.04% resulting in $5.6 million of interest expense. During the twelve months ended December 31, 2021 weighted-average interest rate on Revolving Credit Facility borrowings was 1.21% resulting in $0.4 million of interest expense. Guaranteed Notes due 2028 On December 13, 2022, the Company completed an underwritten offering of $350.0 million aggregate principal amount of its 7.55% Guaranteed Notes due 2028 (the “2028 Notes”). The 2028 Notes were priced at 99.06% of their face amount and have been reflected net of a discount of approximately $3.3 million in the consolidated balance sheet as of December 31, 2022. The Company received approximately $344.6 million of proceeds after the deduction for underwriting discounts and offering expenses. Guaranteed Notes due 2023 On December 20, 2022, the Company used a portion of the net proceeds from the offering of the 2028 Notes to repurchase $295.7 million aggregate principal amount of its outstanding 3.95% guaranteed notes due 2023 (the “2023 Notes”), through a tender offer, together with $4.1 million of accrued and unpaid interest thereon. The Company recognized a $0.4 million loss on early extinguishment of debt related to the total repurchase. On January 20, 2023, the Company completed the redemption of the remaining $54.3 million aggregate principal amount of the 2023 Notes. See Note 21, “Subsequent Events” for further information regarding the redemption. The Company was in compliance with all financial covenants as of December 31, 2022. Certain of the covenants restrict the Company’s ability to obtain alternative sources of capital. As of December 31, 2022, the aggregate scheduled principal payments on the Company's debt obligations were as follows (in thousands): 2023 $ 54,301 2024 350,000 2025 — 2026 88,500 2027 700,000 Thereafter 778,610 Total principal payments 1,971,411 Net unamortized premiums/(discounts) 2,934 Net deferred financing costs (9,307) Outstanding indebtedness $ 1,965,038

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
FAIR VALUE OF FINANCIAL INSTRUMENTS	Dec. 31, 2022
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	10. FAIR VALUE OF FINANCIAL INSTRUMENTS The Company determined the fair values disclosed below using available market information and discounted cash flow analyses as of December 31, 2022 and 2021, respectively. The discount rate used in calculating fair value is the sum of the current risk free rate and the risk premium on the date of measurement of the instruments or obligations. Considerable judgment is necessary to interpret market data and to develop the related estimates of fair value. Accordingly, the estimates presented are not necessarily indicative of the amounts that the Company could realize upon disposition. The use of different estimates and valuation methodologies may have a material effect on the fair value amounts shown. The Company believes that the carrying amounts reflected in the consolidated balance sheets at December 31, 2022 and 2021 approximate the fair values for cash and cash equivalents, accounts receivable, other assets and liabilities, accounts payable and accrued expenses because they are short-term in duration. The following are financial instruments for which the Company’s estimates of fair value differ from the carrying amounts (in thousands): December 31, 2022 December 31, 2021 Carrying Amount (a) Fair Value Carrying Amount (a) Fair Value Unsecured notes payable $ 1,549,760 $ 1,411,351 $ 1,502,368 $ 1,588,780 Variable rate debt $ 415,278 $ 386,988 $ 351,218 $ 344,754 Notes receivable (b) $ — $ — $ 44,430 $ 45,230 (a) Net of deferred financing costs of $7.5 million and $5.8 million for unsecured notes payable, $1.8 million and $0.4 million for variable rate debt as of December 31, 2022 and December 31, 2021, respectively. (b) For further detail, refer to Note 5 “Debt and Preferred Equity Investments.” The Company used quoted market prices as of December 31, 2022 and December 31, 2021 to value the unsecured notes payable and, as such, categorized them as Level 2. The inputs utilized to determine the fair value of the Company’s variable rate debt are categorized as Level 3. The fair value of the variable rate debt was determined using a discounted cash flow model that considered borrowing rates available to the Company for loans with similar terms and characteristics. The inputs utilized to determine fair value of the Company's notes receivable are unobservable and, as such, were categorized as Level 3. Fair value was determined using a discounted cash flow model that considered the contractual interest and principal payments discounted at a blended interest rate of the notes receivable. For the Company’s Level 3 financial instruments for which fair value is disclosed, an increase in the discount rate used to determine fair value would result in a decrease to the fair value. Conversely, a decrease in the discount rate would result in an increase to the fair value. Disclosure about the fair value of financial instruments is based upon pertinent information available to management as of December 31, 2022 and December 31, 2021. Although management is not aware of any factors that would significantly affect the fair value amounts, such amounts were not comprehensively revalued for purposes of these financial statements since December 31, 2022. Current estimates of fair value may differ from the amounts presented herein.

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	12 Months Ended
DERIVATIVE FINANCIAL INSTRUMENTS	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	11. DERIVATIVE FINANCIAL INSTRUMENTS Use of Derivative Financial Instruments The Company’s use of derivative instruments is limited to the utilization of interest rate agreements or other instruments to manage interest rate risk exposures and not for speculative purposes. The principal objective of such arrangements is to minimize the risks and/or costs associated with the Company’s operating and financial structure, as well as to hedge specific transactions. The counterparties to these arrangements are major financial institutions with which the Company and its affiliates may also have other financial relationships. The Company is potentially exposed to credit loss in the event of non-performance by these counterparties. However, because of the high credit ratings of the counterparties, the Company does not anticipate that any of the counterparties will fail to meet these obligations as they come due. The Company does not hedge credit or property value market risks through derivative financial instruments. The Company formally assesses, both at the inception of a hedge and on an on-going basis, whether each derivative is highly-effective in offsetting changes in cash flows of the hedged item. If management determines that a derivative is not highly-effective as a hedge or if a derivative ceases to be a highly-effective hedge, the Company will discontinue hedge accounting prospectively for either the entire hedge or the portion of the hedge that is determined to be ineffective. The related ineffectiveness would be charged to the consolidated statement of operations. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). The variable cash payments (or receipts) are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. To comply with the provisions of the accounting standard for fair value measurements and disclosures, the Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. The following table summarizes the terms and fair values of the Company’s derivative financial instruments as of December 31, 2022 and December 31, 2021. The notional amounts provide an indication of the extent of the Company’s involvement in these instruments at that time but do not represent exposure to credit, interest rate or market risks (amounts presented in thousands). Hedge Product Hedge Type Designation Notional Amount Strike Trade Date Maturity Date Fair value 12/31/2022 12/31/2021 12/31/2022 12/31/2021 Assets Swap Interest Rate Cash Flow (a) $ 250,000 $ — 3.729 % November 23, 2022 June 30, 2027 $ 255 $ — Liabilities Swap Interest Rate Cash Flow (b) $ — $ 250,000 2.868 % October 8, 2015 October 8, 2022 $ — $ (2,461) $ 250,000 $ 250,000 (a) Hedging unsecured variable rate debt. (b) On October 8, 2022, the interest rate hedge contract for this swap expired. The Company measures its derivative instruments at fair value and records them in “Other assets” and (“Other liabilities”) on the Company’s consolidated balance sheets. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. The Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that the inputs utilized to determine the fair value of derivative instruments are classified in Level 2 of the fair value hierarchy. Concentration of Credit Risk Concentrations of credit risk arise for the Company when multiple tenants of the Company are engaged in similar business activities, or are located in the same geographic region, or have similar economic features that impact in a similar manner their ability to meet contractual obligations, including those to the Company. The Company regularly monitors its tenant base to assess potential concentrations of credit risk. Management believes the current credit risk portfolio is reasonably well diversified and does not contain an unusual concentration of credit risk. No tenant accounted for 10% or more of the Company’s rents during 2022, 2021 and 2020.

LIMITED PARTNERS' NONCONTROLLIN

LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY	12 Months Ended
	Dec. 31, 2022
Noncontrolling Interest [Abstract]
LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY	12. LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY Noncontrolling interests in the Parent Company’s financial statements relate to redeemable common limited partnership interests in the Operating Partnership held by parties other than the Parent Company and properties which are consolidated but not wholly owned by the Operating Partnership. Operating Partnership The aggregate book value of the noncontrolling interests associated with the redeemable common limited partnership interests in the accompanying consolidated balance sheet of the Parent Company was $4.9 million and $8.2 million as of December 31, 2022 and December 31, 2021, respectively. Under the applicable accounting guidance, the redemption value of limited partnership units are carried at fair value. The Parent Company believes that the aggregate settlement value of these interests (based on the number of units outstanding and the average closing price of the common shares during the last five business days of the quarter) was approximately $3.2 million and $11.1 million as of December 31, 2022 and December 31, 2021, respectively.

BENEFICIARIES' EQUITY OF THE PA

BENEFICIARIES' EQUITY OF THE PARENT COMPANY	12 Months Ended
BENEFICIARIES' EQUITY OF THE PARENT COMPANY	Dec. 31, 2022
Equity [Abstract]
BENEFICIARIES' EQUITY OF THE PARENT COMPANY	13. BENEFICIARIES' EQUITY OF THE PARENT COMPANY Earnings per Share (EPS) The following table details the number of shares and net income used to calculate basic and diluted earnings per share (in thousands, except share and per share amounts; results may not add due to rounding): Year Ended December 31, 2022 2021 2020 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 53,992 $ 53,992 $ 12,366 $ 12,366 $ 307,326 $ 307,326 Net income attributable to noncontrolling interests (168) (168) (77) (77) (1,799) (1,799) Nonforfeitable dividends allocated to unvested restricted shareholders (456) (456) (421) (421) (410) (410) Net income attributable to common shareholders $ 53,368 $ 53,368 $ 11,868 $ 11,868 $ 305,117 $ 305,117 Denominator Weighted-average shares outstanding 171,491,369 171,491,369 170,878,185 170,878,185 171,926,079 171,926,079 Contingent securities/Share based compensation — 834,277 — 1,395,055 — 390,997 Weighted-average shares outstanding 171,491,369 172,325,646 170,878,185 172,273,240 171,926,079 172,317,076 Earnings per Common Share: Net income attributable to common shareholders $ 0.31 $ 0.31 $ 0.07 $ 0.07 $ 1.77 $ 1.77 The contingent securities/share based compensation impact is calculated using the treasury stock method and relates to employee awards settled in shares of the Parent Company. The effect of these securities is anti-dilutive for periods that the Parent Company incurs a net loss from continuing operations available to common shareholders and therefore is excluded from the dilutive earnings per share calculation in such periods. Redeemable common limited partnership units totaling 516,467 at December 31, 2022, 823,983 at December 31, 2021 and 981,634 at December 31, 2020, respectively, were excluded from the diluted earnings per share computations because they are not dilutive. Unvested restricted shares are considered participating securities which require the use of the two-class method for the computation of basic and diluted earnings per share. For the years ended December 31, 2022, 2021 and 2020, earnings representing nonforfeitable dividends as noted in the table above were allocated to the unvested restricted shares issued to the Company’s executives and other employees under the Company's shareholder-approved long-term incentive plan. Common and Preferred Shares On December 6, 2022, the Parent Company declared a distribution of $0.19 per common share, totaling $32.8 million, which was paid on January 19, 2023 to shareholders of record as of January 5, 2023. The Parent Company maintains a common share repurchase program under which the Board of Trustees has authorized the Parent Company to repurchase common shares. On January 3, 2019, the Board of Trustees authorized the repurchase of up to $150.0 million common shares from and after January 3, 2019. During the years ended December 31, 2021 and 2022, no common shares were repurchased by the Company. During the year ended December 31, 2021, the Company issued 226,695 common shares in a private placement to an unaffiliated third party in exchange for the third party's 1% residual ownership interest in One and Two Commerce Square, an unconsolidated joint venture. Of the 20,000,000 preferred shares authorized, none were outstanding as of December 31, 2022 or December 31, 2021. Common Share Repurchases The Parent Company maintains a common share repurchase program under which the Board of Trustees has authorized the Parent Company to repurchase common shares. On January 3, 2019, the Board of Trustees authorized the repurchase of up to $150.0 million common shares from and after January 3, 2019. During the year ended December 31, 2022 and 2021, the Company did not repurchase any common shares. During the year ended December 31, 2020, the Company repurchased and retired 6,248,483 common shares at an average price of $9.60 per share, totaling $60.0 million. Former Continuous Offering Program On January 10, 2017, the Parent Company entered into a continuous offering program (the “Offering Program”), that permitted the Parent Company to sell up to an aggregate of 16,000,000 common shares in at-the-market offerings. There was no activity under the Offering Program during 2021 and 2020. At December 31, 2022, no common shares remained available for issuance under the Offering Program, which terminated on January 10, 2020.

PARTNERS' EQUITY OF THE PARENT

PARTNERS' EQUITY OF THE PARENT COMPANY	12 Months Ended
PARTNERS' EQUITY OF THE PARENT COMPANY	Dec. 31, 2022
Equity [Abstract]
PARTNERS' EQUITY OF THE PARENT COMPANY	14. PARTNERS' EQUITY OF THE PARENT COMPANY Earnings per Common Partnership Unit The following table details the number of units and net income used to calculate basic and diluted earnings per common partnership unit (in thousands, except unit and per unit amounts; results may not add due to rounding): Year Ended December 31, 2022 2021 2020 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 53,992 $ 53,992 $ 12,366 $ 12,366 $ 307,326 $ 307,326 Net (income) loss attributable to noncontrolling interests 2 2 3 3 (20) (20) Nonforfeitable dividends allocated to unvested restricted unitholders (456) (456) (421) (421) (410) (410) Net income attributable to common unitholders $ 53,538 $ 53,538 $ 11,948 $ 11,948 $ 306,896 $ 306,896 Denominator Weighted-average units outstanding 172,036,481 172,036,481 171,770,843 171,770,843 172,907,713 172,907,713 Contingent securities/Share based compensation — 834,277 — 1,395,055 — 390,997 Total weighted-average units outstanding 172,036,481 172,870,758 171,770,843 173,165,898 172,907,713 173,298,710 Earnings per Common Partnership Unit: Net income attributable to common unitholders $ 0.31 $ 0.31 $ 0.07 $ 0.07 $ 1.77 $ 1.77 Unvested restricted units are considered participating securities which require the use of the two-class method for the computation of basic and diluted earnings per unit. For the years ended December 31, 2022, 2021 and 2020, earnings representing nonforfeitable dividends were allocated to the unvested restricted units issued to the Parent Company’s executives and other employees under the Parent Company’s shareholder-approved long-term incentive plan. Common Partnership Units and Preferred Mirror Units The Operating Partnership issues partnership units to the Parent Company in exchange for the contribution of the net proceeds of any equity security issuance by the Parent Company. The number and terms of such partnership units correspond to the number and terms of the related equity securities issued by the Parent Company. In addition, the Operating Partnership may also issue separate classes of partnership units. Historically, the Operating Partnership has had the following types of partnership units outstanding: (i) Preferred Partnership Units which have been issued to parties other than the Parent Company; (ii) Preferred Mirror Partnership Units which have been issued to the Parent Company; and (iii) Common Partnership Units which include both interests held by the Parent Company and those held by other limited partners. Preferred Mirror Partnership Units In exchange for the proceeds received in corresponding offerings by the Parent Company of preferred shares of beneficial interest, the Operating Partnership has issued to the Parent Company a corresponding amount of Preferred Mirror Partnership Units with terms consistent with that of the preferred securities issued by the Parent Company. No preferred units were outstanding as of December 31, 2022 or December 31, 2021. Common Partnership Units (Redeemable and General) The Operating Partnership has two classes of Common Partnership Units outstanding as of December 31, 2022: (i) Class A Limited Partnership Interest which are held by both the Parent Company and outside third parties and (ii) General Partnership Interests which are held solely by the Parent Company (collectively, the Class A Limited Partnership Interest, and General Partnership Interests are referred to as “Common Partnership Units”). The holders of the Common Partnership Units are entitled to share in cash distributions from, and in profits and losses of, the Operating Partnership, in proportion to their respective percentage interests, subject to preferential distributions on the preferred mirror units and the preferred units. The Common Partnership Units held by the Parent Company (comprised of both General Partnership Units and Class A Limited Partnership Units) are presented as partner’s equity in the consolidated financial statements. Class A Limited Partnership Interest held by parties other than the Parent Company are redeemable at the option of the holder for a like number of common shares of the Parent Company, or cash, or a combination thereof, at the election of the Parent Company. Because the form of settlement of these redemption rights are not within the control of the Operating Partnership, these Common Partnership Units have been excluded from partner’s equity and are presented as redeemable limited partnership units measured at the potential cash redemption value as of the end of the periods presented based on the closing market price of the Parent Company’s common shares at December 31, 2022, 2021 and 2020, which was $6.15, $13.42 and $11.91, respectively. Class A Units of 516,467 as of December 31, 2022, 823,983 as of December 31, 2021, and 981,634 as of December 31, 2020, respectively, were outstanding and owned by outside limited partners of the Operating Partnership. On December 6, 2022, the Operating Partnership declared a distribution of $0.19 per common partnership unit, totaling $32.8 million, which was paid on January 19, 2023 to unitholders of record as of January 5, 2023. During the year ended December 31, 2021, the Operating Partnership issued 226,695 common partnership units to the Parent Company in exchange for a 1% residual ownership interest in One and Two Commerce Square, an unconsolidated joint venture, which was acquired from an unaffiliated third party in exchange for an equal number of common shares of the Parent Company. Common Unit Repurchases In connection with the Parent Company’s common share repurchase program, one common unit of the Operating Partnership is retired for each common share repurchased. During the years ended December 31, 2022 and December 31, 2021, the Company did not repurchase any units. During the year ended December 31, 2020 the Company repurchased and retired 6,248,483 common units at an average price of $9.60 per unit, totaling $60.0 million. During the year ended December 31, 2019, the Company Repurchased 1,337,169 common units at an average price of $12.92 per unit, totaling $17.3 million. The common units repurchased were retired and, as a result, were accounted for in accordance with Maryland law, which does not contemplate treasury stock. The repurchases were recorded as a reduction of common units (at $0.01 par value per unit) and a decrease to General Partnership Capital.

SHARE BASED COMPENSATION, 401(K

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION	15. SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION 401(k) Plan The Company sponsors a 401(k) defined contribution plan for its employees. Each employee may contribute up to 100% of annual compensation, subject to specific limitations under the Internal Revenue Code. At its discretion, the Company can make matching contributions equal to a percentage of the employee’s elective contribution and profit sharing contributions. The Company funds its 401(k) contributions annually and plan participants must be employed as of December 31 in order to receive employer contributions, except for employees eligible for qualifying retirement, as defined under the Internal Revenue Code. The Company contributions were $0.4 million, $0.4 million, and $0.5 million in 2022, 2021, and 2020, respectively. Restricted Share Rights Awards As of December 31, 2022, 553,894 restricted share rights (“Restricted Share Rights”) were outstanding under the Company's long term equity incentive plan. These Restricted Share Rights vest over one The following table summarizes the Company’s Restricted Share Rights activity during the year-ended December 31, 2022: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2022 474,978 $ 13.51 Granted 306,555 $ 13.30 Vested (219,765) $ 13.94 Forfeited (7,874) $ 13.45 Non-vested at December 31, 2022 553,894 $ 13.22 On March 3, 2022, the Compensation Committee of the Parent Company’s Board of Trustees awarded to officers of the Company an aggregate of 258,427 Restricted Share Rights, which vest over three years from the grant date. Each Restricted Share Right entitles the holder to one common share upon settlement. The Parent Company pays dividend equivalents on the Restricted Share Rights prior to the settlement date. Vesting and/or settlement would accelerate if the recipient of the award were to die, become disabled or, in the case of certain of such Restricted Share Rights, retire in a qualifying retirement prior to the vesting or settlement date. Qualifying retirement generally means the recipient’s voluntary termination of employment after reaching at least age 57 and accumulating at least 15 years of service with the Company. In addition, vesting would also accelerate if the Parent Company were to undergo a change of control and, on or before the first anniversary of the change of control, the recipient’s employment were to cease due to a termination without cause or resignation with good reason. The Restricted Share Rights granted in 2022, 2021, and 2020 to certain senior executives include an “outperformance feature” whereby additional shares may be earned, up to 200% of the shares subject to the basic award, based on the Company’s achievement of earnings-based targets and development, or investment, based targets during a three-year performance period with an additional 366 days of service generally required to fully vest. In addition to the basic award, up to an aggregate of 406,179, 388,840, and 316,236 shares may be awarded under the outperformance feature for the 2022, 2021, and 2020 awards, respectively, to those senior officers whose Restricted Share Rights awards include the “outperformance feature.” As of December 31, 2022, the Company has not recognized any compensation expense related to the outperformance feature for the 2020-2021 awards and has recognized $0.1 million related to the outperformance feature for the 2022 award. The Company will continue to evaluate progression towards achievement of the performance metrics on a quarterly basis and recognize compensation expense for the outperformance feature of these awards should it be determined that achievement of these metrics is probable. In addition, on March 3, 2022, the Compensation Committee awarded non-officer employees an aggregate of 48,128 Restricted Share Rights that generally vest in three equal annual installments. Vesting of these awards is subject to acceleration upon death, disability or termination without cause within one year following a change of control. In accordance with the accounting standard for share-based compensation, the Company amortizes share-based compensation costs through the qualifying retirement dates for those grantees who meet the conditions for qualifying retirement during the scheduled vesting period and whose award agreements provide for vesting upon a qualifying retirement. Restricted Performance Share Units Plan The Compensation Committee of the Parent Company’s Board of Trustees has granted performance share-based awards (referred to as Restricted Performance Share Units, or RPSUs) to officers of the Parent Company. The RPSUs are settled in common shares, with the number of common shares issuable in settlement determined based on the Company’s total shareholder return over specified measurement periods compared to total shareholder returns of comparative groups over the measurement periods. The table below presents certain information as to unvested RPSU awards. RPSU Grant Date 3/5/2020 3/5/2021 3/3/2022 Total (Amounts below in shares, unless otherwise noted) Non-vested at January 1, 2022 314,055 374,161 — 688,216 Granted — — 516,852 516,852 Units Cancelled (2,076) (2,922) (3,814) (8,812) Non-vested at December 31, 2022 311,979 371,239 513,038 1,196,256 Measurement Period Commencement Date 1/1/2020 1/1/2021 1/1/2022 Measurement Period End Date 12/31/2022 12/31/2023 12/31/2024 Granted 319,600 380,957 516,852 Fair Value of Units on Grant Date (in thousands) $ 5,389 $ 6,389 $ 6,872 The Company values each RPSU on its grant date using a Monte Carlo simulation. The fair values of each award are being amortized over the three year performance period. For the 2020 and 2021 awards, dividend equivalents are credited as additional RPSUs during the performance period, subject to the same terms and conditions as the original RPSUs. The performance period will be abbreviated and the determination and delivery of earned shares will be accelerated in the event of a change in control or if the recipient of the award were to die, become disabled or retire in a qualifying retirement prior to the end of the otherwise applicable three year performance period; provided that, in the case of qualifying retirement for the March 2022, 2021 and 2020 grants, the number of shares deliverable will be pro-rated based on the portion of the performance period actually worked before retirement. In accordance with the accounting standard for share-based compensation, the Company amortizes stock-based compensation costs for the February 2019 grant through the qualifying retirement date for those executives who meet the conditions for qualifying retirement during the scheduled vesting period. For the year ended December 31, 2022, the Company recognized amortization of the 2022, 2021 and 2020 RPSU awards of $6.2 million, of which $1.1 million was capitalized consistent with the Company’s policies for capitalizing eligible portions of employee compensation. For the year ended December 31, 2021, amortization for the 2021, 2020 and 2019 RPSU awards was $4.3 million, of which $0.5 million was capitalized consistent with the Company’s policies for capitalizing eligible portions of employee compensation. For the year ended December 31, 2020, amortization for the 2020, 2019, and 2018 RPSU awards was $3.0 million, of which $0.4 million was capitalized consistent with the Company’s policies for capitalizing eligible portions of employee compensation. The remaining compensation expense to be recognized with respect to the non-vested RPSUs at December 31, 2022 was approximately $7.5 million and is expected to be recognized over a weighted average remaining vesting period of 1.3 years. The Company issued 277,061 common shares on February 1, 2022 in settlement of RPSUs that had been awarded on February 21, 2019 (with a three year measurement period ended December 31, 2021). Holders of these RPSUs also received a cash dividend equivalent payment of $0.19 per share for these common shares on January 19, 2022. Employee Share Purchase Plan The Parent Company’s shareholders approved the 2007 Non-Qualified Employee Share Purchase Plan (the “ESPP”), which is intended to provide eligible employees with a convenient means to purchase common shares of the Parent Company through payroll deductions and voluntary cash purchases at an amount equal to 85% of the average closing price per share for a specified period. Under the plan document, the maximum participant contribution for the 2022 plan year is limited to the lesser of 20% of compensation or $50,000. The ESPP allows the Parent Company to make open market purchases, which reflects all purchases made under the plan to date. In addition, the number of shares separately reserved for issuance under the ESPP is 1.25 million . E mployees made purchases under the ESPP of $0.6 million during the year ended December 31, 2022, $0.6 million during the year ended December 31, 2021 and $0.5 million during the year ended December 31, 2020. The Company recognized $0.02 million of compensation expense related to the ESPP during the year ended December 31, 2022 and $0.1 million each of the years ended December 31, 2021, and 2020. Compensation expense represents the 15% discount on the purchase price. The Board of Trustees of the Parent Company may terminate the ESPP at its sole discretion at any time. Deferred Compensation In January 2005, the Parent Company adopted a Deferred Compensation Plan (the “Plan”) that allows trustees and certain key employees to defer compensation voluntarily. Compensation expense is recorded for the deferred compensation and a related liability is recognized. Participants may elect designated benchmark investment options for the notional investment of their deferred compensation. The deferred compensation obligation is adjusted for deemed income or loss related to the investments selected. At the time the participants defer compensation, the Company records a liability, which is included in the Company’s consolidated balance sheets. The liability is adjusted for changes in the market value of the participant-selected investments at the end of each accounting period, and the impact of adjusting the liability is recorded as an increase or decrease to compensation cost. The Company has purchased mutual funds which can be utilized as a funding source for the Company’s obligations under the Plan. Participants in the Plan have no interest in any assets set aside by the Company to meet its obligations under the Plan. For each of the years ended December 31, 2022, December 31, 2021 and December 31, 2020, the Company recorded a nominal amount of deferred compensation costs, net of investments in the company-owned policies and mutual funds. Participants in the Plan may elect to have all, or a portion of their deferred compensation invested in the Company’s common shares. The Company holds these shares in a rabbi trust, which is subject to the claims of the Company’s creditors in the event of the Company’s bankruptcy or insolvency. The Plan does not permit diversification of a participant’s deferral allocated to the Company common shares and deferrals allocated to Company common shares can only be settled with a fixed number of shares. In accordance with the accounting standard for deferred compensation arrangements where amounts earned are held in a rabbi trust and invested, the deferred compensation obligation associated with the Company’s common shares is classified as a component of shareholder’s equity and the related shares are treated as shares to be issued and are included in total shares outstanding. At both December 31, 2022 and 2021, 1.2 million of such shares were included in total shares outstanding, respectively. Subsequent changes in the fair value of the common shares are not reflected in operations or shareholders’ equity of the Company.

DISTRIBUTIONS

DISTRIBUTIONS	12 Months Ended
DISTRIBUTIONS	Dec. 31, 2022
Distributions [Abstract]
DISTRIBUTIONS	16. DISTRIBUTIONS The following table provides the tax characteristics of the 2022, 2021 and 2020 distributions paid: Years ended December 31, 2022 2021 2020 (in thousands, except per share amounts) Common Share Distributions: Ordinary income $ 0.47 $ 0.64 $ 0.41 Capital gain 0.29 0.01 0.35 Non-taxable distributions — 0.11 — Distributions per share $ 0.76 $ 0.76 $ 0.76 Percentage classified as ordinary income 62.10 % 83.90 % 53.90 % Percentage classified as capital gain 37.90 % 1.20 % 46.10 % Percentage classified as non-taxable distribution — % 14.90 % — %

INCOME TAXES AND TAX CREDIT TRA

INCOME TAXES AND TAX CREDIT TRANSACTIONS	12 Months Ended
INCOME TAXES AND TAX CREDIT TRANSACTIONS	Dec. 31, 2022
Income Tax Disclosure [Abstract]
INCOME TAXES AND TAX CREDIT TRANSACTIONS	17. INCOME TAXES AND TAX CREDIT TRANSACTIONS Income Tax Provision/Benefit The Company accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases, and for net operating loss, capital loss and tax credit carryforwards. The deferred tax assets and liabilities are measured using the enacted income tax rates in effect for the year in which those temporary differences are expected to be realized or settled. The effect on the deferred tax assets and liabilities from a change in tax rates is recognized in earnings in the period when the new rate is enacted. However, deferred tax assets are recognized only to the extent that it is more likely than not that they will be realized based on consideration of all available evidence, including the future reversals of existing taxable temporary differences, future projected taxable income and tax planning strategies. Valuation allowances are provided if, based upon the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. As of December 31, 2022 and 2021 there were no deferred tax assets included within “Other assets” in the consolidated balance sheets. The Company had no accruals for tax uncertainties as of December 31, 2022 and December 31, 2021. For the years ended December 31, 2022 and 2021, there was no deferred income tax expense and nominal current income tax expense. For the year ended December 31, 2020, there was no deferred income tax expense and $0.2 million of current income tax benefit. These amounts are included in “Income tax (provision) benefit” in the consolidated statements of operations.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	12 Months Ended
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	Dec. 31, 2022
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	18. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The following table details the components of accumulated other comprehensive income (loss) of the Parent Company and the Operating Partnership as of and for the three years ended December 31, 2022 (in thousands): Parent Company Cash Flow Hedges Balance at January 1, 2020 $ (2,370) Change in fair market value during year (5,972) Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests 29 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,561) Change in fair market value during year 4,817 Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests (28) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,020) Change in fair market value during year 5,371 Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests (18) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 564 Balance at December 31, 2022 $ 3,897 Operating Partnership Cash Flow Hedges Balance at January 1, 2020 $ (2,715) Change in fair market value during year (5,972) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,935) Change in fair market value during year 4,817 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,366) Change in fair market value during year 5,371 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 564 Balance at December 31, 2022 $ 3,569 Over time, the unrealized gains and losses held in Accumulated Other Comprehensive Income (“AOCI”) will be reclassified to interest expense when the related hedged items are recognized in earnings. The current balance held in AOCI is expected

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
SEGMENT INFORMATION	Dec. 31, 2022
Segment Reporting [Abstract]
SEGMENT INFORMATION	19. SEGMENT INFORMATION As of December 31, 2022, the Company owns and manages properties within five segments: (1) Philadelphia Central Business District (“Philadelphia CBD”), (2) Pennsylvania Suburbs, (3) Austin, Texas (4) Metropolitan Washington, D.C. and (5) Other. The Philadelphia CBD segment includes properties located in the City of Philadelphia, Pennsylvania. The Pennsylvania Suburbs segment includes properties in Chester, Delaware, and Montgomery counties in the Philadelphia suburbs. The Austin, Texas segment includes properties in the City of Austin, Texas. The Metropolitan Washington, D.C. segment includes properties in the District of Columbia, Northern Virginia and Southern Maryland. The Other segment includes properties located in Camden County, New Jersey and New Castle County, Delaware. In addition to the five segments, the corporate group is responsible for cash and investment management, development of certain real estate properties during the construction period, and certain other general support functions. Land held for development and construction in progress is transferred to operating properties by region upon completion of the associated construction or project. The following tables provide selected asset information and results of operations of the Company’s reportable segments (in thousands): Real estate investments, at cost: December 31, 2022 December 31, 2021 Philadelphia CBD $ 1,517,801 $ 1,460,510 Pennsylvania Suburbs 878,546 866,223 Austin, Texas 851,835 778,145 Metropolitan Washington, D.C. 282,458 280,921 Other 86,600 86,803 Operating Properties $ 3,617,240 $ 3,472,602 Corporate Right of use asset - operating leases, net $ 19,664 $ 20,313 Construction-in-progress $ 218,869 $ 277,237 Land held for development $ 76,499 $ 114,604 Prepaid leasehold interests in land held for development, net $ 35,576 $ 27,762 . Net operating income: Year Ended December 31, 2022 2021 2020 Total revenue Operating expenses (a) Net operating income Total revenue Operating expenses (a) Net operating income Total revenue Operating expenses (a) Net operating income (loss) Philadelphia CBD $ 220,876 $ (79,827) $ 141,049 $ 207,858 $ (73,695) $ 134,163 $ 232,028 $ (82,505) $ 149,523 Pennsylvania Suburbs 128,940 (41,814) 87,126 124,566 (40,011) 84,555 141,613 (46,281) 95,332 Austin, Texas 96,328 (41,141) 55,187 101,680 (39,374) 62,306 102,982 (39,759) 63,223 Metropolitan Washington, D.C. 21,900 (12,539) 9,361 19,865 (15,386) 4,479 40,223 (20,791) 19,432 Other 14,710 (8,626) 6,084 14,015 (9,840) 4,175 13,469 (9,815) 3,654 Corporate 23,346 (10,454) 12,892 18,835 (10,005) 8,830 4,537 (6,305) (1,768) Operating properties $ 506,100 $ (194,401) $ 311,699 $ 486,819 $ (188,311) $ 298,508 $ 534,852 $ (205,456) $ 329,396 (a) Includes property operating expense, real estate taxes and third party management expense. Unconsolidated real estate ventures: Investment in real estate ventures, at equity Equity in income (loss) of real estate venture As of Year ended December 31, December 31, 2022 December 31, 2021 2022 2021 2020 Philadelphia CBD $ 387,301 $ 317,959 $ (11,764) $ (15,191) $ (9,090) Metropolitan Washington, D.C. 83,903 85,867 (2,324) (3,755) (3,019) Mid-Atlantic Office JV 31,005 31,680 412 932 96 MAP Venture (35,411) (24,396) (8,340) (8,683) (6,571) Austin, Texas 65,426 — — — — Total $ 532,224 $ 411,110 $ (22,016) $ (26,697) $ (18,584) Net operating income (“NOI”) is a non-GAAP financial measure, which we define as total revenue less property operating expenses, real estate taxes, and third party management expenses. Property operating expenses that are included in determining NOI consist of costs that are necessary and allocable to our operating properties such as utilities, property-level salaries, repairs and maintenance, property insurance and management fees. General and administrative expenses that are not reflected in NOI primarily consist of corporate-level salaries, amortization of share awards and professional fees that are incurred as part of corporate office management. NOI presented by the Company may not be comparable to NOI reported by other companies that define NOI differently. NOI is the primary measure that is used by the Company's management to evaluate the operating performance of the Company's real estate assets by segment. The Company believes NOI provides useful information to investors regarding the financial condition and results of operations because it reflects only those income and expense items that are incurred at the property level. While NOI is a relevant and widely used measure of operating performance of real estate investment trusts, it does not represent cash flow from operations or net income as defined by GAAP and should not be considered as an alternative to those measures in evaluating our liquidity or operating performance. NOI does not reflect interest expenses, real estate impairment losses, depreciation and amortization costs, capital expenditures and leasing costs. The Company believes that net income (loss), as defined by GAAP, is the most appropriate earnings measure. The following is a reconciliation of consolidated net income (loss), as defined by GAAP, to consolidated NOI, (in thousands): Year Ended December 31, 2022 2021 2020 Net income $ 53,992 $ 12,366 $ 307,326 Plus: Interest expense 68,764 62,617 73,911 Interest expense - amortization of deferred financing costs 3,091 2,836 2,904 Depreciation and amortization 177,984 178,105 188,283 General and administrative expenses 35,006 30,153 30,288 Equity in loss of unconsolidated real estate ventures 22,016 26,697 18,584 Provision for impairment 4,663 — — Loss on early extinguishment of debt 435 — — Less: Interest and investment income 1,905 8,295 1,939 Income tax (provision) benefit (55) (47) 224 Net gain on disposition of real estate 17,677 142 289,461 Net gain on sale of undepreciated real estate 8,007 2,903 201 Net gain on real estate venture transactions 26,718 2,973 75 Consolidated net operating income $ 311,699 $ 298,508 $ 329,396

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
COMMITMENTS AND CONTINGENCIES	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	20. COMMITMENTS AND CONTINGENCIES Legal Proceedings The Company is involved from time to time in litigation on various matters, including disputes with tenants, disputes with vendors, employee disputes and disputes arising out of agreements to purchase or sell properties or joint ventures or disputes relating to state and local taxes. Given the nature of the Company’s business activities, these lawsuits are considered routine to the conduct of its business. The result of any particular lawsuit cannot be predicted, because of the very nature of litigation, the litigation process and its adversarial nature, and the jury system. The Company will establish reserves for specific legal proceedings when it determines that the likelihood of an unfavorable outcome is probable and when the amount of loss is reasonably estimable. The Company does not expect that the liabilities, if any, that may ultimately result from such legal actions will have a material adverse effect on the consolidated financial position, results of operations or cash flows of the Company. Environmental As an owner of real estate, the Company is subject to various environmental laws of federal, state, and local governments. The Company’s compliance with existing laws has not had a material adverse effect on its financial condition and results of operations, and the Company does not believe it will have a material adverse effect in the future. However, the Company cannot predict the impact of unforeseen environmental contingencies or new or changed laws or regulations on its current Properties or on properties that the Company may acquire. Debt Guarantees As of December 31, 2022, the Company's unconsolidated real estate ventures had aggregate indebtedness of $1,204.8 million. These loans are generally mortgage or construction loans, most of which are nonrecourse to the Company, except for customary recourse carve-outs. In addition, during construction undertaken by the unconsolidated real estate ventures, including the 3025 JFK Venture, the Company has provided, and expects to continue to provide, cost overrun and completion guarantees, as well as customary environmental indemnities and guarantees of customary exceptions to nonrecourse provisions in loan agreements. In the agreement with its partner in the 3025 JFK Venture, the Company agreed to provide cost overrun and completion guaranties for the project under development. With respect to the construction loan obtained by 3025 JFK Venture on July 23, 2021, the Company has also provided a carry guarantee and limited payment guarantee up to 25% of the principal balance of the $186.7 million construction loan. The Company has also provided cost overrun and completion guarantees, as well as customary environmental indemnities, in favor of the joint venture partners, for the One Uptown Ventures. See also Note 4, “Investment in Unconsolidated Real Estate Ventures,” for information on the guarantees in favor of the lenders on the construction loans for the One Uptown Ventures. Impact of Natural Disasters and Casualty The Company carries liability insurance to mitigate its exposure to certain losses, including those relating to property damage. The Company records the estimated amount of expected insurance proceeds for property damage and other losses incurred as an asset (typically a receivable from the insurer) and income up to the amount of the losses incurred when receipt of insurance proceeds is deemed probable. Any amount of insurance recovery in excess of the amount of the losses is considered a gain contingency and is not recorded until the proceeds are received. In February 2021, one of the Company's properties in Austin, Texas sustained damage from the winter storms and resulting power grid failures. As a result of the damage, during the year ended December 31, 2021, the Company recorded a fixed asset write-off totaling $1.2 million. During the year ended December 31, 2021, the Company has recorded an estimated $7.2 million of restoration costs, of which $1.9 million is included in Accounts payable and accrued expenses on the consolidated balance sheets as of December 31, 2021. The Company has also sustained business interruption loss of $3.9 million related to unpaid rent, which is also fully covered under the insurance policy. During the year ended December 31, 2021, the Company received $15.3 million of insurance proceeds, resulting in full recovery of the costs incurred to date. The $3.0 million of insurance proceeds received in excess of the fixed asset write-off, total business interruption, and total estimated restoration cost during the year ended December 31, 2021 is included in Other income on the consolidated statement of operations. During year ended December 31, 2022, the Company recognized a $0.8 million reduction of the previously estimated restoration costs and also received $2.8 million of additional insurance proceeds. The reduction of the restoration costs and additional insurance proceeds are included in other income on the consolidated statement of operations. Other Commitments or Contingencies Under the terms of each of the One Uptown joint venture agreements, the Company has provided cost overrun and completion guarantees, as well as customary environmental indemnities, in favor of the joint venture partner, for each of the One Uptown joint ventures. See Note 4, “Investment in Unconsolidated Real Estate Ventures” for further information. In connection with the Schuylkill Yards Project, the Company entered into a neighborhood engagement program and, as of December 31, 2022, had $6.6 million of future fixed contractual obligations. The Company also committed to fund additional contributions under the program. As of December 31, 2022, the Company estimates that these additional contributions, which are not fixed under the terms of agreement, will be $2.2 million. In connection with the formation of the Commerce Square Venture, the Company has committed to investing an additional $20.0 million of preferred equity in the properties on a pari passu basis with its joint venture partner of which $7.2 million has been contributed by the Company as of December 31, 2022. As part of the Company’s September 2004 acquisition of a portfolio of properties (which the Company refers to as the “TRC acquisition”), the Company acquired its interest in Two Logan Square, a 708,844 square foot office building in Philadelphia, Pennsylvania primarily through its ownership of a second and third mortgage secured by this property. This property is consolidated, as the borrower is a variable interest entity and the Company, through its ownership of the second and third mortgages, is the primary beneficiary. On October 21, 2020, the Company also acquired the $79.8 million first mortgage on the property from the third-party mortgage lender pursuant to an agreement with certain of the former owners. Under the agreement, the Company has agreed to not take title to Two Logan until the earlier of June 2026 or the occurrence of certain events related to the ownership interests of certain former owners. If the Company were to sell the restricted property before the expiration of the restricted period in a non-exempt transaction, the Company may be required to make significant payments to certain of the former owners of Two Logan Square on account of tax liabilities attributed to them. Additionally, the Company will be required to pay these certain former owners an amount estimated at approximately $0.6 million to redeem their residual interest in the fee owner of this property. The $0.6 million payment is included within “Other liabilities” on the consolidated balance sheets. The Company invests in its properties and regularly incurs capital expenditures in the ordinary course of business to maintain the properties. The Company believes that such expenditures enhance its competitiveness. The Company also enters into construction, utility and service contracts in the ordinary course of business which may extend beyond one year. These contracts typically provide for cancellation with insignificant or no cancellation penalties.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
SUBSEQUENT EVENTS	Dec. 31, 2022
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	21. SUBSEQUENT EVENTS On January 19, 2023, seven indirect wholly-owned subsidiaries of the Company entered into a term loan agreement secured by seven operating properties in the aggregate principal amount of $245.0 million (the “Secured Facility”). The Secured Facility has a scheduled maturity date of February 6, 2028 and may be prepaid in full on or after March 6, 2025, subject to a prepayment premium, and may be prepaid in full on or after August 6, 2027 without any prepayment premium. The Secured Facility bears interest at 5.875% per year through the maturity date and is interest-only (payable monthly) through the maturity date. The Company used the net proceeds from the term loan for general corporate purposes, including to reduce outstanding borrowings under the Company’s unsecured revolving credit facility. On January 20, 2023, the Company redeemed in full its then outstanding 2023 Notes. The redemption price of the 2023 Notes was approximately $55.2 million (approximately $54.3 million in principal and approximately $0.92 million of accrued and unpaid interest). The aggregate redemption price of the 2023 Notes was paid by the Company from available cash balances.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
Schedule II - Valuation and Qualifying Accounts	Dec. 31, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II Valuation and Qualifying Accounts	Schedule II Valuation and Qualifying Accounts (in thousands) Description Balance at Beginning of Year Additions Deductions (1) Balance at End of Year Allowance for doubtful accounts: December 31, 2022 $ 4,133 $ — $ 186 $ 3,947 December 31, 2021 $ 5,086 $ — $ 953 $ 4,133 December 31, 2020 $ 7,975 $ — $ 2,889 $ 5,086

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
Schedule III - Real Estate and Accumulated Depreciation	Dec. 31, 2022
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real Estate and Accumulated Depreciation	BRANDYWINE REALTY TRUST AND BRANDYWINE OPERATING PARTNERSHIP, L.P. Schedule III Real Estate and Accumulated Depreciation — December 31, 2022 (in thousands) Initial Cost Gross Amount Which Carried Property Name City State Land Building & Improvements Net Improvements (Retirements) Since Acquisition Land Building & Improvements Total (a) Accumulated Depreciation at December 31, 2022 (b) Year of Construction Year Acquired Depreciable Life PENNSYLVANIA SUBURBS Six Tower Bridge (181 Washington Street) Conshohocken PA $ 6,927 $ 14,722 $ 1,176 $ 6,237 $ 16,588 $ 22,825 $ 4,604 1999 2013 (c) 426 West Lancaster Avenue Devon PA 1,689 6,756 9,405 1,686 16,164 17,850 2,727 1990 1998 (c) 640 Freedom Business Center (d) King Of Prussia PA 1,015 20,098 4,603 332 25,384 25,716 16,544 1991 1998 (c) 620 Freedom Business Center (d) King Of Prussia PA 666 13,118 2,372 217 15,939 16,156 10,154 1986 1998 (c) 1000 First Avenue King Of Prussia PA — 13,708 2,971 — 16,679 16,679 12,521 1980 1998 (c) 1060 First Avenue King Of Prussia PA — 13,665 3,979 — 17,644 17,644 12,989 1987 1998 (c) 630 Freedom Business Center Drive (d) King Of Prussia PA 666 13,251 2,864 219 16,562 16,781 10,946 1989 1998 (c) 1020 First Avenue King Of Prussia PA — 10,744 4,306 — 15,050 15,050 11,050 1984 1998 (c) 1040 First Avenue King Of Prussia PA — 14,142 4,915 — 19,057 19,057 14,165 1985 1998 (c) 610 Freedom Business Center Drive (d) King Of Prussia PA 485 9,602 2,289 159 12,217 12,376 8,256 1985 1998 (c) 650 Park Avenue King Of Prussia PA 1,916 4,378 (4,378) 1,916 — 1,916 — 1968 1998 (c) 600 Park Avenue King Of Prussia PA 1,012 4,048 50 1,012 4,098 5,110 2,660 1964 1998 (c) 933 First Avenue King Of Prussia PA 3,127 20,794 (1,125) 3,127 19,669 22,796 4,823 2017 N/A (c) 500 North Gulph Road King Of Prussia PA 1,303 5,201 21,471 1,303 26,672 27,975 4,690 1979 1996 (c) 401 Plymouth Road Plymouth Meeting PA 6,199 16,131 14,515 6,199 30,646 36,845 15,527 2001 2000 (c) Metroplex (4000 Chemical Road) Plymouth Meeting PA 4,373 24,546 5,554 4,373 30,100 34,473 9,860 2007 2001 (c) 610 West Germantown Pike Plymouth Meeting PA 3,651 14,514 5,461 3,651 19,975 23,626 10,440 1987 2002 (c) 600 West Germantown Pike Plymouth Meeting PA 3,652 15,288 4,035 3,652 19,323 22,975 9,682 1986 2002 (c) 630 West Germantown Pike Plymouth Meeting PA 3,558 14,743 3,169 3,558 17,912 21,470 9,015 1988 2002 (c) 620 West Germantown Pike Plymouth Meeting PA 3,572 14,435 4,131 3,572 18,566 22,138 8,409 1990 2002 (c) 660 West Germantown Pike Plymouth Meeting PA 3,694 5,487 19,502 5,405 23,278 28,683 8,467 1987 2012 (c) 351 Plymouth Road Plymouth Meeting PA 1,043 555 — 1,043 555 1,598 246 N/A 2000 (c) 150 Radnor Chester Road Radnor PA 11,925 36,986 21,691 11,897 58,705 70,602 26,556 1983 2004 (c) One Radnor Corporate Center Radnor PA 7,323 28,613 14,397 7,323 43,010 50,333 27,920 1998 2004 (c) 201 King of Prussia Road Radnor PA 8,956 29,811 4,196 8,949 34,014 42,963 22,515 2001 2004 (c) 555 Lancaster Avenue Radnor PA 8,014 16,508 10,772 8,609 26,685 35,294 9,722 1973 2004 (c) Four Radnor Corporate Center Radnor PA 5,406 21,390 10,499 5,705 31,590 37,295 18,534 1995 2004 (c) Five Radnor Corporate Center Radnor PA 6,506 25,525 9,755 6,578 35,208 41,786 16,306 1998 2004 (c) Three Radnor Corporate Center Radnor PA 4,773 17,961 1,788 4,791 19,731 24,522 11,768 1998 2004 (c) Two Radnor Corporate Center Radnor PA 3,937 15,484 2,552 3,942 18,031 21,973 11,383 1998 2004 (c) 130 Radnor Chester Road Radnor PA 2,573 8,338 (258) 2,567 8,086 10,653 4,099 1983 2004 (c) 170 Radnor Chester Road Radnor PA 2,514 8,147 2,008 2,509 10,160 12,669 5,366 1983 2004 (c) 200 Radnor Chester Road Radnor PA 3,366 — 3,740 3,366 3,740 7,106 1,137 2014 2005 (c) 101 West Elm Street W. Conshohocken PA 6,251 25,209 2,846 6,251 28,055 34,306 12,533 1999 2005 (c) 1 West Elm Street W. Conshohocken PA 3,557 14,249 8,203 3,557 22,452 26,009 7,302 1999 2005 (c) 250 King of Prussia Road (e) (i) Radnor PA — 20,566 12,733 976 32,323 33,299 626 N/A 2022 (c) Initial Cost Gross Amount Which Carried December 31, 2022 Property Name City State Land Building & Improvements Net Improvements (Retirements) Since Acquisition Land Building & Improvements Total (a) Accumulated Depreciation at December 31, 2022 (b) Year of Construction Year Acquired Depreciable Life PHILADELPHIA CBD Cira Centre (2929 Arch Street) Philadelphia PA — 208,570 23,843 12,586 219,827 232,413 73,510 2005 N/A (c) Three Logan Square (1717 Arch Street) Philadelphia PA — 98,188 86,126 25,195 159,119 184,314 61,247 1990 2010 (c) One Logan Square (130 North 18th Street) Philadelphia PA 14,496 107,736 21,614 14,473 129,373 143,846 70,363 1998 2004 (c) Two Logan Square (100 North 18th Street) Philadelphia PA 16,066 100,255 34,198 16,066 134,453 150,519 61,597 1988 2004 (c) Cira Centre South Garage (129 South 30th Street) (d) Philadelphia PA — 76,008 26,970 6,638 96,340 102,978 27,789 2010 N/A (c) 1900 Market Street Philadelphia PA 7,768 17,263 61,760 7,768 79,023 86,791 30,016 1981 2012 (c) 3020 Market Street Philadelphia PA — 21,417 7,442 — 28,859 28,859 13,904 1959 2011 (c) 618-634 Market Street Philadelphia PA 13,365 5,791 5,180 13,365 10,971 24,336 7,222 1966 2015 (c) FMC Tower at Cira Centre South (2929 Walnut Street) Philadelphia PA — 400,294 10,689 — 410,983 410,983 85,826 2016 N/A (c) 2100 Market Street Philadelphia PA 18,827 — 6,292 18,854 6,265 25,119 2,280 N/A 2015 (c) 1505-11 Race Street Philadelphia PA 3,662 6,061 8 3,670 6,061 9,731 328 1922 2020 (c) 3000 Market Street (f) Philadelphia PA 18,924 13,080 17,349 18,924 30,429 49,353 2,608 1937 2017 (c) The Bulletin Building (3025 Market Street) (f) Philadelphia PA — 24,377 44,081 — 68,458 68,458 11,490 1953 2017 (c) 3001-3003 JFK Boulevard (g) Philadelphia PA — — 111 — 111 111 32 N/A 2018 N/A METROPOLITAN WASHINGTON, D.C. 6600 Rockledge Drive Bethesda MD — 37,421 7,672 — 45,093 45,093 17,099 1981 2006 (c) 1676 International Drive McLean VA 18,437 97,538 37,113 18,785 134,303 153,088 35,718 1999 2006 (c) 8260 Greensboro Drive McLean VA 7,952 33,964 8,645 8,102 42,459 50,561 14,217 1980 2006 (c) 8521 Leesburg Pike Vienna VA 4,316 30,885 (1,511) 3,587 30,103 33,690 12,032 1984 2006 (c) Dabney Westwood Richmond VA 1,732 — 3,690 819 4,603 5,422 185 NA 1998 (c) AUSTIN, TX 401-405 Colorado Street (h) (i) Austin TX — 100,448 564 — 101,012 101,012 2,728 2022 N/A (c) 11501 Burnet Road - Building 1 Austin TX 3,755 22,702 4 3,755 22,706 26,461 8,876 1991 2015 (c) 11501 Burnet Road - Building 2 Austin TX 2,732 16,305 1,473 2,732 17,778 20,510 7,422 1991 2015 (c) 11501 Burnet Road - Building 3 Austin TX 3,688 22,348 6,421 3,688 28,769 32,457 9,372 1991 2015 (c) 11501 Burnet Road - Building 4 Austin TX 2,614 15,740 3 2,614 15,743 18,357 6,153 1991 2015 (c) 11501 Burnet Road - Building 5 Austin TX 3,689 22,354 4 3,689 22,358 26,047 8,740 1991 2015 (c) 11501 Burnet Road - Building 6 Austin TX 2,676 15,972 13,855 2,676 29,827 32,503 12,555 1991 2015 (c) 11501 Burnet Road - Building 8 Austin TX 1,400 7,422 1,776 1,400 9,198 10,598 3,594 1991 2015 (c) 11501 Burnet Road - Parking Garage Austin TX — 19,826 1,538 — 21,364 21,364 8,740 1991 2015 (c) Four Points Centre 3 (11120 Four Points Drive) Austin TX 1,140 — 40,322 1,141 40,321 41,462 6,849 2019 2013 (c) One Barton Skyway (1501 South MoPac Expressway) Austin TX 10,496 47,670 7,970 10,495 55,641 66,136 6,565 1999 2018 (c) Two Barton Skyway (1601 South MoPac Expressway) Austin TX 10,849 53,868 3,889 10,848 57,758 68,606 7,271 2000 2018 (c) Three Barton Skyway (1221 South MoPac Expressway) Austin TX 10,374 47,624 1,027 10,373 48,652 59,025 5,158 2001 2018 (c) Four Barton Skyway (1301 South MoPac Expressway) Austin TX 13,301 57,041 7,611 13,300 64,653 77,953 7,096 2001 2018 (c) Initial Cost Gross Amount Which Carried December 31, 2022 Property Name City State Land Building & Improvements Net Improvements (Retirements) Since Acquisition Land Building & Improvements Total (a) Accumulated Depreciation at December 31, 2022 (b) Year of Construction Year Acquired Depreciable Life Four Points Centre (11305 Four Points Drive) Austin TX 7,800 43,581 4,515 7,800 48,096 55,896 6,275 2008 2018 (c) River Place - Building 1 (6500 River Place Boulevard) Austin TX 2,004 17,680 562 2,004 18,242 20,246 2,189 2000 2018 (c) River Place - Building 2 (6500 River Place Boulevard) Austin TX 3,137 29,254 806 3,137 30,060 33,197 3,432 2000 2018 (c) River Place - Building 3 (6500 River Place Boulevard) Austin TX 3,064 26,705 447 3,064 27,152 30,216 2,931 2000 2018 (c) River Place - Building 4 (6500 River Place Boulevard Austin TX 2,273 18,617 1,716 2,273 20,333 22,606 2,903 2000 2018 (c) River Place - Building 5 (6500 River Place Boulevard) Austin TX 1,752 14,315 692 1,752 15,007 16,759 1,655 2001 2018 (c) River Place - Building 6 (6500 River Place Boulevard) Austin TX 1,598 12,945 703 1,598 13,648 15,246 1,490 2001 2018 (c) River Place - Building 7 (6500 River Place Boulevard) Austin TX 1,801 16,486 1,208 1,801 17,694 19,495 2,468 2002 2018 (c) Quarry Lake II (4516 Seton Center Parkway) Austin TX 3,970 30,546 1,174 3,867 31,823 35,690 3,611 1998 2018 (c) OTHER Main Street - Plaza 1000 Voorhees NJ 2,732 10,942 284 2,732 11,226 13,958 11,054 1988 1997 (c) Main Street - Piazza Voorhees NJ 696 2,802 3,586 704 6,380 7,084 4,547 1990 1997 (c) Main Street - Promenade Voorhees NJ 532 2,052 311 532 2,363 2,895 1,561 1988 1997 (c) 920 North King Street Wilmington DE 6,141 21,140 7,108 6,141 28,248 34,389 16,427 1989 2004 (c) 300 Delaware Avenue Wilmington DE 6,369 13,739 2,750 6,369 16,489 22,858 10,393 1989 2004 (c) Total: $ 359,777 $ 2,527,685 $ 729,778 $ 403,998 $ 3,213,242 $ 3,617,240 $ 1,063,060 The following table reconciles the real estate investments from January 1, 2020 to December 31, 2022 (in thousands): 2022 2021 2020 Balance at beginning of year $ 3,472,602 $ 3,474,109 $ 4,006,459 Additions: Acquisitions — — 9,722 Capital expenditures and assets placed into service 212,874 134,931 113,221 Less: Dispositions/impairments/placed into redevelopment (32,951) (82,247) (619,086) Retirements (35,285) (54,191) (36,207) Balance at end of year $ 3,617,240 $ 3,472,602 $ 3,474,109 Per consolidated balance sheet $ 3,617,240 $ 3,472,602 $ 3,474,109 The aggregate cost for federal income tax purposes is $3.2 billion as of December 31, 2022. (b) Reconciliation of Accumulated Depreciation: The following table reconciles the accumulated depreciation on real estate investments from January 1, 2020 to December 31, 2022 (in thousands): 2022 2021 2020 Balance at beginning of year $ 957,450 $ 896,561 $ 973,318 Additions: Depreciation expense 147,735 136,171 138,822 Less: Dispositions/impairments/placed into redevelopment (7,341) (24,440) (182,526) Retirements (34,784) (50,842) (33,053) Balance at end of year $ 1,063,060 $ 957,450 $ 896,561 Per consolidated balance sheet $ 1,063,060 $ 957,450 $ 896,561 (c) Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 55 years. (d) Land value represents unamortized prepaid ground lease. (e) 250 King of Prussia Road was partially placed into service in 2022. (f) Reflects original construction date. Significant improvements were made to 3000 Market Street in 1988 and to The Bulletin Building in 2012. (g) Represent leasehold interests in land parcels acquired through prepaid 99-year ground leases. Development has not yet commenced on the parcel. Building and improvements represent costs related to parking operations. (h) 401-405 Colorado Street was partially placed into service in 2021.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Dec. 31, 2022
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Company consolidates variable interest entities (“VIEs”) in which it is considered to be the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or that the holders of the equity investment at risk do not have a controlling financial interest. The primary beneficiary is defined by the entity having both of the following characteristics: (i) the power to direct those matters that most significantly impact the activities of the VIE and (ii) the obligation to absorb losses or the right to receive benefits of the VIE that could potentially be significant to the VIE. For entities that the Company has the obligations to fund losses, its maximum exposure to loss is not limited to the carrying amount of its investments.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Operating Properties	Operating Properties Operating properties are carried at historical cost less accumulated depreciation and impairment losses. The value of operating properties reflects their purchase price or development cost. Acquisition costs related to business combinations are expensed as incurred, whereas the costs related to asset acquisitions are capitalized as incurred. Costs incurred for the renovation and betterment of an operating property are capitalized to the Company’s investment in that property. Ordinary repairs and maintenance are expensed as incurred.
Purchase Price Allocation	Purchase Price Allocation For acquisitions of real estate or in-substance real estate that are accounted for as business combinations, we recognize the assets acquired (including the intangible value of acquired above- or below-market leases, acquired in-place leases and tenant relationship values), liabilities assumed, noncontrolling interests, and previously existing ownership interests at fair value as of the acquisition date. Any excess (deficit) of the consideration transferred relative to the fair value of the net assets acquired is accounted for as goodwill (bargain purchase gain). Acquisition costs related to business combinations are expensed as incurred. Acquisitions of real estate and in-substance real estate that do not meet the definition of a business are accounted for as asset acquisitions. The Company generally expects that acquisitions of real estate or in-substance real estate will not meet the definition of business and therefore are accounted for as asset acquisitions, unless specifically noted otherwise. The accounting model for asset acquisitions is similar to the accounting model for business combinations except that the acquisition consideration (including acquisition costs) is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. As a result, asset acquisitions do not result in recognition of goodwill or a bargain purchase gain. Additionally, because the accounting model for asset acquisitions is a cost accumulation model, preexisting interests in the acquired assets, if any, are not remeasured to fair value but continue to be accounted for at their historical cost. Direct acquisition costs are capitalized if an asset acquisition is probable. If we determine that an asset acquisition is no longer probable, no new costs are capitalized and all capitalized costs that are not recoverable are written off. The purchase price is allocated to the acquired assets and assumed liabilities, including land and buildings, as if vacant based on highest and best use for the acquired assets. The Company assesses and considers fair value of the operating properties based on estimated cash flow projections that utilize discount and/or capitalization rates that it deems appropriate, as well as available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known and anticipated trends, and market and economic conditions. The Company allocates the purchase price of properties considered to be business combinations and asset acquisitions to net tangible and identified intangible assets acquired based on fair values. Above-market and below-market in-place lease values for acquired properties are recorded based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) the Company’s estimate of the fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining noncancellable term of the lease (including the below market fixed renewal periods that are considered probable, if applicable). Capitalized above-market lease values are amortized as a reduction of rental income over the remaining noncancellable terms of the respective leases. Capitalized below-market lease values are amortized as an increase to rental income over the remaining noncancellable terms of the respective leases, including any below market fixed-rate renewal option periods that are considered probable. Other intangible assets also include in-place leases based on the Company’s evaluation of the specific characteristics of each tenant’s lease and the Company’s overall relationship with the respective tenant. The Company estimates the cost to execute leases with terms similar to the remaining lease terms of the in-place leases, including leasing commissions, legal and other related expenses. This intangible asset is amortized to expense over the remaining term of the respective leases and any fixed-rate bargain renewal periods. Factors considered by the Company in this analysis include an estimate of the carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases. In estimating carrying costs, the Company includes real estate taxes, insurance, and other operating expenses, and estimates of lost rents at market rates during the expected lease-up periods, which primarily range from four In the event that a tenant terminates its lease, the unamortized portion of each intangible, including in-place lease values and tenant relationship values, is charged to expense and market rate adjustments (above or below) are recorded to revenue.
Depreciation and Amortization	Depreciation and Amortization The costs of buildings and improvements are depreciated using the straight-line method based on the following useful lives: buildings and improvements (5 to 55 years) and tenant improvements (the shorter of (i) the life of the asset (1 to 16 years) or (ii) the lease term).
Construction-in-Progress	Construction-in-ProgressProject costs directly associated with the development or redevelopment and construction of a real estate project are capitalized as construction-in-progress. Construction-in-progress also includes costs related to ongoing tenant improvement projects. In addition, interest, real estate taxes, and other expenses that are directly associated with the Company’s development or redevelopment activities are capitalized beginning when activities necessary to ready the asset for its intended use are in progress and capital expenditures have been made and ending when the property is placed in service. Interest expense is capitalized using the Company’s weighted average interest rate. Internal direct costs are capitalized to projects in which qualifying expenditures are being incurred.
Ground Leases	Ground Leases The Company is the lessee under long-term ground leases classified as operating leases. The Company makes significant assumptions and judgments when determining the discount rate for the lease to calculate the present value of the lease payments. As the rate implicit in the lease is not readily determinable, the Company estimates the incremental borrowing rate (“IBR”) that it would need to pay to borrow, on a collateralized basis, an amount equal to the lease payments in a similar economic environment, over a similar lease term. The Company utilizes a market-based approach to estimate the IBR for each individual lease. The base IBR is estimated utilizing observable mortgage and corporate bond rates, which are then adjusted to account for considerations related to the Company’s credit rating and the lease term to select an incremental borrowing rate for each lease. The right of use assets and lease liabilities are presented as “Right of use asset - operating leases, net” and “Lease liability - operating leases”, respectively, on the consolidated balance sheet as of December 31, 2022 and 2021, respectively. The lease liabilities and right of use assets are amortized on a straight-line basis over the lease term with the corresponding expense classified in “Property operating expenses” on the consolidated statements of operations. The most recent CPI adjustment is used to determine the present value of the lease payments for an indexed lease and ultimately the right of use asset and corresponding lease liability. Rent payments for amounts in excess of this estimated growth rate will be expensed on a cash basis as incurred and are considered variable lease costs.
Impairment of Real Estate Investments	Impairment of Real Estate Investments The Company reviews its real estate investments for impairment following the end of each quarter for each of its real estate investments where events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company updates leasing and other assumptions regularly, paying particular attention to real estate investments where there is an event or change in circumstances that indicates an impairment in value. Additionally, the Company considers strategic decisions regarding the future development plans for real estate investment under development and other market factors. For real estate investments to be held and used, the Company analyzes recoverability based on the estimated undiscounted future cash flows expected to be generated from the operations and eventual disposition of the assets over, in most cases, a 10-year hold period. If there is significant possibility that the Company will dispose of assets earlier, it analyzes the recoverability using a probability weighted analysis of the undiscounted future cash flows expected to be generated from the operations and eventual disposition of each asset using various probable hold periods. If the recoverability analysis indicates that the carrying value of the tested real estate investment is not recoverable, the real estate investment is written down to its fair value and an impairment is recognized in the amount of the excess of the carrying amount of the asset over its fair value. If and when the Company’s plans change, it revises its recoverability analysis to use cash flows expected from operations and eventual disposition of each asset using hold periods that are consistent with its revised plans. Estimated future cash flows used in such analysis are based on the Company’s plans for the real estate investment and its views of market economic conditions. The estimates consider assumptions, including but not limited to market rental rates, capitalization rates, and recent sales data for comparable real estate investments. Future cash flows are discounted when
Assets Held for Sale	Assets Held for Sale The Company generally reclassifies assets to held for sale when the transaction has been approved by its Board of Trustees, or by officers vested with authority to approve the transaction, and there are no known significant contingencies relating to the sale of the real estate investment within one year of the consideration date and the consummation of the transaction is otherwise considered probable. When a real estate investment is designated as held for sale, the Company stops depreciating the real estate investment and estimates the real estate investment’s fair value, net of selling costs. If the determination is made that the estimated fair value, net of selling costs, is less than the net carrying value of the real estate investment, an impairment is recognized, reducing the net carrying value of the real estate investment to estimated fair value less selling costs. For periods in which a real estate investment is classified as held for sale, the Company classifies the assets and liabilities, as applicable, of the real estate investment as held for sale on the consolidated balance sheet for such periods.
Impairment of Land Held for Development	Impairment of Land Held for Development When demand for build-to-suit properties declines and the ability to sell land held for development deteriorates, or other market factors indicate possible impairment in the recoverability of land held for development, it is reviewed for impairment by comparing its fair value to its carrying value. If the estimated sales value is less than the carrying value, the carrying value is written down to its estimated fair value. Estimated fair value is generally determined using a market valuation approach, comparing the subject property to recent comparable market transactions in a similar location; or using estimated cash flows.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents are highly-liquid investments with original maturities of three months or less. The Company maintains cash equivalents in money market accounts with financial institutions in excess of insured limits, but believes this risk is mitigated by only investing in or through major financial institutions. The Company does not invest its available cash balances in money market funds. As such, available cash balances are appropriately reflected as cash and cash equivalents on the consolidated balance sheets.
Restricted Cash	Restricted Cash Restricted cash consists of cash held as collateral to provide credit enhancement for the Company’s mortgage debt, cash for property taxes, capital expenditures and tenant improvements. Restricted cash also includes cash held by qualified intermediaries for possible investments in like-kind exchanges in accordance with Section 1031 of the Internal Revenue Code in connection with sales of the Company’s properties. Restricted cash is included in “Other assets” in the consolidated balance sheets.
Accounts Receivable And Accrued Rent Receivable	Accounts Receivable and Accrued Rent Receivable Generally, leases with tenants are accounted for as operating leases. Minimum lease payments under tenant leases are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payment terms are recorded as “Accrued rent receivable, net” on the consolidated balance sheets. Included in current tenant receivables are tenant reimbursements which are comprised of amounts recoverable from tenants for common area maintenance expenses and certain other recoverable expenses that are recognized as revenue in the period in which the related expenses are incurred.
Investments in Unconsolidated Real Estate Ventures	Investments in Unconsolidated Real Estate Ventures Under the equity method, investments in real estate ventures are recorded initially at cost and subsequently adjusted for equity in earnings, contributions, distributions, and impairments. The Company generally allocates income and losses from the unconsolidated real estate ventures based on the venture's distribution priorities, which may be different from its stated ownership percentage. For real estate ventures that are constructing assets to commence planned principal operations, the Company capitalizes interest expense to the extent that it is recoverable using the Company’s weighted average interest rate of consolidated debt and its investment balance as a basis. Planned principal operations commence when a property is available to lease and at that point in time, the Company ceases capitalizing interest to its investment basis. At least quarterly, management assesses whether there are any other than temporary impairment indicators of the Company’s investments in real estate ventures. If any indicators of impairment are present, we calculate the fair value of the investment in the unconsolidated real estate venture. An investment is other than temporarily impaired only if the fair value of the investment in a real estate venture, as estimated by management, is less than the carrying value and the decline is other than temporary. To the extent that an other than temporary impairment has occurred, an impairment charge is recorded in the amount of the excess of the carrying amount of the investment over the estimated fair value. Management is required to make significant judgments about the estimated fair value of its investments to determine if an impairment exists. Fair value is generally determined through income valuation approaches, including discounted cash flows and direct capitalization models. When the Company acquires an interest in or contributes assets to a real estate venture project, the difference between the Company’s cost basis in the investment and the value of the real estate venture or asset contributed is amortized over the life of the related assets, intangibles, and liabilities and such adjustment is included in the Company’s share of equity in income of unconsolidated real estate ventures.
Deferred Costs	Deferred Costs Certain costs incurred in connection with property leasing are capitalized as deferred leasing costs. Deferred leasing costs consist primarily of third-party and internal leasing commissions that are amortized using the straight-line method over the life of the respective lease which generally ranges from 1 to 16 years. Management re-evaluates the remaining useful lives of leasing costs in conjunction with changes in the respective lease term.
Notes Receivable	Notes Receivable The Company accounts for notes receivable on its balance sheet at amortized cost, net of allowance for loan losses. Interest income is recognized over the term of the notes receivable and is calculated based on the contractual terms of each note agreement. At inception and on a quarterly basis, the Company evaluates notes receivable for the current estimate of expected credit losses over the contractual term using a probability-of-default method and reports in net income (as a credit loss expense) the amount necessary to adjust the allowance for credit losses to reflect management's current estimate. Management considers performance and/or value of the underlying collateral property as well as the financial and operating capability of the borrower/sponsor in its evaluation.
Deferred Financing Costs	Deferred Financing Costs Costs incurred in connection with debt financing are capitalized as a direct deduction from the carrying value of the debt, except for costs capitalized related to the Company’s unsecured credit facility, which are capitalized within the “Deferred costs, net” caption on the accompanying consolidated balance sheets. Deferred financing costs are charged to interest expense over the terms of the related debt agreements. Deferred financing costs consist primarily of loan fees which are amortized over the related loan term on a basis that approximates the effective interest method. Deferred financing costs are accelerated, when debt is extinguished, as part of the “Interest expense-amortization of deferred financing costs” caption within the Company’s consolidated statements of operations. Original issue discounts are recognized as part of the gain or loss on extinguishment of debt, as appropriate.
Revenue Recognition	Revenue Recognition Rental Revenue The Company generates revenue under leases with tenants occupying the Properties. Generally, leases with tenants are accounted for as operating leases. The operating leases have various expiration dates. As of December 31, 2022 and 2021, the Company did not have any leases classified as direct-financing or sales-type leases. Fixed lease payments under tenant leases, determined to be collectible, are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payments are recorded as “Accrued rent receivable” on the consolidated balance sheets. Variable lease payments are recognized as lease revenue in the period in which changes occur in facts and circumstances on which the variable lease payments are based. Topic 842 requires a binary approach to evaluating leases for collectability. Lessors are required to determine if it is probable that substantially all of the lease payments will be collected from the tenant over the lease term. Should the lessor determine that it is not probable that substantially all of the lease payments will be collected, the standard requires that the lessor write off any accrued rent receivable and begin recognizing lease payments on a cash basis. The Company’s lease revenue is impacted by the Company’s determination of whether improvements to the property, whether made by the Company or by the tenant, are landlord assets. The determination of whether an improvement is a landlord asset requires judgment. In making this judgment, the Company’s primary consideration is whether an improvement would be utilizable by another tenant upon the then-existing tenant vacating the improved space. If the Company has funded an improvement that it determines not to be landlord assets, then it treats the cost of the improvement as a lease incentive. If the tenant has funded an improvement that the Company determines to be landlord assets, then the Company treats the costs of the improvement as deferred revenue and amortizes these costs into revenue over the lease term. For certain leases, the Company also makes significant assumptions and judgments in determining the lease term, including assumptions when the lease provides the tenant with an early termination option or purchase option. The lease term impacts the period over which the Company determines and records lease payments and also impacts the period over which it amortizes lease-related costs. The Company considers all relevant factors that create an economic incentive for the lessee and uses judgment to determine if those factors, considered together, signify that the lessee is reasonably certain to exercise the option. For leases where a tenant executes a lease termination, termination fees are generally recognized over the modified term of the lease as rental income. Additionally, any deferred rents receivable are accelerated over the modified lease term. The Company’s leases also typically provide for tenant reimbursement of a portion of common area maintenance expenses and other operating expenses to the extent that a tenant’s pro rata share of expenses exceeds a base year level set in the lease or to the extent that the tenant has a lease on a triple net basis. As the timing and pattern of revenue recognition is the same, rents and tenant reimbursements are treated as a combined lease component and included in the “Rents” caption within the Company's consolidated statements of operations. Fixed lease payments include contractual rents under lease agreements with tenants recognized on a straight-line basis over the lease term, including amortization of lease incentives and above or below market rent intangibles, and parking income that is fixed under a long-term contract. Variable lease payments include reimbursements billed to tenants, termination fees, bad debt expense, and parking income that is not fixed under a long-term contract. Point of Sale Revenue Point of sale revenue consists of parking, restaurant, and flexible stay revenue from the Company’s hotel operations. Point of sale service obligations are performed daily, and the customer obtains control of those services simultaneously as they are performed. Accordingly, revenue is recorded on an accrual basis as it is earned, coinciding with the services that are provided to the Company’s customers. Parking and flexible stay revenue is recognized within rents and restaurant income is recognized within other income on the consolidated statements of operations. Third party management fees, labor reimbursement, and leasing The Company performs property management services for its managed real estate ventures and third-party property owners of real estate that consist of: (i) providing leasing services, (ii) property inspections, (iii) repairs and maintenance monitoring, and (iv) financial and accounting oversight. For these services, the Company earns management fees monthly, which are based on a fixed percentage of each managed property’s financial results, and is reimbursed for the labor costs incurred by its property management employees as services are rendered to the property owners. The Company determined that control over the services is passed to its customers simultaneously as performance occurs. Accordingly, management fee revenue is earned as the services are provided to the Company’s customers. Lease commissions are earned when the Company, as a broker for the third party property owner, executes a lease agreement with a tenant. Based on the terms of the Company’s lease commission contracts, the Company's performance obligation to the customer has been completed upon execution of each lease agreement. The Company’s lease commissions are earned based on a fixed percentage of rental income generated for each executed lease agreement and there is no variable income component. Development fee revenue is earned through two different sources: (i) the Company performs development services for third parties as an agent and earns fixed development fees based on a percentage of construction costs incurred over the construction period, and (ii) the Company acts as a general contractor on behalf of one of its managed real estate ventures. The Company acts as the principal construction company for the real estate ventures and records gross revenue as it provides construction services based on the quantifiable construction outputs. In applying the cost based output method of revenue recognition, the Company uses the actual costs incurred relative to the total estimated costs to determine its progress towards contract completion and to calculate the corresponding gross revenue and gross profit to recognize. For any costs that do not contribute to satisfying the Company’s performance obligations, it excludes such costs from its output methods of revenue recognition as the amounts are not reflective of transferring control of the outputs to the customer. The use of estimates in this calculation involves significant judgment. Common Development Cost Estimates for Contributions to Development Joint Ventures When land is contributed to a development joint venture, estimated common development costs include actual costs incurred and estimates of future common development costs benefiting the property sold. When land is sold, common development costs, if they cannot be specifically identified, are allocated to each sold parcel based upon its relative sales value. For purposes of allocating common development costs, estimates of future sales proceeds and common development costs are re-evaluated throughout the year, with adjustments being allocated prospectively to the remaining land parcels available for sale. The common development cost estimates for development joint ventures are highly judgmental as they are sensitive to cost escalation, sales price escalation and pace of absorption, which are subject to judgment and are affected by expectations about future market or economic conditions. Changes in the assumptions used to estimate future common development costs could result in a significant impact on the amounts recorded as net gain on disposition of real estate or net gain on sale of undepreciated real estate.
Income Taxes	Income Taxes Parent Company The Parent Company has elected to be treated as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”). In order to continue to qualify as a REIT, the Parent Company is required to, among other things, distribute at least 90% of its annual REIT taxable income to its shareholders and meet certain tests regarding the nature of its income and assets. As a REIT, the Parent Company is not subject to federal and state (in states that follow federal rules) income taxes with respect to the portion of its income that meets certain criteria and is distributed annually to its shareholders. Accordingly, a nominal provision for federal and state (as applicable) income taxes is included in the accompanying consolidated financial statements with respect to the operations of the Parent Company. The Parent Company intends to continue to operate in a manner that allows it to meet the requirements for taxation as a REIT. If the Parent Company fails to qualify as a REIT in any taxable year, it will be subject to federal and state (as applicable) income taxes and may not be able to qualify as a REIT for the four tax years following the year in which it first failed to qualify. The Parent Company is subject to certain local income taxes. Provision for federal income taxes is recorded in the income tax provision line item and state and local income taxes have been included in operating expenses in the Parent Company’s consolidated statements of operations. The Parent Company is subject to a 4% federal excise tax if sufficient taxable income is not distributed within prescribed time limits. The excise tax equals 4% of the annual amount, if any, by which the sum of (a) 85% of the Parent Company’s ordinary income and (b) 95% of the Parent Company’s net capital gain exceeds cash distributions and certain taxes paid by the Parent Company. No excise tax was incurred in 2022, 2021 or 2020. The Parent Company has elected to treat several of its subsidiaries as taxable REIT subsidiaries (each a “TRS”). A TRS is subject to federal, state and local income tax. In general, a TRS may perform non-customary services for tenants, hold assets that the Parent Company, as a REIT, cannot hold directly and generally may engage in any real estate or non-real estate related business. The Company’s taxable REIT subsidiaries did not have material tax provisions or deferred income tax items as of December 31, 2022 and December 31, 2021. Operating Partnership In general, the Operating Partnership is not subject to federal and state income taxes, and accordingly, no provision for income taxes has been made in the accompanying consolidated financial statements. The partners of the Operating Partnership are required to include their respective share of the Operating Partnership’s profits or losses in their respective tax returns. The Operating Partnership’s tax returns and the amount of allocable partnership profits and losses are subject to examination by federal and state taxing authorities. For any year beginning on or after January 1, 2017, the Operating Partnership can be assessed with federal income tax in the course of an audit by the IRS. Under the partnership audit rules included in the Bipartisan Budget Act of 2015, the Operating Partnership has the option to make a push-out election and allocate the partnership adjustments to all the former partners for the tax year under audit. The Operating Partnership may elect to treat a subsidiary as a REIT under Sections 856 through 860 of the Code, if applicable. Each subsidiary REIT would be required to meet the requirements for treatment as a REIT under Sections 856 through 860 of the Code. If a subsidiary REIT fails to qualify as a REIT in any taxable year, that subsidiary REIT would be subject to federal and state income taxes and would not be able to qualify as a REIT for the four subsequent taxable years. Also, each subsidiary REIT would be subject to certain local income taxes. The Operating Partnership has elected to treat several of its subsidiaries as TRSs, which are subject to federal, state and local income tax.
Earnings Per Share and Per Unit	Earnings Per Share Basic earnings per share (“EPS”) is computed by dividing net income available to common shareholders, as adjusted for unallocated earnings, if any, of certain securities, by the weighted average number of common shares outstanding during the year. Diluted EPS reflects the potential dilution that could occur from common shares issuable in connection with awards under share-based compensation plans, including upon the exercise of stock options, and conversion of the noncontrolling interests in the Operating Partnership. Anti-dilutive shares are excluded from the calculation. Earnings Per Unit Basic earnings per unit is computed by dividing net income available to common unitholders, as adjusted for unallocated earnings, if any, of certain securities issued by the Operating Partnership, by the weighted average number of common unit equivalents outstanding during the year. Diluted earnings per unit reflects the potential dilution that could occur from units issuable in connection with awards under share-based compensation plans, including upon the exercise of stock options. Anti-dilutive units are excluded from the calculation.
Share-Based Compensation Plans	Share-Based Compensation PlansThe Parent Company maintains a shareholder-approved equity-incentive plan known as the Amended and Restated 1997 Long-Term Incentive Plan (the “1997 Plan”). The 1997 Plan is administered by the Compensation Committee of the Parent Company’s Board of Trustees. Under the 1997 Plan, the Compensation Committee is authorized to award equity and equity-based awards, including incentive stock options, non-qualified stock options, restricted share rights and performance-based share units.
Comprehensive Income	Comprehensive Income Comprehensive income is recorded in accordance with the provisions of the accounting standard for comprehensive income. The accounting standard establishes standards for reporting comprehensive income and its components in the financial statements. Comprehensive income includes the effective portions of changes in the fair value of derivatives.
Accounting for Derivative Instruments and Hedging Activities	Accounting for Derivative Instruments and Hedging Activities The Company accounts for its derivative instruments and hedging activities in accordance with the accounting standard for derivative and hedging activities. The accounting standard requires the Company to measure every derivative instrument (including certain derivative instruments embedded in other contracts) at fair value and record them on the balance sheet as either an asset or liability. See disclosures below related to the accounting standard for fair value measurements and disclosures. For derivatives designated as cash flow hedges, the effective portions of changes in the fair value of the derivative are reported in other comprehensive income while the ineffective portions are recognized in earnings. The Company actively manages its ratio of fixed-to-floating rate debt. To manage its fixed and floating rate debt in a cost-effective manner, the Company, from time to time, enters into interest rate swap agreements as cash flow hedges, under which it agrees to exchange various combinations of fixed and/or variable interest rates based on agreed upon notional amounts.
Fair Value Measurements	Fair Value Measurements The Company estimates the fair value of its derivatives in accordance with the accounting standard for fair value measurements and disclosures. The accounting standard defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. It also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value. Financial assets and liabilities recorded on the consolidated balance sheets are categorized based on the inputs to the valuation techniques as follows: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access; • Level 2 inputs are inputs, other than quoted prices included in Level 1, which are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals; and • Level 3 inputs are unobservable inputs for the asset or liability, which is typically based on an entity’s own assumptions, as there is little if any, related market activity or information. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.
Risks And Uncertainties - COVID-19	Risks and Uncertainties - COVID-19 The ongoing global COVID-19 pandemic, has slowed global economic activity and caused significant volatility in financial markets, causing many to fear a global recession. The responses of many countries, including the U.S., have disrupted the global economy and supply chains and adversely impacted many industries, including owners and developers of real estate. Moreover, there is significant uncertainty related to the COVID-19 pandemic's impact on the U.S. economy and consumer confidence. Demand for space at the Company's properties is dependent on a variety of macroeconomic factors, such as employment levels, interest rates, changes in stock market valuations, rent levels and availability of competing space. The extent to which the COVID-19 pandemic impacts the Company's results will depend on future developments, many of which are highly uncertain and cannot be predicted. The COVID-19 pandemic has caused continued negative economic impacts, market volatility, and business disruption, which could negatively impact the Company's tenants’ ability to pay rent, the
Recent Accounting Pronouncements	Recent Accounting PronouncementsIn March 2020, the FASB issued ASU 2020-04 Reference Rate Reform (Topic 848) Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The amendments provide practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance is optional and is effective between March 12, 2020 and December 31, 2024. The guidance may be elected over time as reference rate reform activities occur. The Company continues to evaluate the impact of the guidance and may apply elections as applicable as additional changes in the market occur. During the second quarter of 2022, the Company elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. In addition, the Company elected to apply the hedge accounting expedients related to changes in critical terms of derivative or hedged transactions, and bilaterally negotiated contract changes for the refinance of the Company's term loan and associated interest rate swap. The Company continues to evaluate the impact of the guidance and may apply elections as applicable as additional changes in the market occur. See Note 9, “Debt Obligations” for further information regarding our remaining LIBOR-indexed obligations.

ORGANIZATION OF THE PARENT CO_2

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP (Tables)	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Core Portfolio of Operating Properties and Excludes Development, Redevelopment and Held for Sale	The Company’s core portfolio of operating properties (the “Core Properties”) excludes development properties, redevelopment properties, and properties held for sale. The Properties were comprised of the following as of December 31, 2022: Number of Properties Rentable Square Feet Office properties 67 11,848,707 Mixed-use properties 5 942,334 Core Properties 72 12,791,041 Development property 2 350,488 Redevelopment properties 3 436,659 The Properties 77 13,578,188

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	Dec. 31, 2022
Accounting Policies [Abstract]
Schedule of Disaggregation of Revenue	The following is a summary of revenue earned by the Company’s reportable segments (see Note 19 “Segment Information,” for further information) during the year ended December 31, 2022 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 151,034 $ 116,926 $ 60,831 $ 16,686 $ 9,805 $ (1,895) $ 353,387 Variable rent 51,346 11,615 32,958 1,283 2,644 (35) 99,811 Total lease revenue 202,380 128,541 93,789 17,969 12,449 (1,930) 453,198 Amortization of deferred market rents 1,308 10 1,264 — — — 2,582 Daily parking & hotel flexible stay 14,390 — 361 84 236 — 15,071 Total rents 218,078 128,551 95,414 18,053 12,685 (1,930) 470,851 Third party management fees, labor reimbursement and leasing 287 35 486 3,723 1,988 17,613 24,132 Other income 2,510 354 429 123 38 7,663 11,117 Total revenue $ 220,875 $ 128,940 $ 96,329 $ 21,899 $ 14,711 $ 23,346 $ 506,100 The following is a summary of revenue earned by the Company’s reportable segments (see Note 19 “Segment Information,” for further information) during the year ended December 31, 2021 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 149,441 $ 113,748 $ 62,545 $ 12,410 $ 8,020 $ (2,240) $ 343,924 Variable rent 41,585 10,358 34,850 646 2,660 (257) 89,842 Total lease revenue 191,026 124,106 97,395 13,056 10,680 (2,497) 433,766 Amortization of deferred market rents 2,064 (9) 3,322 — — — 5,377 Daily parking & hotel flexible stay 11,758 159 109 117 233 — 12,376 Total rents 204,848 124,256 100,826 13,173 10,913 (2,497) 451,519 Third party management fees, labor reimbursement and leasing 893 34 452 6,548 3,077 15,440 26,444 Other income 2,117 276 402 144 25 5,892 8,856 Total revenue $ 207,858 $ 124,566 $ 101,680 $ 19,865 $ 14,015 $ 18,835 $ 486,819 The following is a summary of revenue earned by the Company’s reportable segments (see Note 19 “Segment Information,” for further information) during the year ended December 31, 2020 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 166,286 $ 128,044 $ 63,366 $ 29,830 $ 8,064 $ (2,412) $ 393,178 Variable rent 51,410 12,951 35,123 3,544 2,401 (1,343) 104,086 Total lease revenue 217,696 140,995 98,489 33,374 10,465 (3,755) 497,264 Amortization of deferred market rents 1,146 (12) 3,531 — 203 — 4,868 Daily parking & hotel flexible stay 10,777 179 49 135 232 — 11,372 Total rents 229,619 141,162 102,069 33,509 10,900 (3,755) 513,504 Third party management fees, labor reimbursement and leasing 927 39 689 6,541 2,560 7,824 18,580 Other income 1,482 412 224 173 9 468 2,768 Total revenue $ 232,028 $ 141,613 $ 102,982 $ 40,223 $ 13,469 $ 4,537 $ 534,852 (a) Corporate includes intercompany eliminations necessary to reconcile to consolidated Company totals.

REAL ESTATE INVESTMENTS (Tables

REAL ESTATE INVESTMENTS (Tables)	12 Months Ended
REAL ESTATE INVESTMENTS (Tables)	Dec. 31, 2022
Real Estate [Abstract]
Schedule of Gross Carrying Value of Operating Properties	As of December 31, 2022 and 2021, the gross carrying value of the operating properties was as follows (in thousands): December 31, 2022 December 31, 2021 Land $ 403,998 $ 410,144 Building and improvements 2,760,357 2,653,492 Tenant improvements 452,885 408,966 Total $ 3,617,240 $ 3,472,602
Schedule of Capitalized Construction Costs	The following table shows the amount of compensation costs (including bonuses and benefits) capitalized for the years presented (in thousands): December 31, 2022 2021 2020 Development $ 5,343 $ 4,815 $ 4,802 Redevelopment 1,484 1,170 543 Tenant Improvements 2,505 1,917 3,021 Total $ 9,332 $ 7,902 $ 8,366
Schedule of Acquired Properties	Property/Portfolio Name Acquisition Date Location Property Type Rentable Square Feet/Acres Purchase Price 631 Park Avenue January 21, 2022 King of Prussia, PA Land 3.3 acres $ 3,650 3151 Market Street (a) April 29, 2022 Philadelphia, PA Leasehold Interest 0.8 acres $ 27,349 (a) On April 29, 2022, the Company acquired, through a 99-year ground lease, the leasehold interest in a 0.8-acre land parcel, located at 3151 Market Street, in Philadelphia, Pennsylvania. The Company prepaid $19.5 million of the ground lease, representing 500,000 square feet of buildable floor to area ratio (“FAR”) to be used for the development of 3151 Market Street, and paid $7.8 million for 200,000 square feet of FAR density usable pursuant to the Schuylkill Yards Project master development agreement. The additional density is included in prepaid leasehold interests in land held for development in the consolidated balance sheets. See below regarding disposition of 500,000 square feet of FAR. The following table summarizes the property acquisitions during the year ended December 31, 2020 (dollars in thousands): Property/Portfolio Name Acquisition Date Location Property Type Rentable Square Feet/Acres Purchase Price (a) 155 King of Prussia Road February 27, 2020 Radnor, PA Land 7.75 acres $ 11,250 1505-11 Race Street November 5, 2020 Philadelphia, PA Office 119,763 $ 9,700 250 King of Prussia Road (b) November 30, 2020 Radnor, PA Office 169,843 $ 20,250 (a) Exclusive of transaction costs and price adjustments. See purchase price allocation table below for a breakout of the net purchase price for wholly owned properties. (b) This property was placed into redevelopment and is therefore included within Construction-in-progress on the consolidated balance sheets.
Schedule of Asset Acquisition	The acquisition values have been allocated as follows (in thousands): 1505-11 Race Street Building, land and improvements $ 9,723 Intangible assets acquired 2,422 Below market lease liabilities assumed (2,193) Total unencumbered acquisition value 9,952 Amortization period of intangible assets 1.5 years Amortization period of below market liabilities assumed 1.5 years
Schedule of Office Properties Sold	The following table summarizes the property dispositions during the years ended December 31, 2022, 2021 and 2020 (dollars in thousands): Property/Portfolio Name Disposition Date Location Property Type Rentable Square Feet/Acres Sales Price Gain/(Loss) on Sale (a) 200 Barr Harbor Drive November 22, 2022 West Conshohocken, PA Office 86,000 $ 30,500 $ 8,740 11501 Burnett Road (h) July 29, 2022 Austin, TX Land 4.7 acres $ 32,513 $ 8,340 3151 Market Street (g) July 14, 2022 Philadelphia, PA Leasehold Interest 0.8 acres $ 30,394 $ 2,583 Gibbsboro Portfolio (f) June 28, 2022 Gibbsboro, NJ Office/Land 42,809/4.0 acres $ 4,100 $ 831 25 M Street (e) April 14, 2022 Washington, D.C. Land 0.8 acres $ 29,675 $ 3,836 Gateway G & H January 20, 2022 Richmond, VA Land 10.0 acres $ 1,600 $ 897 1100 Lenox Drive September 8, 2021 Lawrenceville, NJ Land 5.0 acres $ 2,575 $ 68 2100-2200 Lenox Drive July 6, 2021 Lawrenceville, NJ Land 35.2 acres $ 8,900 $ 842 3025 JFK Boulevard February 2, 2021 Philadelphia, PA Leasehold Interest 1.0 acre $ 34,800 $ 2,000 Mid-Atlantic Office Portfolio (b) (d) December 21, 2020 Various Office 1,128,645 $ 192,943 $ 15,164 One and Two Commerce Square (c) July 21, 2020 Philadelphia, PA Office 1,896,142 $ 115,000 $ 271,905 Keith Valley June 15, 2020 Horsham, PA Land 14.0 Acres $ 4,000 $ 201 52 East Swedesford Road March 19, 2020 Malvern, PA Office 131,077 $ 18,000 $ 2,336 (a) Gain/(Loss) on Sale is net of closing and other transaction related costs. (b) The Company sold a 60% equity interest in a portfolio of twelve suburban office properties containing an aggregate of 1.1 million square feet (“Mid-Atlantic Office Portfolio”), nine of which are located in the Pennsylvania suburbs and three of which are located in Maryland, to an unrelated third party for a gross sales price of $192.9 million. The transaction resulted in deconsolidation of the properties and formation of PA/MD NNN Office JV, LLC (“Mid-Atlantic Office JV”). The Company recorded its investment at fair value and recognized a gain of $15.2 million in “Net gain on disposition of real estate” on the consolidated statements of operations. See Note 4 “Investment in Unconsolidated Real Estate Ventures,” for further information. (c) The Company sold a 30% preferred equity interest in two office buildings located in Philadelphia, Pennsylvania, to an unrelated third party for $115.0 million (the “Commerce Square Venture Transaction”), which resulted in deconsolidation of the properties and formation of Brandywine Commerce I LP and Brandywine Commerce II LP (collectively, the “Commerce Square Venture”). The transaction valued the properties at $600.0 million. The Company recorded its investment at fair value and recognized a gain of $271.9 million in “Net gain on disposition of real estate” on the consolidated statements of operations. See Note 4 “Investment in Unconsolidated Real Estate Ventures,” for further information. (d) The sales price includes $4.1 million of variable consideration held in escrow that will be released to the Company over a six (e) On September 30, 2022, the Company recognized $0.4 million of additional gain on disposition of real estate. (f) Includes $0.7 million of gain on sale of undepreciated real estate and $0.1 million of gain on disposition of real estate included within the consolidated statements of operations for the twelve months ended December 31, 2022. (g) On July 14, 2022, the Company contributed 500,000 square feet of FAR relating to its 99-year prepaid leasehold interest at 3151 Market Street in Philadelphia, Pennsylvania, acquired on April 29, 2022, to a newly formed joint venture with an unaffiliated third party. The Company's initial deemed contribution in the project was $30.4 million and the transaction resulted in deconsolidation of the property and conversion of Brandywine 3151 Market, LP, (formerly a wholly-owned subsidiary of the Operating Partnership) to a real estate venture (“3151 Market Street Venture”). The Company recorded its investment at fair value and recognized a gain, net of transaction costs, of $2.6 million, in “Net gain on sale of undepreciated real estate” on the consolidated statements of operations. See Note 4, “Investment in Unconsolidated Real Estate Ventures,” for further information. (h) On July 29, 2022, the Company contributed a 4.7 acre parcel of land held for development at 11501 Burnet Road in Austin, Texas to a newly formed joint venture with an unaffiliated third party. The project is part of the Uptown ATX master development. The Company's combined contributed initial land investment in the project was $32.5 million and the transaction resulted in the deconsolidation of the property and formation of Brandywine Uptown Office LLC and Brandywine One Uptown Multifamily LLC, (together, “One Uptown Ventures)”). The Company recorded its investment at fair value and recognized a gain of $8.3 million in “Net gain on disposition of real estate” on the consolidated statements of operations. Gain on sale of $8.3 million is calculated as the difference between the estimated relative sales value of the contributed land and the estimated total cost allocations per block. See Note 4, “Investment in Unconsolidated Real Estate Ventures,” for further information.

INVESTMENT IN UNCONSOLIDATED _2

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES (Tables)	12 Months Ended
INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES (Tables)	Dec. 31, 2022
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Financial Position of Real Estate Ventures	The Company’s investment in the unconsolidated real estate ventures as of December 31, 2022 and 2021, and the Company’s share of the unconsolidated real estate ventures’ income (loss) for the years ended December 31, 2022, 2021, and 2020 was as follows (in thousands): Ownership Percentage Carrying Amount Company's Share of unconsolidated real estate venture Income (Loss) Unconsolidated Real Estate Venture Debt at 100%, gross 2022 2021 2022 2021 2020 2022 2021 Office Properties Commerce Square Venture 70% (a) $ 238,105 $ 247,798 $ (12,128) $ (15,501) $ (9,150) $ 206,737 $ 213,069 Mid-Atlantic Office Venture 40% (a) 31,005 31,680 412 932 96 128,904 123,015 Brandywine - AI Venture LLC 50% — — — (721) 185 — — Herndon Innovation Center Metro Portfolio Venture, LLC 15% 15,304 15,844 (536) (174) (358) 207,302 207,302 MAP Venture (b) 50% (35,411) (24,396) (8,340) (8,683) (6,570) 182,053 184,263 Cira Square 20% 27,815 — (985) — — 257,700 — Other 4040 Wilson Venture (c) 50% 29,633 31,059 (1,211) (2,258) (2,162) 145,070 145,000 1919 Venture (d) 50% — 13,791 1,392 427 59 — 88,860 Development Properties 3025 JFK Venture (c) 55% 57,630 56,370 (35) (118) — 60,118 — JBG - 51 N Street (c) 70% 21,208 21,213 (382) (402) (457) — — JBG - 1250 First Street Office (c) 70% 17,759 17,751 (195) (199) (227) — — 3151 Market Street Venture (c) 55% 63,751 — (8) — — — — One Uptown - Office (c) 50% 34,980 — — — — 16,895 — One Uptown - Multifamily (c) 50% 30,445 — — — — — — $ 532,224 $ 411,110 $ (22,016) $ (26,697) $ (18,584) $ 1,204,779 $ 961,509 (a) Ownership percentage represents the Company’s combined interest including preferred and common equity holdings. See “Commerce Square Venture” and “Mid-Atlantic Office JV” sections below for more information. (b) Included within “Other Liabilities” on the consolidated balance sheet. (c) This entity is a VIE. (d) On November 30, 2022, the Company sold its interest in 1919 Venture. See “1919 Venture” sections for more information on the disposal. The following is a summary of the financial position of the unconsolidated real estate ventures in which the Company held interests as of December 31, 2022 and December 31, 2021 (in thousands): December 31, 2022 December 31, 2021 Net property $ 2,117,226 $ 1,563,263 Other assets 506,213 434,687 Other liabilities 446,101 331,947 Debt, net 1,198,213 956,668 Equity (a) 979,125 709,335 (a) This amount does not include the effect of the basis difference between the Company's historical cost basis and the basis recorded at the real estate venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials occur from the impairment of investments, purchases of third party interests in existing real estate ventures and upon the transfer of assets that were previously owned by the Company into a real estate venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the real estate venture level.
Schedule of Results of Operations of Real Estate Ventures with Interests	The following is a summary of results of operations of the unconsolidated real estate ventures in which the Company held interests during the twelve-month periods ended December 31, 2022, 2021 and 2020 (in thousands): Year Ended December 31, 2022 2021 2020 Revenue $ 244,981 $ 214,792 $ 150,276 Operating expenses (124,608) (117,273) (85,812) Interest expense, net (49,007) (30,569) (22,661) Depreciation and amortization (103,378) (97,147) (70,805) Provision for impairment — (1,393) — Net loss $ (32,012) $ (31,590) $ (29,002) Ownership interest % Various Various Various Company's share of net loss $ (21,594) $ (25,972) $ (18,540) Basis adjustments and other (422) (725) (44) Equity in loss of unconsolidated real estate ventures $ (22,016) $ (26,697) $ (18,584)
Schedule of Maturities of Long-term Debt	As of December 31, 2022, the aggregate principal payments of the unconsolidated real estate ventures recourse and non-recourse debt payable to third-parties are as follows (in thousands): 2023 $ 388,789 2024 593,907 2025 60,118 2026 161,965 2027 — Thereafter — Total principal payments 1,204,779 Net deferred financing costs (6,837) Net original issue premium 271 Outstanding indebtedness $ 1,198,213 As of December 31, 2022, the aggregate scheduled principal payments on the Company's debt obligations were as follows (in thousands): 2023 $ 54,301 2024 350,000 2025 — 2026 88,500 2027 700,000 Thereafter 778,610 Total principal payments 1,971,411 Net unamortized premiums/(discounts) 2,934 Net deferred financing costs (9,307) Outstanding indebtedness $ 1,965,038

LEASES (Tables)

LEASES (Tables)	12 Months Ended
LEASES (Tables)	Dec. 31, 2022
Leases [Abstract]
Schedule of Operating Lease Future Contractual Lease Payments	The Company leases properties to tenants under operating leases with various expiration dates. Future contractual lease payments under operating leases at December 31, 2022 are as follows (in thousands): Year 2023 $ 347,142 2024 344,641 2025 325,166 2026 304,102 2027 263,532 Thereafter 1,041,686
Schedule of Lease Costs	The table below summarizes the Company’s operating lease cost (in thousands) recognized through “Property operating expenses” on the consolidated statements of operations (in thousands): Year Ended December 31, Lease Cost 2022 2021 Fixed lease cost $ 2,100 $ 2,100 Variable lease cost 67 43 Total $ 2,167 $ 2,143 Weighted-average remaining lease term (years) 54.6 55.2 Weighted-average discount rate 6.3 % 6.3 %
Schedule of Operating Lease Liability Maturities	Lease payments on noncancellable leases at December 31, 2022 are as follows (in thousands): Year Minimum Rent 2023 $ 1,263 2024 1,305 2025 1,321 2026 1,338 2027 1,355 Thereafter 106,437 Total lease payments $ 113,019 Less: Imputed interest 89,853 Present value of operating lease liabilities $ 23,166

DEFERRED COSTS (Tables)

DEFERRED COSTS (Tables)	12 Months Ended
DEFERRED COSTS (Tables)	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Deferred Costs	As of December 31, 2022 and 2021, the Company’s deferred costs were comprised of the following (in thousands): December 31, 2022 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 155,457 $ (62,920) $ 92,537 Financing costs - Unsecured Credit Facility 4,688 (586) 4,102 Total $ 160,145 $ (63,506) $ 96,639 December 31, 2021 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 143,895 $ (57,445) $ 86,450 Financing costs - Unsecured Credit Facility 6,299 (5,887) 412 Total $ 150,194 $ (63,332) $ 86,862

INTANGIBLE ASSETS AND LIABILI_2

INTANGIBLE ASSETS AND LIABILITIES (Tables)	12 Months Ended
INTANGIBLE ASSETS AND LIABILITIES (Tables)	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Liabilities	As of December 31, 2022 and 2021, the Company’s intangible assets/liabilities were comprised of the following (in thousands): December 31, 2022 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 55,715 $ (37,437) $ 18,278 Tenant relationship value 167 (104) 63 Above market leases acquired 331 (221) 110 Total intangible assets, net $ 56,213 $ (37,762) $ 18,451 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 20,985 $ (10,663) $ 10,322 December 31, 2021 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 72,376 $ (44,066) $ 28,310 Tenant relationship value 167 (97) 70 Above market leases acquired 486 (310) 176 Total intangible assets, net $ 73,029 $ (44,473) $ 28,556 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 27,025 $ (14,044) $ 12,981
Schedule of Amortization for Intangible Assets and Liabilities	As of December 31, 2022, the Company’s annual amortization for its intangible assets/liabilities, assuming no prospective early lease terminations, was as follows (dollars in thousands): Assets Liabilities 2023 $ 6,573 $ 1,516 2024 4,332 1,305 2025 3,154 1,029 2026 1,094 739 2027 809 623 Thereafter 2,489 5,110 Total $ 18,451 $ 10,322

DEBT OBLIGATIONS (Tables)

DEBT OBLIGATIONS (Tables)	12 Months Ended
DEBT OBLIGATIONS (Tables)	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Consolidated Debt Obligations	The following table sets forth information regarding the Company’s consolidated debt obligations outstanding as of December 31, 2022 and 2021 (in thousands): December 31, 2022 December 31, 2021 Effective Maturity UNSECURED DEBT $600 million Unsecured Credit Facility $ 88,500 $ 23,000 SOFR + 1.15% June 2026 Unsecured Term Loan 250,000 250,000 SOFR + 1.30% June 2027 (a) $350.0M 3.95% Guaranteed Notes due 2023 54,301 350,000 3.87% February 2023 (b) $350.0M 4.10% Guaranteed Notes due 2024 350,000 350,000 3.78% October 2024 $450.0M 3.95% Guaranteed Notes due 2027 450,000 450,000 4.03% November 2027 $350.0M 7.55% Guaranteed Notes due 2028 350,000 — 7.73% March 2028 $350.0M 4.55% Guaranteed Notes due 2029 350,000 350,000 4.30% October 2029 Indenture IA (Preferred Trust I) 27,062 27,062 LIBOR + 1.25% March 2035 Indenture IB (Preferred Trust I) 25,774 25,774 LIBOR + 1.25% April 2035 Indenture II (Preferred Trust II) 25,774 25,774 LIBOR + 1.25% July 2035 Principal balance outstanding 1,971,411 1,851,610 Plus: original issue premium (discount), net 2,934 8,187 Less: deferred financing costs (9,307) (6,211) Total unsecured indebtedness $ 1,965,038 $ 1,853,586 (a) On November 23, 2022, the unsecured term loan of $250.0 million was swapped to a fixed rate of 5.01% and matures on June 30, 2027. The effective date of the swap is January 31, 2023. (b) Remaining balance was redeemed on January 20, 2023.
Schedule of Maturities of Long-term Debt	As of December 31, 2022, the aggregate principal payments of the unconsolidated real estate ventures recourse and non-recourse debt payable to third-parties are as follows (in thousands): 2023 $ 388,789 2024 593,907 2025 60,118 2026 161,965 2027 — Thereafter — Total principal payments 1,204,779 Net deferred financing costs (6,837) Net original issue premium 271 Outstanding indebtedness $ 1,198,213 As of December 31, 2022, the aggregate scheduled principal payments on the Company's debt obligations were as follows (in thousands): 2023 $ 54,301 2024 350,000 2025 — 2026 88,500 2027 700,000 Thereafter 778,610 Total principal payments 1,971,411 Net unamortized premiums/(discounts) 2,934 Net deferred financing costs (9,307) Outstanding indebtedness $ 1,965,038

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Financial Instruments with Fair Values Different from their Carrying Amount	The following are financial instruments for which the Company’s estimates of fair value differ from the carrying amounts (in thousands): December 31, 2022 December 31, 2021 Carrying Amount (a) Fair Value Carrying Amount (a) Fair Value Unsecured notes payable $ 1,549,760 $ 1,411,351 $ 1,502,368 $ 1,588,780 Variable rate debt $ 415,278 $ 386,988 $ 351,218 $ 344,754 Notes receivable (b) $ — $ — $ 44,430 $ 45,230 (a) Net of deferred financing costs of $7.5 million and $5.8 million for unsecured notes payable, $1.8 million and $0.4 million for variable rate debt as of December 31, 2022 and December 31, 2021, respectively. (b) For further detail, refer to Note 5 “Debt and Preferred Equity Investments.”

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table summarizes the terms and fair values of the Company’s derivative financial instruments as of December 31, 2022 and December 31, 2021. The notional amounts provide an indication of the extent of the Company’s involvement in these instruments at that time but do not represent exposure to credit, interest rate or market risks (amounts presented in thousands). Hedge Product Hedge Type Designation Notional Amount Strike Trade Date Maturity Date Fair value 12/31/2022 12/31/2021 12/31/2022 12/31/2021 Assets Swap Interest Rate Cash Flow (a) $ 250,000 $ — 3.729 % November 23, 2022 June 30, 2027 $ 255 $ — Liabilities Swap Interest Rate Cash Flow (b) $ — $ 250,000 2.868 % October 8, 2015 October 8, 2022 $ — $ (2,461) $ 250,000 $ 250,000 (a) Hedging unsecured variable rate debt. (b) On October 8, 2022, the interest rate hedge contract for this swap expired.

BENEFICIARIES' EQUITY OF THE _2

BENEFICIARIES' EQUITY OF THE PARENT COMPANY (Tables)	12 Months Ended
BENEFICIARIES' EQUITY OF THE PARENT COMPANY (Tables)	Dec. 31, 2022
Equity [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table details the number of shares and net income used to calculate basic and diluted earnings per share (in thousands, except share and per share amounts; results may not add due to rounding): Year Ended December 31, 2022 2021 2020 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 53,992 $ 53,992 $ 12,366 $ 12,366 $ 307,326 $ 307,326 Net income attributable to noncontrolling interests (168) (168) (77) (77) (1,799) (1,799) Nonforfeitable dividends allocated to unvested restricted shareholders (456) (456) (421) (421) (410) (410) Net income attributable to common shareholders $ 53,368 $ 53,368 $ 11,868 $ 11,868 $ 305,117 $ 305,117 Denominator Weighted-average shares outstanding 171,491,369 171,491,369 170,878,185 170,878,185 171,926,079 171,926,079 Contingent securities/Share based compensation — 834,277 — 1,395,055 — 390,997 Weighted-average shares outstanding 171,491,369 172,325,646 170,878,185 172,273,240 171,926,079 172,317,076 Earnings per Common Share: Net income attributable to common shareholders $ 0.31 $ 0.31 $ 0.07 $ 0.07 $ 1.77 $ 1.77 The following table details the number of units and net income used to calculate basic and diluted earnings per common partnership unit (in thousands, except unit and per unit amounts; results may not add due to rounding): Year Ended December 31, 2022 2021 2020 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 53,992 $ 53,992 $ 12,366 $ 12,366 $ 307,326 $ 307,326 Net (income) loss attributable to noncontrolling interests 2 2 3 3 (20) (20) Nonforfeitable dividends allocated to unvested restricted unitholders (456) (456) (421) (421) (410) (410) Net income attributable to common unitholders $ 53,538 $ 53,538 $ 11,948 $ 11,948 $ 306,896 $ 306,896 Denominator Weighted-average units outstanding 172,036,481 172,036,481 171,770,843 171,770,843 172,907,713 172,907,713 Contingent securities/Share based compensation — 834,277 — 1,395,055 — 390,997 Total weighted-average units outstanding 172,036,481 172,870,758 171,770,843 173,165,898 172,907,713 173,298,710 Earnings per Common Partnership Unit: Net income attributable to common unitholders $ 0.31 $ 0.31 $ 0.07 $ 0.07 $ 1.77 $ 1.77

PARTNERS' EQUITY OF THE PAREN_2

PARTNERS' EQUITY OF THE PARENT COMPANY (Tables)	12 Months Ended
PARTNERS' EQUITY OF THE PARENT COMPANY (Tables)	Dec. 31, 2022
Equity [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table details the number of shares and net income used to calculate basic and diluted earnings per share (in thousands, except share and per share amounts; results may not add due to rounding): Year Ended December 31, 2022 2021 2020 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 53,992 $ 53,992 $ 12,366 $ 12,366 $ 307,326 $ 307,326 Net income attributable to noncontrolling interests (168) (168) (77) (77) (1,799) (1,799) Nonforfeitable dividends allocated to unvested restricted shareholders (456) (456) (421) (421) (410) (410) Net income attributable to common shareholders $ 53,368 $ 53,368 $ 11,868 $ 11,868 $ 305,117 $ 305,117 Denominator Weighted-average shares outstanding 171,491,369 171,491,369 170,878,185 170,878,185 171,926,079 171,926,079 Contingent securities/Share based compensation — 834,277 — 1,395,055 — 390,997 Weighted-average shares outstanding 171,491,369 172,325,646 170,878,185 172,273,240 171,926,079 172,317,076 Earnings per Common Share: Net income attributable to common shareholders $ 0.31 $ 0.31 $ 0.07 $ 0.07 $ 1.77 $ 1.77 The following table details the number of units and net income used to calculate basic and diluted earnings per common partnership unit (in thousands, except unit and per unit amounts; results may not add due to rounding): Year Ended December 31, 2022 2021 2020 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 53,992 $ 53,992 $ 12,366 $ 12,366 $ 307,326 $ 307,326 Net (income) loss attributable to noncontrolling interests 2 2 3 3 (20) (20) Nonforfeitable dividends allocated to unvested restricted unitholders (456) (456) (421) (421) (410) (410) Net income attributable to common unitholders $ 53,538 $ 53,538 $ 11,948 $ 11,948 $ 306,896 $ 306,896 Denominator Weighted-average units outstanding 172,036,481 172,036,481 171,770,843 171,770,843 172,907,713 172,907,713 Contingent securities/Share based compensation — 834,277 — 1,395,055 — 390,997 Total weighted-average units outstanding 172,036,481 172,870,758 171,770,843 173,165,898 172,907,713 173,298,710 Earnings per Common Partnership Unit: Net income attributable to common unitholders $ 0.31 $ 0.31 $ 0.07 $ 0.07 $ 1.77 $ 1.77

SHARE BASED COMPENSATION, 401_2

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Schedule of Company's Restricted Share Activity	The following table summarizes the Company’s Restricted Share Rights activity during the year-ended December 31, 2022: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2022 474,978 $ 13.51 Granted 306,555 $ 13.30 Vested (219,765) $ 13.94 Forfeited (7,874) $ 13.45 Non-vested at December 31, 2022 553,894 $ 13.22
Schedule of Restricted Performance Share Units Plan	The table below presents certain information as to unvested RPSU awards. RPSU Grant Date 3/5/2020 3/5/2021 3/3/2022 Total (Amounts below in shares, unless otherwise noted) Non-vested at January 1, 2022 314,055 374,161 — 688,216 Granted — — 516,852 516,852 Units Cancelled (2,076) (2,922) (3,814) (8,812) Non-vested at December 31, 2022 311,979 371,239 513,038 1,196,256 Measurement Period Commencement Date 1/1/2020 1/1/2021 1/1/2022 Measurement Period End Date 12/31/2022 12/31/2023 12/31/2024 Granted 319,600 380,957 516,852 Fair Value of Units on Grant Date (in thousands) $ 5,389 $ 6,389 $ 6,872

DISTRIBUTIONS (Tables)

DISTRIBUTIONS (Tables)	12 Months Ended
DISTRIBUTIONS (Tables)	Dec. 31, 2022
Distributions [Abstract]
Schedule of Dividends Payable	The following table provides the tax characteristics of the 2022, 2021 and 2020 distributions paid: Years ended December 31, 2022 2021 2020 (in thousands, except per share amounts) Common Share Distributions: Ordinary income $ 0.47 $ 0.64 $ 0.41 Capital gain 0.29 0.01 0.35 Non-taxable distributions — 0.11 — Distributions per share $ 0.76 $ 0.76 $ 0.76 Percentage classified as ordinary income 62.10 % 83.90 % 53.90 % Percentage classified as capital gain 37.90 % 1.20 % 46.10 % Percentage classified as non-taxable distribution — % 14.90 % — %

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	12 Months Ended
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	Dec. 31, 2022
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table details the components of accumulated other comprehensive income (loss) of the Parent Company and the Operating Partnership as of and for the three years ended December 31, 2022 (in thousands): Parent Company Cash Flow Hedges Balance at January 1, 2020 $ (2,370) Change in fair market value during year (5,972) Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests 29 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,561) Change in fair market value during year 4,817 Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests (28) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,020) Change in fair market value during year 5,371 Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests (18) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 564 Balance at December 31, 2022 $ 3,897 Operating Partnership Cash Flow Hedges Balance at January 1, 2020 $ (2,715) Change in fair market value during year (5,972) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,935) Change in fair market value during year 4,817 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,366) Change in fair market value during year 5,371 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 564 Balance at December 31, 2022 $ 3,569

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	12 Months Ended
SEGMENT INFORMATION (Tables)	Dec. 31, 2022
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The following tables provide selected asset information and results of operations of the Company’s reportable segments (in thousands): Real estate investments, at cost: December 31, 2022 December 31, 2021 Philadelphia CBD $ 1,517,801 $ 1,460,510 Pennsylvania Suburbs 878,546 866,223 Austin, Texas 851,835 778,145 Metropolitan Washington, D.C. 282,458 280,921 Other 86,600 86,803 Operating Properties $ 3,617,240 $ 3,472,602 Corporate Right of use asset - operating leases, net $ 19,664 $ 20,313 Construction-in-progress $ 218,869 $ 277,237 Land held for development $ 76,499 $ 114,604 Prepaid leasehold interests in land held for development, net $ 35,576 $ 27,762 . Net operating income: Year Ended December 31, 2022 2021 2020 Total revenue Operating expenses (a) Net operating income Total revenue Operating expenses (a) Net operating income Total revenue Operating expenses (a) Net operating income (loss) Philadelphia CBD $ 220,876 $ (79,827) $ 141,049 $ 207,858 $ (73,695) $ 134,163 $ 232,028 $ (82,505) $ 149,523 Pennsylvania Suburbs 128,940 (41,814) 87,126 124,566 (40,011) 84,555 141,613 (46,281) 95,332 Austin, Texas 96,328 (41,141) 55,187 101,680 (39,374) 62,306 102,982 (39,759) 63,223 Metropolitan Washington, D.C. 21,900 (12,539) 9,361 19,865 (15,386) 4,479 40,223 (20,791) 19,432 Other 14,710 (8,626) 6,084 14,015 (9,840) 4,175 13,469 (9,815) 3,654 Corporate 23,346 (10,454) 12,892 18,835 (10,005) 8,830 4,537 (6,305) (1,768) Operating properties $ 506,100 $ (194,401) $ 311,699 $ 486,819 $ (188,311) $ 298,508 $ 534,852 $ (205,456) $ 329,396 (a) Includes property operating expense, real estate taxes and third party management expense. Unconsolidated real estate ventures: Investment in real estate ventures, at equity Equity in income (loss) of real estate venture As of Year ended December 31, December 31, 2022 December 31, 2021 2022 2021 2020 Philadelphia CBD $ 387,301 $ 317,959 $ (11,764) $ (15,191) $ (9,090) Metropolitan Washington, D.C. 83,903 85,867 (2,324) (3,755) (3,019) Mid-Atlantic Office JV 31,005 31,680 412 932 96 MAP Venture (35,411) (24,396) (8,340) (8,683) (6,571) Austin, Texas 65,426 — — — — Total $ 532,224 $ 411,110 $ (22,016) $ (26,697) $ (18,584)
Schedule of Reconciliation of Consolidated Net Income (Loss)	The following is a reconciliation of consolidated net income (loss), as defined by GAAP, to consolidated NOI, (in thousands): Year Ended December 31, 2022 2021 2020 Net income $ 53,992 $ 12,366 $ 307,326 Plus: Interest expense 68,764 62,617 73,911 Interest expense - amortization of deferred financing costs 3,091 2,836 2,904 Depreciation and amortization 177,984 178,105 188,283 General and administrative expenses 35,006 30,153 30,288 Equity in loss of unconsolidated real estate ventures 22,016 26,697 18,584 Provision for impairment 4,663 — — Loss on early extinguishment of debt 435 — — Less: Interest and investment income 1,905 8,295 1,939 Income tax (provision) benefit (55) (47) 224 Net gain on disposition of real estate 17,677 142 289,461 Net gain on sale of undepreciated real estate 8,007 2,903 201 Net gain on real estate venture transactions 26,718 2,973 75 Consolidated net operating income $ 311,699 $ 298,508 $ 329,396

ORGANIZATION OF THE PARENT CO_3

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP - Narrative (Details)	12 Months Ended
	Dec. 31, 2022 a ft² managementCompany parcel property
Organization of The Parent Company and The Operating Partnership [Line Items]
Number of real estate properties \| property	77
Area of real estate property	13,578,188
Number of management companies \| managementCompany	7
Wholly Owned Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	13,600,000
Parent Company
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of undeveloped parcels of land \| a	159.9
Area of additional undeveloped parcels of land with option to purchase \| a	55.1
Total potential development capacity	11,900,000
Parent Company \| Land Parcel One
Organization of The Parent Company and The Operating Partnership [Line Items]
Lease agreement term (in years)	99 years
Parent Company \| Land Parcel Two
Organization of The Parent Company and The Operating Partnership [Line Items]
Lease agreement term (in years)	99 years
Wholly-owned Management Company Subsidiaries
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	23,000,000
Wholly-owned Management Company Subsidiaries \| Wholly Owned Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	13,600,000
Wholly-owned Management Company Subsidiaries \| Partially Owned Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	9,400,000
Leashold Interest Land
Organization of The Parent Company and The Operating Partnership [Line Items]
Lease agreement term (in years)	99 years
Leashold Interest Land \| Parent Company
Organization of The Parent Company and The Operating Partnership [Line Items]
Number of real estate properties \| parcel	1
Undeveloped parcels of land held \| a	0.8
Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	99.70%
BRSCO \| BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100%
BMI \| BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100%
BPI \| BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100%
BBL \| BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100%
BPM \| BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100%
BBS \| BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100%
BGCS \| BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100%
Unconsolidated Real Estate Ventures \| Unconsolidated Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Number of real estate properties \| property	12

ORGANIZATION OF THE PARENT CO_4

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP - Summary of Core Portfolio of Operating Properties and Excludes Development, Redevelopment and Held for Sale (Details)	Dec. 31, 2022 ft² property
Real Estate Properties [Line Items]
Number of Properties \| property	77
Rentable Square Feet \| ft²	13,578,188
Core Properties
Real Estate Properties [Line Items]
Number of Properties \| property	72
Rentable Square Feet \| ft²	12,791,041
Office properties
Real Estate Properties [Line Items]
Number of Properties \| property	67
Rentable Square Feet \| ft²	11,848,707
Mixed-use properties
Real Estate Properties [Line Items]
Number of Properties \| property	5
Rentable Square Feet \| ft²	942,334
Development property
Real Estate Properties [Line Items]
Number of Properties \| property	2
Rentable Square Feet \| ft²	350,488
Redevelopment properties
Real Estate Properties [Line Items]
Number of Properties \| property	3
Rentable Square Feet \| ft²	436,659

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Change in Depreciable Lives of Real Estate Investments (Details) - Service Life $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) property	Dec. 31, 2021 USD ($)
Real Estate Properties [Line Items]
Number of properties that changed estimated useful lives (in years) \| property	7
Depreciation expense \| $	$ 14.6	$ 9.8
Building
Real Estate Properties [Line Items]
Property, plant, and equipment, estimated useful life	12	35

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Principles of Consolidation (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Assets	$ 3,874,505	$ 3,846,196
Liabilities	2,241,171	2,144,977
Variable Interest Entity
Variable Interest Entity [Line Items]
Assets	47,300	46,500
Liabilities	$ 21,000	$ 21,000

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Purchase Price Allocation and Depreciation and Amortization (Details)	12 Months Ended
	Dec. 31, 2022
Minimum
Construction in Progress [Line Items]
Expected lease-up periods	4 months
Minimum \| Buildings and Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	5 years
Minimum \| Tenant Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	1 year
Maximum
Construction in Progress [Line Items]
Expected lease-up periods	12 months
Maximum \| Buildings and Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	55 years
Maximum \| Tenant Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	16 years

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Impairment of Real Estate Assets (Details)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Disposition of assets, holding period	10 years

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Deferred Costs (Details)	Dec. 31, 2022
Minimum
Lessor, Lease, Description [Line Items]
Deferred cost, amortization period	1 year
Maximum
Lessor, Lease, Description [Line Items]
Deferred cost, amortization period	16 years

SUMMARY OF SIGNIFICANT ACCOUN_9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 506,100	$ 486,819	$ 534,852
Rents
Disaggregation of Revenue [Line Items]
Total revenue	470,851	451,519	513,504
Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	453,198	433,766	497,264
Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	353,387	343,924	393,178
Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	99,811	89,842	104,086
Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	2,582	5,377	4,868
Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	15,071	12,376	11,372
Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	24,132	26,444	18,580
Other income
Disaggregation of Revenue [Line Items]
Total revenue	11,117	8,856	2,768
Philadelphia CBD
Disaggregation of Revenue [Line Items]
Total revenue	220,875	207,858	232,028
Philadelphia CBD \| Rents
Disaggregation of Revenue [Line Items]
Total revenue	218,078	204,848	229,619
Philadelphia CBD \| Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	202,380	191,026	217,696
Philadelphia CBD \| Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	151,034	149,441	166,286
Philadelphia CBD \| Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	51,346	41,585	51,410
Philadelphia CBD \| Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	1,308	2,064	1,146
Philadelphia CBD \| Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	14,390	11,758	10,777
Philadelphia CBD \| Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	287	893	927
Philadelphia CBD \| Other income
Disaggregation of Revenue [Line Items]
Total revenue	2,510	2,117	1,482
Pennsylvania Suburbs
Disaggregation of Revenue [Line Items]
Total revenue	128,940	124,566	141,613
Pennsylvania Suburbs \| Rents
Disaggregation of Revenue [Line Items]
Total revenue	128,551	124,256	141,162
Pennsylvania Suburbs \| Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	128,541	124,106	140,995
Pennsylvania Suburbs \| Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	116,926	113,748	128,044
Pennsylvania Suburbs \| Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	11,615	10,358	12,951
Pennsylvania Suburbs \| Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	10	(9)	(12)
Pennsylvania Suburbs \| Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	0	159	179
Pennsylvania Suburbs \| Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	35	34	39
Pennsylvania Suburbs \| Other income
Disaggregation of Revenue [Line Items]
Total revenue	354	276	412
Austin, Texas
Disaggregation of Revenue [Line Items]
Total revenue	96,329	101,680	102,982
Austin, Texas \| Rents
Disaggregation of Revenue [Line Items]
Total revenue	95,414	100,826	102,069
Austin, Texas \| Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	93,789	97,395	98,489
Austin, Texas \| Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	60,831	62,545	63,366
Austin, Texas \| Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	32,958	34,850	35,123
Austin, Texas \| Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	1,264	3,322	3,531
Austin, Texas \| Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	361	109	49
Austin, Texas \| Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	486	452	689
Austin, Texas \| Other income
Disaggregation of Revenue [Line Items]
Total revenue	429	402	224
Metropolitan Washington, D.C.
Disaggregation of Revenue [Line Items]
Total revenue	21,899	19,865	40,223
Metropolitan Washington, D.C. \| Rents
Disaggregation of Revenue [Line Items]
Total revenue	18,053	13,173	33,509
Metropolitan Washington, D.C. \| Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	17,969	13,056	33,374
Metropolitan Washington, D.C. \| Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	16,686	12,410	29,830
Metropolitan Washington, D.C. \| Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	1,283	646	3,544
Metropolitan Washington, D.C. \| Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0
Metropolitan Washington, D.C. \| Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	84	117	135
Metropolitan Washington, D.C. \| Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	3,723	6,548	6,541
Metropolitan Washington, D.C. \| Other income
Disaggregation of Revenue [Line Items]
Total revenue	123	144	173
Other
Disaggregation of Revenue [Line Items]
Total revenue	14,711	14,015	13,469
Other \| Rents
Disaggregation of Revenue [Line Items]
Total revenue	12,685	10,913	10,900
Other \| Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	12,449	10,680	10,465
Other \| Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	9,805	8,020	8,064
Other \| Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	2,644	2,660	2,401
Other \| Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	0	0	203
Other \| Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	236	233	232
Other \| Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	1,988	3,077	2,560
Other \| Other income
Disaggregation of Revenue [Line Items]
Total revenue	38	25	9
Corporate
Disaggregation of Revenue [Line Items]
Total revenue	23,346	18,835	4,537
Corporate \| Rents
Disaggregation of Revenue [Line Items]
Total revenue	(1,930)	(2,497)	(3,755)
Corporate \| Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	(1,930)	(2,497)	(3,755)
Corporate \| Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	(1,895)	(2,240)	(2,412)
Corporate \| Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	(35)	(257)	(1,343)
Corporate \| Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0
Corporate \| Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0
Corporate \| Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	17,613	15,440	7,824
Corporate \| Other income
Disaggregation of Revenue [Line Items]
Total revenue	$ 7,663	$ 5,892	$ 468

SUMMARY OF SIGNIFICANT ACCOU_10

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Income Taxes (Details) - USD ($) $ in Billions	Dec. 31, 2022	Dec. 31, 2021
Income Tax Contingency [Line Items]
Tax basis of assets, cost for income tax purposes	$ 3.2	$ 3.1
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Income Tax Contingency [Line Items]
Tax basis of assets, cost for income tax purposes	$ 3.2	$ 3.1

REAL ESTATE INVESTMENTS - Sched

REAL ESTATE INVESTMENTS - Schedule of Gross Carrying Value of Operating Properties (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Real Estate [Abstract]
Land	$ 403,998	$ 410,144
Building and improvements	2,760,357	2,653,492
Tenant improvements	452,885	408,966
Total	$ 3,617,240	$ 3,472,602

REAL ESTATE INVESTMENTS - Sch_2

REAL ESTATE INVESTMENTS - Schedule of Capitalized Construction Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Internal direct construction costs	$ 9,332	$ 7,902	$ 8,366
Capitalized interest	4,700	7,000	4,600
Development
Property, Plant and Equipment [Line Items]
Internal direct construction costs	5,343	4,815	4,802
Redevelopment
Property, Plant and Equipment [Line Items]
Internal direct construction costs	1,484	1,170	543
Tenant Improvements
Property, Plant and Equipment [Line Items]
Internal direct construction costs	$ 2,505	$ 1,917	$ 3,021

REAL ESTATE INVESTMENTS - Sch_3

REAL ESTATE INVESTMENTS - Schedule of Acquired Properties (Details) $ in Thousands						12 Months Ended
	Apr. 29, 2022 USD ($)	Jan. 21, 2022 USD ($) a	Nov. 30, 2020 USD ($) ft²	Nov. 05, 2020 USD ($) ft²	Feb. 27, 2020 USD ($) a	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Apr. 29, 2022 ft²	Apr. 29, 2022 a
Business Acquisition [Line Items]
Purchase price						$ 3,446	$ 0	$ 41,950
Area of real estate property \| ft²						13,578,188
Land \| 631 Park Avenue
Business Acquisition [Line Items]
Land area \| a		3.3
Purchase price		$ 3,650
Land \| 3151 Market Street
Business Acquisition [Line Items]
Land area									0.8	0.8
Purchase price	$ 27,349
Lease agreement term (in years)	99 years
Prepaid Rent	$ 19,500
Area of real estate property \| ft²									500,000
Land \| 155 King of Prussia Road
Business Acquisition [Line Items]
Land area \| a					7.75
Purchase price					$ 11,250
Land \| Schuylkill Yards Project
Business Acquisition [Line Items]
Area of real estate property \| ft²									200,000
Operating Lease Costs, Capitalized	$ 7,800
Office \| 1505-11 Race Street
Business Acquisition [Line Items]
Rentable Square Feet \| ft²				119,763
Purchase price				$ 9,700
Office \| 250 King of Prussia Road
Business Acquisition [Line Items]
Rentable Square Feet \| ft²			169,843
Purchase price			$ 20,250

REAL ESTATE INVESTMENTS - Sch_4

REAL ESTATE INVESTMENTS - Schedule of Asset Acquisition (Details) - 1505-11 Race Street $ in Thousands	Nov. 05, 2020 USD ($)
Schedule of Investments [Line Items]
Building, land and improvements	$ 9,723
Intangible assets acquired	2,422
Below market lease liabilities assumed	(2,193)
Total unencumbered acquisition value	$ 9,952
Below Market Lease
Schedule of Investments [Line Items]
Weighted average amortization period	1 year 6 months
Intangible Assets Acquired
Schedule of Investments [Line Items]
Weighted average amortization period	1 year 6 months

REAL ESTATE INVESTMENTS - Sch_5

REAL ESTATE INVESTMENTS - Schedule of Office Properties Sold (Details) $ in Thousands

12 Months Ended

Nov. 22, 2022 USD ($) ft²

Sep. 30, 2022 USD ($)

Jul. 29, 2022 USD ($) a

Jul. 14, 2022 USD ($) a ft²

Jun. 28, 2022 USD ($)

Apr. 14, 2022 USD ($) a

Jan. 20, 2022 USD ($) a

Sep. 08, 2021 USD ($) ft²

Jul. 06, 2021 USD ($) ft²

Feb. 02, 2021 USD ($) a

Dec. 21, 2020 USD ($) ft² property

Jul. 21, 2020 USD ($) ft² property

Jun. 15, 2020 USD ($) a

Mar. 19, 2020 USD ($) ft²

Dec. 31, 2022 USD ($) ft²

Dec. 31, 2021 USD ($)

Dec. 31, 2020 USD ($)

Jun. 28, 2022 ft²

Jun. 28, 2022 a

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Gain (Loss) on Sale

$ 17,677

$ 142

$ 289,461

Sale of ownership interest percentage

60%

Area of real estate property | ft²

13,578,188

Mid-Atlantic Office Portfolio

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Variable consideration

$ 4,100

Mid-Atlantic Office Portfolio | Minimum

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Variable consideration holdback term (in months)

6 months

Mid-Atlantic Office Portfolio | Maximum

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Variable consideration holdback term (in months)

9 months

Commerce Square

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Sales Price

$ 115,000

Sale of ownership interest percentage

30%

Value of assets disposed of

$ 600,000

Net gain on disposition of real estate

$ 271,900

Office | 200 Barr Harbor Drive

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Rentable Square Feet | ft²

86,000

Sales Price

$ 30,500

Gain (Loss) on Sale

$ 8,740

Office | Gibbsboro Portfolio

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Gain (Loss) on Sale

$ 100

Office | Mid-Atlantic Office Portfolio

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Rentable Square Feet | ft²

1,128,645

Sales Price

$ 192,943

Gain (Loss) on Sale

$ 15,164

Number of properties sold | property

Office | Mid-Atlantic Office Portfolio | Pennsylvania

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Number of properties sold | property

Office | Mid-Atlantic Office Portfolio | Maryland

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Number of properties sold | property

Office | Commerce Square

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Rentable Square Feet | ft²

1,896,142

Sales Price

$ 115,000

Gain (Loss) on Sale

$ 271,905

Number of properties sold | property

Office | 52 East Swedesford Road

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Rentable Square Feet | ft²

131,077

Sales Price

$ 18,000

Gain (Loss) on Sale

$ 2,336

Land | 11501 Burnet Road

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | a

4.7

Sales Price

$ 32,513

Gain (Loss) on Sale

$ 8,340

Land | 3151 Market Street

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Area of real estate property | ft²

500,000

Land | Gibbsboro Portfolio

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Gain (Loss) on Sale

$ 700

Land | 25 M Street

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | a

0.8

Sales Price

$ 29,675

Gain (Loss) on Sale

$ 400

$ 3,836

Land | Gateway G & H

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | a

Sales Price

$ 1,600

Gain (Loss) on Sale

$ 897

Land | 1100 Lenox Drive

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | ft²

Sales Price

$ 2,575

Gain (Loss) on Sale

$ 68

Land | 2100-2200 Lenox Drive

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | ft²

35.2

Sales Price

$ 8,900

Gain (Loss) on Sale

$ 842

Land | Keith Valley

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | a

Sales Price

$ 4,000

Gain (Loss) on Sale

$ 201

Leasehold Interest | 3151 Market Street

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | a

0.8

Sales Price

$ 30,394

Gain (Loss) on Sale

$ 2,583

Lease agreement term (in years)

99 years

Leasehold Interest | 3025 JFK Venture

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area | a

Sales Price

$ 34,800

Gain (Loss) on Sale

$ 2,000

Office/Land | Gibbsboro Portfolio

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Land area

42,809

Sales Price

$ 4,100

Gain (Loss) on Sale

$ 831

REAL ESTATE INVESTMENTS - Dispo

REAL ESTATE INVESTMENTS - Dispositions (Narrative) (Details) $ in Thousands				12 Months Ended
	Feb. 23, 2023 USD ($) ft²	Jul. 14, 2022 USD ($) a ft²	Feb. 02, 2021 USD ($)	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 23, 2021 USD ($)	Feb. 02, 2021 ft²	Feb. 02, 2021 a	Nov. 05, 2020 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property \| ft²				13,578,188
Investment in real estate ventures, at equity				$ 532,224	$ 411,110
Net gain on sale of undepreciated real estate				8,007	2,903	$ 201
Net gain on disposition of real estate				$ 17,677	$ 142	$ 289,461
Land \| 3151 Market Street
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property \| ft²		500,000
Land \| 3151 Market Street \| Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property \| ft²	200,000
Leasehold Interest \| 3151 Market Street
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Lease agreement term (in years)		99 years
Land area \| a		0.8
Sales Price		$ 30,394
Net gain on disposition of real estate		$ 2,583
Leasehold Interest \| 3151 Market Street \| Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price	$ 7,800
Net gain on disposition of real estate	$ 800
3025 JFK Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Lease agreement term (in years)			99 years
Land area								1	1
Investment in real estate ventures, at equity			$ 34,800				$ 34,800
Net gain on sale of undepreciated real estate			$ 2,000
1505-11 Race Street
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transaction costs capitalized										$ 300

REAL ESTATE INVESTMENTS - 3151

REAL ESTATE INVESTMENTS - 3151 Market Venture (Narrative) (Details) $ in Thousands		12 Months Ended
	Jul. 14, 2022 USD ($) ft²	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Schedule of Investments [Line Items]
Area of real estate property \| ft²		13,578,188
Net gain on disposition of real estate		$ 17,677	$ 142	$ 289,461
Land \| 3151 Market Street
Schedule of Investments [Line Items]
Area of real estate property \| ft²	500,000
Leasehold Interest \| 3151 Market Street
Schedule of Investments [Line Items]
Lease agreement term (in years)	99 years
Sales Price	$ 30,394
Net gain on disposition of real estate	$ 2,583

REAL ESTATE INVESTMENTS - Held

REAL ESTATE INVESTMENTS - Held for Use Impairment and Sale (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) property	Jan. 20, 2022 USD ($)	Dec. 31, 2021 USD ($) a parcel	Dec. 31, 2020 USD ($) a parcel
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of properties held for use	$ 4,700
Assets held for sale, net	$ 0		$ 562
Number of real estate properties \| property	77
Held for Sale Properties Included in Continuing Operations \| Other Land
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale, net			$ 600
Aggregate sales price		$ 1,600
Held for Sale Properties Included in Continuing Operations \| Other Land \| OTHER
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of land parcels \| parcel			2
Land area \| a			10
Held for Sale Properties Included in Continuing Operations \| Land Held For Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale, net				$ 7,300
Held for Sale Properties Included in Continuing Operations \| Land Held For Development \| OTHER
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Land area \| a				35.2
Number of real estate properties \| parcel				2

INVESTMENT IN UNCONSOLIDATED _3

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Narrative (Details) $ in Thousands, ft² in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) ft² a property apartment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	77
Investment balance \| $	$ 532,224	$ 411,110
Accounts receivable \| $	11,003	11,875
Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Accounts receivable \| $	2,900	2,500
Management Fees \| Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Service and other revenue \| $	8,200	8,100	$ 4,700
Leasing Commission Income \| Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Service and other revenue \| $	2,500	$ 3,800	$ 1,100
Unconsolidated Real Estate Ventures
Schedule of Equity Method Investments [Line Items]
Investment balance \| $	$ 532,200
Unconsolidated Real Estate Ventures \| Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15%
Unconsolidated Real Estate Ventures \| Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70%
Unconsolidated Real Estate Ventures \| Office Properties
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in real estate ventures \| property	5
Rentable square feet \| ft²	9.1
Unconsolidated Real Estate Ventures \| Other Liabilities
Schedule of Equity Method Investments [Line Items]
Investment balance \| $	$ (35,400)
Unconsolidated Real Estate Ventures \| Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	12
Number of real estate properties with negative investment balances \| property	1
Unconsolidated Real Estate Ventures \| Land Held For Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in real estate ventures \| property	2
Land area \| a	1.4
Unconsolidated Real Estate Ventures \| Land Under Active Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in real estate ventures \| property	4
Land area \| a	7.5
Unconsolidated Real Estate Ventures \| Mixed Use Tower
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in real estate ventures \| property	1
Rentable square feet \| ft²	0.2
Number of property units \| apartment	250

INVESTMENT IN UNCONSOLIDATED _4

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Schedule of Investment in Real Estate Ventures and Share of Real Estate Ventures' Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Nov. 30, 2022	Feb. 02, 2021	Dec. 21, 2020
Schedule of Equity Method Investments [Line Items]
Carrying Amount	$ 532,224	$ 411,110
Company's Share of unconsolidated real estate venture Income (Loss)	(22,016)	(26,697)	$ (18,584)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 1,204,779	961,509
Commerce Square Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70%
Carrying Amount	$ 238,105	247,798
Company's Share of unconsolidated real estate venture Income (Loss)	(12,128)	(15,501)	(9,150)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 206,737	213,069
Mid-Atlantic Office Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	40%					40%
Carrying Amount	$ 31,005	31,680
Company's Share of unconsolidated real estate venture Income (Loss)	412	932	96
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 128,904	123,015
Brandywine - AI Venture LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50%
Carrying Amount	$ 0	0
Company's Share of unconsolidated real estate venture Income (Loss)	0	(721)	185
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
Herndon Innovation Center Metro Portfolio Venture, LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	15%
Carrying Amount	$ 15,304	15,844
Company's Share of unconsolidated real estate venture Income (Loss)	(536)	(174)	(358)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 207,302	207,302
MAP Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50%
Carrying Amount	$ (35,411)	(24,396)
Company's Share of unconsolidated real estate venture Income (Loss)	(8,340)	(8,683)	(6,570)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 182,053	184,263
Cira Square
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	20%
Carrying Amount	$ 27,815	0
Company's Share of unconsolidated real estate venture Income (Loss)	(985)	0	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 257,700	0
4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50%
Carrying Amount	$ 29,633	31,059
Company's Share of unconsolidated real estate venture Income (Loss)	(1,211)	(2,258)	(2,162)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 145,070	145,000
1919 Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50%			50%
Carrying Amount	$ 0	13,791
Company's Share of unconsolidated real estate venture Income (Loss)	1,392	427	59
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	88,860
3025 JFK Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	55%				55%
Carrying Amount	$ 57,630	56,370
Company's Share of unconsolidated real estate venture Income (Loss)	(35)	(118)	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 60,118	0
JBG 51 N Street
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70%
Carrying Amount	$ 21,208	21,213
Company's Share of unconsolidated real estate venture Income (Loss)	(382)	(402)	(457)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
JBG 1250 First Street Office
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70%
Carrying Amount	$ 17,759	17,751
Company's Share of unconsolidated real estate venture Income (Loss)	(195)	(199)	(227)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
3151 Market Street Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	55%
Carrying Amount	$ 63,751	0
Company's Share of unconsolidated real estate venture Income (Loss)	(8)	0	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
One Uptown - Office
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50%
Carrying Amount	$ 34,980	0
Company's Share of unconsolidated real estate venture Income (Loss)	0	0	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 16,895	0
One Uptown - Multifamily
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50%
Carrying Amount	$ 30,445	0
Company's Share of unconsolidated real estate venture Income (Loss)	0	0	$ 0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	$ 0

INVESTMENT IN UNCONSOLIDATED _5

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Financial Position of Real Estate Ventures (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Net property	$ 2,904,788	$ 2,955,068
Other assets	78,667	133,094
Other liabilities	52,331	48,683
Equity	1,633,334	1,701,219	$ 1,804,648	$ 1,688,303
Investment In Nonconsolidated Real Estate
Schedule of Equity Method Investments [Line Items]
Net property	2,117,226	1,563,263
Other assets	506,213	434,687
Other liabilities	446,101	331,947
Debt, net	1,198,213	956,668
Equity	$ 979,125	$ 709,335

INVESTMENT IN UNCONSOLIDATED _6

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Schedule of Results of Operations of Real Estate Ventures with Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Revenue	$ 506,100	$ 486,819	$ 534,852
Operating expenses	(412,054)	(396,569)	(424,027)
Interest expense, net	(68,764)	(62,617)	(73,911)
Depreciation and amortization	(177,984)	(178,105)	(188,283)
Provision for impairment	(4,663)	0	0
Net income	53,992	12,366	307,326
Equity in loss of unconsolidated real estate ventures	(22,016)	(26,697)	(18,584)
Investment In Nonconsolidated Real Estate
Schedule of Equity Method Investments [Line Items]
Revenue	244,981	214,792	150,276
Operating expenses	(124,608)	(117,273)	(85,812)
Interest expense, net	(49,007)	(30,569)	(22,661)
Depreciation and amortization	(103,378)	(97,147)	(70,805)
Provision for impairment	0	(1,393)	0
Net income	(32,012)	(31,590)	(29,002)
Company's share of net loss	(21,594)	(25,972)	(18,540)
Basis adjustments and other	$ (422)	$ (725)	$ (44)

INVESTMENT IN UNCONSOLIDATED _7

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Schedule of Maturities of Long-term Debt (Details) - Unconsolidated Real Estate Ventures $ in Thousands	Dec. 31, 2022 USD ($)
Schedule of Equity Method Investments [Line Items]
2023	$ 388,789
2024	593,907
2025	60,118
2026	161,965
2027	0
Thereafter	0
Total principal payments	1,204,779
Net deferred financing costs	(6,837)
Net original issue premium	271
Outstanding indebtedness	$ 1,198,213

INVESTMENT IN UNCONSOLIDATED _8

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - One Uptown Ventures (Details) $ in Thousands			12 Months Ended
	Jul. 29, 2022 USD ($) numberOfLoan	Jun. 30, 2022	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 01, 2021 USD ($) ft² property apartment
Schedule of Equity Method Investments [Line Items]
Investment in real estate ventures, at equity			$ 532,224	$ 411,110
Area of real estate property \| ft²			13,578,188
Unsecured Debt
Schedule of Equity Method Investments [Line Items]
Long-term debt, gross			$ 1,971,411	1,851,610
Unsecured Debt \| $600 million Unsecured Credit Facility
Schedule of Equity Method Investments [Line Items]
Long-term debt, gross			$ 88,500	$ 23,000
Unsecured Debt \| Daily SOFR Adjustment \| $600 million Unsecured Credit Facility
Schedule of Equity Method Investments [Line Items]
Basis spread on interest rate (as percent)		0.10%	0.10%
One Uptown Venture
Schedule of Equity Method Investments [Line Items]
Investment in real estate ventures, at equity					$ 335,600
Number of apartment residences \| apartment					341
Joint venture, funding committed by other party					$ 64,500
Ownership percentage			50%
One Uptown Venture \| Carry Guarantee \| Loans Payable
Schedule of Equity Method Investments [Line Items]
Guarantee obligations, payment (as percent)	30%
One Uptown Venture \| Limited Payment Guarantee \| Loans Payable
Schedule of Equity Method Investments [Line Items]
Guarantee obligations, payment (as percent)	15%
One Uptown Venture \| Construction Loans
Schedule of Equity Method Investments [Line Items]
Number of loans closed \| numberOfLoan	2
Long-term debt, gross	$ 121,700
One Uptown Venture \| Construction Loans \| Multifamily Joint Venture
Schedule of Equity Method Investments [Line Items]
Long-term debt, gross	$ 85,000
One Uptown Venture \| Construction Loans \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Schedule of Equity Method Investments [Line Items]
Basis spread on interest rate (as percent)	3%
One Uptown Venture \| Construction Loans \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate \| Multifamily Joint Venture
Schedule of Equity Method Investments [Line Items]
Basis spread on interest rate (as percent)	2.45%
One Uptown Venture \| Preferred Stock
Schedule of Equity Method Investments [Line Items]
Ownership percentage					50%
One Uptown Venture \| Common Stock
Schedule of Equity Method Investments [Line Items]
Ownership percentage					50%
One Uptown Venture \| Canyon Partners Real Estate
Schedule of Equity Method Investments [Line Items]
Number of joint ventures \| property					2
One Uptown Venture \| Class A Workspace
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²					348,000
One Uptown Venture \| Street Level Retail
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²					15,000

INVESTMENT IN UNCONSOLIDATED _9

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 3151 Market Street Venture (Details) $ in Thousands	Dec. 31, 2022 USD ($) ft²	Jul. 14, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²	13,578,188
Investment in real estate ventures, at equity	$ 532,224		$ 411,110
3151 Market Street
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²		417,000
Investment in real estate ventures, at equity		$ 308,000
3151 Market Street \| Joint Venture With Unaffiliated Third Party
Schedule of Equity Method Investments [Line Items]
Investment in real estate ventures, at equity		$ 55,000
3151 Market Street \| Joint Venture With Unaffiliated Third Party \| Joint Venture With Unaffiliated Third Party
Schedule of Equity Method Investments [Line Items]
Ownership percentage		45%

INVESTMENT IN UNCONSOLIDATED_10

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Cira Square (Details) $ in Thousands		12 Months Ended
	Mar. 17, 2022 USD ($) ft²	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²		13,578,188
Purchase price		$ 3,446	$ 0	$ 41,950
Cira Square REIT, LLC
Schedule of Equity Method Investments [Line Items]
Cost of equity method investment	$ 383,000
Ownership percentage	20%
Purchase price	$ 28,600
Interest rate, maximum	6.75%
Cira Square REIT, LLC \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Schedule of Equity Method Investments [Line Items]
Basis spread on interest rate (as percent)	3.50%
Cira Square REIT, LLC \| Secured Debt
Schedule of Equity Method Investments [Line Items]
Debt instrument, face amount	$ 257,700
Office Properties \| Cira Square REIT, LLC
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²	862,692

INVESTMENT IN UNCONSOLIDATED_11

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 4040 Wilson Venture (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 a ft² property	Dec. 31, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	77
Area of real estate property \| ft²	13,578,188
4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	1
Area of real estate property \| ft²	225,000
Land area \| a	250
Ownership percentage	50%
4040 Wilson Venture \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Schedule of Equity Method Investments [Line Items]
Debt instrument, interest rate	5.70%
4040 Wilson Venture \| Construction Loans
Schedule of Equity Method Investments [Line Items]
Long-term debt, gross \| $		$ 150
4040 Wilson Venture \| Secured Debt \| Mortgage Loan Secured By Property
Schedule of Equity Method Investments [Line Items]
Long-term debt, gross \| $		$ 155
4040 Wilson Venture \| Secured Debt \| Mortgage Loan Secured By Property \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Schedule of Equity Method Investments [Line Items]
Basis spread on interest rate (as percent)	1.80%

INVESTMENT IN UNCONSOLIDATED_12

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Brandywine - AI Venture (Details) $ in Thousands		12 Months Ended
	Nov. 09, 2021 USD ($) ft²	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) ft²
Schedule of Equity Method Investments [Line Items]
Net gain on real estate venture transactions		$ 26,718	$ 2,973	$ 75
Impairment of properties held for use		$ 4,700
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]					Equity in loss of unconsolidated real estate ventures
Fairview Properties \| Brandywine - AI Venture LLC
Schedule of Equity Method Investments [Line Items]
Provision for impairment on assets held for sale			1,400
Impairment of properties held for use					$ 5,600
Fairview Properties \| Brandywine - AI Venture LLC \| Brandywine Realty Trust
Schedule of Equity Method Investments [Line Items]
Provision for impairment on assets held for sale			$ 700
Impairment of properties held for use					$ 2,800
Falls Church, Virginia \| Brandywine - AI Venture LLC
Schedule of Equity Method Investments [Line Items]
Rentable square feet \| ft²	183,618				180,659
Aggregate sales price	$ 27,600
Gross proceeds from sale	12,600
Net gain on real estate venture transactions	$ 3,000				$ 2,200
Debt, net					$ 26,000

INVESTMENT IN UNCONSOLIDATED_13

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 3025 JFK Venture (Details) $ in Thousands	Feb. 02, 2021 a	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jul. 23, 2021 USD ($)	Feb. 02, 2021 ft²	Feb. 02, 2021	Feb. 02, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Investment in real estate ventures, at equity		$ 532,224	$ 411,110
3025 JFK Venture
Schedule of Equity Method Investments [Line Items]
Ownership percentage		55%				55%
3025 JFK Venture
Schedule of Equity Method Investments [Line Items]
Lease agreement term (in years)	99 years
Land area	1				1
Investment in real estate ventures, at equity				$ 34,800			$ 34,800
Area of building to be constructed \| ft²					570,000
Estimated project cost							287,300
Joint venture, funding committed by other party							$ 45,200
Ownership interest held by partner						45%
Construction loan amount		$ 186,700		$ 186,700
Joint venture, funding committed		$ 20,500
3025 JFK Venture \| LIBOR
Schedule of Equity Method Investments [Line Items]
Debt instrument, interest rate, stated percentage				3.50%
Interest rate, floor				0.25%

INVESTMENT IN UNCONSOLIDATED_14

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Mid-Atlantic Office JV (Details) $ in Thousands		12 Months Ended
	Dec. 21, 2020 USD ($) ft² property	Dec. 31, 2022 USD ($) property	Dec. 31, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property		77
Investment in real estate ventures, at equity		$ 532,224	$ 411,110
Mid-Atlantic Office JV Loan
Schedule of Equity Method Investments [Line Items]
Secured construction loan with total borrowing capacity		18,500
Philadelphia CBD
Schedule of Equity Method Investments [Line Items]
Investment in real estate ventures, at equity		387,301	317,959
Metropolitan Washington, D.C.
Schedule of Equity Method Investments [Line Items]
Investment in real estate ventures, at equity		$ 83,903	$ 85,867
Mid-Atlantic Office Venture
Schedule of Equity Method Investments [Line Items]
Ownership percentage	40%	40%
Ownership percentage of total common equity	20%
Joint venture, funding from debt	$ 147,400
Proceeds from issuance of secured debt	$ 120,800
Mid-Atlantic Office Venture \| Mid-Atlantic Office JV Loan \| Maximum
Schedule of Equity Method Investments [Line Items]
Debt instrument, interest rate, stated percentage		5.70%
Mid-Atlantic Office Venture \| Mid-Atlantic Office JV Loan \| LIBOR
Schedule of Equity Method Investments [Line Items]
Basis spread on interest rate (as percent)		3.15%
Mid-Atlantic Office Venture \| Preferred Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25%
Investment in real estate ventures, at equity	$ 20,000
Mid-Atlantic Office Venture \| Common Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15%
Office Properties \| Mid-Atlantic Office Venture
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	12
Rentable square feet \| ft²	1,128,645
Aggregate sales price	$ 192,900
Office Properties \| Mid-Atlantic Office Venture \| Philadelphia CBD
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	9
Office Properties \| Mid-Atlantic Office Venture \| Metropolitan Washington, D.C.
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	3

INVESTMENT IN UNCONSOLIDATED_15

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Commerce Square Venture (Details)	Dec. 31, 2022 property	Dec. 21, 2020 ft²	Jul. 21, 2020 ft² property
Schedule of Equity Method Investments [Line Items]
Sale of ownership interest percentage		60%
Number of real estate properties	77
Commerce Square
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70%
Commerce Square \| Preferred Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	32%
Commerce Square \| Common Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	38%
Commerce Square
Schedule of Equity Method Investments [Line Items]
Sale of ownership interest percentage			30%
Commerce Square \| Office Properties
Schedule of Equity Method Investments [Line Items]
Number of real estate properties			2
Rentable square feet \| ft²		1,896,142	1,896,142

INVESTMENT IN UNCONSOLIDATED_16

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Hernadon Innovation Center Metro Portfolio Venture, LLC (Details)	Dec. 31, 2022 ft² property
Schedule of Equity Method Investments [Line Items]
Area of real estate property	13,578,188
Herndon Innovation Center Metro Portfolio Venture, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15%
Herndon Innovation Center Metro Portfolio Venture, LLC \| Metropolitan Washington, D.C. - Office
Schedule of Equity Method Investments [Line Items]
Number of properties contributed to joint venture \| property	8
Area of real estate property	1,293,197
Herndon Innovation Center Metro Portfolio Venture, LLC \| Metropolitan Washington, D.C. - Office \| Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15%
Herndon Innovation Center Metro Portfolio Venture, LLC \| Metropolitan Washington, D.C. - Office \| Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	85%

INVESTMENT IN UNCONSOLIDATED_17

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - MAP Venture (Details) - MAP Venture $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) ft² property
Schedule of Equity Method Investments [Line Items]
Ground lease annual payments \| $	$ 11.9
Ground lease annual rent expense increase percentage through November 2025	2.50%
Ground lease annual rent expense increase after November 2025	2.50%
Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Number of office properties owned \| property	58
Rentable square feet \| ft²	3,924,783

INVESTMENT IN UNCONSOLIDATED_18

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 1919 Ventures (Details) - USD ($) $ in Millions	Nov. 30, 2022	Dec. 31, 2022
1919 Venture \| Affiliated Entity
Schedule of Equity Method Investments [Line Items]
Repayments of debt	$ 44.4
1919 Venture
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50%	50%
Gross sales	$ 83.2
Gain on disposal	$ 26.7

INVESTMENT IN UNCONSOLIDATED_19

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - JGB Ventures (Details)	Dec. 31, 2022 a joint_venture property
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property	77
JBG 51 N Street
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70%
Area owned by real estate venture of undeveloped parcels of land	0.9
JBG 51 N Street \| JBG Ventures
Schedule of Equity Method Investments [Line Items]
Ownership percentage	30%
JBG 1250 First Street Office
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70%
Area owned by real estate venture of undeveloped parcels of land	0.5
JBG 1250 First Street Office \| JBG Ventures
Schedule of Equity Method Investments [Line Items]
Ownership percentage	30%
JBG Ventures
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| joint_venture	2

DEBT AND PREFERRED EQUITY INV_2

DEBT AND PREFERRED EQUITY INVESTMENTS (Details)		3 Months Ended	12 Months Ended
DEBT AND PREFERRED EQUITY INVESTMENTS (Details)	Nov. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($) property	Dec. 31, 2018 USD ($)	Dec. 31, 2022 property	Sep. 03, 2021 USD ($)
Summary of Investment Holdings [Line Items]
Number of real estate properties \| property					77
Austin Preferred Equity Investment \| Notes Receivable
Summary of Investment Holdings [Line Items]
Note receivable			$ 50,000,000
Number of real estate properties \| property			2
Notes receivable, interest rate (as percent)			9%
Extension option term (in years)			1 year
Note receivable repurchased amount						$ 50,000,000
Gain on financing receivable redemption		$ 2,800,000
1919 Venture
Summary of Investment Holdings [Line Items]
Note receivable				$ 44,400,000
Notes receivable, interest rate (as percent)				4%
Debt, net				$ 44,400,000
Repayment of notes receivable	$ 44,400,000
Ownership Percentage	50%				50%

LEASES - Schedule of Operating

LEASES - Schedule of Operating Lease Future Contractual Lease Payments (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
2023	$ 347,142
2024	344,641
2025	325,166
2026	304,102
2027	263,532
Thereafter	$ 1,041,686

LEASES - Narrative (Details)

LEASES - Narrative (Details)	12 Months Ended
LEASES - Narrative (Details)	Dec. 31, 2022 lease property
Lessee, Lease, Description [Line Items]
Number of ground leases considered operating lease \| lease	6
Number of properties subject to ground leases \| property	3
Minimum
Lessee, Lease, Description [Line Items]
Lease terms (in years)	7 years
Maximum
Lessee, Lease, Description [Line Items]
Lease terms (in years)	62 years

LEASES - Schedule of Lease Cost

LEASES - Schedule of Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Fixed lease cost	$ 2,100	$ 2,100
Variable lease cost	67	43
Total	$ 2,167	$ 2,143
Weighted-average remaining lease term (years)	54 years 7 months 6 days	55 years 2 months 12 days
Weighted-average discount rate	6.30%	6.30%

LEASES - Schedule of Operatin_2

LEASES - Schedule of Operating Lease Liability Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Minimum Rent
2023	$ 1,263
2024	1,305
2025	1,321
2026	1,338
2027	1,355
Thereafter	106,437
Total lease payments	113,019
Less: Imputed interest	89,853
Present value of operating lease liabilities	$ 23,166	$ 22,962

DEFERRED COSTS - Schedule of De

DEFERRED COSTS - Schedule of Deferred Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs [Line Items]
Leasing costs, Total Cost	$ 155,457	$ 143,895
Total Cost	160,145	150,194
Leasing costs, Accumulated Amortization	(62,920)	(57,445)
Total, Accumulated Amortization	(63,506)	(63,332)
Leasing costs, Deferred Costs, net	92,537	86,450
Deferred Costs, net	96,639	86,862
Financing costs - Unsecured Credit Facility
Deferred Costs [Line Items]
Financing costs, Total Cost	4,688	6,299
Financing costs, Accumulated Amortization	(586)	(5,887)
Financing costs, Deferred Costs, net	$ 4,102	$ 412

DEFERRED COSTS - Narrative (Det

DEFERRED COSTS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Capitalized internal direct leasing costs	$ 3	$ 2.1	$ 1.6

INTANGIBLE ASSETS AND LIABILI_3

INTANGIBLE ASSETS AND LIABILITIES - Schedule of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Intangible assets, net:
Total Cost	$ 56,213	$ 73,029
Accumulated Amortization	(37,762)	(44,473)
Total	18,451	28,556
Intangible liabilities, net:
Total Cost	20,985	27,025
Accumulated Amortization	(10,663)	(14,044)
Total	10,322	12,981
In-place lease value
Intangible assets, net:
Total Cost	55,715	72,376
Accumulated Amortization	(37,437)	(44,066)
Total	18,278	28,310
Tenant relationship value
Intangible assets, net:
Total Cost	167	167
Accumulated Amortization	(104)	(97)
Total	63	70
Above market leases acquired
Intangible assets, net:
Total Cost	331	486
Accumulated Amortization	(221)	(310)
Total	$ 110	$ 176

INTANGIBLE ASSETS AND LIABILI_4

INTANGIBLE ASSETS AND LIABILITIES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Tenant Move Outs Prior To End Of Lease Term
Finite-Lived Intangible Assets [Line Items]
Intangible assets written off through accelerated amortization	$ 0.4	$ 3.6	$ 0.3
Tenant Move-Outs
Finite-Lived Intangible Assets [Line Items]
Intangible assets written off through accelerated amortization	$ 0.1	$ 0.6	$ 0.1

INTANGIBLE ASSETS AND LIABILI_5

INTANGIBLE ASSETS AND LIABILITIES - Schedule of Amortization for Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets
2023	$ 6,573
2024	4,332
2025	3,154
2026	1,094
2027	809
Thereafter	2,489
Total	18,451	$ 28,556
Liabilities
2023	1,516
2024	1,305
2025	1,029
2026	739
2027	623
Thereafter	5,110
Total	$ 10,322	$ 12,981

DEBT OBLIGATIONS - Schedule of

DEBT OBLIGATIONS - Schedule of Consolidated Debt Obligations (Details) - Unsecured Debt - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 20, 2022	Dec. 13, 2022	Nov. 23, 2022	Jun. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,971,411,000					$ 1,851,610,000
Plus: original issue premium (discount), net	2,934,000					8,187,000
Less: deferred financing costs	(9,307,000)					(6,211,000)
Total Debt Obligations	1,965,038,000					1,853,586,000
$600 million Unsecured Credit Facility
Debt Instrument [Line Items]
Debt instrument, face amount	600,000,000
Long-term debt, gross	$ 88,500,000					23,000,000
$600 million Unsecured Credit Facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)	1.15%
Unsecured Term Loan
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.01%
Long-term debt, gross	$ 250,000,000			$ 250,000,000	$ 250,000,000	250,000,000
Basis spread on interest rate (as percent)	1.30%
$350.0M 3.95% Guaranteed Notes due 2023
Debt Instrument [Line Items]
Debt instrument, face amount	$ 350,000,000
Debt instrument, interest rate, stated percentage	3.95%	3.95%
Long-term debt, gross	$ 54,301,000	$ 295,700,000				350,000,000
Effective Interest Rate	3.87%
$350.0M 4.10% Guaranteed Notes due 2024
Debt Instrument [Line Items]
Debt instrument, face amount	$ 350,000,000
Debt instrument, interest rate, stated percentage	4.10%
Long-term debt, gross	$ 350,000,000					350,000,000
Effective Interest Rate	3.78%
$450.0M 3.95% Guaranteed Notes due 2027
Debt Instrument [Line Items]
Debt instrument, face amount	$ 450,000,000
Debt instrument, interest rate, stated percentage	3.95%
Long-term debt, gross	$ 450,000,000					450,000,000
Effective Interest Rate	4.03%
$350.0M 7.55% Guaranteed Notes due 2028
Debt Instrument [Line Items]
Debt instrument, face amount	$ 350,000,000		$ 350,000,000
Debt instrument, interest rate, stated percentage	7.55%
Long-term debt, gross	$ 350,000,000					0
Effective Interest Rate	7.73%
$350.0M 4.55% Guaranteed Notes due 2029
Debt Instrument [Line Items]
Debt instrument, face amount	$ 350,000,000
Debt instrument, interest rate, stated percentage	4.55%
Long-term debt, gross	$ 350,000,000					350,000,000
Effective Interest Rate	4.30%
Indenture IA (Preferred Trust I)
Debt Instrument [Line Items]
Long-term debt, gross	$ 27,062,000					27,062,000
Indenture IA (Preferred Trust I) \| LIBOR
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)	1.25%
Indenture IB (Preferred Trust I)
Debt Instrument [Line Items]
Long-term debt, gross	$ 25,774,000					25,774,000
Indenture IB (Preferred Trust I) \| LIBOR
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)	1.25%
Indenture II (Preferred Trust II)
Debt Instrument [Line Items]
Long-term debt, gross	$ 25,774,000					$ 25,774,000
Indenture II (Preferred Trust II) \| LIBOR
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)	1.25%

DEBT OBLIGATIONS - Narrative (D

DEBT OBLIGATIONS - Narrative (Details)				12 Months Ended
DEBT OBLIGATIONS - Narrative (Details)	Dec. 20, 2022 USD ($)	Dec. 13, 2022 USD ($)	Jun. 30, 2022 USD ($) property	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jan. 20, 2023 USD ($)	Nov. 23, 2022 USD ($)
Debt Instrument [Line Items]
Unsecured credit facility				$ 88,500,000	$ 23,000,000
Proceeds from unsecured notes				350,000,000	0	$ 0
Loss on early extinguishment of debt				435,000	0	$ 0
Line of Credit \| Unsecured Term Loan
Debt Instrument [Line Items]
Capitalized costs			$ 2,000,000
Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross				1,971,411,000	1,851,610,000
Unsecured Debt \| Unsecured Term Loan
Debt Instrument [Line Items]
Long-term debt, gross			$ 250,000,000	$ 250,000,000	250,000,000			$ 250,000,000
Basis spread on interest rate (as percent)				1.30%
Debt instrument, interest rate								5.01%
Unsecured Debt \| Unsecured Term Loan \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			1.20%
Unsecured Debt \| Unsecured Term Loan \| Minimum \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			0.80%
Unsecured Debt \| Unsecured Term Loan \| Minimum \| Base Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			0%
Unsecured Debt \| Unsecured Term Loan \| Maximum \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			1.60%
Unsecured Debt \| Unsecured Term Loan \| Maximum \| Base Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			0.60%
Unsecured Debt \| $600 million Unsecured Credit Facility
Debt Instrument [Line Items]
Long-term debt, gross				$ 88,500,000	23,000,000
Debt instrument, face amount				$ 600,000,000
Unsecured Debt \| $600 million Unsecured Credit Facility \| Daily SOFR Adjustment
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			0.10%	0.10%
Unsecured Debt \| Guaranteed Notes due 2028
Debt Instrument [Line Items]
Long-term debt, gross				$ 350,000,000	0
Debt instrument, face amount		$ 350,000,000		$ 350,000,000
Debt instrument, interest rate				7.55%
Percentage of face amount		99.06%
Unsecured term loan, net		$ 3,300,000
Proceeds from unsecured notes		$ 344,600,000
Unsecured Debt \| Guaranteed Notes due 2023
Debt Instrument [Line Items]
Long-term debt, gross	$ 295,700,000			$ 54,301,000	$ 350,000,000
Debt instrument, face amount				$ 350,000,000
Debt instrument, interest rate	3.95%			3.95%
Interest payable				$ 4,100,000
Loss on early extinguishment of debt	$ 400,000
Unsecured Debt \| Guaranteed Notes due 2023 \| Subsequent Event
Debt Instrument [Line Items]
Interest payable							$ 920,000
Redemption on remaining principal amount							$ 54,300,000
Letter of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 50,000,000
Financing costs - Unsecured Credit Facility
Debt Instrument [Line Items]
Unsecured credit facility				$ 88,500,000
Long-term debt, weighted average interest rate				3.04%	1.21%
Interest expense borrowings				$ 5,600,000	$ 400,000
Financing costs - Unsecured Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity			600,000,000
Capitalized costs			4,700,000
Line of credit facility, accordion feature			$ 500,000,000
Basis spread on interest rate (as percent)			0.25%
Financing costs - Unsecured Credit Facility \| Line of Credit \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			1.05%
Financing costs - Unsecured Credit Facility \| Line of Credit \| Minimum \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			0.725%
Financing costs - Unsecured Credit Facility \| Line of Credit \| Minimum \| Base Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			0%
Financing costs - Unsecured Credit Facility \| Line of Credit \| Maximum \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			1.40%
Financing costs - Unsecured Credit Facility \| Line of Credit \| Maximum \| Base Rate
Debt Instrument [Line Items]
Basis spread on interest rate (as percent)			0.40%
Financing costs - Unsecured Credit Facility \| Line of Credit \| 2022 Credit Facility
Debt Instrument [Line Items]
Debt instrument, number of extensions \| property			2
Debt instrument, extension term duration			6 months
Line of credit facility covenant minimum fixed charge coverage ratio			1.5
Line of credit facility covenant maximum leverage ratio			0.60
Line of credit facility covenant maximum unsecured indebtedness to unencumbered asset value ratio			0.60
Line of credit facility covenant maximum secured indebtedness to asset value ratio			0.40
Line of credit facility covenant minimum unencumbered cash flow to interest expense on unsecured debt ratio			1.75
Line of credit facility covenant maximum percent of payments of dividends and distributions			0.95

DEBT OBLIGATIONS - Aggregate Sc

DEBT OBLIGATIONS - Aggregate Scheduled Principal Payments of Debt Obligation, Excluding Amortization of Discounts and Premiums (Details) - Unsecured Debt - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
2023	$ 54,301
2024	350,000
2025	0
2026	88,500
2027	700,000
Thereafter	778,610
Total principal payments	1,971,411	$ 1,851,610
Net unamortized premiums/(discounts)	2,934	8,187
Net deferred financing costs	(9,307)	(6,211)
Debt, net	$ 1,965,038	$ 1,853,586

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note receivable, Carrying Amount	$ 0	$ 44,430
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note receivable, Fair Value	0	45,230
Unsecured notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred financing costs, net	9,307	6,211
Unsecured notes payable \| Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unsecured notes payable, Carrying Amount	1,549,760	1,502,368
Deferred financing costs, net	7,500	5,800
Unsecured notes payable \| Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, Fair Value	1,411,351	1,588,780
Variable rate debt \| Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Variable rate debt, Carrying Amount	415,278	351,218
Deferred financing costs, net	1,800	400
Variable rate debt \| Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, Fair Value	$ 386,988	$ 344,754

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 250,000	$ 250,000
3.729% Interest Rate Swap Maturing June 30, 2027 \| Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	$ 250,000	0
Strike	3.729%
Derivative asset, fair value, gross asset	$ 255	0
2.868% Interest Rate Swap Maturing October 8, 2022 \| Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	$ 0	250,000
Strike	2.868%
Derivative liability, fair value, gross liability	$ 0	$ (2,461)

LIMITED PARTNERS' NONCONTROLL_2

LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Noncontrolling Interest [Abstract]
Aggregate amount related to non-controlling interests classified within equity	$ 4.9	$ 8.2
Settlement value of non controlling interest in operating partnership	$ 3.2	$ 11.1

BENEFICIARIES' EQUITY OF THE _3

BENEFICIARIES' EQUITY OF THE PARENT COMPANY - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator
Net income	$ 53,992	$ 12,366	$ 307,326
Net income attributable to noncontrolling interests, Basic	(168)	(77)	(1,799)
Net income attributable to noncontrolling interests, Diluted	(168)	(77)	(1,799)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(456)	(421)	(410)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(456)	(421)	(410)
Net income attributable to Common Shareholders, Basic	53,368	11,868	305,117
Net income attributable to common shareholders, Diluted	$ 53,368	$ 11,868	$ 305,117
Denominator
Weighted average shares outstanding (in shares)	171,491,369	170,878,185	171,926,079
Contingent securities/Share based compensation (in shares)	834,277	1,395,055	390,997
Diluted weighted average shares outstanding (in shares)	172,325,646	172,273,240	172,317,076
Earnings per Common Share:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.31	$ 0.07	$ 1.77

BENEFICIARIES' EQUITY OF THE _4

BENEFICIARIES' EQUITY OF THE PARENT COMPANY - Narrative (Details) - USD ($)		12 Months Ended
	Dec. 06, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 03, 2019	Jan. 10, 2017
Class of Stock [Line Items]
Amount of dividend declared	$ 32,800,000
Preferred shares authorized (in shares)		20,000,000	20,000,000
Preferred shares outstanding (in shares)		0	0
Authorized amount		$ 0	$ 0			$ 150,000,000
Repurchased and retired (in shares)		0	0	6,248,483	1,337,169
Share price (in usd per share)				$ 9.60	$ 12.92
Repurchased and retired, value				$ 59,999,000	$ 17,300,000
Common stock, shares authorized (in shares)		400,000,000	400,000,000
Common shares remain available for issuance (in shares)		0
Offering Program
Class of Stock [Line Items]
Common stock, shares authorized (in shares)							16,000,000
Common shares issued under offering program (in shares)			0	0
Commerce Square
Class of Stock [Line Items]
Units issued to acquire noncontrolling interest (in shares)			226,695
Percent of noncontrolling interest acquired			1%
Dividend Declared
Class of Stock [Line Items]
Dividends declared, amount per share (in usd per share)	$ 0.19
Redeemable Common Limited Partnership Units
Class of Stock [Line Items]
Redeemable common limited partnership units (in shares)		516,467	823,983	981,634

PARTNERS' EQUITY OF THE PAREN_3

PARTNERS' EQUITY OF THE PARENT COMPANY - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator
Net income	$ 53,992	$ 12,366	$ 307,326
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(456)	(421)	(410)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	$ (456)	$ (421)	$ (410)
Denominator
Weighted average shares outstanding (in shares)	171,491,369	170,878,185	171,926,079
Contingent securities/Share based compensation (in shares)	834,277	1,395,055	390,997
Diluted weighted average shares outstanding (in shares)	172,325,646	172,273,240	172,317,076
Earnings per Common Partnership Unit:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Net income	$ 53,992	$ 12,366	$ 307,326
Net income attributable to noncontrolling interests	2	3	(20)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(456)	(421)	(410)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(456)	(421)	(410)
Net income attributable to common unitholders, Basic	53,538	11,948	306,896
Net income attributable to common unitholders, Diluted	$ 53,538	$ 11,948	$ 306,896
Denominator
Weighted average shares outstanding (in shares)	172,036,481	171,770,843	172,907,713
Contingent securities/Share based compensation (in shares)	834,277	1,395,055	390,997
Diluted weighted average shares outstanding (in shares)	172,870,758	173,165,898	173,298,710
Earnings per Common Partnership Unit:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.31	$ 0.07	$ 1.77
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.31	$ 0.07	$ 1.77

PARTNERS' EQUITY OF THE PAREN_4

PARTNERS' EQUITY OF THE PARENT COMPANY - Narrative (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Dec. 06, 2022 USD ($) $ / shares	Dec. 31, 2022 class_of_units $ / shares shares	Dec. 31, 2021 $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares
Earnings Per Common Partnership Unit [Line Items]
Number of classes of partnership units \| class_of_units		2
Amount of dividend declared \| $	$ 32,800
Repurchased and retired (in shares)		0	0	6,248,483	1,337,169
Share price (in usd per share) \| $ / shares				$ 9.60	$ 12.92
Repurchased and retired, value \| $				$ 59,999	$ 17,300
Common stock, par or stated value per share (in usd per share) \| $ / shares		$ 0.01	$ 0.01
Commerce Square
Earnings Per Common Partnership Unit [Line Items]
Percent of noncontrolling interest acquired			1%
Shelf Registration
Earnings Per Common Partnership Unit [Line Items]
Number of shares issued (in shares)			226,695
Dividend Declared
Earnings Per Common Partnership Unit [Line Items]
Dividends payable (in dollars per share) \| $ / shares	$ 0.19
Class A Units
Earnings Per Common Partnership Unit [Line Items]
Redeemable limited partnership unit price (in dollars per share) \| $ / shares		$ 6.15	$ 13.42	$ 11.91
Limited partners' capital account, units outstanding (in units)		516,467	823,983	981,634
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Earnings Per Common Partnership Unit [Line Items]
Preferred units, outstanding (in units)		0	0
Repurchase program, number of mirror unit of operating partnership retired for each common share repurchased		1

SHARE BASED COMPENSATION, 401_3

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION - Narrative (Details)			12 Months Ended
	Mar. 03, 2022 installment shares	Feb. 01, 2022 $ / shares shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, maximum annual contribution per employee, percent			100%
Defined contribution plan, employer discretionary contribution amount			$ 400,000	$ 400,000	$ 500,000
Number of vesting installments \| installment	3
Accelerated vesting period (in years)	1 year
Number of shares to be issued under deferred compensation plan included in total shares outstanding \| shares			1,200,000	1,200,000
Restricted Share Rights Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares) \| shares			553,894	474,978
Unrecognized compensation expenses			$ 1,900,000
Weighted average period over which options will be recognized			10 months 17 days
Share-based compensation expense			$ 4,500,000	$ 4,100,000	4,300,000
Share-based compensation expense, capitalized			$ 700,000	500,000	400,000
Granted (in shares) \| shares	258,427		306,555
Number of restricted share right will get settled for common share \| shares	1
Accumulated service period for voluntary termination (in years)	15 years
Restricted Share Rights Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			1 year
Restricted Share Rights Awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years		3 years
Restricted Performance Share Units Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)		3 years
Unrecognized compensation expenses			$ 7,500,000
Weighted average period over which options will be recognized			1 year 3 months 18 days
Share-based compensation expense			$ 6,200,000	4,300,000	3,000,000
Share-based compensation expense, capitalized			$ 1,100,000	$ 500,000	$ 400,000
Common shares issued for share based compensation \| shares		277,061
Dividends payable (in dollars per share) \| $ / shares		$ 0.19
Restricted Performance Share Units Plan \| Executive Officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares) \| shares			1,196,256	688,216
Granted (in shares) \| shares			516,852
Performance earning potential (as percent)			200%
Outperformance feature measurement term (in years)			3 years
Additional vesting period (in days)			366 days
Restricted Performance Share Units Plan \| Executive Officers \| 2022 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 100,000
Awards issuable under outperformance feature (in shares) \| shares			406,179
Restricted Performance Share Units Plan \| Executive Officers \| 2021 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 0
Awards issuable under outperformance feature (in shares) \| shares				388,840
Restricted Performance Share Units Plan \| Executive Officers \| 2020 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			0
Awards issuable under outperformance feature (in shares) \| shares					316,236
Restricted Performance Share Units Plan \| Non-Officer Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares) \| shares	48,128
Employee Share Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 20,000	$ 100,000	$ 100,000
Share-based compensation, percentage of closing price			85%
Maximum participant contribution, percentage of compensation			20%
Maximum participant contribution, dollar amount			$ 50,000
Aggregate share-based awards awarded to executives \| shares			1,250,000
Stock issued during period, value, employee stock purchase plan			$ 600,000	$ 600,000	$ 500,000
Share-based compensation arrangement by share-based payment award, discount from market price, purchase			15%

SHARE BASED COMPENSATION, 401_4

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION - Schedule of Company's Restricted Share Activity (Details) - Restricted Share Rights Awards - $ / shares		12 Months Ended
	Mar. 03, 2022	Dec. 31, 2022
Shares
Beginning balance (in shares)		474,978
Granted (in shares)	258,427	306,555
Vested (in shares)		(219,765)
Forfeited (in shares)		(7,874)
Ending balance (in shares)		553,894
Weighted Average Grant Date Fair Value
Non-vested, beginning balance (in dollars per share)		$ 13.51
Granted (in dollars per share)		13.30
Vested (in dollars per share)		13.94
Forfeited (in dollars per share)		13.45
Non-vested, ending balance (in dollars per share)		$ 13.22

SHARE BASED COMPENSATION, 401_5

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION - Schedule of Restricted Performance Share Units Plan (Details) - Executive Officers - Restricted Performance Share Units Plan - USD ($) $ in Thousands				12 Months Ended
	Mar. 03, 2022	Mar. 05, 2021	Mar. 05, 2020	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				688,216
Granted (in shares)				516,852
Units Cancelled (in shares)				(8,812)
Ending balance (in shares)				1,196,256
3/5/2020 RSPU Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				314,055
Granted (in shares)				0
Units Cancelled (in shares)				(2,076)
Ending balance (in shares)				311,979
Granted (in shares)			319,600
Fair Value of Units on Grant Date			$ 5,389
3/5/2021 RSPU Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				374,161
Granted (in shares)				0
Units Cancelled (in shares)				(2,922)
Ending balance (in shares)				371,239
Granted (in shares)		380,957
Fair Value of Units on Grant Date		$ 6,389
3/3/2022 RSPU Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				0
Granted (in shares)				516,852
Units Cancelled (in shares)				(3,814)
Ending balance (in shares)				513,038
Granted (in shares)	516,852
Fair Value of Units on Grant Date	$ 6,872

DISTRIBUTIONS (Details)

DISTRIBUTIONS (Details) - $ / shares	12 Months Ended
DISTRIBUTIONS (Details) - $ / shares	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Common Share Distributions:
Ordinary income (in usd per share)	$ 0.47	$ 0.64	$ 0.41
Capital gain (in usd per share)	0.29	0.01	0.35
Non-taxable distributions (in usd per share)	0	0.11	0
Distributions per share (in usd per share)	$ 0.76	$ 0.76	$ 0.76
Percentage classified as ordinary income	62.10%	83.90%	53.90%
Percentage classified as capital gain	37.90%	1.20%	46.10%
Percentage classified as non-taxable distribution	0%	14.90%	0%

INCOME TAXES AND TAX CREDIT T_2

INCOME TAXES AND TAX CREDIT TRANSACTIONS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Examination [Line Items]
Accruals for tax uncertainties	$ 0	$ 0
Deferred income tax expense	0	0	$ 0
Current income tax expense (benefit)	0	0	$ (200,000)
Other Assets
Income Tax Examination [Line Items]
Deferred tax assets	$ 0	$ 0

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Parent Company
Beneficiaries' Equity, beginning balance		$ 1,701,219	$ 1,804,648	$ 1,688,303
Change in fair market value during year		5,371	4,817	(5,972)
Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests		(18)	(28)	29
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	564	752	752
Beneficiaries' Equity, ending balance		1,633,334	1,701,219	1,804,648
Operating Partnership
Change in fair market value during year		5,371	4,817	(5,972)
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	564	752	752
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Parent Company
Change in fair market value during year		5,371	4,817	(5,972)
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	564	752	752
Operating Partnership
Partners' Equity, beginning balance		1,690,079	1,793,082	1,672,915
Change in fair market value during year		5,371	4,817	(5,972)
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	564	752	752
Partners' Equity, ending balance		1,630,139	1,690,079	1,793,082
Accumulated Other Comprehensive Income (Loss)
Parent Company
Beneficiaries' Equity, beginning balance		(2,020)	(7,561)	(2,370)
Beneficiaries' Equity, ending balance		3,897	(2,020)	(7,561)
Accumulated Other Comprehensive Income (Loss) \| BRANDYWINE OPERATING PARTNERSHIP, L.P.
Operating Partnership
Partners' Equity, beginning balance		(2,366)	(7,935)	(2,715)
Partners' Equity, ending balance		$ 3,569	$ (2,366)	$ (7,935)

[1]Amounts reclassified from comprehensive income to interest expense within the Consolidated Statements of Operations.

SEGMENT INFORMATION - Narrative

SEGMENT INFORMATION - Narrative (Details)	12 Months Ended
SEGMENT INFORMATION - Narrative (Details)	Dec. 31, 2022 segment
Segment Reporting [Abstract]
Number of reportable segments	5

SEGMENT INFORMATION - Real Esta

SEGMENT INFORMATION - Real Estate Investments, at Cost of Company's Reportable Segments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating properties	$ 3,617,240	$ 3,472,602	$ 3,474,109
Right of use asset - operating leases, net	19,664	20,313
Construction-in-progress	218,869	277,237
Land held for development	76,499	114,604
Prepaid leasehold interests in land held for development, net	35,576	27,762
Philadelphia CBD
Segment Reporting Information [Line Items]
Operating properties	1,517,801	1,460,510
Pennsylvania Suburbs
Segment Reporting Information [Line Items]
Operating properties	878,546	866,223
Austin, Texas
Segment Reporting Information [Line Items]
Operating properties	851,835	778,145
Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Operating properties	282,458	280,921
Other
Segment Reporting Information [Line Items]
Operating properties	$ 86,600	$ 86,803

SEGMENT INFORMATION - Net Opera

SEGMENT INFORMATION - Net Operating Income of Company's Reportable Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total revenue	$ 506,100	$ 486,819	$ 534,852
Operating expenses	(194,401)	(188,311)	(205,456)
Net operating income	311,699	298,508	329,396
Philadelphia CBD
Segment Reporting Information [Line Items]
Total revenue	220,875	207,858	232,028
Pennsylvania Suburbs
Segment Reporting Information [Line Items]
Total revenue	128,940	124,566	141,613
Austin, Texas
Segment Reporting Information [Line Items]
Total revenue	96,329	101,680	102,982
Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Total revenue	21,899	19,865	40,223
Operating Segments \| Philadelphia CBD
Segment Reporting Information [Line Items]
Total revenue	220,876	207,858	232,028
Operating expenses	(79,827)	(73,695)	(82,505)
Net operating income	141,049	134,163	149,523
Operating Segments \| Pennsylvania Suburbs
Segment Reporting Information [Line Items]
Total revenue	128,940	124,566	141,613
Operating expenses	(41,814)	(40,011)	(46,281)
Net operating income	87,126	84,555	95,332
Operating Segments \| Austin, Texas
Segment Reporting Information [Line Items]
Total revenue	96,328	101,680	102,982
Operating expenses	(41,141)	(39,374)	(39,759)
Net operating income	55,187	62,306	63,223
Operating Segments \| Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Total revenue	21,900	19,865	40,223
Operating expenses	(12,539)	(15,386)	(20,791)
Net operating income	9,361	4,479	19,432
Operating Segments \| Other
Segment Reporting Information [Line Items]
Total revenue	14,710	14,015	13,469
Operating expenses	(8,626)	(9,840)	(9,815)
Net operating income	6,084	4,175	3,654
Corporate
Segment Reporting Information [Line Items]
Total revenue	23,346	18,835	4,537
Operating expenses	(10,454)	(10,005)	(6,305)
Net operating income	$ 12,892	$ 8,830	$ (1,768)

SEGMENT INFORMATION - Unconsoli

SEGMENT INFORMATION - Unconsolidated Real Estate Ventures of Company's Reportable Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Investment in real estate ventures, at equity	$ 532,224	$ 411,110
Equity in income (loss) of real estate venture	(22,016)	(26,697)	$ (18,584)
Philadelphia CBD
Segment Reporting Information [Line Items]
Investment in real estate ventures, at equity	387,301	317,959
Equity in income (loss) of real estate venture	(11,764)	(15,191)	(9,090)
Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Investment in real estate ventures, at equity	83,903	85,867
Equity in income (loss) of real estate venture	(2,324)	(3,755)	(3,019)
Mid-Atlantic Office Venture
Segment Reporting Information [Line Items]
Investment in real estate ventures, at equity	31,005	31,680
Equity in income (loss) of real estate venture	412	932	96
MAP Venture
Segment Reporting Information [Line Items]
Investment in real estate ventures, at equity	(35,411)	(24,396)
Equity in income (loss) of real estate venture	(8,340)	(8,683)	(6,571)
Austin, Texas
Segment Reporting Information [Line Items]
Investment in real estate ventures, at equity	65,426	0
Equity in income (loss) of real estate venture	$ 0	$ 0	$ 0

SEGMENT INFORMATION - Schedule

SEGMENT INFORMATION - Schedule of Reconciliation of Consolidated Net Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting [Abstract]
Net income	$ 53,992	$ 12,366	$ 307,326
Plus:
Interest expense	68,764	62,617	73,911
Interest expense - amortization of deferred financing costs	3,091	2,836	2,904
Depreciation and amortization	177,984	178,105	188,283
General and administrative expenses	35,006	30,153	30,288
Equity in loss of unconsolidated real estate ventures	22,016	26,697	18,584
Provision for impairment	4,663	0	0
Loss on early extinguishment of debt	435	0	0
Less:
Interest and investment income	1,905	8,295	1,939
Income tax (provision) benefit	(55)	(47)	224
Net gain on disposition of real estate	17,677	142	289,461
Net gain on sale of undepreciated real estate	8,007	2,903	201
Net gain on real estate venture transactions	26,718	2,973	75
Consolidated net operating income	$ 311,699	$ 298,508	$ 329,396

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands		1 Months Ended	12 Months Ended
COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	Oct. 21, 2020 USD ($)	Feb. 28, 2021 property	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jul. 23, 2021 USD ($)	Sep. 30, 2004 ft²
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness			$ 1,204,779	$ 961,509
Limited payment guarantee, percent of principle balance (up to)					25%
Commerce Square \| Preferred Equity Investment Obligation
Property Subject to or Available for Operating Lease [Line Items]
Other commitments			20,000
Amount committed to date			7,200
Schuylkill Yards Project
Property Subject to or Available for Operating Lease [Line Items]
Other commitments			6,600
Estimated potential additional contribution obligation			2,200
Natural Disasters and Other Casualty Events
Property Subject to or Available for Operating Lease [Line Items]
Number of properties damaged \| property		1
Write-off of fixed assets				1,200
Restoration liability			800	7,200
Business interruption costs				3,900
Insurance proceeds			2,800	15,300
Natural Disasters and Other Casualty Events \| Other Income
Property Subject to or Available for Operating Lease [Line Items]
Insurance proceeds				3,000
Natural Disasters and Other Casualty Events \| Accounts Payable and Accrued Liabilities
Property Subject to or Available for Operating Lease [Line Items]
Restoration liability				$ 1,900
3025 JFK Venture
Property Subject to or Available for Operating Lease [Line Items]
Construction loan amount			186,700		$ 186,700
Unconsolidated Real Estate Ventures
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness			1,204,800
Two Logan Square
Property Subject to or Available for Operating Lease [Line Items]
Rentable square feet \| ft²						708,844
Settlement liabilities			$ 600
Two Logan Square \| Secured Debt
Property Subject to or Available for Operating Lease [Line Items]
Repayments of long-term debt	$ 79,800

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details)			12 Months Ended
SUBSEQUENT EVENTS (Details)	Jan. 20, 2023 USD ($)	Jan. 19, 2023 USD ($) property subsidiary	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 20, 2022
Subsequent Event [Line Items]
Repayments of unsecured notes			$ 296,134,000	$ 0	$ 0
Secured Facility \| Subsequent Event \| Secured Debt
Subsequent Event [Line Items]
Number of wholly owned subsidiaries participating in a loan agreement \| subsidiary		7
Number of operating properties \| property		7
Debt instrument, face amount		$ 245,000,000
Debt instrument, interest rate		5.875%
Guaranteed Notes due 2023 \| Unsecured Debt
Subsequent Event [Line Items]
Debt instrument, face amount			$ 350,000,000
Debt instrument, interest rate			3.95%			3.95%
Interest payable			$ 4,100,000
Guaranteed Notes due 2023 \| Subsequent Event \| Unsecured Debt
Subsequent Event [Line Items]
Repayments of unsecured notes	$ 55,200,000
Redemption of principal amount	54,300,000
Interest payable	$ 920,000

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Allowance for doubtful accounts:
Balance at Beginning of Year	$ 4,133	$ 5,086	$ 7,975
Additions	0	0	0
Deductions	186	953	2,889
Balance at End of Year	$ 3,947	$ 4,133	$ 5,086

Schedule III - Real Estate an_2

Schedule III - Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Initial Cost
Land	$ 359,777
Buildings and Improvements	2,527,685
Net Improvements (Retirements) Since Acquisition	729,778
Gross Amount Which Carried
Land	403,998
Buildings and Improvements	3,213,242
Total	3,617,240	$ 3,472,602	$ 3,474,109	$ 4,006,459
Accumulated Depreciation at December 31, 2022	1,063,060	$ 957,450	$ 896,561	$ 973,318
PENNSYLVANIA SUBURBS \| Six Tower Bridge (181 Washington Street)
Initial Cost
Land	6,927
Buildings and Improvements	14,722
Net Improvements (Retirements) Since Acquisition	1,176
Gross Amount Which Carried
Land	6,237
Buildings and Improvements	16,588
Total	22,825
Accumulated Depreciation at December 31, 2022	4,604
PENNSYLVANIA SUBURBS \| 426 West Lancaster Avenue
Initial Cost
Land	1,689
Buildings and Improvements	6,756
Net Improvements (Retirements) Since Acquisition	9,405
Gross Amount Which Carried
Land	1,686
Buildings and Improvements	16,164
Total	17,850
Accumulated Depreciation at December 31, 2022	2,727
PENNSYLVANIA SUBURBS \| 640 Freedom Business Center
Initial Cost
Land	1,015
Buildings and Improvements	20,098
Net Improvements (Retirements) Since Acquisition	4,603
Gross Amount Which Carried
Land	332
Buildings and Improvements	25,384
Total	25,716
Accumulated Depreciation at December 31, 2022	16,544
PENNSYLVANIA SUBURBS \| 620 Freedom Business Center
Initial Cost
Land	666
Buildings and Improvements	13,118
Net Improvements (Retirements) Since Acquisition	2,372
Gross Amount Which Carried
Land	217
Buildings and Improvements	15,939
Total	16,156
Accumulated Depreciation at December 31, 2022	10,154
PENNSYLVANIA SUBURBS \| 1000 First Avenue
Initial Cost
Land	0
Buildings and Improvements	13,708
Net Improvements (Retirements) Since Acquisition	2,971
Gross Amount Which Carried
Land	0
Buildings and Improvements	16,679
Total	16,679
Accumulated Depreciation at December 31, 2022	12,521
PENNSYLVANIA SUBURBS \| 1060 First Avenue
Initial Cost
Land	0
Buildings and Improvements	13,665
Net Improvements (Retirements) Since Acquisition	3,979
Gross Amount Which Carried
Land	0
Buildings and Improvements	17,644
Total	17,644
Accumulated Depreciation at December 31, 2022	12,989
PENNSYLVANIA SUBURBS \| 630 Freedom Business Center Drive
Initial Cost
Land	666
Buildings and Improvements	13,251
Net Improvements (Retirements) Since Acquisition	2,864
Gross Amount Which Carried
Land	219
Buildings and Improvements	16,562
Total	16,781
Accumulated Depreciation at December 31, 2022	10,946
PENNSYLVANIA SUBURBS \| 1020 First Avenue
Initial Cost
Land	0
Buildings and Improvements	10,744
Net Improvements (Retirements) Since Acquisition	4,306
Gross Amount Which Carried
Land	0
Buildings and Improvements	15,050
Total	15,050
Accumulated Depreciation at December 31, 2022	11,050
PENNSYLVANIA SUBURBS \| 1040 First Avenue
Initial Cost
Land	0
Buildings and Improvements	14,142
Net Improvements (Retirements) Since Acquisition	4,915
Gross Amount Which Carried
Land	0
Buildings and Improvements	19,057
Total	19,057
Accumulated Depreciation at December 31, 2022	14,165
PENNSYLVANIA SUBURBS \| 610 Freedom Business Center Drive
Initial Cost
Land	485
Buildings and Improvements	9,602
Net Improvements (Retirements) Since Acquisition	2,289
Gross Amount Which Carried
Land	159
Buildings and Improvements	12,217
Total	12,376
Accumulated Depreciation at December 31, 2022	8,256
PENNSYLVANIA SUBURBS \| 650 Park Avenue
Initial Cost
Land	1,916
Buildings and Improvements	4,378
Net Improvements (Retirements) Since Acquisition	(4,378)
Gross Amount Which Carried
Land	1,916
Buildings and Improvements	0
Total	1,916
Accumulated Depreciation at December 31, 2022	0
PENNSYLVANIA SUBURBS \| 600 Park Avenue
Initial Cost
Land	1,012
Buildings and Improvements	4,048
Net Improvements (Retirements) Since Acquisition	50
Gross Amount Which Carried
Land	1,012
Buildings and Improvements	4,098
Total	5,110
Accumulated Depreciation at December 31, 2022	2,660
PENNSYLVANIA SUBURBS \| 933 First Avenue
Initial Cost
Land	3,127
Buildings and Improvements	20,794
Net Improvements (Retirements) Since Acquisition	(1,125)
Gross Amount Which Carried
Land	3,127
Buildings and Improvements	19,669
Total	22,796
Accumulated Depreciation at December 31, 2022	4,823
PENNSYLVANIA SUBURBS \| 500 North Gulph Road
Initial Cost
Land	1,303
Buildings and Improvements	5,201
Net Improvements (Retirements) Since Acquisition	21,471
Gross Amount Which Carried
Land	1,303
Buildings and Improvements	26,672
Total	27,975
Accumulated Depreciation at December 31, 2022	4,690
PENNSYLVANIA SUBURBS \| 401 Plymouth Road
Initial Cost
Land	6,199
Buildings and Improvements	16,131
Net Improvements (Retirements) Since Acquisition	14,515
Gross Amount Which Carried
Land	6,199
Buildings and Improvements	30,646
Total	36,845
Accumulated Depreciation at December 31, 2022	15,527
PENNSYLVANIA SUBURBS \| Metroplex (4000 Chemical Road)
Initial Cost
Land	4,373
Buildings and Improvements	24,546
Net Improvements (Retirements) Since Acquisition	5,554
Gross Amount Which Carried
Land	4,373
Buildings and Improvements	30,100
Total	34,473
Accumulated Depreciation at December 31, 2022	9,860
PENNSYLVANIA SUBURBS \| 610 West Germantown Pike
Initial Cost
Land	3,651
Buildings and Improvements	14,514
Net Improvements (Retirements) Since Acquisition	5,461
Gross Amount Which Carried
Land	3,651
Buildings and Improvements	19,975
Total	23,626
Accumulated Depreciation at December 31, 2022	10,440
PENNSYLVANIA SUBURBS \| 600 West Germantown Pike
Initial Cost
Land	3,652
Buildings and Improvements	15,288
Net Improvements (Retirements) Since Acquisition	4,035
Gross Amount Which Carried
Land	3,652
Buildings and Improvements	19,323
Total	22,975
Accumulated Depreciation at December 31, 2022	9,682
PENNSYLVANIA SUBURBS \| 630 West Germantown Pike
Initial Cost
Land	3,558
Buildings and Improvements	14,743
Net Improvements (Retirements) Since Acquisition	3,169
Gross Amount Which Carried
Land	3,558
Buildings and Improvements	17,912
Total	21,470
Accumulated Depreciation at December 31, 2022	9,015
PENNSYLVANIA SUBURBS \| 620 West Germantown Pike
Initial Cost
Land	3,572
Buildings and Improvements	14,435
Net Improvements (Retirements) Since Acquisition	4,131
Gross Amount Which Carried
Land	3,572
Buildings and Improvements	18,566
Total	22,138
Accumulated Depreciation at December 31, 2022	8,409
PENNSYLVANIA SUBURBS \| 660 West Germantown Pike
Initial Cost
Land	3,694
Buildings and Improvements	5,487
Net Improvements (Retirements) Since Acquisition	19,502
Gross Amount Which Carried
Land	5,405
Buildings and Improvements	23,278
Total	28,683
Accumulated Depreciation at December 31, 2022	8,467
PENNSYLVANIA SUBURBS \| 351 Plymouth Road
Initial Cost
Land	1,043
Buildings and Improvements	555
Net Improvements (Retirements) Since Acquisition	0
Gross Amount Which Carried
Land	1,043
Buildings and Improvements	555
Total	1,598
Accumulated Depreciation at December 31, 2022	246
PENNSYLVANIA SUBURBS \| 150 Radnor Chester Road
Initial Cost
Land	11,925
Buildings and Improvements	36,986
Net Improvements (Retirements) Since Acquisition	21,691
Gross Amount Which Carried
Land	11,897
Buildings and Improvements	58,705
Total	70,602
Accumulated Depreciation at December 31, 2022	26,556
PENNSYLVANIA SUBURBS \| One Radnor Corporate Center
Initial Cost
Land	7,323
Buildings and Improvements	28,613
Net Improvements (Retirements) Since Acquisition	14,397
Gross Amount Which Carried
Land	7,323
Buildings and Improvements	43,010
Total	50,333
Accumulated Depreciation at December 31, 2022	27,920
PENNSYLVANIA SUBURBS \| 201 King of Prussia Road
Initial Cost
Land	8,956
Buildings and Improvements	29,811
Net Improvements (Retirements) Since Acquisition	4,196
Gross Amount Which Carried
Land	8,949
Buildings and Improvements	34,014
Total	42,963
Accumulated Depreciation at December 31, 2022	22,515
PENNSYLVANIA SUBURBS \| 555 Lancaster Avenue
Initial Cost
Land	8,014
Buildings and Improvements	16,508
Net Improvements (Retirements) Since Acquisition	10,772
Gross Amount Which Carried
Land	8,609
Buildings and Improvements	26,685
Total	35,294
Accumulated Depreciation at December 31, 2022	9,722
PENNSYLVANIA SUBURBS \| Four Radnor Corporate Center
Initial Cost
Land	5,406
Buildings and Improvements	21,390
Net Improvements (Retirements) Since Acquisition	10,499
Gross Amount Which Carried
Land	5,705
Buildings and Improvements	31,590
Total	37,295
Accumulated Depreciation at December 31, 2022	18,534
PENNSYLVANIA SUBURBS \| Five Radnor Corporate Center
Initial Cost
Land	6,506
Buildings and Improvements	25,525
Net Improvements (Retirements) Since Acquisition	9,755
Gross Amount Which Carried
Land	6,578
Buildings and Improvements	35,208
Total	41,786
Accumulated Depreciation at December 31, 2022	16,306
PENNSYLVANIA SUBURBS \| Three Radnor Corporate Center
Initial Cost
Land	4,773
Buildings and Improvements	17,961
Net Improvements (Retirements) Since Acquisition	1,788
Gross Amount Which Carried
Land	4,791
Buildings and Improvements	19,731
Total	24,522
Accumulated Depreciation at December 31, 2022	11,768
PENNSYLVANIA SUBURBS \| Two Radnor Corporate Center
Initial Cost
Land	3,937
Buildings and Improvements	15,484
Net Improvements (Retirements) Since Acquisition	2,552
Gross Amount Which Carried
Land	3,942
Buildings and Improvements	18,031
Total	21,973
Accumulated Depreciation at December 31, 2022	11,383
PENNSYLVANIA SUBURBS \| 130 Radnor Chester Road
Initial Cost
Land	2,573
Buildings and Improvements	8,338
Net Improvements (Retirements) Since Acquisition	(258)
Gross Amount Which Carried
Land	2,567
Buildings and Improvements	8,086
Total	10,653
Accumulated Depreciation at December 31, 2022	4,099
PENNSYLVANIA SUBURBS \| 170 Radnor Chester Road
Initial Cost
Land	2,514
Buildings and Improvements	8,147
Net Improvements (Retirements) Since Acquisition	2,008
Gross Amount Which Carried
Land	2,509
Buildings and Improvements	10,160
Total	12,669
Accumulated Depreciation at December 31, 2022	5,366
PENNSYLVANIA SUBURBS \| 200 Radnor Chester Road
Initial Cost
Land	3,366
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	3,740
Gross Amount Which Carried
Land	3,366
Buildings and Improvements	3,740
Total	7,106
Accumulated Depreciation at December 31, 2022	1,137
PENNSYLVANIA SUBURBS \| 101 West Elm Street
Initial Cost
Land	6,251
Buildings and Improvements	25,209
Net Improvements (Retirements) Since Acquisition	2,846
Gross Amount Which Carried
Land	6,251
Buildings and Improvements	28,055
Total	34,306
Accumulated Depreciation at December 31, 2022	12,533
PENNSYLVANIA SUBURBS \| 1 West Elm Street
Initial Cost
Land	3,557
Buildings and Improvements	14,249
Net Improvements (Retirements) Since Acquisition	8,203
Gross Amount Which Carried
Land	3,557
Buildings and Improvements	22,452
Total	26,009
Accumulated Depreciation at December 31, 2022	7,302
PENNSYLVANIA SUBURBS \| 250 King of Prussia Road
Initial Cost
Land	0
Buildings and Improvements	20,566
Net Improvements (Retirements) Since Acquisition	12,733
Gross Amount Which Carried
Land	976
Buildings and Improvements	32,323
Total	33,299
Accumulated Depreciation at December 31, 2022	626
PHILADELPHIA CBD \| Cira Centre (2929 Arch Street)
Initial Cost
Land	0
Buildings and Improvements	208,570
Net Improvements (Retirements) Since Acquisition	23,843
Gross Amount Which Carried
Land	12,586
Buildings and Improvements	219,827
Total	232,413
Accumulated Depreciation at December 31, 2022	73,510
PHILADELPHIA CBD \| Three Logan Square (1717 Arch Street)
Initial Cost
Land	0
Buildings and Improvements	98,188
Net Improvements (Retirements) Since Acquisition	86,126
Gross Amount Which Carried
Land	25,195
Buildings and Improvements	159,119
Total	184,314
Accumulated Depreciation at December 31, 2022	61,247
PHILADELPHIA CBD \| One Logan Square (130 North 18th Street)
Initial Cost
Land	14,496
Buildings and Improvements	107,736
Net Improvements (Retirements) Since Acquisition	21,614
Gross Amount Which Carried
Land	14,473
Buildings and Improvements	129,373
Total	143,846
Accumulated Depreciation at December 31, 2022	70,363
PHILADELPHIA CBD \| Two Logan Square (100 North 18th Street)
Initial Cost
Land	16,066
Buildings and Improvements	100,255
Net Improvements (Retirements) Since Acquisition	34,198
Gross Amount Which Carried
Land	16,066
Buildings and Improvements	134,453
Total	150,519
Accumulated Depreciation at December 31, 2022	61,597
PHILADELPHIA CBD \| Cira Centre South Garage (129 South 30th Street)
Initial Cost
Land	0
Buildings and Improvements	76,008
Net Improvements (Retirements) Since Acquisition	26,970
Gross Amount Which Carried
Land	6,638
Buildings and Improvements	96,340
Total	102,978
Accumulated Depreciation at December 31, 2022	27,789
PHILADELPHIA CBD \| 1900 Market Street
Initial Cost
Land	7,768
Buildings and Improvements	17,263
Net Improvements (Retirements) Since Acquisition	61,760
Gross Amount Which Carried
Land	7,768
Buildings and Improvements	79,023
Total	86,791
Accumulated Depreciation at December 31, 2022	30,016
PHILADELPHIA CBD \| 3020 Market Street
Initial Cost
Land	0
Buildings and Improvements	21,417
Net Improvements (Retirements) Since Acquisition	7,442
Gross Amount Which Carried
Land	0
Buildings and Improvements	28,859
Total	28,859
Accumulated Depreciation at December 31, 2022	13,904
PHILADELPHIA CBD \| 618-634 Market Street
Initial Cost
Land	13,365
Buildings and Improvements	5,791
Net Improvements (Retirements) Since Acquisition	5,180
Gross Amount Which Carried
Land	13,365
Buildings and Improvements	10,971
Total	24,336
Accumulated Depreciation at December 31, 2022	7,222
PHILADELPHIA CBD \| FMC Tower at Cira Centre South (2929 Walnut Street)
Initial Cost
Land	0
Buildings and Improvements	400,294
Net Improvements (Retirements) Since Acquisition	10,689
Gross Amount Which Carried
Land	0
Buildings and Improvements	410,983
Total	410,983
Accumulated Depreciation at December 31, 2022	85,826
PHILADELPHIA CBD \| 2100 Market Street
Initial Cost
Land	18,827
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	6,292
Gross Amount Which Carried
Land	18,854
Buildings and Improvements	6,265
Total	25,119
Accumulated Depreciation at December 31, 2022	2,280
PHILADELPHIA CBD \| 1505-11 Race Street
Initial Cost
Land	3,662
Buildings and Improvements	6,061
Net Improvements (Retirements) Since Acquisition	8
Gross Amount Which Carried
Land	3,670
Buildings and Improvements	6,061
Total	9,731
Accumulated Depreciation at December 31, 2022	328
PHILADELPHIA CBD \| 3000 Market Street
Initial Cost
Land	18,924
Buildings and Improvements	13,080
Net Improvements (Retirements) Since Acquisition	17,349
Gross Amount Which Carried
Land	18,924
Buildings and Improvements	30,429
Total	49,353
Accumulated Depreciation at December 31, 2022	2,608
PHILADELPHIA CBD \| The Bulletin Building (3025 Market Street)
Initial Cost
Land	0
Buildings and Improvements	24,377
Net Improvements (Retirements) Since Acquisition	44,081
Gross Amount Which Carried
Land	0
Buildings and Improvements	68,458
Total	68,458
Accumulated Depreciation at December 31, 2022	11,490
PHILADELPHIA CBD \| 3001-3003 JFK Boulevard
Initial Cost
Land	0
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	111
Gross Amount Which Carried
Land	0
Buildings and Improvements	111
Total	111
Accumulated Depreciation at December 31, 2022	32
METROPOLITAN WASHINGTON, D.C. \| 6600 Rockledge Drive
Initial Cost
Land	0
Buildings and Improvements	37,421
Net Improvements (Retirements) Since Acquisition	7,672
Gross Amount Which Carried
Land	0
Buildings and Improvements	45,093
Total	45,093
Accumulated Depreciation at December 31, 2022	17,099
METROPOLITAN WASHINGTON, D.C. \| 1676 International Drive
Initial Cost
Land	18,437
Buildings and Improvements	97,538
Net Improvements (Retirements) Since Acquisition	37,113
Gross Amount Which Carried
Land	18,785
Buildings and Improvements	134,303
Total	153,088
Accumulated Depreciation at December 31, 2022	35,718
METROPOLITAN WASHINGTON, D.C. \| 8260 Greensboro Drive
Initial Cost
Land	7,952
Buildings and Improvements	33,964
Net Improvements (Retirements) Since Acquisition	8,645
Gross Amount Which Carried
Land	8,102
Buildings and Improvements	42,459
Total	50,561
Accumulated Depreciation at December 31, 2022	14,217
METROPOLITAN WASHINGTON, D.C. \| 8521 Leesburg Pike
Initial Cost
Land	4,316
Buildings and Improvements	30,885
Net Improvements (Retirements) Since Acquisition	(1,511)
Gross Amount Which Carried
Land	3,587
Buildings and Improvements	30,103
Total	33,690
Accumulated Depreciation at December 31, 2022	12,032
METROPOLITAN WASHINGTON, D.C. \| Dabney Westwood
Initial Cost
Land	1,732
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	3,690
Gross Amount Which Carried
Land	819
Buildings and Improvements	4,603
Total	5,422
Accumulated Depreciation at December 31, 2022	185
AUSTIN, TX \| 401-405 Colorado Street
Initial Cost
Land	0
Buildings and Improvements	100,448
Net Improvements (Retirements) Since Acquisition	564
Gross Amount Which Carried
Land	0
Buildings and Improvements	101,012
Total	101,012
Accumulated Depreciation at December 31, 2022	2,728
AUSTIN, TX \| 11501 Burnet Road - Building 1
Initial Cost
Land	3,755
Buildings and Improvements	22,702
Net Improvements (Retirements) Since Acquisition	4
Gross Amount Which Carried
Land	3,755
Buildings and Improvements	22,706
Total	26,461
Accumulated Depreciation at December 31, 2022	8,876
AUSTIN, TX \| 11501 Burnet Road - Building 2
Initial Cost
Land	2,732
Buildings and Improvements	16,305
Net Improvements (Retirements) Since Acquisition	1,473
Gross Amount Which Carried
Land	2,732
Buildings and Improvements	17,778
Total	20,510
Accumulated Depreciation at December 31, 2022	7,422
AUSTIN, TX \| 11501 Burnet Road - Building 3
Initial Cost
Land	3,688
Buildings and Improvements	22,348
Net Improvements (Retirements) Since Acquisition	6,421
Gross Amount Which Carried
Land	3,688
Buildings and Improvements	28,769
Total	32,457
Accumulated Depreciation at December 31, 2022	9,372
AUSTIN, TX \| 11501 Burnet Road - Building 4
Initial Cost
Land	2,614
Buildings and Improvements	15,740
Net Improvements (Retirements) Since Acquisition	3
Gross Amount Which Carried
Land	2,614
Buildings and Improvements	15,743
Total	18,357
Accumulated Depreciation at December 31, 2022	6,153
AUSTIN, TX \| 11501 Burnet Road - Building 5
Initial Cost
Land	3,689
Buildings and Improvements	22,354
Net Improvements (Retirements) Since Acquisition	4
Gross Amount Which Carried
Land	3,689
Buildings and Improvements	22,358
Total	26,047
Accumulated Depreciation at December 31, 2022	8,740
AUSTIN, TX \| 11501 Burnet Road - Building 6
Initial Cost
Land	2,676
Buildings and Improvements	15,972
Net Improvements (Retirements) Since Acquisition	13,855
Gross Amount Which Carried
Land	2,676
Buildings and Improvements	29,827
Total	32,503
Accumulated Depreciation at December 31, 2022	12,555
AUSTIN, TX \| 11501 Burnet Road - Building 8
Initial Cost
Land	1,400
Buildings and Improvements	7,422
Net Improvements (Retirements) Since Acquisition	1,776
Gross Amount Which Carried
Land	1,400
Buildings and Improvements	9,198
Total	10,598
Accumulated Depreciation at December 31, 2022	3,594
AUSTIN, TX \| 11501 Burnet Road - Parking Garage
Initial Cost
Land	0
Buildings and Improvements	19,826
Net Improvements (Retirements) Since Acquisition	1,538
Gross Amount Which Carried
Land	0
Buildings and Improvements	21,364
Total	21,364
Accumulated Depreciation at December 31, 2022	8,740
AUSTIN, TX \| Four Points Centre 3, 11120 Four Points Drive
Initial Cost
Land	1,140
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	40,322
Gross Amount Which Carried
Land	1,141
Buildings and Improvements	40,321
Total	41,462
Accumulated Depreciation at December 31, 2022	6,849
AUSTIN, TX \| One Barton Skyway (1501 South MoPac Expressway)
Initial Cost
Land	10,496
Buildings and Improvements	47,670
Net Improvements (Retirements) Since Acquisition	7,970
Gross Amount Which Carried
Land	10,495
Buildings and Improvements	55,641
Total	66,136
Accumulated Depreciation at December 31, 2022	6,565
AUSTIN, TX \| Two Barton Skyway (1601 South MoPac Expressway)
Initial Cost
Land	10,849
Buildings and Improvements	53,868
Net Improvements (Retirements) Since Acquisition	3,889
Gross Amount Which Carried
Land	10,848
Buildings and Improvements	57,758
Total	68,606
Accumulated Depreciation at December 31, 2022	7,271
AUSTIN, TX \| Three Barton Skyway (1221 South MoPac Expressway)
Initial Cost
Land	10,374
Buildings and Improvements	47,624
Net Improvements (Retirements) Since Acquisition	1,027
Gross Amount Which Carried
Land	10,373
Buildings and Improvements	48,652
Total	59,025
Accumulated Depreciation at December 31, 2022	5,158
AUSTIN, TX \| Four Barton Skyway (1301 South MoPac Expressway)
Initial Cost
Land	13,301
Buildings and Improvements	57,041
Net Improvements (Retirements) Since Acquisition	7,611
Gross Amount Which Carried
Land	13,300
Buildings and Improvements	64,653
Total	77,953
Accumulated Depreciation at December 31, 2022	7,096
AUSTIN, TX \| Four Points Centre (11305 Four Points Drive)
Initial Cost
Land	7,800
Buildings and Improvements	43,581
Net Improvements (Retirements) Since Acquisition	4,515
Gross Amount Which Carried
Land	7,800
Buildings and Improvements	48,096
Total	55,896
Accumulated Depreciation at December 31, 2022	6,275
AUSTIN, TX \| River Place - Building 1 (6500 River Place Boulevard)
Initial Cost
Land	2,004
Buildings and Improvements	17,680
Net Improvements (Retirements) Since Acquisition	562
Gross Amount Which Carried
Land	2,004
Buildings and Improvements	18,242
Total	20,246
Accumulated Depreciation at December 31, 2022	2,189
AUSTIN, TX \| River Place - Building 2 (6500 River Place Boulevard)
Initial Cost
Land	3,137
Buildings and Improvements	29,254
Net Improvements (Retirements) Since Acquisition	806
Gross Amount Which Carried
Land	3,137
Buildings and Improvements	30,060
Total	33,197
Accumulated Depreciation at December 31, 2022	3,432
AUSTIN, TX \| River Place - Building 3 (6500 River Place Boulevard)
Initial Cost
Land	3,064
Buildings and Improvements	26,705
Net Improvements (Retirements) Since Acquisition	447
Gross Amount Which Carried
Land	3,064
Buildings and Improvements	27,152
Total	30,216
Accumulated Depreciation at December 31, 2022	2,931
AUSTIN, TX \| River Place - Building 4 (6500 River Place Boulevard
Initial Cost
Land	2,273
Buildings and Improvements	18,617
Net Improvements (Retirements) Since Acquisition	1,716
Gross Amount Which Carried
Land	2,273
Buildings and Improvements	20,333
Total	22,606
Accumulated Depreciation at December 31, 2022	2,903
AUSTIN, TX \| River Place - Building 5 (6500 River Place Boulevard)
Initial Cost
Land	1,752
Buildings and Improvements	14,315
Net Improvements (Retirements) Since Acquisition	692
Gross Amount Which Carried
Land	1,752
Buildings and Improvements	15,007
Total	16,759
Accumulated Depreciation at December 31, 2022	1,655
AUSTIN, TX \| River Place - Building 6 (6500 River Place Boulevard)
Initial Cost
Land	1,598
Buildings and Improvements	12,945
Net Improvements (Retirements) Since Acquisition	703
Gross Amount Which Carried
Land	1,598
Buildings and Improvements	13,648
Total	15,246
Accumulated Depreciation at December 31, 2022	1,490
AUSTIN, TX \| River Place - Building 7 (6500 River Place Boulevard)
Initial Cost
Land	1,801
Buildings and Improvements	16,486
Net Improvements (Retirements) Since Acquisition	1,208
Gross Amount Which Carried
Land	1,801
Buildings and Improvements	17,694
Total	19,495
Accumulated Depreciation at December 31, 2022	2,468
AUSTIN, TX \| Quarry Lake II (4516 Seton Center Parkway)
Initial Cost
Land	3,970
Buildings and Improvements	30,546
Net Improvements (Retirements) Since Acquisition	1,174
Gross Amount Which Carried
Land	3,867
Buildings and Improvements	31,823
Total	35,690
Accumulated Depreciation at December 31, 2022	3,611
OTHER \| Main Street-Plaza 1000
Initial Cost
Land	2,732
Buildings and Improvements	10,942
Net Improvements (Retirements) Since Acquisition	284
Gross Amount Which Carried
Land	2,732
Buildings and Improvements	11,226
Total	13,958
Accumulated Depreciation at December 31, 2022	11,054
OTHER \| Main Street-Piazza
Initial Cost
Land	696
Buildings and Improvements	2,802
Net Improvements (Retirements) Since Acquisition	3,586
Gross Amount Which Carried
Land	704
Buildings and Improvements	6,380
Total	7,084
Accumulated Depreciation at December 31, 2022	4,547
OTHER \| Main Street-Promenade
Initial Cost
Land	532
Buildings and Improvements	2,052
Net Improvements (Retirements) Since Acquisition	311
Gross Amount Which Carried
Land	532
Buildings and Improvements	2,363
Total	2,895
Accumulated Depreciation at December 31, 2022	1,561
OTHER \| 920 North King Street
Initial Cost
Land	6,141
Buildings and Improvements	21,140
Net Improvements (Retirements) Since Acquisition	7,108
Gross Amount Which Carried
Land	6,141
Buildings and Improvements	28,248
Total	34,389
Accumulated Depreciation at December 31, 2022	16,427
OTHER \| 300 Delaware Avenue
Initial Cost
Land	6,369
Buildings and Improvements	13,739
Net Improvements (Retirements) Since Acquisition	2,750
Gross Amount Which Carried
Land	6,369
Buildings and Improvements	16,489
Total	22,858
Accumulated Depreciation at December 31, 2022	$ 10,393

Schedule III - Real Estate an_3

Schedule III - Real Estate and Accumulated Depreciation - Reconciliations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at the Beginning of the Year	$ 3,472,602	$ 3,474,109	$ 4,006,459
Additions:
Acquisitions	0	0	9,722
Capital expenditures and assets placed into service	212,874	134,931	113,221
Less:
Dispositions/impairments/placed into redevelopment	(32,951)	(82,247)	(619,086)
Retirements	(35,285)	(54,191)	(36,207)
Balance at the end of the year	3,617,240	3,472,602	3,474,109
Per consolidated balance sheet	3,617,240	3,472,602	3,474,109
Tax basis of assets, cost for income tax purposes	3,200,000	3,100,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at the beginning of the year	957,450	896,561	973,318
Additions:
Depreciation expense	147,735	136,171	138,822
Less:
Dispositions/impairments/placed into redevelopment	(7,341)	(24,440)	(182,526)
Retirements	(34,784)	(50,842)	(33,053)
Balance at the end of the year	1,063,060	957,450	896,561
Per consolidated balance sheet	$ 1,063,060	$ 957,450	$ 896,561
Leashold Interest Land
Less:
Lease agreement term (in years)	99 years
Maximum
Less:
Useful life (in years)	55 years