Mallinckrodt (MNKTQ) 10-Q3 Nov 202020 Q2 Quarterly reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
Document And Entity Information - shares	Sep. 25, 2020	Oct. 30, 2020
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-35803
Entity Registrant Name	Mallinckrodt plc
Entity Incorporation, State or Country Code	L2
Entity Tax Identification Number	98-1088325
Entity Address, Address Line One	College Business & Technology Park
Entity Address, City or Town	Dublin
Entity Address, Postal Zip Code	15
Entity Address, Country	IE
City Area Code	1
Local Phone Number	696 0000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Central Index Key	0001567892
Trading Symbol	MNKKQ(1)
Title of 12(b) Security	Ordinary shares, par value $0.20 per share
Current Fiscal Year End Date	--12-25
Entity Filer Category	Large Accelerated Filer
Document Period End Date	Sep. 25, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Ordinary Shares Outstanding		84,604,862
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Address, Address Line Two	Cruiserath
Entity Address, Address Line Three	Blanchardstown
Country Region	353

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)	$ 698.3	$ 743.7	$ 1,530.6	$ 2,357.6
Cost of sales	403	419.4	1,171.7	1,309.3
Gross profit	295.3	324.3	358.9	1,048.3
Selling, general and administrative expenses	220.8	205.7	683.2	661.8
Research and development expenses	65.5	103.1	225.8	268
Restructuring charges, net	3.2	7.2	15.8	11.2
Non-restructuring impairment charges	0	0	63.5	113.5
Gains on divestiture	(9.7)	0	(10.1)	0
Medicaid lawsuit (Note 11)			640.2
Opioid-related litigation settlement (Note 11)	(25.8)	0	(34.1)	0
Operating income (loss)	41.5	8.3	(690.3)	(6.2)
Interest expense	(62.2)	(77.6)	(200.9)	(231.8)
Interest income	0.9	2.9	5.4	6.6
Other income, net	0	37.9	1.1	128.6
Loss from continuing operations before income taxes	(19.8)	(28.5)	(884.7)	(102.8)
Income tax benefit	(211.6)	(27.6)	(69.2)	(256.6)
Income (loss) from continuing operations	191.8	(0.9)	(815.5)	153.8
(Loss) income from discontinued operations, net of income taxes	(0.2)	(0.2)	23.8	$ 6.8
Net income (loss)	$ 191.6	$ (1.1)	$ (791.7)
Basic earnings (loss) per share (Note 5):
Income (loss) from continuing operations	$ 2.27	$ (0.01)	$ (9.66)	$ 1.84
(Loss) income from discontinued operations	0	0	0.28	0.08
Net income (loss)	$ 2.26	$ (0.01)	$ (9.38)	$ 1.92
Basic weighted-averaged shares outstanding (in shares)	84.6	84	84.4	83.8
Diluted earnings (loss) per share (Note 5):
Income (loss) from continuing operations	$ 2.27	$ (0.01)	$ (9.66)	$ 1.83
(Loss) income from discontinued operations	0	0	0.28	0.08
Net income (loss)	$ 2.26	$ (0.01)	$ (9.38)	$ 1.91
Diluted weighted-average shares outstanding (in shares)	84.6	84	84.4	84.2
Sales [Member]
Medicaid lawsuit (Note 11)	$ 0.7	$ 0	$ 535.1	$ 0
Operating Expense [Member]
Medicaid lawsuit (Note 11)	(0.2)	0	105.1	0
Retained Earnings (Deficit)
Net income (loss)	$ 191.6	$ (1.1)	$ (791.7)	$ 160.6

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Net income (loss)	$ 191.6	$ (1.1)	$ (791.7)
Other comprehensive income (loss), net of tax:
Currency translation adjustments	1	(2.1)	0.7	$ 1.6
Derivatives, net of tax	0	0.3	0.1	1
Benefit plans, net of tax	(0.6)	(0.2)	(1.3)	(0.9)
Total other comprehensive income (loss), net of tax	0.4	(2)	(0.5)	1.7
Comprehensive income (loss)	$ 192	$ (3.1)	$ (792.2)	$ 162.3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
Preferred shares, shares outstanding (in shares)	0	0
Current Assets:
Cash and cash equivalents	$ 844.2	$ 790.9
Accounts receivable, less allowance for doubtful accounts of $3.7 and $4.0	516.1	577.5
Inventories	343.3	312.1
Prepaid expenses and other current assets	360.9	150.2
Total current assets	2,064.5	1,830.7
Property, plant and equipment, net	851.4	896.5
Intangible assets, net	6,355.9	7,018
Other assets	433.1	593.7
Total Assets	9,704.9	10,338.9
Current Liabilities:
Current maturities of long-term debt	5,241.3	633.6
Accounts payable	79.1	139.8
Accrued payroll and payroll-related costs	73.1	105.2
Accrued interest	89.1	62.9
Medicaid lawsuit liability	640.2	0
Accrued and other current liabilities	381	485.4
Total current liabilities	6,503.8	1,426.9
Long-term debt	0	4,741.2
Opioid-related litigation settlement liability (Note 11)	1,609.3	1,643.4
Pension and postretirement benefits	61.4	62.4
Environmental liabilities	60	60
Other income tax liabilities	118.5	227.1
Other liabilities	186.2	237.2
Other liabilities	8,539.2	8,398.2
Shareholders' Equity:
Preferred shares	0	0
Ordinary A shares	0	0
Ordinary shares	18.8	18.7
Ordinary shares held in treasury at cost	(1,616.1)	(1,615.7)
Additional paid-in capital	5,580	5,562.5
Retained deficit	(2,808.6)	(2,016.9)
Accumulated other comprehensive loss	(8.4)	(7.9)
Total Shareholders' Equity	1,165.7	1,940.7
Total Liabilities and Shareholders' Equity	$ 9,704.9	$ 10,338.9
Ordinary A
Ordinary A shares, shares outstanding (in shares)	0	0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) $ in Millions	Sep. 25, 2020USD ($)$ / sharesshares	Sep. 25, 2020€ / shares	Dec. 27, 2019USD ($)$ / sharesshares	Dec. 27, 2019€ / shares
Allowance for doubtful accounts \| $	$ 3.7		$ 4
Preferred shares, par value (in usd per share) \| $ / shares	$ 0.20		$ 0.20
Preferred shares, shares authorized (in shares)	500,000,000		500,000,000
Preferred shares, shares issued (in shares)	0		0
Preferred shares, shares outstanding (in shares)	0		0
Ordinary shares, par value (in usd per share) \| $ / shares	$ 0.20		$ 0.20
Ordinary shares, shares authorized (in shares)	500,000,000		500,000,000
Ordinary shares, shares issued (in shares)	94,104,519		93,459,206
Ordinary shares, shares outstanding (in shares)	84,598,497		84,105,786
Ordinary shares held in treasury at cost (in shares)	9,506,022		9,353,420
Ordinary A
Ordinary shares, par value (in usd per share) \| € / shares		€ 1		€ 1
Ordinary shares, shares authorized (in shares)	40,000		40,000
Ordinary shares, shares issued (in shares)	0		0
Ordinary A shares, shares outstanding (in shares)	0		0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Net (loss) income	$ 191.6	$ (1.1)	$ (791.7)
Gain (Loss) on Extinguishment of Debt			0	$ (98.6)
Disposal Group, Including Discontinued Operations, Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect			0	(15.1)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Excluding Disposal Group			77.9	159.3
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect			77.9	174.4
Restricted Cash and Investments, Noncurrent	36.1	28	36.1	28
Restricted Cash and Investments, Current	20.2	0	20.2	0
Cash Flows From Operating Activities:
Net (loss) income	191.6	(1.1)	(791.7)
Adjustments to reconcile net cash from operating activities:
Depreciation and amortization			675.5	723.5
Share-based compensation			17.6	30.6
Deferred income taxes			304	(301.9)
Non-cash impairment charges			63.5	113.5
Gains on divestiture			(10.1)	0
Other non-cash items			(21.6)	(31.7)
Changes in assets and liabilities, net of the effects of acquisitions:
Accounts receivable, net			61.1	68.7
Inventories			(43.9)	(32)
Accounts payable			(52.4)	(27.8)
Income taxes			(431.2)	17.2
Medicaid lawsuit (Note 11)			640.2	0
Other			(116.3)	(88)
Net Cash From Operating Activities			294.7	534.1
Cash Flows From Investing Activities:
Capital expenditures			(42.4)	(108.7)
Proceeds from divestitures, net of cash			(0.7)	0
Other			6.7	13.7
Net Cash From Investing Activities			(36.4)	(95)
Cash Flows From Financing Activities:
Issuance of external debt			0	695
Repayment of external debt			(134.6)	(940.1)
Payments of Financing Costs			9.3	0
Debt financing costs			(9.3)	0
Repurchase of shares			(0.4)	(2.5)
Other			(36.3)	(17.6)
Net Cash Provided From Financing Activities			(180.6)	(265.2)
Effect of currency rate changes on cash			0.2	0.5
Net change in cash, cash equivalents and restricted cash			77.9	174.4
Cash, cash equivalents and restricted cash at beginning of period			822.6	367.5
Cash, cash equivalents and restricted cash at end of period	900.5	526.8	900.5	526.8
Cash and cash equivalents, end of period	844.2	498.8	844.2	498.8
Restricted Cash and Investments, Noncurrent	36.1	28	36.1	28
Retained Earnings (Deficit)
Net (loss) income	191.6	(1.1)	(791.7)	160.6
Cash Flows From Operating Activities:
Net (loss) income	$ 191.6	$ (1.1)	$ (791.7)	$ 160.6

Condensed Consolidated Statem_4

Condensed Consolidated Statement of Changes in Shareholders' Equity Statement - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Ordinary Shares	Treasury Shares	Additional Paid-In Capital	Retained Earnings (Deficit)	Retained Earnings (Deficit)Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive LossCumulative Effect, Period of Adoption, Adjustment
Shares, Outstanding			92,700,000	9,400,000
Beginning balance at Dec. 28, 2018	$ 2,887.3		$ 18.5	$ (1,617.4)	$ 5,528.2	$ (1,017.7)		$ (24.3)
Beginning balance (Accounting Standards Update 2018-02 [Member]) at Dec. 28, 2018		$ 0					$ (0.5)		$ 0.5
Net (loss) income	154.9					154.9
Other Comprehensive Income (Loss), Net of Tax	1.3							1.3
Stock Issued During Period, Value, Stock Options Exercised	0.3				0.3
Vesting of restricted shares (in shares)			200,000	0
Vesting of restricted shares (in usd)	(0.4)		$ 0.1	$ (0.5)	0
Share-based compensation	$ 10				10
Reissuance of treasury shares (in shares)	0
Reissuance of treasury shares	$ (0.5)			(0.9)		(0.4)
Ending balance at Mar. 29, 2019	3,053.9		18.6	(1,617)	5,538.5	(863.7)		(22.5)
Beginning balance at Dec. 28, 2018	2,887.3		18.5	(1,617.4)	5,528.2	(1,017.7)		(24.3)
Beginning balance (Accounting Standards Update 2018-02 [Member]) at Dec. 28, 2018		$ 0					$ (0.5)		$ 0.5
Net (loss) income						160.6
Ending balance at Sep. 27, 2019	3,080.4		$ 18.7	$ (1,615.6)	5,559.2	(859.8)		(22.1)
Shares, Outstanding			92,900,000	9,400,000
Beginning balance at Mar. 29, 2019	3,053.9		$ 18.6	$ (1,617)	5,538.5	(863.7)		(22.5)
Net (loss) income	6.8					6.8
Other Comprehensive Income (Loss), Net of Tax	2.4							2.4
Stock Issued During Period, Value, Stock Options Exercised	0.2				0.2
Vesting of restricted shares (in shares)			400,000	100,000
Vesting of restricted shares (in usd)	(1.9)		$ 0.1	$ (2)	0
Share-based compensation	$ 12.8				12.8
Reissuance of treasury shares (in shares)	(100,000)
Reissuance of treasury shares	$ (1)			(1.6)		(0.6)
Ending balance at Jun. 28, 2019	3,075.2		$ 18.7	$ (1,617.4)	5,551.5	(857.5)		(20.1)
Shares, Outstanding			93,300,000	9,400,000
Net (loss) income	(1.1)					(1.1)
Other Comprehensive Income (Loss), Net of Tax	(2)							(2)
Vesting of restricted shares (in shares)			100,000	0
Vesting of restricted shares (in usd)	(0.1)		$ 0	$ 0	(0.1)
Share-based compensation	$ 7.8				7.8
Reissuance of treasury shares (in shares)	(100,000)
Reissuance of treasury shares	$ (0.6)			(1.8)		(1.2)
Ending balance at Sep. 27, 2019	$ 3,080.4		$ 18.7	$ (1,615.6)	5,559.2	(859.8)		(22.1)
Shares, Outstanding			93,400,000	9,300,000
Shares, Outstanding			93,500,000	9,400,000
Beginning balance, ordinary shares (in shares) at Dec. 27, 2019	93,459,206
Beginning balance, treasury shares (in shares) at Dec. 27, 2019	9,353,420
Beginning balance at Dec. 27, 2019	$ 1,940.7		$ 18.7	$ (1,615.7)	5,562.5	(2,016.9)		(7.9)
Net (loss) income	(50.2)					(50.2)
Other Comprehensive Income (Loss), Net of Tax	(1.3)							(1.3)
Vesting of restricted shares (in shares)			100,000	0
Vesting of restricted shares (in usd)	(0.1)		$ 0	$ 0	(0.1)
Share-based compensation	6.7				6.7
Ending balance at Mar. 27, 2020	$ 1,895.8		18.7	(1,615.7)	5,569.1	(2,067.1)		(9.2)
Beginning balance, ordinary shares (in shares) at Dec. 27, 2019	93,459,206
Beginning balance, treasury shares (in shares) at Dec. 27, 2019	9,353,420
Beginning balance at Dec. 27, 2019	$ 1,940.7		18.7	(1,615.7)	5,562.5	(2,016.9)		(7.9)
Net (loss) income	$ (791.7)					(791.7)
Ending balance, ordinary shares (in shares) at Sep. 25, 2020	94,104,519
Ending balance, treasury shares (in shares) at Sep. 25, 2020	9,506,022
Ending balance at Sep. 25, 2020	$ 1,165.7		$ 18.8	$ (1,616.1)	5,580	(2,808.6)		(8.4)
Shares, Outstanding			93,600,000	9,400,000
Beginning balance at Mar. 27, 2020	1,895.8		$ 18.7	$ (1,615.7)	5,569.1	(2,067.1)		(9.2)
Net (loss) income	(933.1)					(933.1)
Other Comprehensive Income (Loss), Net of Tax	0.4							0.4
Vesting of restricted shares (in shares)			500,000	100,000
Vesting of restricted shares (in usd)	(0.2)		$ 0.1	$ (0.3)	0
Share-based compensation	6.6				6.6
Ending balance at Jun. 26, 2020	969.5		$ 18.8	$ (1,616)	5,575.7	(3,000.2)		(8.8)
Shares, Outstanding			94,100,000	9,500,000
Net (loss) income	191.6					191.6
Other Comprehensive Income (Loss), Net of Tax	0.4							0.4
Vesting of restricted shares (in shares)			0	0
Vesting of restricted shares (in usd)	(0.1)		$ 0	$ (0.1)	0
Share-based compensation	$ 4.3				4.3
Ending balance, ordinary shares (in shares) at Sep. 25, 2020	94,104,519
Ending balance, treasury shares (in shares) at Sep. 25, 2020	9,506,022
Ending balance at Sep. 25, 2020	$ 1,165.7		$ 18.8	$ (1,616.1)	$ 5,580	$ (2,808.6)		$ (8.4)
Shares, Outstanding			94,100,000	9,500,000

Background and Basis of Present

Background and Basis of Presentation	9 Months Ended
Background and Basis of Presentation	Sep. 25, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	1. Background and Basis of Presentation Background Mallinckrodt plc is a global business of multiple wholly owned subsidiaries (collectively, "Mallinckrodt" or "the Company") that develop, manufacture, market and distribute specialty pharmaceutical products and therapies. Areas of focus include autoimmune and rare diseases in specialty areas like neurology, rheumatology, nephrology, pulmonology and ophthalmology; immunotherapy and neonatal respiratory critical care therapies; analgesics and gastrointestinal products. The Company operates in two reportable segments, which are further described below: • Specialty Brands includes innovative specialty pharmaceutical brands; and • Specialty Generics includes niche specialty generic drugs and active pharmaceutical ingredients ("API(s)"). The Company owns or has rights to use the trademarks and trade names that are used in conjunction with the operation of its business. One of the more important trademarks that the Company owns or has rights to use that appears in this Quarterly Report on Form 10-Q is "Mallinckrodt," which is a registered trademark or the subject of pending trademark applications in the United States ("U.S.") and other jurisdictions. Solely for convenience, the Company only uses the ™ or ® symbols the first time any trademark or trade name is mentioned in the following notes. Such references are not intended to indicate in any way that the Company will not assert, to the fullest extent permitted under applicable law, its rights to its trademarks and trade names. Each trademark or trade name of any other company appearing in the following notes is, to the Company's knowledge, owned by such other company. Basis of Presentation The unaudited condensed consolidated financial statements have been prepared in U.S. dollars and in accordance with accounting principles generally accepted in the U.S. ("GAAP"). The preparation of the unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities, disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses. Actual results may differ from those estimates. The unaudited condensed consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries and entities in which they own or control more than 50.0% of the voting shares, or have the ability to control through similar rights. All intercompany balances and transactions have been eliminated in consolidation and all normal recurring adjustments necessary for a fair presentation have been included in the results reported. The results of entities disposed of are included in the unaudited condensed consolidated financial statements up to the date of disposal, and where appropriate, these operations have been reported in discontinued operations. Divestitures of product lines and businesses not meeting the criteria for discontinued operations have been reflected in operating income (loss). The fiscal year end balance sheet data was derived from audited consolidated financial statements, but do not include all of the annual disclosures required by GAAP; accordingly these unaudited condensed consolidated financial statements should be read in conjunction with the Company's audited annual consolidated financial statements included in its Annual Report on Form 10-K for the fiscal year ended December 27, 2019 filed with the U.S. Securities and Exchange Commission ("SEC") on February 26, 2020. Going Concern The accompanying unaudited condensed consolidated financial statements are prepared in accordance with GAAP applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. On October 12, 2020, Mallinckrodt plc and certain of its subsidiaries voluntarily initiated proceedings (the "Chapter 11 Cases") under chapter 11 of title 11 ("Chapter 11") of the United States Code (the "Bankruptcy Code"), to modify its capital structure, including restructuring portions of its debt, and resolve potential legal liabilities, including but not limited to those described in Note 11 as Opioid-Related Matters and Acthar Gel-Related Matters . In connection with the filing of the Chapter 11 Cases, the Company entered into a Restructuring Support Agreement (as defined in Note 14) as part of a prearranged plan of reorganization. See Note 14 for further information on the voluntary petitions for reorganization and the Restructuring Support Agreement. Substantial doubt about the Company's ability to continue as a going concern exists in light of its Chapter 11 Cases. The Company's ability to continue as a going concern is contingent upon, among other things, its ability to, subject to the approval by the U.S. Bankruptcy Court for the District of Delaware (the "Bankruptcy Court"), implement a plan of reorganization, emerge from the Chapter 11 proceedings and generate sufficient liquidity following the reorganization to meet its obligations, most notably its opioid and Acthar Gel ® -related claims and outstanding debt, and operating needs. Although management believes that the reorganization of the Company through the Chapter 11 proceedings will appropriately position the Company upon emergence, the commencement of these proceedings constituted an event of default under certain of the Company’s debt agreements, enforcement of any remedies in respect of which is automatically stayed as a result of the Chapter 11 proceedings. There are a number of risks and uncertainties associated with the Company’s bankruptcy, including, among others that: (a) the Company’s prearranged plan of reorganization may never be confirmed or become effective, (b) the Restructuring Support Agreement may be terminated by one or more of the parties thereto, (c) the Bankruptcy Court may grant or deny motions in a manner that is adverse to the Company and its subsidiaries, and (d) the Chapter 11 Cases may be converted into cases under chapter 7 of the Bankruptcy Code. The transactions contemplated by the Restructuring Support Agreement are subject to approval by the Bankruptcy Court, among other conditions. Accordingly, no assurance can be given that the transactions described therein will be consummated. As a result, the Company has concluded that management’s plans at this stage do not alleviate substantial doubt about the Company’s ability to continue as a going concern. The unaudited condensed consolidated financial statements do not include any adjustments related to the recoverability and classification of recorded asset amounts and classification of liabilities that might result from the outcome of this uncertainty. Fiscal Year

Revenue from Contracts with Cus

Revenue from Contracts with Customers Revenue from Contracts with Customers (Notes)	9 Months Ended
	Sep. 25, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	2. Revenue from Contracts with Customers Product Sales Revenue See Note 13 for presentation of the Company's net sales by product family. Reserves for variable consideration The following table reflects activity in the Company's sales reserve accounts: Rebates and Chargebacks Product Returns Other Sales Deductions Total Balance as of December 28, 2018 $ 354.3 $ 34.0 $ 17.1 $ 405.4 Provisions 1,772.9 18.8 50.7 1,842.4 Payments or credits (1,844.4) (22.9) (41.2) (1,908.5) Balance as of September 27, 2019 $ 282.8 $ 29.9 $ 26.6 $ 339.3 Balance as of December 27, 2019 $ 295.8 $ 28.4 $ 13.2 $ 337.4 Provisions 1,453.7 22.3 44.3 1,520.3 Provision for Medicaid lawsuit (Note 11) (1) 535.1 — — 535.1 Payments or credits (1,461.3) (24.3) (45.8) (1,531.4) Balance as of September 25, 2020 (1) $ 823.3 $ 26.4 $ 11.7 $ 861.4 (1) Excludes the $105.1 million that is reflected as a component of operating expenses as it represents a pre-acquisition contingency related to the portion of the liability that arose from sales of Acthar Gel prior to the Company’s acquisition of Questcor Pharmaceuticals Inc. ("Questcor") in August 2014. See Note 11 for further detail on the status of the Medicaid lawsuit. Product sales transferred to customers at a point in time and over time were as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Product sales transferred at a point in time 79.5 % 81.4 % 78.5 % 81.7 % Product sales transferred over time 20.5 18.6 21.5 18.3 Transaction price allocated to the remaining performance obligations The following table includes estimated revenue from contracts extending greater than one year for certain of the Company's hospital products that are expected to be recognized in the future related to performance obligations that were unsatisfied or partially unsatisfied as of September 25, 2020: Remainder of Fiscal 2020 $ 49.3 Fiscal 2021 106.0 Fiscal 2022 41.0 Fiscal 2023 9.9 Thereafter 0.3 Costs to fulfill a contract As of September 25, 2020 and December 27, 2019, the total net book value of the devices used in the Company's portfolio of drug-device combination products, which are used in satisfying future performance obligations, were $26.8 million and $26.5 million, respectively, and were classified in property, plant and equipment, net, on the unaudited condensed consolidated balance sheets. The associated depreciation expense recognized during the nine months ended September 25, 2020 and September 27, 2019 was $4.0 million and $5.1 million, respectively. Product Royalty Revenues The Company licenses certain rights to Amitiza ® (lubiprostone) ("Amitiza") to a third party in exchange for royalties on net sales of the product. The Company recognizes such royalty revenue as the related sales occur. The royalty rates consist of several tiers ranging from 18.0% to 26.0% with the royalty rate resetting every year. The associated royalty revenue recognized was as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Royalty revenue $ 20.4 $ 19.5 $ 52.3 $ 56.3 Contract Liabilities The following table reflects the balance of the Company's contract liabilities at the end of each period: September 25, December 27, Accrued and other current liabilities $ 3.0 $ 5.6 Other liabilities 0.4 0.6 Contract liabilities $ 3.4 $ 6.2 Revenue recognized during the nine months ended September 25, 2020 and September 27, 2019 from amounts included in contract liabilities at the beginning of the period was $4.7 million and $10.3 million, respectively, inclusive of the Company's wholly owned subsidiary BioVectra Inc. ("BioVectra"), prior to the completion of the sale of this business in November 2019.

Restructuring and Related Charg

Restructuring and Related Charges	9 Months Ended
Restructuring and Related Charges	Sep. 25, 2020
Restructuring and Related Activities [Abstract]
Restructuring and Related Charges	3. Restructuring and Related Charges During fiscal 2018 and 2016, the Company launched restructuring programs designed to improve its cost structure. Charges of $100.0 million to $125.0 million were provided for under each program. Each program generally commenced upon substantial completion of the previous program. In addition to the aforementioned programs, the Company has taken restructuring actions to generate synergies from its acquisitions. Net restructuring and related charges by segment were as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Specialty Brands $ — $ — $ 0.1 $ 0.4 Specialty Generics — 6.7 0.1 9.3 Corporate 3.2 0.5 15.6 1.5 Restructuring charges, net $ 3.2 $ 7.2 $ 15.8 $ 11.2 Net restructuring and related charges by program were comprised of the following: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, 2018 Program $ 3.2 $ 6.7 $ 17.8 $ 9.3 2016 Program — 0.5 (0.1) 2.7 Acquisition Programs — — (1.9) (0.8) Total charges expected to be settled in cash $ 3.2 $ 7.2 $ 15.8 $ 11.2 The following table summarizes cash activity for restructuring reserves, substantially all of which related to contract termination costs, employee severance and benefits and exiting of certain facilities: 2018 Program 2016 Program Acquisition Programs Total Balance as of December 27, 2019 $ 2.7 $ 31.3 $ 0.2 $ 34.2 Charges 18.1 0.1 — 18.2 Changes in estimate (0.3) (0.2) (1.9) (2.4) Cash payments (19.3) (30.7) (0.2) (50.2) Currency translation and other — — 1.9 1.9 Balance as of September 25, 2020 $ 1.2 $ 0.5 $ — $ 1.7 As of September 25, 2020, net restructuring and related charges incurred cumulative to date were as follows: 2018 Program 2016 Program Specialty Brands $ 3.0 $ 68.1 Specialty Generics 10.1 14.6 Corporate 19.7 28.8 $ 32.8 $ 111.5 All of the restructuring reserves were included in accrued and other current liabilities on the Company's unaudited condensed consolidated balance sheets. Amounts paid in the future may differ from the amount currently recorded.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 25, 2020
Income Tax Disclosure [Abstract]
Income Tax Disclosure	4. Income Taxes On March 27, 2020, the U.S. government enacted the Coronavirus Aid, Relief, and Economic Security ("CARES") Act. The CARES Act was a response to the market volatility and instability resulting from the novel coronavirus ("COVID-19") pandemic. It includes provisions to support individuals and businesses in the form of loans, grants, and tax changes among other types of relief. Estimates of the effects of the changes to the U.S. tax code have been incorporated into the Company’s nine months ended September 25, 2020 provision for income taxes, as applicable. The CARES Act income tax provisions applicable to the Company include, but are not limited to (1) carrybacks of certain net operating losses ("NOL(s)") generated in tax years beginning after December 31, 2017 and before January 1, 2021 to the preceding five taxable years, (2) suspension of the 80.0% taxable income limitation for NOLs generated in tax years beginning after December 31, 2017 and before January 1, 2021, (3) increase in the limitation of the interest expense deduction under Internal Revenue Code ("IRC") §163(j) from 30.0% to 50.0% of adjusted taxable income for any taxable year beginning in 2019 or 2020, (4) expansion of the charitable contribution deduction limit to 25.0% of taxable income versus the previous 10.0% limitation for contributions made during 2020, and (5) acceleration of alternative minimum tax credits being refunded incrementally in tax years 2018, 2019, 2020 and 2021 to recover the entire remaining balance in either the 2018 or 2019 tax year. As a result of the CARES Act, the Company is able to carryback a portion of its prior year and estimated current year U.S. Federal NOLs resulting in anticipated cash tax refunds of $201.0 million and $117.4 million, respectively. A tax benefit of $285.3 million has been recognized during the nine months ended September 25, 2020. The carryback of the U.S. Federal NOLs has an ancillary effect on the Company’s unrecognized tax benefits, as disclosed below. As further discussed in Note 1, the Company concluded that there is substantial doubt about its ability to continue as a going concern within one year from the date of issuance of the unaudited condensed consolidated financial statements. The Company considered this in determining that certain net deferred tax assets were no longer more likely than not realizable. As a result, an increase in valuation allowance of $341.6 million on the Company’s net deferred tax assets was recorded for the three months ended June 26, 2020. Approximately $202.7 million of this increase was a valuation allowance placed on prior year deferred tax assets predominantly related to U.S. Federal NOLs and the Opioid-Related Litigation Settlement charge (as defined in Note 11). The remaining $138.9 million increase was placed on the Company's net deferred tax assets resulting from current year activity predominantly related to the Acthar Gel Medicaid Retrospective Rebate (as defined in Note 11) accrual. As a result, all of the Company's net deferred tax assets as of the nine months ended September 25, 2020 are fully offset by a valuation allowance. The Company recognized an income tax benefit of $211.6 million on a loss from continuing operations before income taxes of $19.8 million for the three months ended September 25, 2020, and an income tax benefit of $27.6 million on a loss from continuing operations before income taxes of $28.5 million for the three months ended September 27, 2019. This resulted in effective tax rates of 1,068.7% and 96.8% for the three months ended September 25, 2020 and September 27, 2019, respectively. The income tax benefit for the three months ended September 25, 2020 was comprised of $201.4 million of current tax benefit and $10.2 million of deferred tax benefit. The current tax benefit was primarily the result of the CARES Act and unrecognized tax benefits, partially offset by the fiscal 2020 reorganization of the Company's intercompany financing and associated legal entity ownership. The deferred tax benefit was predominantly related to the fiscal 2020 reorganization of the Company's intercompany financing and associated legal entity ownership. The income tax benefit for the three months ended September 27, 2019 was comprised of $3.3 million of current tax expense and $30.9 million of deferred tax benefit. The deferred tax benefit was predominantly related to previously acquired intangibles and the generation of tax loss and credit carryforwards net of valuation allowances. The Company recognized an income tax benefit of $69.2 million on a loss from continuing operations before income taxes of $884.7 million for the nine months ended September 25, 2020, and an income tax benefit of $256.6 million on a loss from continuing operations before income taxes of $102.8 million for the nine months ended September 27, 2019. This resulted in effective tax rates of 7.8% and 249.6% for the nine months ended September 25, 2020 and September 27, 2019, respectively. The income tax expense for the nine months ended September 25, 2020 was comprised of $370.3 million of current tax benefit and $301.1 million of deferred tax expense. The current tax benefit was primarily the result of the CARES Act and unrecognized tax benefits, partially offset by the fiscal 2020 reorganization of the Company's intercompany financing and associated legal entity ownership. The deferred tax expense was predominantly related to the valuation allowance noted above, recorded against the Company's net deferred tax assets, and unrecognized tax benefits, partially offset by a tax benefit predominantly related to the fiscal 2020 reorganization of the Company's intercompany financing and associated legal entity ownership. The income tax benefit for the nine months ended September 27, 2019 was comprised of $47.4 million of current tax expense and $304.0 million of deferred tax benefit. The deferred tax benefit was predominantly related to previously acquired intangibles, the generation of tax loss and credit carryforwards net of valuation allowances, the non-restructuring impairment charges, as well as the 2019 reorganization of the Company's intercompany financing and associated legal entity ownership, which eliminated the interest bearing deferred tax obligation. The income tax benefit was $211.6 million for the three months ended September 25, 2020, compared with an income tax benefit of $27.6 million for the three months ended September 27, 2019. The $184.0 million net increase in the tax benefit included an increase of $235.7 million attributed to the CARES Act, and an increase of $1.2 million attributed to the fiscal 2019 gain on debt repurchased partially offset by a decrease of $32.0 million attributed to the fiscal 2020 reorganization of the Company's intercompany financing and associated legal entity ownership, a decrease of $12.3 million attributed to changes in the timing, amount and jurisdictional mix of income, a decrease of $6.5 million attributed to separation costs and a decrease of $2.1 million attributed to net restructuring. The income tax benefit was $69.2 million for the nine months ended September 25, 2020, compared with an income tax benefit of $256.6 million for the nine months ended September 27, 2019. The $187.4 million net decrease in the tax benefit included a decrease of $229.1 million predominantly attributed to the fiscal 2019 reorganization of the Company's intercompany financing and associated legal entity ownership including related adjustments to elections on the fiscal 2019 U.S. tax return primarily as a result of changes to the NOL carryback provisions in the CARES Act, a decrease of $202.7 million attributed to a valuation allowance recorded against the Company's net deferred tax assets, a decrease of $30.0 million attributed to changes in the timing, amount and jurisdictional mix of income, a decrease of $9.9 million attributed to separation costs, a decrease of $8.5 million attributed to non-restructuring impairment charges, a decrease of $2.6 million attributed to net restructuring, partially offset by an increase of $285.3 million attributed to the CARES Act and an increase of $10.1 million attributed to the fiscal 2019 gain on debt repurchased. During the nine months ended September 25, 2020, and fiscal 2019, the net cash payments for income taxes were $42.9 million and $30.7 million, respectively. On July 15, 2020, the activities of the Company's principal executive offices were relocated from the United Kingdom ("U.K.") to Ireland, which resulted in a change in the Company's tax residence to Ireland. Mallinckrodt plc has always been and remains incorporated in Ireland. Relocation of Mallinckrodt plc’s tax residence to Ireland allows the Company to mitigate the potential impacts of the U.K.’s departure from the European Union and align with the Company's commercial activity in Ireland. The Company continues to be subject to taxation in various tax jurisdictions worldwide. Accordingly, in fiscal 2020 the Company will report the Irish tax jurisdiction as the Company's domestic jurisdiction using an Irish statutory tax rate of 12.5% versus the U.K. statutory rate of 19.0%, and the International jurisdiction will represent areas outside the Irish tax jurisdiction. There is no material financial impact to this change. In August 2020, a settlement was reached with the Internal Revenue Service ("IRS") related to the audit of Mallinckrodt Hospital Products Inc.'s ("MHP") (formerly known as Cadence Pharmaceuticals, Inc. ("Cadence")) tax year ended September 26, 2014. Cadence was acquired as a U.S. subsidiary on March 19, 2014. Following the acquisition of Cadence, the Company transferred certain rights and risks in Ofirmev intellectual property ("Transferred IP") to one of the Company's wholly owned non-U.S. subsidiaries. The transfer occurred at a price determined in conjunction with external advisors, in accordance with applicable Treasury Regulations and with reference to the $1,329.0 million taxable consideration the Company paid to the shareholders of Cadence. The IRS asserted the transfer price of the Transferred IP was understated. The settlement increased the transfer price of the Transferred IP, resulting in an increase to taxable income of $356.5 million and underpayment interest of $11.8 million. The increase to taxable income was satisfied through a noncash offset against the Company's U.S. Federal NOLs and interest expense for the tax year ended September 25, 2020, while the underpayment interest was satisfied through a cash payment of $11.8 million. The Company was adequately reserved for this; therefore there were no impacts to the unaudited condensed consolidated statement of operations for the three months ended September 25, 2020. During the three months ended September 25, 2020, the Company commenced the fiscal 2020 reorganization of its intercompany financing and associated legal entity ownership to align its Specialty Brands and Specialty Generics businesses in preparation for the Chapter 11 bankruptcy filing, described in Note 14. As a result, for the three months ended September 25, 2020, the Company recognized current income tax expense of $44.2 million and a deferred income tax benefit of $12.2 million with a corresponding reduction to net deferred tax liabilities. In addition, a current tax benefit of $234.7 million was recognized due to the impact of the CARES Act on the fiscal 2020 reorganization, as described above. Finally, the fiscal 2020 reorganization substantially contributed to a deferred tax asset of $312.2 million for the portion of the Company's estimated fiscal 2020 U.S. Federal NOL that is not impacted by the CARES Act, which is fully offset with a valuation allowance. The Company's unrecognized tax benefits, excluding interest, totaled $336.9 million and $398.6 million as of September 25, 2020 and December 27, 2019, respectively. The net decrease of $61.7 million primarily resulted from settlements of $80.3 million, a lapse of statute of limitations of $35.7 million, and a net decrease of prior period tax positions of $4.3 million, offset by an increase to current period tax positions of $58.6 million. If favorably settled, $77.0 million of unrecognized tax benefits as of September 25, 2020 would benefit the effective tax rate. The total amount of accrued interest and penalties related to these obligations was $15.7 million and $32.9 million as of September 25, 2020 and December 27, 2019, respectively. Due to a lapse of the statute of limitations noted above, $18.1 million of tax and interest on unrecognized tax benefits related to the Nuclear Imaging business were eliminated, and a benefit of $17.3 million was recorded in discontinued operations within the unaudited condensed consolidated statement of operations for the nine months ended September 25, 2020. It is reasonably possible that within the next twelve months the unrecognized tax benefits could decrease by up to $25.0 million and the amount of related interest and penalties could decrease by up to $6.0 million as a result of payments or releases due to the resolution of examinations, appeals and litigation and the expiration of various statutes of limitation.

Earnings per Share

Earnings per Share	9 Months Ended
Earnings per Share	Sep. 25, 2020
Earnings Per Share [Abstract]
Earnings per Share	5. Earnings (Loss) per Share Basic earnings (loss) per share is computed by dividing net income (loss) by the number of weighted-average shares outstanding during the period. Diluted earnings (loss) per share is computed using the weighted-average shares outstanding and, if dilutive, potential ordinary shares outstanding during the period. Potential ordinary shares represent the incremental ordinary shares issuable for restricted share units and share option exercises. The Company calculated the dilutive effect of outstanding restricted share units and share options on earnings per share by application of the treasury stock method. Dilutive securities, including participating securities, are not included in the computation of loss per share when the Company reports a net loss from continuing operations as the impact would be anti-dilutive. The weighted-average number of shares outstanding used in the computations of basic and diluted earnings (loss) per share were as follows ( in millions ): Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Basic 84.6 84.0 84.4 83.8 Dilutive impact of restricted share units and share options — — — 0.4 Diluted 84.6 84.0 84.4 84.2 The computation of diluted weighted-average shares outstanding for both the three and nine months ended September 25, 2020 excluded approximately 5.8 million shares of equity awards, and for both the three and nine months ended September 27, 2019 excluded approximately 7.1 million shares of equity awards, respectively, because the effect would have been anti-dilutive.

Inventories

Inventories	9 Months Ended
Inventories	Sep. 25, 2020
Inventory, Net [Abstract]
Inventories	6. Inventories Inventories were comprised of the following at the end of each period: September 25, December 27, Raw materials and supplies $ 52.6 $ 62.7 Work in process 204.9 166.5 Finished goods 85.8 82.9 $ 343.3 $ 312.1

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
Property, Plant and Equipment	Sep. 25, 2020
Property, Plant and Equipment
Property, Plant and Equipment Disclosure	7. Property, Plant and Equipment The gross carrying amount and accumulated depreciation of property, plant and equipment were comprised of the following at the end of each period: September 25, December 27, 2019 Property, plant and equipment, gross $ 1,901.2 $ 1,900.1 Less: accumulated depreciation (1,049.8) (1,003.6) Property, plant and equipment, net $ 851.4 $ 896.5 Depreciation expense was as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Depreciation expense $ 25.5 $ 24.5 $ 75.7 $ 73.7

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
Goodwill and Intangible Assets	Sep. 25, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	8. Intangible Assets The gross carrying amount and accumulated amortization of intangible assets were comprised of the following at the end of each period: September 25, 2020 December 27, 2019 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortizable: Completed technology $ 10,394.6 $ 4,417.0 $ 10,456.9 $ 3,822.8 License agreements 120.1 77.1 120.1 74.1 Trademarks 77.7 22.7 77.7 20.1 Total $ 10,592.4 $ 4,516.8 $ 10,654.7 $ 3,917.0 Non-Amortizable: Trademarks $ 35.0 $ 35.0 In-process research and development 245.3 245.3 Total $ 280.3 $ 280.3 Ofirmev ® During the three months ended June 26, 2020, due to decreased demand as a result of the deprioritization of non-critical medical treatment in the face of the COVID-19 pandemic, along with increased generic competition anticipated in the marketplace post the product's loss of exclusivity in December 2020, the Company identified a triggering event with respect to the Ofirmev intangible asset within the Specialty Brands segment and assessed the recoverability of the definite-lived asset. Additionally, the Company evaluated whether these events warranted a revision to the remaining period of amortization that previously extended to March 2022. As a result of this analysis, the Company revised the useful life to end December 25, 2020, commensurate with the final period of market exclusivity. After this change in estimate of the asset's useful life, the Company determined that the undiscounted cash flows related to the Ofirmev intangible asset were less than its net book value, which required the Company to record an impairment charge for the difference between the fair value of the Ofirmev intangible asset and its net book value. The Company determined the fair value of the Ofirmev intangible asset using the income approach, a level three measurement technique. For purposes of determining fair value, the Company made various assumptions regarding estimated future cash flows, the discount rate and other factors in determining the fair value of the intangible asset. The Company's projections in relation to the Ofirmev intangible asset included long-term net sales and operating income at lower than historical levels. These changes in assumptions resulted in a fair value of the Ofirmev intangible asset that was less than its net book value. Therefore, the Company recorded an impairment charge of $63.5 million during the three months ended June 26, 2020. The remaining intangible asset value of $26.1 million as of September 25, 2020 will be amortized prospectively over the remaining useful life. Terlipressin During September 2020, the U.S. Food and Drug Administration ("FDA") issued a Complete Response Letter ("CRL") regarding the Company's New Drug Application ("NDA") seeking approval for the investigational agent terlipressin to treat adults with hepatorenal syndrome type 1 ("HRS-1"). The CRL stated that, based on the available data, the agency cannot approve the terlipressin NDA in its current form and requires more information to support a positive risk-benefit profile for terlipressin for patients with HRS-1. In response to receipt of the CRL, on October 26, 2020, the Company had an End of Review Meeting with the FDA where both parties engaged in constructive dialogue in an effort to clarify a viable path to approval. As the Company continues to engage with the FDA over the coming months, it will continue to assess the impact of any changes to planned revenue or earnings on the fair value of the associated in-process research and development asset of $81.0 million included within intangible assets, net on the unaudited condensed consolidated balance sheets as of September 25, 2020 and December 27, 2019. The Company annually tests the indefinite-lived intangible assets for impairment, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable by either a qualitative or income approach. Management relies on a number of qualitative factors when considering a potential impairment such as changes to planned revenue or earnings that could affect significant inputs used to determine the fair value of the indefinite-lived intangible asset. Intangible asset amortization expense Intangible asset amortization expense was as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Amortization expense $ 210.6 $ 210.4 $ 599.8 $ 649.8 The estimated aggregate amortization expense on intangible assets owned by the Company is expected to be as follows: Remainder of Fiscal 2020 $ 171.4 Fiscal 2021 581.1 Fiscal 2022 581.1 Fiscal 2023 581.1 Fiscal 2024 581.1

Debt

Debt	9 Months Ended
Debt	Sep. 25, 2020
Debt Disclosure [Abstract]
Debt Disclosure	9. Debt Debt was comprised of the following at the end of each period: September 25, 2020 December 27, 2019 Principal Unamortized Discount and Debt Issuance Costs Principal Unamortized Discount and Debt Issuance Costs Current maturities of long-term debt (1) : 4.875% senior notes due April 2020 $ — $ — $ 614.8 $ 0.6 9.50% debentures due May 2022 10.4 — — — 5.75% senior notes due August 2022 610.3 2.5 — — 8.00% debentures due March 2023 4.4 — — — 4.75% senior notes due April 2023 133.7 0.6 — — 5.625% senior notes due October 2023 514.7 3.6 — — Term loan due September 2024 1,509.1 13.1 15.6 0.2 Term loan due February 2025 400.5 5.3 4.1 0.1 5.50% senior notes due April 2025 387.2 3.1 — — 10.00% first lien senior notes due April 2025 495.0 8.2 — — 10.00% second lien senior notes due April 2025 322.9 8.5 — — Revolving credit facility 900.0 2.0 — — Total current debt 5,288.2 46.9 634.5 0.9 Long-term debt: 9.50% debentures due May 2022 — — 10.4 — 5.75% senior notes due August 2022 — — 610.3 3.7 8.00% debentures due March 2023 — — 4.4 — 4.75% senior notes due April 2023 — — 133.7 0.8 5.625% senior notes due October 2023 — — 514.7 4.4 Term loan due September 2024 — — 1,505.2 15.5 Term loan due February 2025 — — 399.5 6.1 5.50% senior notes due April 2025 — — 387.2 3.6 10.00% first lien senior notes due April 2025 — — — — 10.00% second lien senior notes due April 2025 — — 322.9 9.9 Revolving credit facility — — 900.0 3.1 Total long-term debt — — 4,788.3 47.1 Total debt $ 5,288.2 $ 46.9 $ 5,422.8 $ 48.0 (1) As of September 25, 2020, the Company was in full compliance with the provisions and covenants associated with its debt agreements. The commencement of the Chapter 11 Cases on October 12, 2020 constituted an event of default under certain of the Company's debt agreements. Accordingly, all long-term debt was classified as current on the unaudited condensed consolidated balance sheet as of September 25, 2020. However, any efforts to enforce payment obligations under the debt instruments are automatically stayed as a result of the Chapter 11 Cases. See Note 14 for further information. The Company's debt instruments are further described within the notes to the financial statements included within the Company's Annual Report filed on Form 10-K for the fiscal year ended December 27, 2019. As of September 25, 2020, the applicable interest rate and outstanding borrowings on the Company's variable-rate debt instruments were as follows: Applicable interest rate Outstanding borrowings Term loan due September 2024 3.50 % $ 1,509.1 Term loan due February 2025 3.75 400.5 Revolving credit facility 2.52 900.0 As of September 25, 2020, the Company was fully drawn on its $900.0 million revolving credit facility. On April 7, 2020, the Company, Mallinckrodt International Finance S.A. and Mallinckrodt CB LLC ("the Issuers") entered into an exchange agreement (the "Exchange Agreement") with certain third parties (collectively, the "Exchanging Holders"). Pursuant to the Exchange Agreement, the Exchanging Holders agreed to exchange with the Issuers, on April 7, 2020, their holdings of 4.875% senior unsecured notes that had a maturity date of April 15, 2020 ("2020 Notes") issued by the Issuers (the "Existing Notes") (consisting of approximately $495.0 million aggregate principal amount of the Existing Notes) for new 10.00% First Lien Senior Secured Notes due 2025 issued by the Issuers (the "First Lien 2025 Notes"), at a rate of $1,000 of First Lien 2025 Notes for every $1,000 of Existing Notes exchanged (such exchange, the "Exchange"). The Issuers and Exchanging Holders consummated the Exchange on April 7, 2020. Interest on the First Lien 2025 Notes is payable semi-annually in cash on April 15th and October 15th of each year, commencing on October 15, 2020. The Issuers may redeem some or all of the First Lien 2025 Notes prior to April 15, 2022 by paying a "make-whole" premium. The Issuers may redeem some or all of the First Lien 2025 Notes on or after April 15, 2022 at specified redemption prices. In addition, prior to April 15, 2022, the Issuers may redeem up to 40% of the aggregate principal amount of the First Lien 2025 Notes with the net proceeds of certain equity offerings. The Issuers may also redeem all, but not less than all, of the First Lien 2025 Notes at any time at a price of 100% of their principal amount, plus accrued and unpaid interest, if any, in the event the Issuers become obligated to pay additional amounts as a result of changes affecting certain withholding tax laws applicable to payments on the First Lien 2025 Notes. The Issuers are obligated to offer to repurchase (a) all of the First Lien 2025 Notes at a price of 101% of their principal amount plus accrued and unpaid interest, if any, as a result of certain change of control events and (b) First Lien 2025 Notes using asset sale proceeds at a price of 100% of their principal amount plus accrued and unpaid interest, if any, in the event of certain asset sales. These obligations are subject to certain qualifications and exceptions. The First Lien 2025 Notes are subject to an indenture that contains certain customary covenants and events of default (subject in certain cases to customary grace and cure periods). The occurrence of an event of default under the indenture could result in the acceleration of the First Lien 2025 Notes and could cause a cross-default that could result in the acceleration of other indebtedness of the Company and its subsidiaries. The First Lien 2025 Notes are jointly and severally guaranteed, subject to certain exceptions, on a secured, unsubordinated basis by the Company and each of its subsidiaries (other than the Issuers) (the "Note Guarantors") that guarantees the obligations under the Issuers’ existing senior secured credit facilities. The First Lien 2025 Notes and the guarantees thereof are secured by liens on the same assets of the Issuers and the Note Guarantors that are subject to liens securing the existing senior secured credit facilities, subject to certain exceptions. On April 15, 2020, the Company paid in full the remaining approximately $119.8 million in principal amount of outstanding 2020 Notes at the maturity thereof with cash on hand.

Guarantees

Guarantees	9 Months Ended
Guarantees	Sep. 25, 2020
Guarantees [Abstract]
Guarantees	10. Guarantees In disposing of assets or businesses, the Company has from time to time provided representations, warranties and indemnities to cover various risks and liabilities, including unknown damage to assets, environmental risks involved in the sale of real estate, liability to investigate and remediate environmental contamination at waste disposal sites and manufacturing facilities, and unidentified tax liabilities related to periods prior to disposition. The Company assesses the probability of potential liabilities related to such representations, warranties and indemnities and adjusts potential liabilities as a result of changes in facts and circumstances. The Company believes, given the information currently available, that the ultimate resolutions will not have a material adverse effect on its financial condition, results of operations and cash flows. In connection with the sale of the Specialty Chemical business (formerly known as Mallinckrodt Baker) in fiscal 2010, the Company agreed to indemnify the purchaser with respect to various matters, including certain environmental, health, safety, tax and other matters. The indemnification obligations relating to certain environmental, health and safety matters have a term of 17 years from the sale, while some of the other indemnification obligations have an indefinite term. The amount of the liability relating to all of these indemnification obligations included in other liabilities on the Company's unaudited condensed consolidated balance sheets as of September 25, 2020 and December 27, 2019 was $15.5 million and $15.0 million, respectively, of which $12.8 million and $12.3 million, respectively, related to environmental, health and safety matters. The value of the environmental, health and safety indemnity was measured based on the probability-weighted present value of the costs expected to be incurred to address environmental, health and safety claims made under the indemnity. The aggregate fair value of these indemnification obligations did not differ significantly from their aggregate carrying value as of September 25, 2020 and December 27, 2019. As of September 25, 2020, the maximum future payments the Company could be required to make under these indemnification obligations were $70.2 million. The Company was required to pay $30.0 million into an escrow account as collateral to the purchaser, of which $19.0 million and $18.9 million remained in restricted cash, included in other long-term assets on the unaudited condensed consolidated balance sheets as of September 25, 2020 and December 27, 2019, respectively. The Company has recorded liabilities for known indemnification obligations included as part of environmental liabilities, which are discussed in Note 11.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 25, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies The Company is subject to various legal proceedings and claims, including patent infringement claims, product liability matters, personal injury, environmental matters, employment disputes, contractual disputes and other commercial disputes, including those described below. Although it is not feasible to predict the outcome of these matters, the Company believes, unless otherwise indicated below, given the information currently available, that their ultimate resolution will not have a material adverse effect on its financial condition, results of operations and cash flows. Subsequent to September 25, 2020, the Company announced that Mallinckrodt plc and certain of its subsidiaries voluntarily initiated the Chapter 11 Cases under the Bankruptcy Code in the Bankruptcy Court. As a result of initiating the Chapter 11 Cases, all litigations and proceedings against the Company have been automatically stayed, subject to certain limited exceptions. In addition, the Company has requested an order from the Bankruptcy Court enjoining all litigations against the Company and various individuals named in certain of the litigations described below that might otherwise be subject to such an exception. For further information about the Chapter 11 cases, refer to Note 14. Governmental Proceedings Opioid-Related Matters Since 2017, multiple U.S. states, counties, a territory, other governmental persons or entities and private plaintiffs have filed lawsuits against certain entities of the Company, as well as various other manufacturers, distributors, pharmacies, pharmacy benefit managers, individual doctors and/or others, asserting claims relating to defendants' alleged sales, marketing, distribution, reimbursement, prescribing, dispensing and/or other practices with respect to prescription opioid medications, including certain of the Company's products. As of November 3, 2020, the cases the Company is aware of include, but are not limited to, approximately 2,618 cases filed by counties, cities, Native American tribes and/or other government-related persons or entities; approximately 270 cases filed by hospitals, health systems, unions, health and welfare funds or other third-party payers; approximately 128 cases filed by individuals; approximately six cases filed by schools and school boards; and 17 cases filed by the Attorneys General for New Mexico, Kentucky, Rhode Island, Georgia, Florida, Alaska, New York, Nevada, South Dakota, New Hampshire, Louisiana, Illinois, Mississippi, West Virginia, Puerto Rico, Ohio, and Idaho, with Idaho being the only state Attorney General to file in federal as opposed to state court. As of November 3, 2020, the Mallinckrodt defendants in these cases consist of Mallinckrodt plc and the following subsidiaries of Mallinckrodt plc: Mallinckrodt Enterprises LLC, Mallinckrodt LLC, SpecGx LLC, Mallinckrodt Brand Pharmaceuticals Inc., Mallinckrodt Inc., MNK 2011 Inc., and Mallinckrodt Enterprises Holdings, Inc. On November 22, 2019, the Delaware Attorney General filed a motion in the Superior Court of the State of Delaware to amend its complaint to add certain entities of the Company, which the court granted on December 18, 2019. The Delaware Attorney General has not yet filed its amended complaint. The Hawaii Attorney General filed a complaint against the Company on June 3, 2019. On December 27, 2019, the First Circuit Court entered a written order dismissing the Hawaii Attorney General's claims against all defendants without prejudice, finding that the allegations in the State's complaint failed to give notice of the claims against the defendants. Certain of the lawsuits have been filed as putative class actions. On October 8, 2020, the State of Rhode Island filed a lawsuit against the Company's President and Chief Executive Officer, Mark C. Trudeau, asserting similar claims relating to the marketing and distribution of prescription opioid medications. Most pending federal lawsuits have been coordinated in a federal multi-district litigation ("MDL") pending in the U.S. District Court for the Northern District of Ohio. The MDL court has issued a series of case management orders permitting motion practice addressing threshold legal issues in certain cases, allowing discovery, setting pre-trial deadlines and setting a trial date on October 21, 2019 for two cases originally filed in the Northern District of Ohio by Summit County and Cuyahoga County against opioid manufacturers, distributors, and pharmacies ("Track 1 Cases"). The counties claimed that opioid manufacturers' marketing activities changed the medical standard of care for treating both chronic and acute pain, which led to increases in the sales of their prescription opioid products. They also alleged that opioid manufacturers' and distributors' failure to maintain effective controls against diversion was a substantial cause of the opioid crisis. On September 30, 2019, the Company announced that Mallinckrodt plc, along with its wholly owned subsidiaries Mallinckrodt LLC and SpecGx LLC, had executed a definitive settlement agreement and release with Cuyahoga and Summit Counties in Ohio. The settlement fully resolves the Track 1 cases against all named Mallinckrodt entities that were scheduled to go to trial in October 2019 in the MDL. Under the agreement, the Company paid $24.0 million in cash on October 1, 2019. In addition, the Company will provide $6.0 million in generic products, including addiction treatment products, and will also provide a $0.5 million payment in two years in recognition of the counties' time and expenses. Further, in the event of a comprehensive resolution of government-related opioid claims, the Company has agreed that the two plaintiff counties will receive the value they would have received under such a resolution, less the payments described above. All named Mallinckrodt entities were dismissed with prejudice from the lawsuit. The value of the settlement should not be extrapolated to any other opioid-related cases or claims. On October 21, 2019, the MDL court issued a Stipulated Dismissal Order dismissing the claims against the remaining manufacturers and distributors pursuant to a settlement agreement, and severing the claims against the remaining pharmacy defendants to be heard in a subsequent trial, currently scheduled for November 9, 2020. Judge Polster issued Suggestions of Remand for City and County of San Francisco, California and City of Chicago, Illinois. Both cases have been remanded, respectively, to the Northern District of California and the Northern District of Illinois. Manufacturer defendants moved to dismiss the City of San Francisco action on April 20, 2020, which the Company joined. The motion was granted in part and denied in part on September 30, 2020. On October 23, 2020, the MDL court set a trial for October 25, 2021. Additionally, all manufacturer defendants, including us, were severed from the "Track Two" MDL cases, City of Huntington and Cabell County Commission, West Virginia. Those cases have subsequently been remanded to the Southern District of West Virginia. Other lawsuits remain pending in various state courts. In some jurisdictions, such as Arizona, California, Connecticut, Illinois, Massachusetts, New York, Pennsylvania, South Carolina, Texas, Utah and West Virginia, certain of the 247 state lawsuits have been consolidated or coordinated for pre-trial proceedings before a single court within their respective state court systems. State cases are generally at the pleading and/or discovery stage. Trials have been set in certain state cases, including in Arizona (June 1, 2021), Florida (April 4, 2022), Georgia (May 26, 2022), Maryland (December 7, 2021), Missouri (June 2022), 2021), Nevada (April 18, 2022), New Mexico (September 6, 2022), Rhode Island (January 19, 2021), and West Virginia (November 1, 2021). In Texas, the first of two bellwether trials is set to be ready for jury trial on September 27, 2021. The Company is not named as a defendant in the primary bellwether for that first trial, but is named as a defendant in the alternate bellwether for the first trial. The date and candidates for the second bellwether trial have not yet been selected. On March 26, 2020, the Supreme Court of Tennessee granted defendants’ application for permission to appeal the judgment of the Tennessee Court of Appeals in Effler et al. v. Purdue Pharma , LP et al., No. 16596, which reversed the Circuit Court for Campbell County’s grant of defendants’ motion to dismiss plaintiffs’ claims under Tennessee’s Drug Dealer Liability Act (DDLA). Oral argument in the Effler appeal was held on September 2, 2020. A successful ruling from the Tennessee Supreme Court in Effler would also require dismissal of the DDLA claim brought by the district attorney general plaintiffs in Staubus et al. v. Purdue Pharma, LP et al. , No. C-41916. The Staubus trial has been continued in the Circuit Court for Sullivan County. There is no trial date set at this time. The lawsuits assert a variety of claims, including, but not limited to, public nuisance, negligence, civil conspiracy, fraud, violations of the Racketeer Influenced and Corrupt Organizations Act ("RICO") or similar state laws, violations of state Controlled Substances Acts or state False Claims Acts ("FCA"), product liability, consumer fraud, unfair or deceptive trade practices, false advertising, insurance fraud, unjust enrichment, negligence and negligent misrepresentation, and other common law and statutory claims arising from defendants' manufacturing, distribution, marketing and promotion of opioids and seek restitution, damages, injunctive and other relief and attorneys' fees and costs. The claims generally are based on alleged misrepresentations and/or omissions in connection with the sale and marketing of prescription opioid medications and/or an alleged failure to take adequate steps to prevent diversion. Opioid-Related Litigation Settlement. On February 25, 2020, the Company announced that it had reached an agreement in principle with a court-appointed plaintiffs' executive committee representing the interest of thousands of plaintiffs in the MDL and supported by a broad-based group of 48 state and U.S. Territory Attorneys General on the terms of a global settlement that would resolve all opioid-related claims against the Company and its subsidiaries (the "Opioid-Related Litigation Settlement"). The Opioid-Related Litigation Settlement contemplated the filing of voluntary petitions under Chapter 11 of the U.S. Bankruptcy Code ("Chapter 11") by certain subsidiaries of Mallinckrodt plc operating the Specialty Generics business (the "Specialty Generics Subsidiaries") and the establishment of a trust for the benefit of plaintiffs holding opioid-related claims against the Company (the "Opioid Claimant Trust"). Subject to the Settlement Closing (as defined below), the Opioid-Related Litigation Settlement also provided that the Company would make certain structured payments to the Opioid Claimant Trust. It was contemplated that, pursuant to the terms of a channeling injunction and third-party release, which would be subject to court approval, all persons or entities asserting opioid-related claims against the Company would recover solely from the Opioid Claimant Trust on account of such claims. The Opioid-Related Litigation Settlement provided for: • the payment of $300.0 million upon Specialty Generics' emergence from the completed Chapter 11 case; • the payment to the Opioid Claimant Trust of additional cash totaling $1,300.0 million, consisting of $200.0 million on each of the first and second anniversaries of emergence and $150.0 million on each of the third through eighth anniversaries of emergence; and • the issuance of warrants ("Settlement Warrants") upon emergence from the contemplated Chapter 11 process to the Opioid Claimant Trust to purchase ordinary shares of the Company with an eight year term at a strike price of $3.15 per ordinary share that would represent approximately 19.99% of the Company's fully diluted outstanding shares, including after giving effect to the exercise of the warrants, provided that such warrants could not be exercised during any calendar quarter in a quantity that would exceed 5.0% of the number of shares outstanding. The Opioid-Related Litigation Settlement included a number of conditions to its consummation (such consummation, the "Settlement Closing") such as, among other things, bankruptcy court approval of the bankruptcy plan effectuating the Opioid-Related Litigation Settlement, the emergence of the Specialty Generics Subsidiaries from bankruptcy and other conditions. In connectio n with New York State’s support of the Opioid-Related Litigation Settlement, on March 9, 2020, the State of New York and Suffolk County, together with Mallinckrodt LLC and SpecGx LLC, jointly filed a motion to sever, or remove, Mallinckrodt LLC and SpecGx LLC from the New York State opioid trial, which, as of March 10, 2020, was postponed due to COVID-19. Nassau County opposed the motion. On May 12, 2020, the Court denied the motion to sever without prejudice to renewal after a new trial date has been set. On October 28, 2020, the presiding judge said the trial may begin in January 2021. As a result of the Opioid-Related Litigation Settlement, the Company recorded an accrual for this contingency of $1,600.0 million related to the structured cash payments and $43.4 million related to the Settlement Warrants in the consolidated balance sheet as of December 27, 2019. As of September 25, 2020, the Settlement Warrants were valued at $9.3 million. Refer to Note 12 for further information regarding the valuation of the Settlement Warrants. In conjunction with the Company's Chapter 11 filing on October 12, 2020, the Company entered into a Restructuring Support Agreement (as defined in Note 14) which includes a proposed resolution of all opioid-related claims against the Company and its subsidiaries that supersedes the Opioid-Related Litigation Settlement. For further information on the terms of this proposed resolution, refer to Note 14. Other Opioid-Related Matters. In addition to the lawsuits described above, certain entities of the Company have received subpoenas and civil investigative demands ("CID(s)") for information concerning the sale, marketing and/or distribution of prescription opioid medications and the Company's suspicious order monitoring programs, including from the U.S. DOJ and the Attorneys General for Missouri, New Hampshire, Kentucky, Washington, Alaska, South Carolina, Puerto Rico, New York, West Virginia, Indiana, the Divisions of Consumer Protection and Occupational and Professional Licensing of the Utah Department of Commerce, and the New York State Department of Financial Services. The Company has been contacted by the coalition of State Attorneys General investigating the role manufacturers and distributors may have had in contributing to the increased use of opioids in the U.S. On January 27, 2018, the Company received a grand jury subpoena from the U.S. Attorneys' Office ("USAO") for the Southern District of Florida for documents related to the distribution, marketing and sale of generic oxymorphone products. On April 17, 2019, the Company received a grand jury subpoena from the USAO for the Eastern District of New York ("EDNY") for documents related to the sales and marketing of controlled substances, the policies and procedures regarding controlled substances, and other related documents. On June 4, 2019, the Company received a rider from the USAO for EDNY requesting additional documents regarding the Company's anti-diversion program. The Company is responding or has responded to these subpoenas, CIDs and any informal requests for documents. In August 2018, the Company received a letter from the leaders of the Energy and Commerce Committee in the U.S. House of Representatives requesting a range of documents relating to its marketing and distribution of opioids. The Company completed its response to this letter in December 2018. The Company received a follow-up letter in January 2020 and provided the committee a response. The Company is cooperating with the investigation. The Attorneys General for Kentucky, Alaska, New York, New Hampshire, West Virginia and Puerto Rico have subsequently filed lawsuits against the Company. Similar subpoenas and investigations may be brought by others or the foregoing matters may be expanded or result in litigation. The Company intends to vigorously defend itself in these matters. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with these investigations and/or lawsuits. On April 21, 2020, New York Governor Andrew Cuomo announced that the New York State Department of Financial Services had filed a Statement of Charges against Mallinckrodt, including allegations that it misrepresented the safety and efficacy of its branded and unbranded opioid products and downplayed the risks of negative outcomes to patients, resulting in claims for payment of medically unnecessary opioid prescriptions to commercial insurance companies. The Statement of Charges claims that Mallinckrodt violated Section 403 of the New York Insurance Law, which prohibits fraudulent insurance acts and includes penalties of up to $5,000 plus the amount of the fraudulent claim for each violation. It further alleges that Mallinckrodt violated Section 408 of the Financial Services Law, which prohibits intentional fraud or intentional misrepresentation of a material fact with respect to a financial product or service and includes penalties of up to $5,000 per violation. The Department claims that each fraudulent prescription constitutes a separate violation of these laws. A hearing on the Statement of Charges was scheduled for January 25, 2021, but the Department of Financial Services agreed to a voluntary stay on October 15, 2020. The Company intends to vigorously defend itself in this matter. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with this lawsuit. On June 1, 2020, a putative class action lawsuit was filed against Mallinckrodt plc, Mallinckrodt Canada ULC, the Canadian Ministry of Health ("Province") and the College of Pharmacists of British Columbia ("College") in the Supreme Court of British Columbia, captioned Laura Shaver v. Mallinckrodt Canada ULC, et al., No. VLC-S-S-205793. The action purports to be brought on behalf of any persons (1) prescribed Methadose for opioid agonist treatment in British Columbia after March 1, 2014, (2) covered by Pharmacare Plan C within British Columbia who were prescribed Methadose for opioid agonist treatment after February 1, 2014, (3) who transitioned from compounded methadone to Methadose for opioid agonist treatment in British Columbia after March 1, 2014, or (4) covered by Pharmacare Plan C within British Columbia who were transitioned from compounded methadone to Methadose for opioid agonist treatment after February 1, 2014. The suit generally alleges that the Province’s decision to grant Methadose coverage under Pharmacare Plan C and remove compounded methadone from coverage under Pharmacare Plan C had adversely affected those being treated for opioid use disorder. The suit asserts that the Province, the College and the Mallinckrodt defendants failed to warn patients about, and made false representations concerning, the efficacy of Methadose and the risks of switching from compounded methadone to Methadose. The suit seeks general, special, aggravated, punitive and exemplary damages in an unspecified amount, costs and interest and injunctive relief against the Province, the College and the Mallinckrodt defendants. Pursuant to two orders granted by the Ontario Superior Court of Justice (Commercial List) on October 15, 2020, the Chapter 11 proceedings commenced by Mallinckrodt plc and Mallinckrodt Canada ULC pursuant to the U.S. Bankruptcy Code were recognized and given effect in Canada. Among other things, the Canadian Court has stayed all proceedings against the Mallinckrodt defendants, including the British Columbia class action proceedings. The Company intends to vigorously defend itself in this matter. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with this lawsuit. New York State Opioid Stewardship Act . On October 24, 2018, the Company filed suit in the U.S. District Court for the Southern District of New York against the State of New York, asking the court to declare New York State's Opioid Stewardship Act ("OSA") unconstitutional and to enjoin its enforcement. On December 19, 2018, the court declared the OSA unconstitutional and granted the Company's motion for preliminary injunctive relief. On January 17, 2019, the State of New York appealed the court's decision. On September 14, 2020, a panel of the U.S. Court of Appeals for the Second Circuit reversed in part the lower court’s judgment, finding that the lower court should have dismissed the Company’s (and other parties’) challenges to the OSA for lack of subject matter jurisdiction. The Company disagrees with the decision and continues to evaluate its options with respect to the decision. In April 2019, the State of New York passed its 2020 budget, which amended the OSA so that if the OSA decision is reversed on appeal, the OSA would apply only to the sale or distribution of certain opioids in New York for 2017 and 2018 and, effective July 1, 2019, imposed an excise tax on certain opioids. DEA Investigation. In November 2011 and October 2012, the Company received subpoenas from the U.S. Drug Enforcement Administration ("DEA") requesting production of documents relating to its suspicious order monitoring program for controlled substances. The USAO for the Eastern District of Michigan investigated the possibility that the Company failed to report suspicious orders of controlled substances during the period 2006-2011 in violation of the Controlled Substances Act and its related regulations. The USAO for the Northern District of New York and Office of Chief Counsel for the U.S. DEA investigated the possibility that the Company failed to maintain appropriate records and security measures with respect to manufacturing of certain controlled substances at its Hobart facility during the period 2012-2013. In July 2017, the Company entered into a final settlement with the DEA and the USAOs for the Eastern District of Michigan and the Northern District of New York to settle these investigations. As part of the agreement, the Company paid $35.0 million to resolve all potential claims and agreed, as part of a Memorandum of Agreement ("MOA"), to utilize all available transaction information to identify suspicious orders of any Mallinckrodt controlled substance product and to report to the DEA when it concludes that chargeback data or other information indicates that a downstream registrant poses a risk of diversion, among other things. The MOA remained in effect until July 10, 2020, but the Company is continuing to utilize all available transaction information to identify suspicious orders for reporting to the DEA beyond that date. Acthar Gel-Related Matters Medicaid Lawsuit. In May 2019, the Company filed a lawsuit under the Administrative Procedure Act ("APA") in the U.S. District Court for the District of Columbia (the "District Court") against the U.S. Department of Health and Human Services ("HHS") and CMS (collectively, the "Agency"). The dispute involves the base date AMP under the Medicaid Drug Rebate Program for Mallinckrodt's Acthar Gel. A drug's "base date AMP" is used to calculate the Medicaid rebate amount payable by the drug's manufacturer to state Medicaid agencies when the drug is prescribed to Medicaid beneficiaries. At issue in the lawsuit is whether the FDA's 2010 approval of a new drug application for use of Acthar Gel in treating infantile spasms rendered Acthar Gel eligible for a new base date AMP, as indicated by CMS' written communications in 2012. In May 2019, CMS indicated that if the Company failed to revert to use of the original base date AMP in its calculation of Acthar Gel Medicaid rebates, CMS would identify the Company as being out of compliance with its Medicaid Drug Rebate Program reporting requirements, among other potential actions, triggering certain negative consequences. As such, the Company filed a lawsuit alleging (i) that CMS has violated the Medicaid drug rebate statute, (ii) that CMS has violated its own regulations defining "single source drug," (iii) that CMS has failed to adequately explain its change in position based on two letters that CMS sent Questcor in 2012 regarding the base date AMP for Acthar Gel, (iv) that CMS failed to give the Company fair notice of its latest position, and (v) that CMS should be prohibited from applying its new position retrospectively. The District Court held a hearing regarding this matter in August 2019. In March 2020, the Company received an adverse decision from the District Court, which upheld CMS' decision to reverse its previous determination of the base date AMP used to calculate Acthar Gel rebates. On March 16, 2020, the Company filed an Emergency Motion for Reconsideration and Stay of Entry of Judgment Pending Reconsideration Or, Alternatively, Injunction Pending Appeal with the District Court. In response, the government agreed that CMS would not require the Company to change the Medicaid rebate calculation for Acthar Gel until June 14, 2020, to allow the District Court time to decide the Company’s reconsideration motion. The District Court denied the Company's motion for reconsideration on May 29, 2020. On June 2, 2020, the Company appealed the District Court's decision to the U.S. Court of Appeals for the D.C. Circuit (the "Court of Appeals") and filed an Emergency Motion for Injunction Pending Appeal and to Expedite Briefing and Argument. The Court of Appeals denied the Company's request for an injunction pending appeal on June 15, 2020. The Company appealed the District Court's decision to the Court of Appeals, which heard oral argument on September 24, 2020. As previously disclosed, the Company recorded an accrual of $640.2 million related to the retrospective liability (the "Acthar Gel Medicaid Retrospective Rebate") in the unaudited condensed consolidated balance sheet as of September 25, 2020, of which $535.1 million and $105.1 million have been reflected as a component of net sales and operating expenses, respectively, in the unaudited condensed consolidated statement of operations for the nine months ended September 25, 2020. The $105.1 million reflected as a component of operating expenses represents a pre-acquisition contingency related to the portion of the Acthar Gel Medicaid Retrospective Rebate that arose from sales of Acthar Gel prior to the Company’s acquisition of Questcor in August 2014. On October 12, 2020, the Company announced a settlement in principle, which is conditioned upon the Company entering the Chapter 11 restructuring process, to resolve various Acthar Gel-related matters, including the Medicaid lawsuit, an associated FCA lawsuit and an FCA lawsuit relating to Acthar Gel’s previous owner’s interactions with an independent charitable foundation (the "Acthar Gel-Related Settlement"). The Company has agreed to pay $260.0 million over seven years and to reset Acthar Gel’s Medicaid rebate calculation as of July 1, 2020, such that state Medicaid programs will receive 100% rebates on Acthar Gel Medicaid sales, based on current Acthar Gel pricing. Additionally, upon execution of the settlement, the Company will dismiss its appeal, which is currently pending in the Court of Appeals. The Company expects that the Acthar Gel-Related Settlement – which would resolve the Medicaid lawsuit, the associated FCA lawsuit in Boston and an FCA lawsuit in the Eastern District of Pennsylvania relating to Acthar’s previous owner’s interactions with an independent charitable foundation – will be completed over the next several months, subject to Bankruptcy Court approval. U.S. House Committee Investigation. In January 2019, the Company along with 11 other pharmaceutical companies, received a letter from the U.S. House Committee on Oversight and Reform requesting information relating to the Company's pricing strategy for Acthar Gel and related matters. The Company cooperated with the Committee's investigation. The Company’s President and Chief Executive Officer Mark C. Trudeau accepted an invitation from the Committee to discuss the Company’s pricing policies and modernization strategy for Acthar Gel at a hearing before the Committee, which took place on October 1, 2020. Boston Civil Investigative Demand. In January 2019, the Company received a CID from the USAO for the District of Massachusetts for documents related to the Company's participation in the Medicaid Drug Rebate Program. The Company responded to the government's requests and cooperated with the investigation. In March 2020, the U.S. District Court for the District of Massachusetts unsealed a qui tam complaint under the federal FCA against the Company in which the DOJ and 28 states have intervened alleging that the Company had failed to pay the correct amount of rebates for its Acthar Gel product. Other related legal proceedings involving the Company, including the litigation described as the Medicaid Lawsuit , are discussed above. The Company disagrees with the government's characterization of the facts and applicable law. The Company moved to dismiss the DOJ's Complaint in Intervention in July 2020 and moved to dismiss the complaint of the intervening states in September 2020. As previously disclosed, in the event that the Company does not prevail in its Medicaid lawsuit the potential for damages in this matter could be up to approximately $1,280.0 million, after subtracting out potential restitution, related to the Acthar Gel Medicaid Retrospective Rebate. The Company has not recognized an accrual for this contingency in its financial results for the nine months ended September 25, 2020. As discussed above, on October 12, 2020, the Company announced a settlement in principle to resolve various Acthar Gel-related matters, including the Medicaid lawsuit and this associated Boston FCA lawsuit as well as an FCA lawsuit relating to Acthar Gel’s previous owner’s interactions with an independent charitable foundation (see "Acthar Gel-Related Settlement" above). On October 14, 2020, the court entered an order acknowledging the automatic stay of this litigation as to the Company pursuant to §362 of the Bankruptcy Code. Questcor EDPA Qui Tam Litigation. In September 2012, Questcor received a subpoena from the USAO for the Eastern District of Pennsylvania for information relating to its promotional practices related to Acthar Gel. The investigation eventually expanded to include Questcor's provision of financial and other support to patients, including through charitable foundations and related matters. The Company cooperated with the investigation. In March 2019, the U.S. District Court for the Eastern District of Pennsylvania unsealed two qui tam actions involving the allegations under investigation by the USAO for the Eastern District of Pennsylvania. The DOJ intervened in both actions, which were later consolidated. In September 2019, the Company executed a settlement agreement with the DOJ for $15.4 million and finalized settlements with the three qui tam plaintiffs. These settlements were paid during the three months ended September 27, 2019 and resolve the portion of the investigation and litigation involving Questcor's promotional practices related to Acthar Gel. In June 2019, the DOJ filed its Complaint in Intervention in the litigation, alleging claims under the federal False Claim Act based on Questcor's relationship with and donations to an independent charitable patient co-pay foundation. The Company disagrees with the DOJ's characterization of the facts and applicable law. In January 2020, the court denied the Company's motion to dismiss the Complaint in Intervention. As discussed above, on October 12, 2020, the Company announced a settlement in principle to resolve various Acthar Gel-related matters, including the Medicaid lawsuit and associated Boston FCA lawsuit as well as this Questcor EDPA Qui Tam lawsuit (see "Acthar Gel-Related Settlement" above). On October 15, 2020, the court entered an order acknowledging the automatic stay of this

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	9 Months Ended
Financial Instruments and Fair Value Measurements	Sep. 25, 2020
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurements	12. Financial Instruments and Fair Value Measurements Fair value is defined as the exit price that would be received from the sale of an asset or paid to transfer a liability, using assumptions that market participants would use in pricing an asset or liability. The fair value guidance establishes a three-level fair value hierarchy, which maximizes the use of observable inputs and minimizes the use of unobservable inputs used in measuring fair value. The levels within the hierarchy are as follows: Level 1— observable inputs such as quoted prices in active markets for identical assets or liabilities; Level 2— significant other observable inputs that are observable either directly or indirectly; and Level 3— significant unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions. The following tables provide a summary of the significant assets and liabilities that are measured at fair value on a recurring basis at the end of each period: September 25, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 31.8 $ 22.5 $ 9.3 $ — Equity securities 28.0 28.0 — — $ 59.8 $ 50.5 $ 9.3 $ — Liabilities: Deferred compensation liabilities $ 33.2 $ — $ 33.2 $ — Contingent consideration and acquired contingent liabilities 27.2 — — 27.2 Settlement Warrants 9.3 — — 9.3 $ 69.7 $ — $ 33.2 $ 36.5 December 27, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 30.6 $ 21.0 $ 9.6 $ — Equity securities 26.2 26.2 — — $ 56.8 $ 47.2 $ 9.6 $ — Liabilities: Deferred compensation liabilities $ 39.2 $ — $ 39.2 $ — Contingent consideration and acquired contingent liabilities 69.3 — — 69.3 Settlement Warrants 43.4 — — 43.4 $ 151.9 $ — $ 39.2 $ 112.7 Debt and equity securities held in rabbi trusts. Debt securities held in rabbi trusts primarily consist of U.S. government and agency securities and corporate bonds. When quoted prices are available in an active market, the investments are classified as level 1. When quoted market prices for a security are not available in an active market, they are classified as level 2. Equity securities held in rabbi trusts primarily consist of U.S. common stocks, which are valued using quoted market prices reported on nationally recognized securities exchanges. Equity securities. Equity securities consist of shares in Silence Therapeutics plc ("Silence"), for which quoted prices are available in an active market; therefore, the investment is classified as level 1 and is valued based on quoted market prices reported on an internationally recognized securities exchange. Deferred compensation liabilities. The Company maintains a non-qualified deferred compensation plan in the U.S., which permits eligible employees of the Company to defer a portion of their compensation. A recordkeeping account is set up for each participant and the participant chooses from a variety of funds for the deemed investment of their accounts. The recordkeeping accounts generally correspond to the funds offered in the Company's U.S. tax-qualified defined contribution retirement plan and the account balance fluctuates with the investment returns on those funds. Contingent consideration and acquired contingent liabilities. As of September 25, 2020, the Company maintains various contingent consideration and acquired contingent liabilities associated with the acquisitions of Questcor, Stratatech Corporation ("Stratatech"), and Ocera Therapeutics, Inc. ("Ocera"). The contingent liability associated with the acquisition of Questcor pertains to the Company's license agreement with Novartis AG and Novartis Pharma AG (collectively "Novartis") related to Synacthen, otherwise known as the Company's development product MNK-1411. Under the terms of this agreement, the Company made a $25.0 million payment during the nine months ended September 25, 2020 and subsequently suspended its rights and obligations to Novartis under such agreement. As of September 25, 2020 there are no further contingent liabilities associated with Synacthen. The Company determined the fair value of the contingent consideration associated with the acquisition of Questcor to be zero and $24.5 million as of September 25, 2020 and December 27, 2019, respectively. As part of the acquisition of Stratatech, the Company provided contingent consideration to the prior shareholders of Stratatech, primarily in the form of regulatory filing and approval milestones associated with the deep partial thickness and full thickness indications associated with StrataGraft ® . For each indication, the Company is responsible for a payment upon acceptance of the Company's submission and another upon approval by the FDA. Accordingly, upon acceptance by the FDA of the Company's deep partial thickness submission during the three months ended September 25, 2020, the Company made a $20.0 million payment to the prior shareholders of Stratatech. The Company assesses the likelihood and timing of making such payments at each balance sheet date. The fair value of the contingent payments was measured based on the net present value of a probability-weighted assessment. The Company determined the fair value of the contingent consideration associated with the acquisition of Stratatech to be $15.8 million and $29.0 million as of September 25, 2020 and December 27, 2019, respectively. As part of the acquisition of Ocera, the Company provided contingent consideration to the prior shareholders of Ocera in the form of both patient enrollment clinical study milestones and sales-based milestones associated with MNK-6105 and MNK-6106. The Company determined the fair value of the contingent consideration based on an option pricing model to be $11.4 million and $15.8 million as of September 25, 2020 and December 27, 2019, respectively. Of the total fair value of the contingent consideration of $27.2 million, $13.2 million was classified as current and $14.0 million was classified as non-current in the unaudited condensed consolidated balance sheet as of September 25, 2020. The following table summarizes the activity for contingent consideration: Balance as of December 27, 2019 $ 69.3 Payments (45.0) Accretion expense 0.5 Fair value adjustments 2.4 Balance as of September 25, 2020 $ 27.2 Settlement Warrants. Under the Opioid-Related Litigation Settlement, it was contemplated that the Company would issue Settlement Warrants upon emergence from the contemplated Chapter 11 process to the Opioid Claimant Trust to purchase ordinary shares of the Company with an eight year term at a strike price of $3.15 per ordinary share that would represent approximately 19.99% of the Company's fully diluted outstanding shares, including after giving effect to the exercise of the warrants, provided that such warrants may not be exercised during any calendar quarter in a quantity that would exceed 5.0% of the number of shares outstanding. The fair value of the Settlement Warrants has been estimated using the Black-Scholes pricing model. Use of a valuation model requires management to make certain assumptions with respect to selected model inputs. The expected volatility assumption is based on the historical and implied volatility of the Company's peer group with similar business models. The expected term assumption is based on the contractual term of the Settlement Warrants, including the maximum exercise restriction of 5.0% per calendar quarter, which resulted in the valuation of four separate tranches. The expected annual dividend per share is based on the Company's current intentions regarding payment of cash dividends. The risk-free interest rate is based on U.S. Treasury zero-coupon issues with a remaining term equal to the expected term assumed. The estimated fair value for the Settlement Warrants will be subject to revaluation at each balance sheet date with any changes in fair value recorded as a non-cash gain or (loss) in the unaudited condensed consolidated statements of operations until the Settlement Warrants are issued, at which point they will be recorded as equity or as a liability based upon the facts and circumstances at the time of issuance. The key assumptions used to estimate the fair value of the Settlement Warrants were as follows: September 25, December 27, 2019 Expected share price volatility 60.1 % 54.4 % Weighted-average risk-free rate 0.5 % 1.8 % Expected annual dividend per share — % — % Weighted-average expected term (in years) 7.6 7.6 Share price $ 1.14 $ 3.45 Subsequent to September 25, 2020, the Company announced that Mallinckrodt plc and certain of its subsidiaries voluntarily initiated the Chapter 11 Cases under the Bankruptcy Code in the Bankruptcy Court. In conjunction with the Chapter 11 filing, the Company entered into a Restructuring Support Agreement (as defined in Note 14) which includes a proposed resolution of all opioid-related claims against the Company and its subsidiaries that supersedes the Opioid-Related Litigation Settlement. The Restructuring Support Agreement includes new terms whereby the warrants equal to approximately 19.99% of the post-emergence fully diluted outstanding shares. These new terms may have a material impact to the recorded fair value of the warrants as of September 25, 2020, but such impact cannot be reasonably estimated at this time. For further information on the terms of this proposed resolution, refer to Note 14. Financial Instruments Not Measured at Fair Value The following methods and assumptions were used by the Company in estimating fair values for financial instruments not measured at fair value as of September 25, 2020 and December 27, 2019: • The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and the majority of other current assets and liabilities approximate fair value because of their short-term nature. The Company classifies cash on hand and deposits in banks, including commercial paper, money market accounts and other investments it may hold from time to time, with an original maturity of three months or less, as cash and cash equivalents (level 1). The fair value of restricted cash was equivalent to its carrying value of $56.3 million and $31.7 million as of September 25, 2020 and December 27, 2019, (level 1), respectively. As of September 25, 2020, $20.2 million and $36.1 million of the restricted cash balance was included in prepaid and other current assets and other assets, respectively, on the unaudited condensed consolidated balance sheet. As of December 27, 2019, substantially all of the restricted cash was included in other assets on the consolidated balance sheet. • The Company has received a portion of consideration as part of contingent earn-out payments related to the sale of the Nuclear Imaging business in the form of preferred equity certificates. These securities are classified as held-to-maturity and are carried at amortized cost, which approximates fair value (level 3), of $29.8 million and $18.9 million as of September 25, 2020 and December 27, 2019, respectively. These securities are included in other assets on the unaudited condensed consolidated balance sheets. • The Company's life insurance contracts are carried at cash surrender value, which is based on the present value of future cash flows under the terms of the contracts (level 3). Significant assumptions used in determining the cash surrender value include the amount and timing of future cash flows, interest rates and mortality charges. The fair value of these contracts approximates the carrying value of $51.3 million and $51.1 million as of September 25, 2020 and December 27, 2019, respectively. These contracts are included in other assets on the unaudited condensed consolidated balance sheets. • The carrying value of the Company's revolving credit facility approximates the fair value due to the short-term nature of this instrument, and is therefore classified as level 1. The Company's 4.875%, 5.75%, 4.75%, 5.625%, 5.50% and 10.00% first and second lien senior notes are classified as level 1, as quoted prices are available in an active market for these notes. Since the quoted market prices for the Company's term loans and 9.50% and 8.00% debentures are not available in an active market, they are classified as level 2 for purposes of developing an estimate of fair value. The following table presents the carrying values and estimated fair values of the Company's debt as of the end of each period: September 25, 2020 December 27, 2019 Carrying Fair Carrying Fair Level 1: 4.875% senior notes due April 2020 $ — $ — $ 614.8 $ 480.0 5.75% senior notes due August 2022 610.3 159.8 610.3 251.0 4.75% senior notes due April 2023 133.7 19.8 133.7 53.7 5.625% senior notes due October 2023 514.7 125.5 514.7 193.2 5.50% senior notes due April 2025 387.2 93.1 387.2 135.5 10.00% first lien senior notes due April 2025 495.0 516.1 — — 10.00% second lien senior notes due April 2025 322.9 252.6 322.9 253.8 Revolving credit facility 900.0 900.0 900.0 900.0 Level 2: 9.50% debentures due May 2022 10.4 4.2 10.4 5.4 8.00% debentures due March 2023 4.4 1.3 4.4 2.0 Term loan due September 2024 1,509.1 1,318.8 1,520.8 1,240.0 Term loan due February 2025 400.5 349.1 403.6 326.2 Total Debt $ 5,288.2 $ 3,740.3 $ 5,422.8 $ 3,840.8 Concentration of Credit and Other Risks Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of accounts receivable. The Company generally does not require collateral from customers. A portion of the Company's accounts receivable outside the U.S. includes sales to government-owned or supported healthcare systems in several countries, which are subject to payment delays. Payment is dependent upon the financial stability and creditworthiness of those countries' national economies. The following table shows net sales attributable to distributors that accounted for 10.0% or more of the Company's total segment net sales, which excludes the one-time charge related to the Medicaid lawsuit: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, CuraScript, Inc. 28.1 % 31.1 % 27.7 % 30.2 % The following table shows accounts receivable attributable to distributors that accounted for 10.0% or more of the Company's gross accounts receivable at the end of each period: September 25, December 27, AmerisourceBergen Corporation 26.5 % 31.3 % McKesson Corporation 18.1 15.3 CuraScript, Inc. 13.2 12.1 The following table shows net sales attributable to products that accounted for 10.0% or more of the Company's total segment net sales, which excludes the one-time charge related to the Medicaid lawsuit: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Acthar Gel 27.9 % 30.9 % 27.9 % 30.5 % INOmax 20.3 18.4 21.2 18.1 Ofirmev 12.7 11.6 10.5 11.5

Segment Data

Segment Data	9 Months Ended
Segment Data	Sep. 25, 2020
Segment Reporting [Abstract]
Segment Data	13. Segment Data The Company operates in two reportable segments, which are further described below: • Specialty Brands includes innovative specialty pharmaceutical brands; and • Specialty Generics includes niche specialty generic drugs and APIs. Management measures and evaluates the Company's operating segments based on segment net sales and operating income. Management excludes corporate expenses from segment operating income. In addition, certain amounts that management considers to be non-recurring or non-operational are excluded from segment net sales and operating income because management and the chief operating decision maker evaluate the operating results of the segments excluding such items. These items may include, but are not limited to, depreciation and amortization, share-based compensation, net restructuring and related charges, non-restructuring impairment charges, separation costs, research and development ("R&D") upfront payments, changes related to the Opioid-Related Litigation Settlement and the Acthar Gel Medicaid Retrospective Rebate incurred as a result of the Medicaid lawsuit. During the three months ended September 25, 2020, the Company began excluding depreciation and share-based compensation from its evaluation of the operating results of its segments. As a result, prior period segment operating income has been recast to reflect this change on a comparable basis. Although these amounts are excluded from segment net sales and operating income, as applicable, they are included in reported consolidated net sales and operating income (loss) and are reflected in the reconciliations presented below. Selected information by reportable segment was as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Net sales: Specialty Brands $ 539.6 $ 580.4 $ 1,553.0 $ 1,812.4 Specialty Generics 159.4 163.3 512.7 545.2 Segment net sales 699.0 743.7 2,065.7 2,357.6 Medicaid lawsuit (Note 11) (0.7) — (535.1) — Net sales $ 698.3 $ 743.7 $ 1,530.6 $ 2,357.6 Operating income: Specialty Brands $ 291.8 $ 277.0 $ 765.0 $ 894.2 Specialty Generics 43.1 36.3 155.5 125.4 Segment operating income 334.9 313.3 920.5 1,019.6 Unallocated amounts: Corporate and unallocated expenses (1) (42.1) (15.3) (152.3) (76.6) Depreciation and amortization (236.1) (234.9) (675.5) (723.5) Share-based compensation (4.3) (7.8) (17.6) (30.6) Restructuring and related charges, net (3.2) (7.2) (15.8) (11.2) Non-restructuring impairment charges — — (63.5) (113.5) Separation costs (2) (33.0) (19.8) (75.0) (50.4) R&D upfront payment (3) — (20.0) (5.0) (20.0) Opioid-related litigation settlement (4) 25.8 — 34.1 — Medicaid lawsuit (Note 11) (0.5) — (640.2) — Operating income (loss) $ 41.5 $ 8.3 $ (690.3) $ (6.2) (1) Includes administration expenses and certain compensation, legal, environmental and other costs not charged to the Company's reportable segments. (2) These costs, which are included in SG&A expenses, primarily relate to professional fees, costs incurred in preparation for the Chapter 11 proceedings as the Company works to resolve opioid and other legal uncertainties, incremental costs incurred to build out the corporate infrastructure of the previously planned spin-off of the Company's Specialty Generics segment, as well as rebranding initiatives associated with the Specialty Brands ongoing transformation. (3) Represents R&D expense incurred related to an upfront payment made to acquire product rights in Japan for terlipressin during the nine months ended September 25, 2020 and an upfront payment made to Silence in connection with the license and collaboration agreement entered into during the three and nine months ended September 27, 2019. (4) Represents the change in the Settlement Warrants' fair value. Refer to Note 12 for further information regarding the valuations of the Settlement Warrants. Net sales by product family within the Company's reportable segments were as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Acthar Gel (1) $ 195.3 $ 229.8 $ 576.6 $ 720.1 INOmax 141.9 136.8 438.5 427.6 Ofirmev 88.7 86.1 216.0 272.2 Therakos 62.6 60.9 174.1 183.6 Amitiza (2) 47.7 52.6 138.2 157.6 Other (3) 3.4 14.2 9.6 51.3 Specialty Brands 539.6 580.4 1,553.0 1,812.4 Hydrocodone (API) and hydrocodone-containing tablets 20.0 15.7 71.9 51.2 Oxycodone (API) and oxycodone-containing tablets 16.1 17.2 48.0 53.3 Acetaminophen (API) 54.9 48.5 154.5 143.1 Other controlled substances 62.4 72.9 223.8 265.7 Other 6.0 9.0 14.5 31.9 Specialty Generics 159.4 163.3 512.7 545.2 Segment net sales 699.0 743.7 2,065.7 2,357.6 Medicaid lawsuit (Note 11) (0.7) — (535.1) — Net sales $ 698.3 $ 743.7 $ 1,530.6 $ 2,357.6 (1) The three and nine months ended September 25, 2020 includes the prospective change to the Medicaid rebate calculation beginning in June 2020, which impacted Acthar Gel net sales by $22.2 million and $30.8 million, respectively. See Note 11 for further detail on the status of the Medicaid lawsuit. (2) Amitiza consists of both product net sales and royalties. Refer to Note 2 for further details on Amitiza's revenues. (3) The three and nine months ended September 27, 2019 includes $10.5 million and $36.8 million of net sales, respectively, related to BioVectra prior to the completion of the sale of this business in November 2019.

Subsequent Events

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 25, 2020
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events Commitments and Contingencies Certain litigation matters occurred during the nine months ended September 25, 2020 or prior, but had subsequent updates through the issuance of this report. See further discussion in Note 11. Chapter 11 Restructuring Voluntary Petitions for Reorganization On October 12, 2020 (the "Petition Date"), Mallinckrodt plc and certain of its subsidiaries voluntarily initiated the Chapter 11 Cases under the Bankruptcy Code in the Bankruptcy Court. The entities that filed the Chapter 11 Cases include the Company, substantially all of the Company’s U.S. subsidiaries, including certain subsidiaries of Mallinckrodt plc operating the Specialty Generics business (the "Specialty Generics Subsidiaries") and the Specialty Brands business (the "Specialty Brands Subsidiaries"), and certain of the Company’s international subsidiaries (together with the Company, Specialty Generics Subsidiaries and Specialty Brands Subsidiaries, the "Debtors"). The Debtors have filed a motion with the Bankruptcy Court seeking joint administration of the Chapter 11 Cases under the caption In re Mallinckrodt plc, Case No. 20-12522 (JTD). On October 14, 2020, the Company received Bankruptcy Court approval of its customary motions filed on the Petition Date seeking court authorization to continue to support its business operations during the Chapter 11 Cases, including the continued payment of employee wages and benefits without interruption, payment of critical and foreign vendors, and continuation of customer programs. Under the interim Court order, the Company will make adequate protection payments of an incremental 200 basis points on the senior secured term loans and senior secured revolving credit facility during the Chapter 11 Cases. These adequate protection payments are expected to be classified as interest expense, beginning during the three months ending December 25, 2020. Restructuring Support Agreement On October 11, 2020, the Company and the other Debtors entered into a Restructuring Support Agreement (the "RSA") with creditors holding approximately 84%, by aggregate principal amount, of the Company’s outstanding guaranteed unsecured senior notes and with a group of governmental plaintiffs in the opioid litigation pending against the Company and certain of its subsidiaries, including 50 state and territory attorneys general and the court-appointed plaintiffs’ executive committee in the opioid multidistrict litigation (collectively, the "Supporting Parties"). The RSA incorporates the terms agreed to by the parties reflected in the term sheets attached to the RSA, including an agreement by the Supporting Parties to support the following: • A proposed resolution of all opioid-related claims against the Company and its subsidiaries . Under the terms of the amended proposed settlement (the "Amended Proposed Opioid-Related Litigation Settlement"), which would become effective upon Mallinckrodt’s emergence from the Chapter 11 process, subject to court approval and other conditions: ◦ Opioid claims would be channeled to one or more trusts, which would receive $1,600.0 million in structured payments consisting of (i) a $450.0 million payment upon the Company’s emergence from Chapter 11; (ii) a $200.0 million payment upon each of the first and second anniversaries of emergence; and (iii) a $150.0 million payment upon each of the third through seventh anniversaries of emergence with a one-year prepayment option at a discount for all but the first payment. ◦ Opioid claimants would also receive warrants for approximately 19.99% of the Company’s fully diluted outstanding shares, including after giving effect to the exercise of the warrants, exercisable at a strike price reflecting an aggregate equity value of $1,551.0 million. ◦ Upon commencing the Chapter 11 filing, the Company will comply with an agreed-upon operating injunction with respect to the operation of its opioid business. • A proposed resolution with the U.S. Department of Justice and other governmental parties to settle a range of litigation matters and disputes relating to Acthar Gel . ◦ The Company has reached an agreement in principle with the DOJ and other governmental parties to settle a range of litigation matters and disputes relating to Acthar Gel, referred to herein as the Acthar Gel-Related Settlement. Under the settlement in principle, which is conditioned upon the Company entering the Chapter 11 restructuring process, the Company has agreed to pay $260.0 million to the DOJ and other parties over seven years and reset Acthar Gel’s Medicaid rebate calculation as of July 1, 2020, such that state Medicaid programs will receive 100% rebates on Acthar Gel Medicaid sales, based on current Acthar Gel pricing. Additionally, upon execution of the settlement, the Company will dismiss its appeal of the Medicaid lawsuit, currently pending in the Court of Appeals for the D.C. Circuit. In turn, the U.S. Government will drop its demand for approximately $640 million in retrospective Medicaid rebates for Acthar Gel and agree to dismiss a FCA lawsuit in Boston relating to the Medicaid lawsuit and an unrelated FCA suit in the Eastern District of Pennsylvania relating to legacy Questcor interactions with an independent charitable foundation. Mallinckrodt has entered into the agreement in principle to settle with the DOJ and other governmental parties solely to move past these litigation matters and disputes and will make no admission of liability or wrongdoing. The Company expects to complete the settlement with the DOJ, as well as various states that are party to the Boston FCA litigation, over the next several months, subject to court approval. • The reinstatement of the agreements associated with the Company’s senior secured term loans, senior secured revolving credit facility, 10.00% first and second lien senior notes . At the end of the court-supervised process, all allowed claims under these agreements are expected to be reinstated at existing rates and maturities. • A restructuring of the Company’s unsecured notes under the Guaranteed Unsecured Notes Indentures (as defined below). At the end of the court-supervised process, holders of allowed claims under the Guaranteed Unsecured Notes Indentures and the Guaranteed Unsecured Notes (as defined below) are expected to receive their pro rata share of $375.0 million of new secured second lien notes due seven years after emergence and 100% of the ordinary shares of Mallinckrodt, subject to dilution by the warrants described above and certain other equity. • A proposed resolution of other remaining claims and treatment of equity holders. At the end of the court-supervised process, trade creditors and holders of allowed general unsecured claims are expected to share in $150.0 million in cash, and equity holders and holders of the 9.50% debentures due May 2022, the 8.00% debentures due March 2023 and the 4.75% senior notes due April 2023 are expected to receive no recovery. The restructuring transactions contemplated by the RSA will be effectuated through a plan of reorganization to be proposed by the Debtors (the "Plan"), which among other things as outlined above, provides for a financial restructuring that would reduce the Company’s total debt by approximately $1,300.0 million. Pursuant to the RSA, each of the Debtors and the Supporting Parties has made certain customary commitments to each other in connection with the pursuit of the transactions contemplated by the term sheets attached thereto. The Debtors have agreed, among other things, to use commercially reasonable efforts to make all requisite filings with the Bankruptcy Court; continue to involve and update the Supporting Parties’ representatives in the bankruptcy process; and satisfy certain other covenants. The Supporting Parties have committed to support and vote for the Plan and have agreed to use commercially reasonable efforts to take, or refrain from taking, certain actions in furtherance of such support. The RSA contains milestones for the progress of the Chapter 11 Cases (the "Milestones"), which include the dates by which the Debtors are required to, among other things, obtain certain orders of the Court and consummate the Debtors’ emergence from bankruptcy. Among other dates set forth in the RSA, the agreement contemplates that the Court shall have entered an order confirming the Plan no later than eleven months after the Petition Date and that the Debtors shall have emerged from bankruptcy no later than fifteen months after the Petition Date. Each of the parties to the RSA may terminate the agreement (and thereby their support for the Plan) under certain limited circumstances. Any Debtor may terminate the RSA upon, among other circumstances: (i) its board of directors, after consultation with legal counsel, reasonably determining in good faith that performance under the RSA would be inconsistent with its fiduciary duties; and (ii) certain actions by the Bankruptcy Court, including dismissing the Chapter 11 Cases or converting the Chapter 11 Cases into cases under chapter 7 of the Bankruptcy Code. The Supporting Parties also have specified termination rights, including, among other circumstances, termination rights that arise if any of the Milestones have not been achieved, extended, or waived. Termination by one of these creditor groups will result in the termination of the RSA as to the terminating group only, with the RSA remaining in effect with respect to the Debtors and the non-terminating group. The transactions contemplated by the RSA are subject to approval by the Bankruptcy Court, among other conditions. Accordingly, no assurance can be given that the transactions described therein will be consummated. Event of default The commencement of the Chapter 11 Cases above constituted an event of default under certain of the Company’s debt agreements. Subject to any applicable provisions of the Bankruptcy Code, the Company’s debt instruments and agreements described within the notes to the financial statements included within the Company’s Annual Report filed on Form 10-K for the fiscal year ended December 27, 2019 (other than the 9.50% debentures due May 2022, the 8.00% debentures due March 2023 and the 4.75% senior notes due April 2023) provide that, as a result of the commencement of the Chapter 11 Cases, the principal amount, together with accrued and unpaid interest thereon, and in the case of the indebtedness outstanding under the senior notes, premium, if any, thereon, shall be immediately due and payable. Accordingly, all long-term debt was classified as current on the unaudited condensed consolidated balance sheet as of September 25, 2020. However, any efforts to enforce payment obligations under the debt instruments are automatically stayed as a result of the Chapter 11 Cases and the creditors’ rights in respect of the debt instruments are subject to the applicable provisions of the Bankruptcy Code. Adoption of Accounting Standards Codification ("ASC") 852 - Reorganizations For periods occurring after the Petition Date, the Company will adopt Financial Accounting Standards Board ASC Topic 852 - Reorganizations, which specifies the accounting and financial reporting requirements for entities reorganizing through Chapter 11 bankruptcy proceedings. These requirements include distinguishing transactions associated with the reorganization separate from activities related to the ongoing operations of the business. The Company is currently assessing whether or not it qualifies for fresh start accounting upon emergence from Chapter 11. If the Company were to meet the requirements to adopt the fresh start accounting rules, its assets and liabilities would be recorded at fair value as of the fresh start reporting date, which may differ materially from the recorded values of assets and liabilities on our unaudited condensed consolidated balance sheets. While the Chapter 11 Cases are pending, the Debtors do not anticipate making interest payments due under their respective unsecured debt instruments; however, the Debtors expect to pay all interest payments in full as they come due under their respective senior secured debt instruments. The total aggregate amount of interest paid pursuant to the Company's unsecured debt instruments that were outstanding as of September 25, 2020 was $64.2 million and $147.3 million during the nine months ended September 25, 2020 and the fiscal year ended December 27, 2019, respectively. The total aggregate amount of interest payments due under the Company's unsecured debt instruments for the remainder of 2020, which it does not expect to pay is $28.8 million. Notice of Delisting On October 12, 2020, the Company was notified by the staff of NYSE Regulation, Inc. ("NYSE Regulation") that it had determined to commence proceedings to delist the ordinary shares of the Company from the NYSE. NYSE Regulation reached its decision that the Company is no longer suitable for listing pursuant to NYSE Listed Company Manual Section 802.01D after the Company announced that it had commenced the Chapter 11 Cases. Trading in the Company’s ordinary shares was also suspended on October 12, 2020. On October 13, 2020, the Company’s ordinary shares began trading on the OTC Pink Marketplace under the symbol "MNKKQ." The Company decided not to appeal NYSE’s determination and, on October 13, 2020, NYSE filed a Form 25 with the U.S. Securities and Exchange Commission to remove the Company's ordinary shares from listing and registration on the NYSE.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
Revenue from Contracts with Customers (Tables)	Sep. 25, 2020
Disaggregation of Revenue [Line Items]
Sales Reserves Rollforward	The following table reflects activity in the Company's sales reserve accounts: Rebates and Chargebacks Product Returns Other Sales Deductions Total Balance as of December 28, 2018 $ 354.3 $ 34.0 $ 17.1 $ 405.4 Provisions 1,772.9 18.8 50.7 1,842.4 Payments or credits (1,844.4) (22.9) (41.2) (1,908.5) Balance as of September 27, 2019 $ 282.8 $ 29.9 $ 26.6 $ 339.3 Balance as of December 27, 2019 $ 295.8 $ 28.4 $ 13.2 $ 337.4 Provisions 1,453.7 22.3 44.3 1,520.3 Provision for Medicaid lawsuit (Note 11) (1) 535.1 — — 535.1 Payments or credits (1,461.3) (24.3) (45.8) (1,531.4) Balance as of September 25, 2020 (1) $ 823.3 $ 26.4 $ 11.7 $ 861.4 (1) Excludes the $105.1 million that is reflected as a component of operating expenses as it represents a pre-acquisition contingency related to the portion of the liability that arose from sales of Acthar Gel prior to the Company’s acquisition of Questcor Pharmaceuticals Inc. ("Questcor") in August 2014. See Note 11 for further detail on the status of the Medicaid lawsuit.
Disaggregation of Revenue	Product sales transferred to customers at a point in time and over time were as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Product sales transferred at a point in time 79.5 % 81.4 % 78.5 % 81.7 % Product sales transferred over time 20.5 18.6 21.5 18.3 Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Royalty revenue $ 20.4 $ 19.5 $ 52.3 $ 56.3
Contract with Customer, Timing of Satisfaction of Performance Obligation and Payment	The following table includes estimated revenue from contracts extending greater than one year for certain of the Company's hospital products that are expected to be recognized in the future related to performance obligations that were unsatisfied or partially unsatisfied as of September 25, 2020: Remainder of Fiscal 2020 $ 49.3 Fiscal 2021 106.0 Fiscal 2022 41.0 Fiscal 2023 9.9 Thereafter 0.3
Contract with Customer, Asset and Liability	The following table reflects the balance of the Company's contract liabilities at the end of each period: September 25, December 27, Accrued and other current liabilities $ 3.0 $ 5.6 Other liabilities 0.4 0.6 Contract liabilities $ 3.4 $ 6.2

Restructuring and Related Cha_2

Restructuring and Related Charges (Tables)	9 Months Ended
Restructuring and Related Charges (Tables)	Sep. 25, 2020
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Charges by Segment	Net restructuring and related charges by segment were as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Specialty Brands $ — $ — $ 0.1 $ 0.4 Specialty Generics — 6.7 0.1 9.3 Corporate 3.2 0.5 15.6 1.5 Restructuring charges, net $ 3.2 $ 7.2 $ 15.8 $ 11.2
Schedule of Net Restructuring and Related Charges	Net restructuring and related charges by program were comprised of the following: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, 2018 Program $ 3.2 $ 6.7 $ 17.8 $ 9.3 2016 Program — 0.5 (0.1) 2.7 Acquisition Programs — — (1.9) (0.8) Total charges expected to be settled in cash $ 3.2 $ 7.2 $ 15.8 $ 11.2
Schedule of Restructuring Reserves Reconciliation by Program	The following table summarizes cash activity for restructuring reserves, substantially all of which related to contract termination costs, employee severance and benefits and exiting of certain facilities: 2018 Program 2016 Program Acquisition Programs Total Balance as of December 27, 2019 $ 2.7 $ 31.3 $ 0.2 $ 34.2 Charges 18.1 0.1 — 18.2 Changes in estimate (0.3) (0.2) (1.9) (2.4) Cash payments (19.3) (30.7) (0.2) (50.2) Currency translation and other — — 1.9 1.9 Balance as of September 25, 2020 $ 1.2 $ 0.5 $ — $ 1.7
Schedule of Restructuring Charges Incurred Cumulative to Date	As of September 25, 2020, net restructuring and related charges incurred cumulative to date were as follows: 2018 Program 2016 Program Specialty Brands $ 3.0 $ 68.1 Specialty Generics 10.1 14.6 Corporate 19.7 28.8 $ 32.8 $ 111.5

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
Earnings per Share (Tables)	Sep. 25, 2020
Earnings Per Share [Abstract]
Schedule of Earnings per Share	The weighted-average number of shares outstanding used in the computations of basic and diluted earnings (loss) per share were as follows ( in millions ): Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Basic 84.6 84.0 84.4 83.8 Dilutive impact of restricted share units and share options — — — 0.4 Diluted 84.6 84.0 84.4 84.2

Inventories (Tables)

Inventories (Tables)	9 Months Ended
Inventories (Tables)	Sep. 25, 2020
Inventory, Net [Abstract]
Schedule of Inventories	Inventories were comprised of the following at the end of each period: September 25, December 27, Raw materials and supplies $ 52.6 $ 62.7 Work in process 204.9 166.5 Finished goods 85.8 82.9 $ 343.3 $ 312.1

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
Property, Plant and Equipment (Tables)	Sep. 25, 2020
Property, Plant and Equipment
Property, Plant and Equipment	The gross carrying amount and accumulated depreciation of property, plant and equipment were comprised of the following at the end of each period: September 25, December 27, 2019 Property, plant and equipment, gross $ 1,901.2 $ 1,900.1 Less: accumulated depreciation (1,049.8) (1,003.6) Property, plant and equipment, net $ 851.4 $ 896.5
Depreciation of Fixed Assets	Depreciation expense was as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Depreciation expense $ 25.5 $ 24.5 $ 75.7 $ 73.7

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
Goodwill and Intangible Assets (Tables)	Sep. 25, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The gross carrying amount and accumulated amortization of intangible assets were comprised of the following at the end of each period: September 25, 2020 December 27, 2019 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortizable: Completed technology $ 10,394.6 $ 4,417.0 $ 10,456.9 $ 3,822.8 License agreements 120.1 77.1 120.1 74.1 Trademarks 77.7 22.7 77.7 20.1 Total $ 10,592.4 $ 4,516.8 $ 10,654.7 $ 3,917.0 Non-Amortizable: Trademarks $ 35.0 $ 35.0 In-process research and development 245.3 245.3 Total $ 280.3 $ 280.3
Intangible Asset Amortization Expense	Intangible asset amortization expense was as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Amortization expense $ 210.6 $ 210.4 $ 599.8 $ 649.8
Schedule of Future Amortization Expense, Intangible Assets	The estimated aggregate amortization expense on intangible assets owned by the Company is expected to be as follows: Remainder of Fiscal 2020 $ 171.4 Fiscal 2021 581.1 Fiscal 2022 581.1 Fiscal 2023 581.1 Fiscal 2024 581.1

Debt (Tables)

Debt (Tables)	9 Months Ended
Debt (Tables)	Sep. 25, 2020
Debt Disclosure [Abstract]
Schedule of Debt including Capital Lease Obligation	Debt was comprised of the following at the end of each period: September 25, 2020 December 27, 2019 Principal Unamortized Discount and Debt Issuance Costs Principal Unamortized Discount and Debt Issuance Costs Current maturities of long-term debt (1) : 4.875% senior notes due April 2020 $ — $ — $ 614.8 $ 0.6 9.50% debentures due May 2022 10.4 — — — 5.75% senior notes due August 2022 610.3 2.5 — — 8.00% debentures due March 2023 4.4 — — — 4.75% senior notes due April 2023 133.7 0.6 — — 5.625% senior notes due October 2023 514.7 3.6 — — Term loan due September 2024 1,509.1 13.1 15.6 0.2 Term loan due February 2025 400.5 5.3 4.1 0.1 5.50% senior notes due April 2025 387.2 3.1 — — 10.00% first lien senior notes due April 2025 495.0 8.2 — — 10.00% second lien senior notes due April 2025 322.9 8.5 — — Revolving credit facility 900.0 2.0 — — Total current debt 5,288.2 46.9 634.5 0.9 Long-term debt: 9.50% debentures due May 2022 — — 10.4 — 5.75% senior notes due August 2022 — — 610.3 3.7 8.00% debentures due March 2023 — — 4.4 — 4.75% senior notes due April 2023 — — 133.7 0.8 5.625% senior notes due October 2023 — — 514.7 4.4 Term loan due September 2024 — — 1,505.2 15.5 Term loan due February 2025 — — 399.5 6.1 5.50% senior notes due April 2025 — — 387.2 3.6 10.00% first lien senior notes due April 2025 — — — — 10.00% second lien senior notes due April 2025 — — 322.9 9.9 Revolving credit facility — — 900.0 3.1 Total long-term debt — — 4,788.3 47.1 Total debt $ 5,288.2 $ 46.9 $ 5,422.8 $ 48.0
Schedule of Applicable Interest Rate on Variable-rate Debt	As of September 25, 2020, the applicable interest rate and outstanding borrowings on the Company's variable-rate debt instruments were as follows: Applicable interest rate Outstanding borrowings Term loan due September 2024 3.50 % $ 1,509.1 Term loan due February 2025 3.75 400.5 Revolving credit facility 2.52 900.0

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
Financial Instruments and Fair Value Measurements (Tables)	Sep. 25, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis	The following tables provide a summary of the significant assets and liabilities that are measured at fair value on a recurring basis at the end of each period: September 25, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 31.8 $ 22.5 $ 9.3 $ — Equity securities 28.0 28.0 — — $ 59.8 $ 50.5 $ 9.3 $ — Liabilities: Deferred compensation liabilities $ 33.2 $ — $ 33.2 $ — Contingent consideration and acquired contingent liabilities 27.2 — — 27.2 Settlement Warrants 9.3 — — 9.3 $ 69.7 $ — $ 33.2 $ 36.5 December 27, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 30.6 $ 21.0 $ 9.6 $ — Equity securities 26.2 26.2 — — $ 56.8 $ 47.2 $ 9.6 $ — Liabilities: Deferred compensation liabilities $ 39.2 $ — $ 39.2 $ — Contingent consideration and acquired contingent liabilities 69.3 — — 69.3 Settlement Warrants 43.4 — — 43.4 $ 151.9 $ — $ 39.2 $ 112.7
Schedule of Reconciliation of Changes in Fair Value of Contingent Liabilities	The following table summarizes the activity for contingent consideration: Balance as of December 27, 2019 $ 69.3 Payments (45.0) Accretion expense 0.5 Fair value adjustments 2.4 Balance as of September 25, 2020 $ 27.2
Schedule of Share-based Payment Awared, Warrants, Valuation Assumptions [Table Text Block] [Table Text Block]	The key assumptions used to estimate the fair value of the Settlement Warrants were as follows: September 25, December 27, 2019 Expected share price volatility 60.1 % 54.4 % Weighted-average risk-free rate 0.5 % 1.8 % Expected annual dividend per share — % — % Weighted-average expected term (in years) 7.6 7.6 Share price $ 1.14 $ 3.45
Schedule of Carrying Amount and Fair Value of Long-term Debt	The following table presents the carrying values and estimated fair values of the Company's debt as of the end of each period: September 25, 2020 December 27, 2019 Carrying Fair Carrying Fair Level 1: 4.875% senior notes due April 2020 $ — $ — $ 614.8 $ 480.0 5.75% senior notes due August 2022 610.3 159.8 610.3 251.0 4.75% senior notes due April 2023 133.7 19.8 133.7 53.7 5.625% senior notes due October 2023 514.7 125.5 514.7 193.2 5.50% senior notes due April 2025 387.2 93.1 387.2 135.5 10.00% first lien senior notes due April 2025 495.0 516.1 — — 10.00% second lien senior notes due April 2025 322.9 252.6 322.9 253.8 Revolving credit facility 900.0 900.0 900.0 900.0 Level 2: 9.50% debentures due May 2022 10.4 4.2 10.4 5.4 8.00% debentures due March 2023 4.4 1.3 4.4 2.0 Term loan due September 2024 1,509.1 1,318.8 1,520.8 1,240.0 Term loan due February 2025 400.5 349.1 403.6 326.2 Total Debt $ 5,288.2 $ 3,740.3 $ 5,422.8 $ 3,840.8
Schedules of Concentration of Risk	The following table shows net sales attributable to distributors that accounted for 10.0% or more of the Company's total segment net sales, which excludes the one-time charge related to the Medicaid lawsuit: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, CuraScript, Inc. 28.1 % 31.1 % 27.7 % 30.2 % The following table shows accounts receivable attributable to distributors that accounted for 10.0% or more of the Company's gross accounts receivable at the end of each period: September 25, December 27, AmerisourceBergen Corporation 26.5 % 31.3 % McKesson Corporation 18.1 15.3 CuraScript, Inc. 13.2 12.1 The following table shows net sales attributable to products that accounted for 10.0% or more of the Company's total segment net sales, which excludes the one-time charge related to the Medicaid lawsuit: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Acthar Gel 27.9 % 30.9 % 27.9 % 30.5 % INOmax 20.3 18.4 21.2 18.1 Ofirmev 12.7 11.6 10.5 11.5

Segment Data (Tables)

Segment Data (Tables)	9 Months Ended
Segment Data (Tables)	Sep. 25, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information by Reportable Segment	Selected information by reportable segment was as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Net sales: Specialty Brands $ 539.6 $ 580.4 $ 1,553.0 $ 1,812.4 Specialty Generics 159.4 163.3 512.7 545.2 Segment net sales 699.0 743.7 2,065.7 2,357.6 Medicaid lawsuit (Note 11) (0.7) — (535.1) — Net sales $ 698.3 $ 743.7 $ 1,530.6 $ 2,357.6 Operating income: Specialty Brands $ 291.8 $ 277.0 $ 765.0 $ 894.2 Specialty Generics 43.1 36.3 155.5 125.4 Segment operating income 334.9 313.3 920.5 1,019.6 Unallocated amounts: Corporate and unallocated expenses (1) (42.1) (15.3) (152.3) (76.6) Depreciation and amortization (236.1) (234.9) (675.5) (723.5) Share-based compensation (4.3) (7.8) (17.6) (30.6) Restructuring and related charges, net (3.2) (7.2) (15.8) (11.2) Non-restructuring impairment charges — — (63.5) (113.5) Separation costs (2) (33.0) (19.8) (75.0) (50.4) R&D upfront payment (3) — (20.0) (5.0) (20.0) Opioid-related litigation settlement (4) 25.8 — 34.1 — Medicaid lawsuit (Note 11) (0.5) — (640.2) — Operating income (loss) $ 41.5 $ 8.3 $ (690.3) $ (6.2) (1) Includes administration expenses and certain compensation, legal, environmental and other costs not charged to the Company's reportable segments. (2) These costs, which are included in SG&A expenses, primarily relate to professional fees, costs incurred in preparation for the Chapter 11 proceedings as the Company works to resolve opioid and other legal uncertainties, incremental costs incurred to build out the corporate infrastructure of the previously planned spin-off of the Company's Specialty Generics segment, as well as rebranding initiatives associated with the Specialty Brands ongoing transformation. (3) Represents R&D expense incurred related to an upfront payment made to acquire product rights in Japan for terlipressin during the nine months ended September 25, 2020 and an upfront payment made to Silence in connection with the license and collaboration agreement entered into during the three and nine months ended September 27, 2019. (4) Represents the change in the Settlement Warrants' fair value. Refer to Note 12 for further information regarding the valuations of the Settlement Warrants.
Schedule of Net Sales from External Customers by Products	Net sales by product family within the Company's reportable segments were as follows: Three Months Ended Nine Months Ended September 25, September 27, September 25, September 27, Acthar Gel (1) $ 195.3 $ 229.8 $ 576.6 $ 720.1 INOmax 141.9 136.8 438.5 427.6 Ofirmev 88.7 86.1 216.0 272.2 Therakos 62.6 60.9 174.1 183.6 Amitiza (2) 47.7 52.6 138.2 157.6 Other (3) 3.4 14.2 9.6 51.3 Specialty Brands 539.6 580.4 1,553.0 1,812.4 Hydrocodone (API) and hydrocodone-containing tablets 20.0 15.7 71.9 51.2 Oxycodone (API) and oxycodone-containing tablets 16.1 17.2 48.0 53.3 Acetaminophen (API) 54.9 48.5 154.5 143.1 Other controlled substances 62.4 72.9 223.8 265.7 Other 6.0 9.0 14.5 31.9 Specialty Generics 159.4 163.3 512.7 545.2 Segment net sales 699.0 743.7 2,065.7 2,357.6 Medicaid lawsuit (Note 11) (0.7) — (535.1) — Net sales $ 698.3 $ 743.7 $ 1,530.6 $ 2,357.6 (1) The three and nine months ended September 25, 2020 includes the prospective change to the Medicaid rebate calculation beginning in June 2020, which impacted Acthar Gel net sales by $22.2 million and $30.8 million, respectively. See Note 11 for further detail on the status of the Medicaid lawsuit. (2) Amitiza consists of both product net sales and royalties. Refer to Note 2 for further details on Amitiza's revenues. (3) The three and nine months ended September 27, 2019 includes $10.5 million and $36.8 million of net sales, respectively, related to BioVectra prior to the completion of the sale of this business in November 2019.

Revenue from Contracts with C_3

Revenue from Contracts with Customers Future Performance Obligations (Details) $ in Millions	Sep. 25, 2020USD ($)
Remainder of Fiscal 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 49.3
Fiscal 2021
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	106
Fiscal 2022
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	41
Fiscal 2023
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	9.9
Thereafter
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0.3

Revenue from Contracts with C_4

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 25, 2020		Sep. 27, 2019	Sep. 25, 2020		Sep. 27, 2019	Dec. 27, 2019	Dec. 28, 2018
Disaggregation of Revenue [Line Items]
Revenue Reserves		$ 861.4		$ 339.3	$ 861.4		$ 339.3	$ 337.4	$ 405.4
Revenue Reserve Provision					1,520.3		1,842.4
Revenue Reserve Payments or Credits					(1,531.4)		(1,908.5)
Deferred Revenue, Revenue Recognized					4.7		10.3
Contract with Customer, Liability		3.4			3.4			6.2
Contract with Customer, Liability, Current		3			3			5.6
Capitalized Contract Cost, Gross		26.8			26.8			26.5
Capitalized Contract Cost, Amortization					4		5.1
Contract with Customer, Liability, Noncurrent		0.4			0.4			0.6
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		698.3		743.7	1,530.6		2,357.6
Medicaid lawsuit (Note 11)					640.2
Medicaid Lawsuit [Member]
Disaggregation of Revenue [Line Items]
Decrease in revenue		22.2			30.8
Operating Expense [Member]
Disaggregation of Revenue [Line Items]
Medicaid lawsuit (Note 11)		(0.2)		0	105.1		0
Sales [Member]
Disaggregation of Revenue [Line Items]
Medicaid lawsuit (Note 11)		$ 0.7		$ 0	$ 535.1		$ 0
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue		79.50%		81.40%	78.50%		81.70%
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue		20.50%		18.60%	21.50%		18.30%
Royalty [Member]
Disaggregation of Revenue [Line Items]
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		$ 20.4		$ 19.5	$ 52.3		$ 56.3
Rebates and Chargebacks [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves		823.3	[1]	282.8	823.3	[1]	282.8	295.8	354.3
Revenue Reserve Provision					1,453.7		1,772.9
Revenue Reserve Payments or Credits					(1,461.3)		(1,844.4)
Rebates and Chargebacks [Member] \| Sales [Member]
Disaggregation of Revenue [Line Items]
Medicaid lawsuit (Note 11)	[1]				535.1
Allowance for Sales Returns [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves		26.4		29.9	26.4		29.9	28.4	34
Revenue Reserve Provision					22.3		18.8
Revenue Reserve Payments or Credits					(24.3)		(22.9)
Medicaid lawsuit (Note 11)					0
Other Sales Deductions [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves		$ 11.7		$ 26.6	11.7		26.6	$ 13.2	$ 17.1
Revenue Reserve Provision					44.3		50.7
Revenue Reserve Payments or Credits					(45.8)		$ (41.2)
Medicaid lawsuit (Note 11)					$ 0
Minimum
Disaggregation of Revenue [Line Items]
Royalty Rate Percentage					18.00%
Maximum
Disaggregation of Revenue [Line Items]
Royalty Rate Percentage					26.00%

[1]	Excludes the $105.1 million that is reflected as a component of operating expenses as it represents a pre-acquisition contingency related to the portion of the liability that arose from sales of Acthar Gel prior to the Company’s acquisition of Questcor Pharmaceuticals Inc. ("Questcor") in August 2014. See Note 11 for further detail on the status of the Medicaid lawsuit.

Restructuring and Related Cha_3

Restructuring and Related Charges (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019	Feb. 01, 2018
Restructuring Cost and Reserve
Restructuring charges, net	$ 3.2	$ 7.2	$ 15.8	$ 11.2
Restructuring Fiscal 2018 Plan \| Minimum
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					$ 100
Restructuring Fiscal 2018 Plan \| Maximum
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					$ 125

Restructuring and Related Cha_4

Restructuring and Related Charges (Schedule of Restructuring and Related Charges by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Restructuring Cost and Reserve
Restructuring charges, net	$ 3.2	$ 7.2	$ 15.8	$ 11.2
Specialty Brands
Restructuring Cost and Reserve
Restructuring and related charges, net	0	0	0.1	0.4
Specialty Generics
Restructuring Cost and Reserve
Restructuring and related charges, net	0	6.7	0.1	9.3
Corporate
Restructuring Cost and Reserve
Restructuring and related charges, net	$ 3.2	$ 0.5	$ 15.6	$ 1.5

Restructuring and Related Cha_5

Restructuring and Related Charges (Schedule of Net Restructuring and Related Charges) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Restructuring Cost and Reserve
Total charges expected to be settled in cash	$ 3.2	$ 7.2	$ 15.8	$ 11.2
Restructuring Fiscal 2018 Plan
Restructuring Cost and Reserve
Restructuring and related charges, net	3.2	6.7	17.8	9.3
Restructuring Fiscal 2016 Plan
Restructuring Cost and Reserve
Restructuring and related charges, net	0	0.5	(0.1)	2.7
Acquisitions
Restructuring Cost and Reserve
Restructuring and related charges, net	$ 0	$ 0	$ (1.9)	$ (0.8)

Restructuring and Related Cha_6

Restructuring and Related Charges (Schedule of Restructuring Reserves by Type of Cost) (Details) $ in Millions	9 Months Ended
	Sep. 25, 2020USD ($)
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 34.2
Charges	18.2
Changes in estimate	(2.4)
Currency translation and other	1.9
Cash payments	(50.2)
Ending Balance	1.7
Restructuring Fiscal 2018 Plan
Restructuring Reserve [Roll Forward]
Beginning Balance	2.7
Charges	18.1
Changes in estimate	(0.3)
Currency translation and other	0
Cash payments	(19.3)
Ending Balance	1.2
Restructuring Fiscal 2016 Plan
Restructuring Reserve [Roll Forward]
Beginning Balance	31.3
Charges	0.1
Changes in estimate	(0.2)
Currency translation and other	0
Cash payments	(30.7)
Ending Balance	0.5
Acquisitions
Restructuring Reserve [Roll Forward]
Beginning Balance	0.2
Charges	0
Changes in estimate	(1.9)
Currency translation and other	(1.9)
Cash payments	(0.2)
Ending Balance	$ 0

Restructuring and Related Cha_7

Restructuring and Related Charges (Schedule of Restructuring Charges Incurred Cumulative to Date) (Details) $ in Millions	Sep. 25, 2020USD ($)
Restructuring Fiscal 2016 Plan
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	$ 111.5
Restructuring Fiscal 2016 Plan \| Specialty Brands
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	68.1
Restructuring Fiscal 2016 Plan \| Specialty Generics
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	14.6
Restructuring Fiscal 2016 Plan \| Corporate
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	28.8
Restructuring Fiscal 2018 Plan
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	32.8
Restructuring Fiscal 2018 Plan \| Specialty Brands
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	3
Restructuring Fiscal 2018 Plan \| Specialty Generics
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	10.1
Restructuring Fiscal 2018 Plan \| Corporate
Restructuring Cost and Reserve
Restructuring costs incurred cumulative to date	$ 19.7

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	Mar. 19, 2014	Sep. 25, 2020	Jun. 26, 2020	Mar. 27, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019	Dec. 27, 2019
Income Taxes [Line Items]
Income tax benefit		$ (211.6)			$ (27.6)	$ (69.2)	$ (256.6)
Increase (decrease) tax benefit		184				187.4
Increase (Decrease) Tax Benefit, Intercompany Financing Reorganization		32				229.1
(Loss) income from continuing operations before income taxes		$ (19.8)			$ (28.5)	$ (884.7)	$ (102.8)
Effective tax rate		1068.70%			96.80%	7.80%	249.60%
Current Income Tax Expense (Benefit)		$ 201.4			$ (3.3)	$ 370.3	$ (47.4)
Deferred Income Tax Expense (Benefit)		10.2			$ (30.9)	(301.1)	(304)
Income Taxes Paid, Net				$ 30.7		42.9
Unrecognized tax benefits		336.9				336.9		$ 398.6
Unrecognized tax benefits, net increase						(61.7)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations		35.7
Unrecognized tax benefits, which if favorably settled would benefit the effective tax rate		77				77
Interest accrued on unrecognized tax benefits		15.7				15.7		$ 32.9
Unrecognized tax benefits that would impact effective tax rate, upper bound of change		25				25
Income tax penalties and interest accrued that would impact effective tax rate, upper bound of change		6				6
Increase (Decrease) Tax Expense (Benefit), Change in Operating Income		12.3				30
Increase (Decrease), Tax Expense (Benefit), Gain on Debt Repurchases		(1.2)				(10.1)
Increase (Decrease), Tax Expense (Benefit), Restructuring		2.1				2.6
Increase (Decrease), Tax Expense (Benefit), CARES Act		235.7				285.3
Increase (Decrease), Tax Expense (Benefit), Separation Costs		6.5				9.9
Increase (Decrease), Tax Expense (Benefit), Non-restructuring Impairment Charges						8.5
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions		58.6
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities						80.3
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			$ 341.6
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions						4.3
Opioid-Related Litigation Settlement charge [Member]
Income Taxes [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount			202.7			202.7
Medicaid Lawsuit [Member]
Income Taxes [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount			$ 138.9
Cadence Pharmaceuticals, Inc. [Member]
Income Taxes [Line Items]
Business Combination, Consideration Transferred	$ 1,329
Increase (Decrease), Taxable Income						356.5
Income Tax Examination, Penalties and Interest Expense						11.8
Nuclear Imaging
Income Taxes [Line Items]
Income tax benefit		17.3
Unrecognized Tax Benefits, Interest on Income Taxes Expense		18.1
CARES Act [Member]
Income Taxes [Line Items]
Proceeds from Income Tax Refunds						201	$ 117.4
Income tax benefit						(285.3)
Current Income Tax Expense (Benefit)		(234.7)
2020 Intercompany Financing and Legal Reorganization [Member]
Income Taxes [Line Items]
Current Income Tax Expense (Benefit)		44.2
Deferred Income Tax Expense (Benefit)		(12.2)
Deferred Tax Assets, Tax Deferred Expense		$ 312.2				$ 312.2

Earnings per Share (Details)

Earnings per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
Earnings per Share (Details) - shares shares in Millions	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Earnings Per Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5.8	7.1	5.8	7.1
Weighted-average shares outstanding - basic (in shares)	84.6	84	84.4	83.8
Dilutive impact of restricted share units and share options (in shares)	0	0	0	0.4
Weighted-average shares outstanding - diluted (in shares)	84.6	84	84.4	84.2

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
Raw materials and supplies	$ 52.6	$ 62.7
Work in process	204.9	166.5
Finished goods	85.8	82.9
Inventory, Net, Total	$ 343.3	$ 312.1

Property, Plant and Equipment_2

Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
Property, Plant and Equipment
Property, plant and equipment, gross	$ 1,901.2	$ 1,900.1
Less: accumulated depreciation	(1,049.8)	(1,003.6)
Property, plant and equipment, net	$ 851.4	$ 896.5

Property, Plant and Equipment D

Property, Plant and Equipment Depreciation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Property, Plant and Equipment
Depreciation	$ 25.5	$ 24.5	$ 75.7	$ 73.7

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 25, 2020	Jun. 26, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019	Dec. 27, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Non-restructuring impairment charges	$ 0	$ 63.5	$ 0	$ 63.5	$ 113.5
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	10,592.4			10,592.4		$ 10,654.7
Accumulated amortization	4,516.8			4,516.8		3,917
Intangible assets, net	6,355.9			6,355.9		7,018
Non-Amortizable intangible assets, gross	280.3			280.3		280.3
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	35			35		35
In-process Research and Development
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	245.3			245.3		245.3
Completed Technology
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	10,394.6			10,394.6		10,456.9
Accumulated amortization	4,417			4,417		3,822.8
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	77.7			77.7		77.7
Accumulated amortization	22.7			22.7		20.1
Licensing Agreements [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	120.1			120.1		120.1
Accumulated amortization	77.1			77.1		74.1
Ofirmev
Schedule of Intangible Asset by Major Class [Line Items]
Intangible assets, net	26.1			26.1
Terlipressin [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Intangible assets, net	$ 81			$ 81		$ 81

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Schedule of Intangible Asset Amortization Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets	$ 210.6	$ 210.4	$ 599.8	$ 649.8

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets (Schedule of Future Amortization Expense, Intangible Assets) (Details) $ in Millions	Sep. 25, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of Fiscal 2020	$ 171.4
Fiscal 2021	581.1
Fiscal 2022	581.1
Fiscal 2023	581.1
Fiscal 2024	$ 581.1

Debt (Details)

Debt (Details) - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
Current maturities of long-term debt
Debt Issuance Costs, Current, Net		$ 0.9
Long-term Debt, Current Maturities		634.5
Long-term debt
Long-term Debt	$ 0	4,788.3
Total Debt	5,288.2	5,422.8
Debt Issuance Costs	0	47.1
Total Debt Issuance Costs	46.9	48
Term Loan due 2025 \| Secured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	5.3	0.1
Long-term Debt, Current Maturities	400.5	4.1
Long-term debt
Long-term Debt	0	399.5
Debt Issuance Costs	0	6.1
Loans Payable	400.5	403.6
Term Loan due 2024 \| Secured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	13.1	0.2
Long-term Debt, Current Maturities	1,509.1	15.6
Long-term debt
Long-term Debt	0	1,505.2
Debt Issuance Costs	0	15.5
Loans Payable	1,509.1	1,520.8
4.88% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0	0.6
Long-term Debt, Current Maturities	0	614.8
Long-term debt
Long-term Debt		614.8
9.50% Debenture \| Debentures
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0	0
Long-term Debt, Current Maturities	10.4	0
Long-term debt
Long-term Debt	0	10.4
Debt Issuance Costs	0	0
5.75% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	2.5	0
Long-term Debt, Current Maturities	610.3	0
Long-term debt
Long-term Debt	0	610.3
Debt Issuance Costs	0	3.7
8.00% Debenture \| Debentures
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0	0
Long-term Debt, Current Maturities	4.4	0
Long-term debt
Long-term Debt	0	4.4
Debt Issuance Costs	0	0
4.75% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0.6	0
Long-term Debt, Current Maturities	133.7	0
Long-term debt
Long-term Debt	0	133.7
Debt Issuance Costs	0	0.8
5.625% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	3.6	0
Long-term Debt, Current Maturities	514.7	0
Long-term debt
Long-term Debt	0	514.7
Debt Issuance Costs	0	4.4
5.50% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	3.1	0
Long-term Debt, Current Maturities	387.2	0
Long-term debt
Long-term Debt	0	387.2
Debt Issuance Costs	0	3.6
2017 Revolving Credit Facility \| Secured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	2	0
Long-term Debt, Current Maturities	900	0
Long-term debt
Long-term Debt	0	900
Debt Issuance Costs	0	3.1
10.00% Second Lien Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	8.5	0
Long-term Debt, Current Maturities	322.9	0
Long-term debt
Long-term Debt	0	322.9
Debt Issuance Costs	0	9.9
10.00% First Lien Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	8.2	0
Long-term Debt, Current Maturities	495	0
Long-term debt
Long-term Debt	0	0
Debt Issuance Costs	$ 0	$ 0

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	Apr. 15, 2020	Apr. 07, 2020	Sep. 25, 2020
Debt Instrument
Exchange of Debt, Amount		$ 495,000,000
4.88% Senior Notes
Debt Instrument
Debt Instrument, Face Amount		$ 1,000
Repayments of Debt	$ 119,800,000
Debt Instrument, Interest Rate, Stated Percentage		4.875%
4.88% Senior Notes \| 10.00% First Lien Senior Notes
Debt Instrument
Debt Conversion, Converted Instrument, Amount		$ 1,000
10.00% First Lien Senior Notes
Debt Instrument
Debt Instrument, Redemption Price, Percentage		100.00%
Debt Instrument, Interest Rate, Stated Percentage		10.00%
10.00% First Lien Senior Notes \| Maximum
Debt Instrument
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed		40.00%
Unsecured Debt \| 2017 Revolving Credit Facility
Debt Instrument
Line of Credit Facility, Maximum Borrowing Capacity			$ 900,000,000
Option A [Member] \| 10.00% First Lien Senior Notes
Debt Instrument
Debt Instrument, Repurchase Percentage		101.00%
Option B [Member] \| 10.00% First Lien Senior Notes
Debt Instrument
Debt Instrument, Repurchase Percentage		100.00%

Debt (Schedule of Applicable In

Debt (Schedule of Applicable Interest Rates on Variable-rate Debt) (Details) - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
2017 Revolving Credit Facility
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Interest rate	2.52%
Long-term Line of Credit	$ 900
Term Loan due 2025 \| Secured Debt
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time	3.75%
Loans Payable	$ 400.5	$ 403.6
Term Loan due 2024 \| Secured Debt
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time	3.50%
Loans Payable	$ 1,509.1	$ 1,520.8

Guarantees (Details)

Guarantees (Details) - USD ($) $ in Millions	9 Months Ended
Guarantees (Details) - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
Others
Guarantor Obligations [Line Items]
Maximum future payments	$ 31.2
Asset Pledged as Collateral [Member]
Guarantor Obligations [Line Items]
Restricted Cash	$ 37.3
Mallinckrodt Baker \| Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, obligation term	17 years
Maximum future payments	$ 70.2
Escrow Deposit	30
Mallinckrodt Baker \| Indemnification Agreement \| Other current and non-current liabilities
Guarantor Obligations [Line Items]
Guarantors obligation	15.5	$ 15
Mallinckrodt Baker \| Indemnification Agreement \| Other current and non-current assets
Guarantor Obligations [Line Items]
Escrow Deposit	19	18.9
Mallinckrodt Baker \| Environmental, Health and Safety Matters \| Indemnification Agreement \| Other current and non-current liabilities
Guarantor Obligations [Line Items]
Guarantors obligation	$ 12.8	$ 12.3

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details)

Oct. 12, 2020USD ($)

Feb. 25, 2020USD ($)$ / shares

Mar. 19, 2014USD ($)

Sep. 25, 2020USD ($)Case

Jun. 26, 2020USD ($)

Mar. 27, 2020USD ($)

Dec. 27, 2019USD ($)

Sep. 27, 2019USD ($)

Sep. 25, 2020USD ($)Caselawsuit

Sep. 27, 2019USD ($)

Dec. 27, 2019USD ($)

Oct. 11, 2020USD ($)

Apr. 07, 2020

Loss Contingencies [Line Items]

Environmental liabilities

$ 61,300,000

Interest Payable, Installment Sales

28,200,000

$ 47,400,000

28,200,000

$ 47,400,000

Decrease, Interest Payable, Installment Sales

19,200,000

Medicaid lawsuit (Note 11)

640,200,000

Sales [Member]

Loss Contingencies [Line Items]

Medicaid lawsuit (Note 11)

$ 700,000

$ 0

535,100,000

$ 0

Operating Expenses

Loss Contingencies [Line Items]

Medicaid lawsuit (Note 11)

$ 105,100,000

Asbestos Matters

Loss Contingencies [Line Items]

Pending claims | Case

11,800

Estimation of liability, historical term

5 years

Estimation of liability, expected future term of claims

7 years

Marietta, GA Litigation [Member]

Loss Contingencies [Line Items]

Proceeds from Customers

$ 2,000,000

Accrued and other current liabilities

Loss Contingencies [Line Items]

Environmental liabilities, current

$ 1,300,000

Minimum | Environmental Remediation

Loss Contingencies [Line Items]

Loss Contingency, Estimate of Possible Loss

37,800,000

Maximum | Environmental Remediation

Loss Contingencies [Line Items]

Loss Contingency, Estimate of Possible Loss

86,900,000

Questcor Subpoena [Member]

Loss Contingencies [Line Items]

Payments for Legal Settlements

15,400,000

Boston Civil Investigative Demand [Member]

Loss Contingencies [Line Items]

Loss Contingency Accrual

Boston Civil Investigative Demand [Member] | Maximum

Loss Contingencies [Line Items]

Loss Contingency, Estimate of Possible Loss

1,280,000,000

Medicaid Lawsuit [Member]

Loss Contingencies [Line Items]

Loss Contingency Accrual

Decrease in revenue

22,200,000

30,800,000

Medicaid Lawsuit [Member] | Subsequent Event [Member]

Loss Contingencies [Line Items]

Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Total

$ 260,000,000

Medicaid Lawsuit [Member] | Maximum | Subsequent Event [Member]

Loss Contingencies [Line Items]

Loss Contingency, Estimate of Possible Loss

$ 640,000,000

Track 1 Cases [Member]

Loss Contingencies [Line Items]

Payments for Legal Settlements

$ 24,000,000

Loss Contingency Accrual, Product Liability, Gross

6,000,000

Loss Contingency, Accrual, Noncurrent

500,000

$ 500,000

Opioid crisis [Member] | Cities, Counties, and/or Other Government-related Persons/Entities [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

2,618

Opioid crisis [Member] | Hospitals, Health Systems, Unions, Health and Welfare Fund or Third-Party Payers [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

270

Opioid crisis [Member] | Individuals [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

128

Opioid crisis [Member] | Schools and School Boards [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

Opioid crisis [Member] | State Attorney Generals [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

Opioid crisis [Member] | U.S. States [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

247

Opioid Claimant Trust [Member]

Loss Contingencies [Line Items]

Warrant, Exercise Price | $ / shares

$ 3.15

Litigation Settlement, Amount Awarded to Other Party, Settlement Closing Amount

$ 300,000,000

Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Total

1,300,000,000

Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Year One & Two

200,000,000

Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Year Three through Eight

$ 150,000,000

Opioid Claimant Trust [Member] | Maximum

Loss Contingencies [Line Items]

Acquisition of Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners, Quarterly Limit

5.00%

Loss Contingency Accrual

$ 1,600,000,000

1,600,000,000

Warrant Expense, Opioid-related Settlement

$ 9,300,000

$ 43,400,000

New York State Department of Financial Services [Member]

Loss Contingencies [Line Items]

Loss Contingency, Estimate of Possible Loss

$ 5,000

5,000

Humana Inc. [Member] | Acthar

Loss Contingencies [Line Items]

Proceeds from Customers

700,000,000

Cadence Pharmaceuticals, Inc. [Member]

Loss Contingencies [Line Items]

Business Combination, Consideration Transferred

$ 1,329,000,000

Increase (Decrease), Taxable Income

356,500,000

Income Tax Examination, Penalties and Interest Expense

$ 11,800,000

4.88% Senior Notes

Loss Contingencies [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

4.875%

Other Ownership Interest [Member] | Opioid Claimant Trust [Member] | Maximum

Loss Contingencies [Line Items]

Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners

19.99%

Financial Instruments and Fai_3

Financial Instruments and Fair Value Measurements (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 25, 2020	Sep. 25, 2020	Sep. 25, 2020	Dec. 27, 2019	Apr. 07, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent Consideration, Liability, Current		$ 13.2	$ 13.2
Contingent Consideration, Liability, Noncurrent		14	14
4.88% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage					4.875%
StrataGraft [Member] \| Stratatech
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Business Combination, Contingent Consideration, Milestone Payment		20
Level 3 \| Other current and non-current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash surrender value of life insurance		51.3	51.3	$ 51.1
Level 3 \| Recurring \| Questcor Pharmaceuticals, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent liability		0	0	24.5
Level 3 \| StrataGraft [Member] \| Recurring \| Stratatech
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent liability		15.8	15.8	29
Level 3 \| MNK-6105 [Member] \| Recurring \| Ocera [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent consideration		$ 11.4	$ 11.4	15.8
Level 2 \| Debentures \| 8.00% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		8.00%	8.00%
Level 2 \| Debentures \| 9.50% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		9.50%	9.50%
Level 1 \| Senior Notes \| 4.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		4.75%	4.75%
Level 1 \| Senior Notes \| 5.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
Level 1 \| Senior Notes \| 4.88% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		4.875%	4.875%
Level 1 \| Senior Notes \| 5.50% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.50%	5.50%
Level 1 \| Senior Notes \| 10.00% Second Lien Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		10.00%	10.00%
Level 1 \| Unsecured Debt \| 5.625% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.625%	5.625%
Nuclear Imaging \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent Consideration, Equity Certificates		$ 29.8	$ 29.8	18.9
Indemnification Agreement \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Restricted Cash and Cash Equivalents		56.3	56.3	31.7
Indemnification Agreement \| Level 1 \| Other Assets, Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Restricted Cash and Cash Equivalents		20.2	20.2
Indemnification Agreement \| Level 1 \| Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Restricted Cash and Cash Equivalents		36.1	36.1
Novartis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Business Combination, Contingent Consideration, Annual Payments			(25)
Contingent Liabilities \| Level 3 \| Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value adjustment			(2.4)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value		$ 27.2	27.2	$ 69.3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements			$ (45)
Opioid Claimant Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate			60.10%	54.40%
Warrant, Exercise Price	$ 3.15
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate			0.50%	1.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			0.00%	0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term			7 years 7 months 6 days	7 years 7 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 1.14	$ 3.45
Opioid Claimant Trust [Member] \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Acquisition of Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners, Quarterly Limit	5.00%
Other Ownership Interest [Member] \| Opioid Claimant Trust [Member] \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	19.99%

Financial Instruments and Fai_4

Financial Instruments and Fair Value Measurements (Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
Assets:
Other Assets, Fair Value Disclosure	$ 28	$ 26.2
Assets, Fair Value Disclosure	59.8	56.8
Recurring
Assets:
Rabbi Trust Investments, Fair Value Disclosure	31.8	30.6
Liabilities:
Deferred Compensation Liability, Fair Value	33.2	39.2
Contingent consideration and acquired contingent liabilities	27.2	69.3
Settlement Warrants, Fair Value Disclosure	9.3	43.4
Total liabilities at fair value	69.7	151.9
Recurring \| Level 1
Assets:
Rabbi Trust Investments, Fair Value Disclosure	22.5	21
Other Assets, Fair Value Disclosure	28	26.2
Assets, Fair Value Disclosure	50.5	47.2
Liabilities:
Deferred Compensation Liability, Fair Value	0	0
Contingent consideration and acquired contingent liabilities	0	0
Settlement Warrants, Fair Value Disclosure	0	0
Total liabilities at fair value	0	0
Recurring \| Level 2
Assets:
Rabbi Trust Investments, Fair Value Disclosure	9.3	9.6
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	9.3	9.6
Liabilities:
Deferred Compensation Liability, Fair Value	33.2	39.2
Contingent consideration and acquired contingent liabilities	0	0
Settlement Warrants, Fair Value Disclosure	0	0
Total liabilities at fair value	33.2	39.2
Recurring \| Level 3
Assets:
Rabbi Trust Investments, Fair Value Disclosure	0	0
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Liabilities:
Deferred Compensation Liability, Fair Value	0	0
Contingent consideration and acquired contingent liabilities	27.2	69.3
Settlement Warrants, Fair Value Disclosure	9.3	43.4
Total liabilities at fair value	$ 36.5	$ 112.7

Financial Instruments and Fai_5

Financial Instruments and Fair Value Measurements (Schedule of Reconciliation of Changes in Fair Value of Contingent Liabilities) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 25, 2020	Dec. 27, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent Consideration, Liability, Current	$ 13.2
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Contingent Consideration, Liability, Noncurrent	14
Level 3 \| Recurring \| Contingent Liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	69.3
Accretion expense	0.5
Fair value adjustment	2.4
Ending balance	27.2
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	(45)
Questcor Pharmaceuticals, Inc. \| Level 3 \| Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of contingent liability	0	$ 24.5
StrataGraft [Member] \| Stratatech \| Level 3 \| Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of contingent liability	15.8	29
MNK-6105 [Member] \| Ocera [Member] \| Level 3 \| Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Contingent Consideration, Liability	$ 11.4	$ 15.8

Financial Instruments and Fai_6

Financial Instruments and Fair Value Measurements (Schedule of Carrying Amount and Fair Value of Long-term Debt) (Details) - USD ($) $ in Millions	Sep. 25, 2020	Apr. 07, 2020	Dec. 27, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities			$ 634.5
Total debt, fair value	$ 3,740.3		3,840.8
Long-term Debt	0		4,788.3
Total Debt	5,288.2		5,422.8
4.88% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage		4.875%
10.00% First Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage		10.00%
Secured Debt \| Term Loan due 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	1,509.1		15.6
Loans Payable	1,509.1		1,520.8
Long-term Debt	0		1,505.2
Loans Payable, Fair Value Disclosure	1,318.8		1,240
Secured Debt \| 2017 Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	900		0
Total debt, fair value	900		900
Long-term Debt	0		900
Secured Debt \| Term Loan due 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	400.5		4.1
Loans Payable	400.5		403.6
Long-term Debt	0		399.5
Loans Payable, Fair Value Disclosure	349.1		326.2
Unsecured Debt \| 4.88% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	0		614.8
Total debt, fair value	0		480
Long-term Debt			614.8
Unsecured Debt \| 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	610.3		0
Total debt, fair value	159.8		251
Long-term Debt	0		610.3
Unsecured Debt \| 4.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	133.7		0
Total debt, fair value	19.8		53.7
Long-term Debt	0		133.7
Unsecured Debt \| 5.625% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	514.7		0
Total debt, fair value	125.5		193.2
Long-term Debt	0		514.7
Unsecured Debt \| 5.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	387.2		0
Total debt, fair value	93.1		135.5
Long-term Debt	0		387.2
Unsecured Debt \| 10.00% Second Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	322.9		0
Total debt, fair value	252.6		253.8
Long-term Debt	0		322.9
Unsecured Debt \| 10.00% First Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	495		0
Total debt, fair value	516.1		0
Long-term Debt	0		0
Debentures \| 9.50% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	10.4		0
Total debt, fair value	4.2		5.4
Long-term Debt	0		10.4
Debentures \| 8.00% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	4.4		0
Total debt, fair value	1.3		2
Long-term Debt	$ 0		$ 4.4
Level 1 \| Unsecured Debt \| 5.625% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.625%
Level 1 \| Senior Notes \| 4.88% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.875%
Level 1 \| Senior Notes \| 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Level 1 \| Senior Notes \| 4.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Level 1 \| Senior Notes \| 5.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Level 1 \| Senior Notes \| 10.00% Second Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	10.00%
Level 2 \| Debentures \| 9.50% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	9.50%
Level 2 \| Debentures \| 8.00% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	8.00%

Financial Instruments and Fai_7

Financial Instruments and Fair Value Measurements (Schedules of Concentration of Risk) (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019	Dec. 27, 2019
Distributor Concentration Risk \| Revenue from Contract with Customer Benchmark [Member] \| CuraScript, Inc
Concentration Risk
Concentration Risk, Percentage	28.10%	31.10%	27.70%	30.20%
Distributor Concentration Risk \| Accounts Receivable Attributable to Distributors \| Amerisource Bergen Corporation [Member]
Concentration Risk
Concentration Risk, Percentage			26.50%		31.30%
Distributor Concentration Risk \| Accounts Receivable Attributable to Distributors \| McKesson Corporation [Member]
Concentration Risk
Concentration Risk, Percentage			18.10%		15.30%
Distributor Concentration Risk \| Accounts Receivable Attributable to Distributors \| CuraScript, Inc
Concentration Risk
Concentration Risk, Percentage			13.20%		12.10%
Product Concentration Risk \| Net Sales Attributable to Products \| Acthar
Concentration Risk
Concentration Risk, Percentage	27.90%	30.90%	27.90%	30.50%
Product Concentration Risk \| Net Sales Attributable to Products \| Inomax
Concentration Risk
Concentration Risk, Percentage	20.30%	18.40%	21.20%	18.10%
Product Concentration Risk \| Net Sales Attributable to Products \| Ofirmev
Concentration Risk
Concentration Risk, Percentage	12.70%	11.60%	10.50%	11.50%

Segment Data (Schedule of Segme

Segment Data (Schedule of Segment Reporting Information by Business Segment) (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 25, 2020		Jun. 26, 2020	Sep. 27, 2019	Sep. 25, 2020		Sep. 27, 2019
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		$ 698.3			$ 743.7	$ 1,530.6		$ 2,357.6
Operating Income (Loss)		41.5			8.3	(690.3)		(6.2)
Depreciation and amortization		(210.6)			(210.4)	(599.8)		(649.8)
Employee Benefits and Share-based Compensation		(4.3)			(7.8)	(17.6)		(30.6)
Opioid-related litigation settlement (Note 11)		(25.8)			0	(34.1)		0
Non-restructuring impairment charges		0		$ (63.5)	0	(63.5)		(113.5)
Medicaid lawsuit charge						(640.2)
Sales [Member]
Medicaid lawsuit charge		(0.7)			0	(535.1)		0
Medicaid Lawsuit [Member]
Decrease in revenue		22.2				30.8
Specialty Brands
Restructuring and related charges, net		0			0	(0.1)		(0.4)
Specialty Generics
Restructuring and related charges, net		0			(6.7)	(0.1)		(9.3)
Operating Segments
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		699			743.7	2,065.7		2,357.6
Operating Income (Loss)		334.9			313.3	920.5		1,019.6
Operating Segments \| Specialty Brands
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		539.6			580.4	1,553		1,812.4
Operating Income (Loss)		291.8			277	765		894.2
Operating Segments \| Specialty Generics
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		159.4			163.3	512.7		545.2
Operating Income (Loss)		43.1			36.3	155.5		125.4
Corporate, Non-Segment
Corporate and unallocated expenses	[1]	(42.1)			(15.3)	(152.3)		(76.6)
Depreciation and amortization		(236.1)			(234.9)	(675.5)		(723.5)
Restructuring and related charges, net		(3.2)			(7.2)	(15.8)		(11.2)
Separation Costs	[2]	(33)			(19.8)	(75)		(50.4)
Opioid-related litigation settlement (Note 11)		25.8	[3]		0	34.1	[3]	0
R&D Upfront Payment		0	[4]		(20)	(5)	[4]	(20)
Medicaid lawsuit charge		$ 0.5			$ 0	$ 640.2		$ 0

[1]	Includes administration expenses and certain compensation, legal, environmental and other costs not charged to the Company's reportable segments.
[2]	These costs, which are included in SG&A expenses, primarily relate to professional fees, costs incurred in preparation for the Chapter 11 proceedings as the Company works to resolve opioid and other legal uncertainties, incremental costs incurred to build out the corporate infrastructure of the previously planned spin-off of the Company's Specialty Generics segment, as well as rebranding initiatives associated with the Specialty Brands ongoing transformation.
[3]	Represents the change in the Settlement Warrants' fair value. Refer to Note 12 for further information regarding the valuations of the Settlement Warrants.
[4]	Represents R&D expense incurred related to an upfront payment made to acquire product rights in Japan for terlipressin during the nine months ended September 25, 2020 and an upfront payment made to Silence in connection with the license and collaboration agreement entered into during the three and nine months ended September 27, 2019.

Segment Data (Schedule of Net S

Segment Data (Schedule of Net Sales from External Customers by Products) (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 25, 2020		Sep. 27, 2019		Sep. 25, 2020		Sep. 27, 2019
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		$ 698.3		$ 743.7		$ 1,530.6		$ 2,357.6
Medicaid lawsuit (Note 11)						640.2
Sales [Member]
Segment Reporting Information
Medicaid lawsuit (Note 11)		0.7		0		535.1		0
Medicaid Lawsuit [Member]
Segment Reporting Information
Decrease in revenue		22.2				30.8
Operating Segments
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		699		743.7		2,065.7		2,357.6
Operating Segments \| Specialty Generics
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		159.4		163.3		512.7		545.2
Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		539.6		580.4		1,553		1,812.4
Corporate, Non-Segment
Segment Reporting Information
Medicaid lawsuit (Note 11)		(0.5)		0		(640.2)		0
Acthar \| Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		195.3	[1]	229.8		576.6	[1]	720.1
Inomax \| Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		141.9		136.8		438.5		427.6
Ofirmev \| Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		88.7		86.1		216		272.2
Therakos immunotherapy \| Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		62.6		60.9		174.1		183.6
Amitiza [Member] \| Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)	[2]	47.7		52.6		138.2		157.6
BioVectra Inc [Member] \| Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)				10.5				36.8
Other \| Operating Segments \| Specialty Generics
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		6		9		14.5		31.9
Other \| Operating Segments \| Specialty Brands
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		3.4		14.2	[3]	9.6		51.3	[3]
Hydrocodone (API) [Member] \| Operating Segments \| Specialty Generics
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		20		15.7		71.9		51.2
Oxycodone (API) [Member] \| Operating Segments \| Specialty Generics
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		16.1		17.2		48		53.3
Acetaminophen (API) [Member] \| Operating Segments \| Specialty Generics
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		54.9		48.5		154.5		143.1
Other Controlled Substances [Member] \| Operating Segments \| Specialty Generics
Segment Reporting Information
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		$ 62.4		$ 72.9		$ 223.8		$ 265.7

[1]	The three and nine months ended September 25, 2020 includes the prospective change to the Medicaid rebate calculation beginning in June 2020, which impacted Acthar Gel net sales by $22.2 million and $30.8 million, respectively. See Note 11 for further detail on the status of the Medicaid lawsuit.
[2]	Amitiza consists of both product net sales and royalties. Refer to Note 2 for further details on Amitiza's revenues.
[3]	The three and nine months ended September 27, 2019 includes $10.5 million and $36.8 million of net sales, respectively, related to BioVectra prior to the completion of the sale of this business in November 2019.

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Millions	Oct. 12, 2020	Oct. 11, 2020	Feb. 25, 2020	Dec. 25, 2020	Sep. 25, 2020	Dec. 27, 2019
Subsequent Event [Line Items]
Long-term Debt					$ 0	$ 4,788.3
Opioid Claimant Trust [Member]
Subsequent Event [Line Items]
Litigation Settlement, Amount Awarded to Other Party, Settlement Closing Amount			$ 300
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Year One & Two			200
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Year Three through Eight			150
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Total			$ 1,300
Opioid Claimant Trust [Member] \| Maximum
Subsequent Event [Line Items]
Loss Contingency Accrual						1,600
Opioid Claimant Trust [Member] \| Maximum \| Other Ownership Interest [Member]
Subsequent Event [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			19.99%
Medicaid Lawsuit [Member]
Subsequent Event [Line Items]
Loss Contingency Accrual					0
Subsequent Event [Member] \| Medicaid Lawsuit [Member]
Subsequent Event [Line Items]
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Total	$ 260
Subsequent Event [Member] \| Medicaid Lawsuit [Member] \| Maximum
Subsequent Event [Line Items]
Loss Contingency, Estimate of Possible Loss		$ 640
Subsequent Event [Member] \| Restructuring Support Agreement [Member]
Subsequent Event [Line Items]
Litigation Settlement, Amount Awarded to Other Party		150
Notes Reduction		1,300
Subsequent Event [Member] \| Restructuring Support Agreement [Member] \| Opioid Claimant Trust [Member]
Subsequent Event [Line Items]
Litigation Settlement, Amount Awarded to Other Party, Settlement Closing Amount		450
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Year One & Two		200
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Year Three through Eight		150
Subsequent Event [Member] \| Restructuring Support Agreement [Member] \| Opioid Claimant Trust [Member] \| Maximum
Subsequent Event [Line Items]
Loss Contingency Accrual		1,600
Equity Value of Opioid Claimants' Ownership		$ 1,551
Subsequent Event [Member] \| Restructuring Support Agreement [Member] \| Opioid Claimant Trust [Member] \| Maximum \| Other Ownership Interest [Member]
Subsequent Event [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		19.99%
Unsecured Debt
Subsequent Event [Line Items]
Interest Paid, Excluding Capitalized Interest, Operating Activities					$ 64.2	$ 147.3
Unsecured Debt \| Subsequent Event [Member]
Subsequent Event [Line Items]
Interest Paid, Excluding Capitalized Interest, Operating Activities				$ 28.8
Unsecured Debt \| Subsequent Event [Member] \| Restructuring Support Agreement [Member]
Subsequent Event [Line Items]
Holders of Principal Debt, Percentage		84.00%
Secured Debt \| Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)	200.00%
Secured Debt \| Subsequent Event [Member] \| Restructuring Support Agreement [Member]
Subsequent Event [Line Items]
Long-term Debt		$ 375
Long-term Debt, Term		7 years