Casa Systems (CASSQ) 10-K25 Feb 212020 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2020	Jan. 29, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Registrant Name	Casa Systems, Inc.
Entity Central Index Key	0001333835
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	false
Entity Public Float			$ 126.4
Entity Common Stock, Shares Outstanding		84,009,729
Entity File Number	001-38324
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	75-3108867
Entity Address, Address Line One	100 Old River Road
Entity Address, City or Town	Andover
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01810
City Area Code	978
Local Phone Number	688-6706
Document Annual Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	CASA
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	Portions of the Registrant’s definitive proxy statement relating to its 2021 Annual Stockholders’ Meeting expected to be filed pursuant to Regulation 14A within 120 days after the Registrant’s fiscal year end of December 31, 2020 are incorporated by reference into Part III of this Annual Report on Form 10-K.

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 157,455	$ 113,638
Accounts receivable, net of provision for doubtful accounts of $58 and $20 as of December 31, 2020 and 2019, respectively	94,124	93,100
Inventory	101,204	93,604
Prepaid expenses and other current assets	3,864	4,884
Prepaid income taxes	14,087	3,217
Total current assets	370,734	308,443
Property and equipment, net	28,880	35,910
Accounts receivable, net of current portion	143	575
Deferred tax assets	1,150	69
Goodwill	50,177	50,347
Intangible assets, net	35,844	41,148
Other assets	6,038	7,820
Total assets	492,966	444,312
Current liabilities:
Accounts payable	41,203	25,890
Accrued expenses and other current liabilities	39,793	34,567
Accrued income taxes	7,463
Deferred revenue	15,531	25,485
Current portion of long-term debt, net of unamortized debt issuance costs	15,171	8,524
Total current liabilities	119,161	94,466
Accrued income taxes, net of current portion	9,520	12,381
Deferred tax liabilities	7,282	8,993
Deferred revenue, net of current portion	3,520	4,583
Long-term debt, net of current portion and unamortized debt issuance costs	276,085	284,756
Other non-current liabilities	1,024	569
Total liabilities	416,592	405,748
Commitments and contingencies (Note 18)
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares issued and outstanding
Common stock, $0.001 par value; 500,000 shares authorized; 85,329 and 84,333 shares issued as of December 31, 2020 and 2019, respectively; 83,607 and 83,838 shares outstanding as of December 31, 2020 and 2019, respectively	85	84
Treasury stock, at cost; 1,722 and 495 shares at December 31, 2020 and 2019, respectively	(4,826)	(1,795)
Additional paid-in capital	183,041	169,561
Accumulated other comprehensive income (loss)	337	(2,222)
Accumulated deficit	(102,263)	(127,064)
Total stockholders’ equity	76,374	38,564
Total liabilities and stockholders’ equity	$ 492,966	$ 444,312

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Provision for doubtful accounts	$ 58	$ 20
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares, outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	85,329,000	84,333,000
Common stock, shares outstanding	83,607,000	83,838,000
Treasury stock, shares	1,722,000	495,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue	$ 393,246	$ 282,297	$ 297,127
Cost of revenue:
Total cost of revenue	192,647	119,765	79,161
Gross profit	200,599	162,532	217,966
Operating expenses:
Research and development	84,370	83,331	70,974
Selling, general and administrative	92,016	88,320	68,026
Total operating expenses	176,386	171,651	139,000
Income (loss) from operations	24,213	(9,119)	78,966
Other income (expense):
Interest income	999	4,406	6,259
Interest expense	(16,895)	(20,522)	(19,763)
Gain (loss) on foreign currency, net	452	298	(911)
Other income, net	980	522	1,387
Total other income (expense), net	(14,464)	(15,296)	(13,028)
Income (loss) before (benefit from) provision for income taxes	9,749	(24,415)	65,938
(Benefit from) provision for income taxes	(15,052)	23,791	(7,068)
Net income (loss)	24,801	(48,206)	73,006
Other comprehensive income (loss) —foreign currency translation adjustment, net of tax	2,559	(1,064)	(1,352)
Comprehensive income (loss)	27,360	(49,270)	71,654
Net income (loss) attributable to common stockholders:
Basic and diluted	$ 24,801	$ (48,206)	$ 73,006
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.30	$ (0.57)	$ 0.87
Diluted	$ 0.29	$ (0.57)	$ 0.79
Weighted-average number of shares used to compute net income (loss) per share attributable to common stockholders:
Basic	83,465	83,853	83,539
Diluted	85,278	83,853	91,877
Product
Revenue:
Total revenue	$ 346,083	$ 241,377	$ 256,989
Cost of revenue:
Total cost of revenue	187,706	113,059	74,350
Service
Revenue:
Total revenue	47,163	40,920	40,138
Cost of revenue:
Total cost of revenue	$ 4,941	$ 6,706	$ 4,811

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Accumulated DeficitCumulative Effect, Period of Adoption, Adjustment
Balance at Dec. 31, 2017	$ 50,156		$ 81		$ 128,798	$ 194	$ (78,917)
Balance, shares at Dec. 31, 2017			81,043
Exercise of stock options and common stock issued upon vesting of equity awards, net of shares withheld for employee taxes	14,716		$ 7		14,709
Exercise of stock options and common stock issued upon vesting of equity awards, net of shares withheld for employee taxes, shares			7,090
Foreign currency translation adjustment, net of tax	(1,352)					(1,352)
Follow-on offering selling stockholders profit disgorgement, net of offering costs of $41	3,770				3,770
Stock repurchase program	(75,102)		$ (5)				(75,097)
Stock repurchase program, shares			(5,172)
Stock-based compensation	9,662				9,662
Net income (loss)	73,006						73,006
Balance at Dec. 31, 2018	74,856	$ 2,150	$ 83		156,939	(1,158)	(81,008)	$ 2,150
Balance, shares at Dec. 31, 2018			82,961
Exercise of stock options and common stock issued upon vesting of equity awards, net of shares withheld for employee taxes	1,679		$ 1		1,678
Exercise of stock options and common stock issued upon vesting of equity awards, net of shares withheld for employee taxes, shares			1,372
Foreign currency translation adjustment, net of tax	(1,064)					(1,064)
Repurchases of treasury shares	(1,795)			$ (1,795)
Repurchases of treasury shares, shares				495
Stock-based compensation	10,944				10,944
Net income (loss)	(48,206)						(48,206)
Balance at Dec. 31, 2019	$ 38,564		$ 84		169,561	(2,222)	(127,064)
Balance, shares at Dec. 31, 2019			84,333
Balance Treasury, shares at Dec. 31, 2019	495			495
Balance Treasury at Dec. 31, 2019	$ 1,795			$ (1,795)
Exercise of stock options and common stock issued upon vesting of equity awards, net of shares withheld for employee taxes	555		$ 1		554
Exercise of stock options and common stock issued upon vesting of equity awards, net of shares withheld for employee taxes, shares			996
Foreign currency translation adjustment, net of tax	2,559					2,559
Repurchases of treasury shares	(3,031)			$ (3,031)
Repurchases of treasury shares, shares				1,227
Stock-based compensation	12,926				12,926
Net income (loss)	24,801						24,801
Balance at Dec. 31, 2020	$ 76,374		$ 85		$ 183,041	$ 337	$ (102,263)
Balance, shares at Dec. 31, 2020			85,329
Balance Treasury, shares at Dec. 31, 2020	1,722			1,722
Balance Treasury at Dec. 31, 2020	$ 4,826			$ (4,826)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Stockholders Equity [Abstract]
Foreign currency translation adjustment, tax	$ (49)	$ 261	$ (343)
Follow-on offering selling shareholders profit disgorgement, offering costs			$ 41

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)		$ 24,801		$ (48,206)		$ 73,006
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization		17,970		14,722		9,454
Stock-based compensation		13,155		9,821		8,894
Deferred income taxes		(2,526)		19,641		(11,517)
Change in provision for excess and obsolete inventory		1,616		545		(5,883)
Increase (decrease) in provision for doubtful accounts		38		560		(282)
Gain on disposal of assets		115
Changes in operating assets and liabilities:
Accounts receivable		(350)		1,881		34,716
Inventory		(9,774)		(21,276)		(11,051)
Prepaid expenses and other assets		2,837		(3,679)		(1,084)
Prepaid income taxes		(11,745)		16		146
Accounts payable		17,015		1,554		4,197
Accrued expenses and other current liabilities		6,254		(7,827)		6,124
Accrued income taxes		5,297		2,724		(3,088)
Deferred revenue		(11,061)		(9,498)		(5,087)
Net cash provided by (used in) operating activities		53,642		(39,022)		98,545
Cash flows used in investing activities:
Purchases of property and equipment		(5,153)		(8,591)		(7,966)
Purchases of intangible assets		(432)
Acquisition of a business, net of cash acquired				(109,431)
Net cash used in investing activities		(5,585)		(118,022)		(7,966)
Cash flows used in financing activities:
Principal repayments of debt		(9,644)		(6,820)		(3,304)
Drawdowns on revolving credit facility		6,500
Proceeds from exercise of stock options		1,195		2,687		14,730
Payments of dividends and equitable adjustments		(683)		(2,590)		(7,325)
Follow-on offering selling stockholders profit disgorgement						3,811
Repurchases of common stock		(3,031)		(1,795)		(75,102)
Payments of initial public offering costs		0		0		(1,148)
Employee taxes paid related to net share settlement of equity awards		(640)		(1,009)		(13)
Net cash used in financing activities		(6,303)		(9,527)		(68,351)
Effect of exchange rate changes on cash and cash equivalents		2,050		(378)		(1,442)
Net increase (decrease) in cash, cash equivalents and restricted cash		43,804		(166,949)		20,786
Cash, cash equivalents and restricted cash at beginning of year		114,657	[1]	281,606	[1]	260,820
Cash, cash equivalents and restricted cash at end of year	[1]	158,461		114,657		281,606
Supplemental disclosures of cash flow information:
Cash paid for interest		12,917		18,885		18,348
Cash paid for income taxes		2,969		4,334		7,268
Supplemental disclosures of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable		128		727		1,255
Unpaid dividends and equitable adjustments included in accrued expenses and other current liabilities		63		731		3,336
Release of customer incentives included in accounts receivable and accrued expenses and other current liabilities		$ 157		$ 5,735		$ 8,556

[1]	See Note 2 of the accompanying notes for a reconciliation of the ending balance of cash, cash equivalents and restricted cash shown in these consolidated statements of cash flows.

Nature of Business and Basis of

Nature of Business and Basis of Presentation	12 Months Ended
Nature of Business and Basis of Presentation	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Casa Systems, Inc. (the “Company”) was incorporated under the laws of the State of Delaware on February 28, 2003. The Company is a global communications technology company headquartered in Andover, Massachusetts and has wholly owned subsidiaries in China, France, Canada, Ireland, Spain, Colombia, the Netherlands, Hong Kong, Australia, Germany, the United Kingdom and New Zealand. The Company offers physical, virtual and cloud-native 5G infrastructure and customer premise networking equipment for public and private high-speed data and multi-service communications networks. The Company’s core and edge convergence technology enables communications service providers and enterprises to cost-effectively and dynamically increase network speed, add bandwidth capacity and new services, reduce network complexity and reduce operating and capital expenditures. The Company is subject to a number of risks similar to other companies of comparable size and other companies selling and providing services to the communications industry. These risks include, but are not limited to, the level of capital spending by the communications industry, a lengthy sales cycle, dependence on the development of new products and services, unfavorable economic and market conditions, competition from larger and more established companies, limited management resources, dependence on a limited number of contract manufacturers and suppliers, the rapidly changing nature of the technology used by the communications industry and reliance on resellers and sales agents. Failure by the Company to anticipate or to respond adequately to technological developments in its industry, changes in customer or supplier requirements, changes in regulatory requirements or industry standards, or any significant delays in the development or introduction of products could have a material adverse effect on the Company’s operating results, financial condition and cash flows. The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”), and may remain an emerging growth company until the last day of the fiscal year following the fifth anniversary of the initial public offering, subject to specified conditions. The JOBS Act provides that an emerging growth company can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected not to “opt out” of such extended transition period, which means that when a standard is issued or revised and it has different application dates for public or private companies, the Company will adopt the new or revised standard at the time private companies adopt the new or revised standard, provided that the Company continues to be an emerging growth company. The JOBS Act provides that the decision to take advantage of the extended transition period for complying with new or revised accounting standards is irrevocable. The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts and results of operations of the Company and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and judgments relied upon by management in preparing these consolidated financial statements include revenue recognition, provision for doubtful accounts, reserves for excess and obsolete inventory, valuation of inventory and deferred inventory costs, the expensing and capitalization of software-related research and development costs, amortization and depreciation periods, the recoverability of net deferred tax assets, valuations of uncertain tax positions, warranty allowances, the valuation of equity instruments and stock-based compensation expense. Although the Company regularly reassesses the assumptions underlying these estimates, actual results could differ materially from these estimates. Changes in estimates are recorded in the period in which they become known. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances existing at the time such estimates are made . The emergence of COVID-19 around the world, and particularly in the United States and China, presents various risks to the Company, not all of which the Company is able to fully evaluate or even to foresee at the current time, and could have a material effect upon the estimates and judgments relied upon by management in preparing these consolidated financial statements. While the COVID-19 pandemic did not significantly adversely affect the Company’s financial results and business operations in the year ended December 31, 2020, economic and health conditions in the United States and across most of the globe changed rapidly during the year, and are continuing to change after the end of the year. Globally, all aspects of the Company’s business remain fully operational. However, increasing demand for certain of the Company’s products has increased pressure on its supply chain which could impact continued availability of inventory requirements. The Company will continue to monitor its business very closely for any effects of COVID-19 for as long as necessary on an ongoing basis. Subsequent Event Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. The Company has evaluated all subsequent events and determined that there are no material recognized or unrecognized subsequent events requiring disclosure in these consolidated financial statements. Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents include all highly liquid investments maturing within three months from the date of purchase. As of December 31, 2020 and 2019, the Company’s cash and cash equivalents consisted of investments in certificates of deposit and money market mutual funds. Restricted cash, which was included in other assets as of December 31, 2020 and 2019, consisted of a certificate of deposit of $1,006 and $1,019, respectively, in each period pledged as collateral for a stand-by letter of credit required to support a contractual obligation. The following table is a reconciliation of cash, cash equivalents and restricted cash included in the accompanying consolidated balance sheets that sum to the total cash, cash equivalents and restricted cash included in the accompanying consolidated statements of cash flows. December 31, 2020 December 31, 2019 Cash and cash equivalents $ 157,455 $ 113,638 Restricted cash included in other assets 1,006 1,019 $ 158,461 $ 114,657 Accounts Receivable Accounts receivable are presented net of a provision for doubtful accounts, which is an estimate of amounts that may not be collectible. Accounts receivable for arrangements with customary payment terms, which are one year or less, are recorded at invoiced amounts and do not bear interest. The Company generally does not require collateral, but may, in certain instances based on its credit assessment, require full or partial prepayment prior to shipment. The Company may, in limited circumstances, grant payment terms longer than one year. Payments due beyond 12 months from the balance sheet date are recorded as non-current assets. Accounts receivable as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Current portion of accounts receivable, net: Accounts receivable, net $ 93,480 $ 91,273 Accounts receivable, extended payment arrangements 644 1,827 94,124 93,100 Accounts receivable, net of current portion: Accounts receivable, extended payment arrangements 143 575 $ 94,267 $ 93,675 The Company performs ongoing credit evaluations of its customers and, if necessary, provides a provision for doubtful accounts and expected losses. When assessing and recording its provision for doubtful accounts, the Company evaluates the age of its accounts receivable, current economic trends, creditworthiness of customers, customer payment history, and other specific customer and transaction information. The Company writes off accounts receivable against the provision when it determines a balance is uncollectible and no longer actively pursues collection of the receivable. Adjustments to the provision for doubtful accounts are recorded as selling, general and administrative expenses in the consolidated statements of operations and comprehensive income (loss). A summary of changes in the provision for doubtful accounts for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Provision for doubtful accounts at beginning of year $ 20 $ 410 $ 692 Provisions and recoveries 38 560 — Write-offs — (950 ) (282 ) Provision for doubtful accounts at end of year $ 58 $ 20 $ 410 As of December 31, 2020 and 2019, the Company concluded that all amounts due under extended payment term arrangements were collectible and no reserve for credit losses was recorded. During the years ended December 31, 2020, 2019 and 2018, the Company did not provide a reserve for credit losses and did not write off any uncollectible receivables due under extended payment term arrangements. Inventories The Company values inventories at the lower of cost or market value. The Company computes cost using the first-in first-out convention. Inventories are composed of hardware and related component parts of finished goods. The Company establishes provisions for excess and obsolete inventories after evaluating historical sales, future demand, market conditions, expected product life cycles, and current inventory levels to reduce such inventories to their estimated net realizable value. The Company makes such provisions in the normal course of business and charges them to cost of revenue in its consolidated statements of operations and comprehensive income (loss). The Company includes deferred inventory costs within inventory in its consolidated balance sheets. Deferred inventory costs represent the cost of products that have been delivered to the customer for which revenue associated with the arrangement has been deferred as a result of not meeting all of the required revenue recognition criteria, such as receipt of customer acceptance. The Company recognizes deferred inventory costs as cost of revenue in its consolidated statements of operations and comprehensive income (loss) when the related revenue is recognized. Property and Equipment The Company states property and equipment at historical cost less accumulated depreciation. The Company computes depreciation using the straight-line method over the estimated useful lives of the assets. The Company records leasehold improvements at cost with any reimbursement from the landlord being accounted for as deferred rent, which is amortized using the straight-line method over the lease term. The Company also includes costs for trial systems held and used by its customers pursuant to evaluation agreements within property and equipment. The Company depreciates trial systems held and used by its customers over the estimated useful life of such assets, which is two years. Whenever a trial system is sold to a customer and the selling price is recorded as revenue, the Company removes the related net book value of the trial system sold from property and equipment and records it as a cost of revenue. The Company expenses maintenance and repairs expenditures as incurred. Estimated useful lives of the respective property and equipment assets are as follows: Estimated Useful Life Computers and purchased software 3 – 4 years Leasehold improvements Shorter of lease term or 7 years Furniture and fixtures 6 – 8 years Machinery and equipment 3 – 5 years Building 40 years Building improvements 5 – 40 years Trial systems at customers’ sites 2 years Upon retirement or sale, the Company removes the cost of assets disposed of and the related accumulated depreciation from the accounts and any resulting gain or loss is included in income (loss) from operations. Impairment of Long-Lived Assets The Company evaluates its long-lived assets, which consist primarily of property and equipment and intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. The Company measures recoverability of assets to be held and used by a comparison of the carrying amount of an asset to the future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the Company measures the impairment to be recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset, less the cost to sell. No events or changes in circumstances existed to require an impairment assessment during the years ended December 31, 2020, 2019 and 2018. Deferred Offering Costs The Company paid deferred offering costs of $1,148 during the year ended December 31, 2018. No deferred offering costs were paid during the years ended December 31, 2020 and 2019. Concentration of Risks Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. Cash and cash equivalents consist of demand deposits, savings accounts, commercial paper, money market mutual funds, and certificates of deposit with financial institutions, which may exceed Federal Deposit Insurance Corporation limits. The Company has not experienced any losses related to its cash and cash equivalents and does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. We grant credit to customers in the ordinary course of business. Credit evaluations are performed on an ongoing basis to reduce credit risk, and no collateral is required from our customers. An allowance for uncollectible accounts is provided for those accounts receivable considered to be uncollectible based upon historical experience and credit evaluation. Due to these factors, no additional losses beyond the amounts provided for collection losses is believed by management to be probable in the Company’s accounts receivable. Significant customers are those that represent 10% or more of revenue or accounts receivable and are set forth in the following tables: Revenue Accounts Receivable, Net Year Ended December 31, December 31, 2020 2019 2018 2020 2019 Customer A * 14 % 27 % * 11 % Customer B * * 11 % * * Customer C * * 12 % * 14 % Customer D * * 14 % * * Customer E * * * * 19 % Customer F 20 % 12 % * * * Customer G 11 % * * 14 % * * Less than 10% of total Customer B was a related party until October 19, 2018, Liberty Global Affiliates (see Note 17). Certain of the components and subassemblies included in the Company’s products are obtained from a single source or a limited group of suppliers. Although the Company seeks to reduce dependence on those limited sources of suppliers and manufacturers, the partial or complete loss of certain of these sources could have a material adverse effect on the Company’s operating results, financial condition and cash flows and damage its customer relationships. Goodwill and Intangible Assets Goodwill represents the excess purchase price over the estimated fair value of net assets acquired as of the acquisition date. Goodwill has been recorded in connection with the acquisition of NetComm on July 1, 2019 (refer to Note 3). The Company tests goodwill for impairment on an annual basis and between annual tests when impairment indicators are identified, and goodwill is written down when impaired. The Company performs its annual goodwill impairment test during its fourth quarter. For its annual goodwill impairment test, the Company operates under one reporting unit and the fair value of its reporting unit has been determined based on the Company’s enterprise value. As part of the annual goodwill impairment test, the Company has the option to perform a qualitative assessment to determine whether further impairment testing is necessary. Examples of events and circumstances that might indicate that the reporting unit’s fair value is less than its carrying amount include macro-economic conditions such as deterioration in the entity’s operating environment or industry or market considerations; entity-specific events such as increasing costs, declining financial performance, or loss of key personnel; or other events such as a sustained decrease in the stock price on either an absolute basis or relative to peers. If, as a result of its qualitative assessment, it is more likely than not (i.e., greater than 50% chance) that the fair value of the Company’s reporting unit is less than its carrying amount, the quantitative impairment test will be required. Otherwise, no further testing will be required. The Company completed its qualitative assessment and concluded that as of December 31, 2020, it is not more likely than not that the fair value of the Company’s reporting unit is less than its carrying amount. The Company amortizes its acquired intangible assets subject to amortization using the straight-line method over their estimated useful lives, ranging from 3 to 10 years. Purchased software licenses are classified as intangible assets and are amortized using the straight-line method over their estimated useful lives, typically ranging from 3 to 4 years. The Company evaluates the recoverability of intangible assets periodically by taking into account events or circumstances that may warrant revised estimates of useful lives or that indicate the asset may be impaired. The Company considered potential impairment indicators of acquired intangible assets at December 31, 2020 and noted no indicators of impairment. Product Warranties Substantially all of the Company’s products are covered by a warranty for software and hardware for periods ranging from 90 days to one year. In addition, in conjunction with customers’ renewals of maintenance and support contracts, the Company offers an extended warranty for periods typically of one to three years for agreed-upon fees. In the event of a failure of a hardware product or software covered by these warranties, the Company must repair or replace the software or hardware or, if those remedies are insufficient, and at the discretion of the Company, provide a refund. The Company’s warranty reserve, which is included in accrued expenses and other current liabilities in the consolidated balance sheets, reflects estimated material, labor and other costs related to potential or actual software and hardware warranty claims for which the Company expects to incur an obligation. The Company’s estimates of anticipated rates of warranty claims and the costs associated therewith are primarily based on historical information and future forecasts. The Company periodically assesses the adequacy of the warranty reserve and adjusts the amount as necessary. If the historical data used to calculate the adequacy of the warranty reserve are not indicative of future requirements, additional or reduced warranty reserves may be required. A summary of changes in the amount reserved for warranty costs for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Warranty reserve at beginning of year $ 2,448 $ 926 $ 1,246 Provisions 2,745 3,603 1,886 Acquired warranty reserve — 1,867 — Charges (2,839 ) (3,948 ) (2,206 ) Warranty reserve at end of year $ 2,354 $ 2,448 $ 926 The increase in the warranty charges and reserve for the year ended December 31, 2019 is primarily due to warranty obligations obtained with the acquisition of NetComm on July 1, 2019. Revenue Recognition Effective January 1, 2019, the Company adopted ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”) using the modified retrospective transition method. This method was applied to contracts that were not complete as of the date of initial application. The following is a summary of new and/or revised significant accounting policies affected by the Company’s adoption of ASC 606, which relate primarily to revenue and cost recognition. Refer to Note 2, Summary of Significant Accounting Policies, in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 for the policies in effect for revenue and cost recognition prior to January 1, 2019. The Company generates revenue from sales of its products, along with associated maintenance, support and extended hardware warranty services, and to a lesser extent, from sales of professional services. The Company also generates revenue from sales of additional line cards and software-based capacity expansions. Maintenance and support services include telephone support, bug fixes and unspecified software upgrades and updates provided on a when-and-if-available basis and/or extended hardware warranty. In its consolidated statements of operations and comprehensive income (loss), the Company classifies revenue from sales of cable products and fixed wireless access and fixed telco devices as product revenue, and revenue from maintenance and support and professional services as service revenue. In accordance with ASC 606, the Company recognizes revenue when a customer obtains control of promised products or services. The amount of revenue recognized reflects the consideration that the Company expects to be entitled to receive in exchange for these products or services. To achieve the core principle of this standard, the Company applies the following five steps: 1) Identify the contract with a customer 2) Identify the performance obligations in the contract 3) Determine the transaction price includes v ariable consideration in the transaction price if, in its judgment, it is probable that no significant future reversal of cumulative revenue under the contract will occur . 4) Allocate the transaction price to performance obligations in the contract 5) Recognize revenue when or as the Company satisfies a performance obligation Performance Obligations The majority of the Company’s contracts with customers contain multiple performance obligations including products and maintenance services, and on a limited basis, professional services. For these contracts, the Company accounts for individual performance obligations separately if they are considered distinct. The Company’s cable, wireless and fixed telco products, maintenance services and professional services are considered distinct performance obligations. When multiple performance obligations exist in a customer contract, the Company allocates the transaction price to the separate performance obligations on a relative SSP basis. The Company determines SSP using its judgment and based on the best evidence available, which may include the selling price of products when sold on a standalone basis to similar customers in similar circumstances, or in the absence of standalone sales, taking into consideration the Company’s historical pricing practices by customer type, selling method (i.e. resellers or direct), and geographic-specific market factors. Product revenue The Company’s cable, wireless and fixed telco products generally have both software and non-software (i.e., hardware) components that function together to deliver the products’ essential functionality. The Company’s hardware generally cannot be used apart from the embedded software and is considered one distinct performance obligation. The Company recognizes revenue for both new and existing customers at a point in time when control of the products is transferred to the customer, which is typically when title and risk of loss have transferred and the right to payment is enforceable. The Company also earns revenue from the sale of perpetual software licenses and/or software-enabled capacity expansions. Revenue on perpetual software licenses and software-enabled capacity expansions for existing customers are also distinct performance obligations as they are separately identifiable and provide additional bandwidth capacity on hardware products already purchased by the customer. The Company recognizes revenue on perpetual software licenses and software-enabled capacity expansions when control is transferred, which is typically as the software entitlements are made available to the customer. When customer contracts require acceptance of product and services, the Company considers the nature of the acceptance provisions to determine if they are substantive or considered perfunctory to determine if these acceptance provisions impact the timing of revenue recognition. When acceptance provisions are considered substantive, the Company will defer revenue on all performance obligations in the contract subject to acceptance until acceptance has been received. The Company does not defer revenue when acceptance provisions are deemed perfunctory. Maintenance and Support Services and Professional Services Revenue The Company generally sells its products with maintenance and support services, a distinct performance obligation that includes the stand-ready obligation to provide telephone support, bug fixes and unspecified software upgrades and updates provided on a when-and-if-available basis and/or extended hardware warranty. After the initial sale, customers may purchase annual renewals of support contracts. The Company’s telephone support and unspecified upgrades and updates are delivered over time and the Company therefore recognizes revenue ratably over the contract term, which is typically one year, but can be as long as five years. The Company also generates revenue from sales of professional services, such as installation, configuration and training. Professional services are a distinct performance obligation since the Company’s products are functional without these services and can generally be performed by the customer or a third party. The Company generally recognizes fee-based professional services delivered at a point in time as the professional services are completed and upon receipt of acceptance if applicable. The sale of the Company’s products generally includes a 90-day warranty on the software and a one-year obligation. The Company records a warranty accrual for the initial software and hardware warranty included with product sales and does not defer revenue . Resellers and Sales Agents The Company markets and sells its products through its direct global sales force, supported by sales agents, and through resellers. The Company’s resellers receive an order from an end customer prior to placing an order with the Company, and the Company confirms the identification of or is aware of the end customer prior to accepting such order. The Company invoices the reseller an amount that reflects a reseller discount and records revenue based on the amount of the discounted transaction value. Aside from wireless and fixed telco hardware products, the Company’s resellers do not stock inventory received from the Company. When the Company transacts with a reseller, the contract is with the reseller and not with the end customer. Whether the Company transacts business with and receives the order directly from the reseller or a customer, its revenue recognition policy and resulting pattern of revenue recognition for the order are the same. The Company has assessed whether it is principal (i.e., reports revenue on a gross basis) or agent (i.e., reports revenues on a net basis) by evaluating whether it has control of the good or service before it is transferred to the reseller. Generally, the Company controls the promised good or service before transferring it to the reseller and acts as the principal in the transaction. Accordingly, the Company reports revenues on a gross basis. The Company also uses sales agents that assist in the sales process with certain customers, primarily located in the Latin America and Asia-Pacific regions. Sales agents are not resellers. If a sales agent is engaged in the sales process, the Company receives the order directly from the end customer and sells the products and services directly to the end customer, and the Company pays a commission to the sales agent, calculated as a percentage of the related transaction value. Accounting considerations related to sales agent commissions are discussed in the “Costs to Obtain or Fulfill a Contract” section below. Costs to Obtain or Fulfill a Contract The Company capitalizes commission expenses paid to internal sales personnel and sales agent commissions that are incremental to obtaining customer contracts, for which the related revenue is recognized over a future period greater than 12 months. These costs are incurred on initial sales of product, professional services and maintenance and support contract renewals. The Company defers these costs and amortizes them over the period of benefit, which is generally considered to be the contract term. The Company has elected to use the practical expedient, allowing the Company to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the entity otherwise would have recognized is one year or less. Commissions paid relating to maintenance and support contract renewals of twelve months or less are expensed as incurred as commissions paid on renewals are commensurate with commissions paid on initial sales transactions. Costs to obtain a contract for professional services contracts are expensed as incurred in accordance with the practical expedient as the contractual period of our professional services contracts are one year or less. The Company periodically reviews the carrying amount of capitalized contract costs to determine whether events or changes in circumstances have occurred that could impact the period of benefit. Deferred Revenue The Company recognizes amounts billed in excess of revenue recognized as deferred revenue. Deferred revenue includes customer deposits, amounts billed for maintenance and support services contracts in advance of services being performed, amounts for trade-in right liabilities and amounts related to contracts that have been deferred as a result of not meeting the required revenue recognition criteria as of the end of the reporting period. The Company reports deferred revenue expected to be recognized as revenue more than one year subsequent to the balance sheet date within long-term liabilities in the consolidated balance sheets. The Company defers recognition of direct costs, such as cost of goods and services, until recognition of the related revenue. The Company classifies such costs as current assets if the related deferred revenue is classified as current and as non-current assets if the related deferred revenue is classified as non-current. Other Revenue Recognition Policies The Company’s customary payment terms are generally 90 days or less. The Company has elected to apply the practical expedient that allows an entity to not adjust the promised amount of consideration in customer contracts for the effect of a significant financing component when the period between the transfer of product and services and payment of the related consideration is less than one year. If the Company provides extended payment terms that represent a significant financing component, the Company adjusts the amount of promised consideration for the time value of money using an appropriate discount rate and recognizes interest income separate from the revenue recognized on contracts with customers. During the year ended December 31, 2020 and 2019, the Company recorded $64 and $160, respectively, in interest income in its consolidated statements of operations and comprehensive income (loss) related to arrangements with customers that were determined to have a significant financing component. In limited instances, the Company has offered future rebates to customers based on a fixed or variable percentage of actual sales volumes over specified periods. The future rebates earned based on the customer’s purchasing from the Company in one period may be used as credits to be applied by them against accounts receivable due to the Company in later periods. The Company accounts for these future rebates as variable consideration and reduces the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will occur when the variable consideration is resolved. The Company estimates the reduction of the transaction price based on historical activity and other relevant factors and recognizes it when the Company recognizes revenue for the transfer of goods and services to the customer on which the future rebate was earned. Other forms of contingent revenue or variable consideration are infrequent. The Company excludes any taxes assessed by a governmental authority that are directly imposed on a revenue-producing transaction (e.g., sales, use and value added taxes) from its transaction price. The Company records billings to customers for reimbursement of out-of-pocket expenses, including travel, lodging and meals, as revenue, and the associated costs incurred by the Company as cost of revenue. Revenue related to the reimbursement of out-of-pocket costs are accounted for as variable consideration. The Company accounts for any shipping and handling activities as a fulfilment cost rather than an additional promised service. The Company records shipping and handling billed to customers as an offset to cost of revenue. Transition Disclosures In accordance with the modified retrospective method transition requirements, the Company has presented the financial statement line items impacted and adjusted to compare to presentation under ASC Topic 605, Revenue Recognition As of December 31, 2019 Balance Sheet As Reported under ASC 606 Adjustments Without adoption of ASC 606 Assets: Accounts receivable $ 93,100 $ 47 $ 93,147 Inventory 93,604 186 93,790 Prepaid expenses and other current assets 4,884 54 4,938 Prepaid income taxes 3,217 330 3,547 Accounts receivable, net of current portion 575 23 598 Deferred tax assets 69 1,757 1,826 Other assets 7,820 (69 ) 7,751 Total assets $ 444,312 $ 2,328 $ 446,640 Liabilities: Accrued expenses and other current liabilities $ 34,567 $ (491 ) $ 34,076 Deferred revenue 25,485 8,194 33,679 Deferred revenue, net of current portion 4,583 1,856 6,439 Total liabilities 405,748 9,559 415,307 Stockholders’ Equity: Accumulated deficit (127,064 ) (7,231 ) (134,295 ) Total stockholders’ equity 38,564 (7,231 ) 31,333 Total liabilities and stockholders’ equity $ 444,312 $ 2,328 $ 446,640 Total reported assets under ASC 606 as of December 31, 2019 were $2,328 less than the total assets without the adoption of ASC 606 largely due to decreases in deferred tax assets, prepaid income taxes and deferred inventory costs related to contracts for which deferred revenue was adjuste

Business Acquisition

Business Acquisition	12 Months Ended
Business Acquisition	Dec. 31, 2020
Business Combinations [Abstract]
Business Acquisition	3. Business Acquisition On July 1, 2019, the Company acquired 100% of the equity interests in NetComm for cash consideration of $161,963 AUD ($112,674 USD, based on an exchange rate of USD $0.700 per AUD $1.00 on July 1, 2019) The Company allocated the total purchase price to NetComm’s net tangible and intangible assets based upon their estimated fair values as of the date of Acquisition. NetComm’s cash and cash equivalents balance at the Acquisition date was $3,243; as such, total consideration net of cash acquired was $109,431. The Company accounted for NetComm’s existing debt of approximately $3,507 as of the Acquisition date as an assumed liability. All contractual accounts receivable as of July 1, 2019, which totaled $18,142, have been collected as of December 31, 2020. Based upon the purchase price and the valuation, the allocation of the total purchase price was as follows: Purchase Price Allocation Assets acquired Fair value of tangible assets: Accounts receivable $ 18,142 Inventory 24,138 Prepaid expenses and other current assets 2,240 Property, plant and equipment 8,010 Deferred tax assets 365 Other assets 13 Goodwill 50,177 Identifiable intangible assets 44,000 Total assets acquired $ 147,085 Liabilities assumed Accounts payable $ (9,719 ) Accrued expenses (13,178 ) Accrued income taxes (140 ) Deferred tax liabilities (10,621 ) Current portion of long-term debt (3,507 ) Other liabilities (489 ) Total liabilities assumed $ (37,654 ) Net assets acquired $ 109,431 The allocation of the purchase price and the estimated useful lives associated with certain assets is as follows : Amount Estimated Useful Life Net tangible assets $ 15,254 — Identifiable intangible assets: Developed technology 25,000 7 years Customer relationships 18,000 10 years Trade name 1,000 3 years Goodwill 50,177 — Total purchase price $ 109,431 The Company allocated $44,000 to identifiable intangible assets consisting of developed technology, amortized over seven years using a straight-line amortization method; customer relationships, amortized over ten years using a straight-line amortization method; and a trade name, amortized over three years using a straight-line amortization method. The weighted-average life of the identifiable intangible assets recognized from the Acquisition was 8.2 years. The intangible assets acquired in the Acquisition are not deductible for tax purposes. NetComm is a global leader in the development of fixed wireless and fiber-to-the-distribution-point broadband solutions. With the Acquisition, the combined Company now offers a broad, highly competitive product portfolio for new 4G and 5G fixed wireless access products and customer premise equipment for public and private service providers and enterprise networks. This factor contributed to a purchase price in excess of fair value of NetComm’s net tangible and intangible assets, leading to the recognition of goodwill of $50,177. Additional factors that contributed to the establishment of goodwill included the strategic benefit of expanding the breadth of the Company’s product offerings; the value of NetComm’s highly trained work force; the expected revenue growth over time that is attributable to increased market penetration from future products and customers, and cross-selling by the sales force; and the synergies expected to result from reducing redundant infrastructure such as corporate costs and field operations. The goodwill acquired in the Acquisition is not deductible for tax purposes. The results of operations of NetComm have been included in the Company’s consolidated statements of operations and comprehensive (loss) income since the completion of the Acquisition on July 1, 2019. For the year ended December 31, 2019, NetComm contributed $75,769 to the Company’s consolidated net revenues and $1,424 in after tax losses to the Company’s consolidated net loss. Transactions costs of $3,494 are included in selling, general and administrative expenses in the consolidated statements of operations and comprehensive (loss) income for the year ended December 31, 2019. The unaudited pro forma financial information shown below summarizes the combined results of operations for the Company and NetComm as if the closing of the Acquisition had occurred on January 1, 2017, the first day of the Company’s fiscal year 2018. The unaudited pro forma financial information includes adjustments that are directly attributable to the business combination and are factually supportable. The adjustments primarily reflect the amortization of acquired intangible assets, the conversion of NetComm’s financial results from International Financial Reporting Standards to U.S. GAAP, transaction costs related to the Acquisition, as well as the pro forma tax impact for such adjustments at the statutory rate. The pro forma financial information also reflects a $3,200 adjustment for the amortization of the step up of inventory fair value that is directly attributable to the business combination, but is not expected to have a continuing impact on the results of operations. The unaudited pro forma results below do not reflect the expected realization of cost savings following the Acquisition or anticipated costs the Company will incur to realize such synergies. These savings are expected to result from streamlining of product development initiatives, alignment of overlapping functional areas, such as sales and marketing and certain general and administrative functions. Although management expects that cost savings will result from the Acquisition, there can be no assurance that these cost savings will be achieved. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the Acquisition had occurred on January 1, 2017, nor are they indicative of future results of operations. The unaudited pro forma combined results of the Company and NetComm are as follows: Year Ended December 31, 2020 2019 2018 Net revenue $ 393,246 $ 375,306 $ 436,791 Net income (loss) 25,134 (47,898 ) 68,808

Goodwill and Intangibles

Goodwill and Intangibles	12 Months Ended
Goodwill and Intangibles	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangibles	4. Goodwill and Intangibles Intangible assets, net Intangible assets, net consisted of intangible assets resulting from the acquisition of NetComm and purchased software to be used in our products. Intangible assets, net consisted of the following at December 31, 2020 and 2019, respectively: As of December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology 25,000 (5,358 ) 19,642 Customer relationships 18,000 (2,700 ) 15,300 Trade name 1,000 (498 ) 502 Purchased Software 432 (32 ) 400 Totals as of December 31, 2020 $ 44,432 $ (8,588 ) $ 35,844 As of December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology 25,000 (1,786 ) 23,214 Customer relationships 18,000 (900 ) 17,100 Trade name 1,000 (166 ) 834 Totals as of December 31, 2019 $ 44,000 $ (2,852 ) $ 41,148 As of December 31, 2020, amortization expense on existing intangible assets for the next five years and beyond is summarized as follows: Year Ending December 31, 2021 $ 5,849 2022 5,681 2023 5,484 2024 5,372 2025 5,372 Thereafter 8,086 $ 35,844 A Year Ended December 31, 2020 2019 Product cost of revenue $ 3,571 $ 1,786 Research and development 32 — Selling, general and administrative 2,133 1,066 Totals $ 5,736 $ 2,852 Goodwill The changes in the carrying value of goodwill are as follows: Carrying Value of Goodwill Balance at December 31, 2018 $ — NetComm Acquisition 50,347 Balance at December 31, 2019 50,347 Adjustment recorded to preliminary purchase price allocation (170 ) Balance at December 31, 2020 $ 50,177

Inventory

Inventory	12 Months Ended
Inventory	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventory	5. Inventory Inventory as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Raw materials $ 50,904 $ 19,821 Work in process 19 17 Finished goods: Manufactured finished goods 49,764 69,503 Deferred inventory costs 517 4,263 $ 101,204 $ 93,604 The increase in gross inventory balances was due to manufacturing to fill existing orders and to meet anticipated future demand for the Company’s products.

Property and Equipment

Property and Equipment	12 Months Ended
Property and Equipment	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property and Equipment	6. Property and Equipment Property and equipment as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Computers and purchased software $ 24,865 $ 22,294 Leasehold improvements 4,148 4,380 Furniture and fixtures 2,644 2,794 Machinery and equipment 36,701 40,002 Land 3,091 3,091 Building 4,765 4,765 Building improvements 7,244 6,776 Trial systems at customers’ sites 5,300 6,039 88,758 90,141 Less: Accumulated depreciation and amortization (59,878 ) (54,231 ) $ 28,880 $ 35,910 During the years ended December 31, 2020, 2019 and 2018, the Company transferred trial systems (into) from inventory into (from) property and equipment with values of $(1,259), $(502) and $(357), respectively, net of transfers of trial systems to cost of revenue. In addition, the Company transferred $(805), $(261) and $371 of equipment from inventory into property and equipment during the years ended December 31, 2020, 2019 and 2018, respectively. Total depreciation and amortization expense on property and equipment totaled $12,234, $11,870, and $9,454 for the years ended December 31, 2020, 2019 and 2018, respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
Accrued Expenses and Other Current Liabilities	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	7. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Accrued compensation and related taxes $ 22,722 $ 18,540 Accrued warranty (see Note 2) 2,354 2,448 Dividends and equitable adjustments payable (see Note 12) 63 750 Accrued customer incentives 20 233 Other accrued expenses 14,634 12,596 $ 39,793 $ 34,567

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	8. Fair Value Measurements The Company’s cash equivalents include certificates of deposit and money market mutual funds, which are valued using Level 1 or Level 2 inputs in the fair value hierarchy. The Company’s marketable securities consist of certificates of deposit, which are valued using Level 2 inputs in the fair value hierarchy. The Company’s foreign currency forward contracts are valued using Level 2 inputs in the fair value hierarchy. The Company values its SARs using Level 3 inputs in the fair value hierarchy based on management’s judgment and the assumptions set forth in Note 13 as there is no market activity to derive an estimate of their fair value. The Company records changes in the fair value of SARs in operating expenses in the consolidated statements of operations and comprehensive income (loss). The following tables present information about the fair value of the Company’s financial assets and liabilities as of December 31, 2020 and 2019 and indicate the level of the fair value hierarchy utilized to determine such fair values: Fair Value Measurements as of December 31, 2020 Using: Level 1 Level 2 Level 3 Total Assets: Certificates of deposit—restricted cash $ — $ 1,006 $ — $ 1,006 Money market mutual funds 114,404 — — 114,404 $ 114,404 $ 1,006 $ — $ 115,410 Liabilities: SARs $ — $ — $ 493 $ 493 $ — $ — $ 493 $ 493 Fair Value Measurements as of December 31, 2019 Using: Level 1 Level 2 Level 3 Total Assets: Certificates of deposit $ — $ 10,933 $ — $ 10,933 Certificates of deposit—restricted cash — 1,019 — 1,019 Money market mutual funds 53,763 — — 53,763 Foreign currency forward contracts — 23 — 23 $ 53,763 $ 11,975 $ — $ 65,738 Liabilities: SARs $ — $ — $ 264 $ 264 Foreign currency forward contracts — 50 — 50 $ — $ 50 $ 264 $ 314 During the years ended December 31, 2020, 2019 and 2018 there were no The liability for SARs in the table above consists of the fair value of the SARs granted to the Company’s employees. The fair values of the SARs are based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The Company’s valuation of these SARs utilized the Black-Scholes option-pricing model, which incorporates assumptions and estimates to determine their fair values (see Note 2 ). The Company assesses these assumptions and estimates on a quarterly basis as additional information impacting the assumptions is obtained. The Company recognizes c hanges in the fair value of the SARs liability as stock-based compensation expense in the consolidated statements of operations and comprehensive income (loss) . The following table provides a summary of changes in the fair values of the Company’s SARs liability, for which fair value is determined by Level 3 inputs: Year Ended December 31, 2020 2019 2018 Fair value at beginning of the year $ 264 $ 1,387 $ 2,155 Change in fair value 229 (1,123 ) (768 ) Exercises — — — Fair value at end of year $ 493 $ 264 $ 1,387 The Company’s cash, cash equivalents and restricted cash as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Cash $ 43,051 $ 48,942 Cash equivalents and restricted cash: Certificates of deposit — 10,933 Certificates of deposit—restricted cash 1,006 1,019 Money market mutual funds 114,404 53,763 Total cash equivalents and restricted cash 115,410 65,715 Total cash, cash equivalents and restricted cash $ 158,461 $ 114,657

Derivative Instruments

Derivative Instruments	12 Months Ended
Derivative Instruments	Dec. 31, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments	9. Derivative Instruments The Company has certain international customers that are billed in foreign currencies. To mitigate the volatility related to fluctuations in the foreign exchange rates for accounts receivable denominated in foreign currencies, the Company enters into foreign currency forward contracts. As of December 31, 2020, the Company had no foreign currency forward contracts outstanding. As of December 31, 2019, The Company’s foreign currency forward contracts described above economically hedged certain risks, but were not designated as hedges for financial reporting purposes, and accordingly, the Company recorded all changes in the fair value of the derivative instruments as unrealized foreign currency transaction gains or losses and included them in the consolidated statements of operations and comprehensive income (loss) as a component of other income (expense). The Company records derivative instruments in the consolidated balance sheet at their fair values. As of December 31, 2020, the Company recorded no asset or liability relating to outstanding foreign currency forward contracts. As of December 31, 2019, the Company recorded an asset of $23 and a liability of $50 related to outstanding foreign currency forward contracts, which were included in prepaid expenses and other current assets and in accrued expenses and other current liabilities, respectively, in the consolidated balance sheets. The Company also faces exposure to foreign currency exchange rate fluctuations, as a certain portion of its expenses are denominated in currencies other than U.S. Dollars. In certain instances, the Company utilizes forward contracts to hedge against foreign currency fluctuations. These contracts are used to minimize foreign gains or losses, as the gains or losses on the derivative are intended to offset the losses or gains on the underlying exposure. The Company does not engage in foreign currency speculation. The Company designed its foreign currency risk management strategy principally to mitigate the potential financial impact of changes in the value of transactions and balances denominated in foreign currencies resulting from changes in foreign currency exchange rates. The Company may enter into cash flow hedges which utilize foreign currency forward contracts to hedge specific forecasted transactions of its foreign subsidiaries with the goal of protecting its budgeted expenses against foreign currency exchange rate changes compared to its budgeted rates. During the year ended December 31, 2020, the Company settled two cash flow hedges with notional amounts of 8,500 AUD and 5,000 AUD to hedge certain Australian Dollar cash flows incurred during the period. The Company reclassified the amount of $752 from other comprehensive income (loss) for the year ended December 30, 2020. The Company recognized the full amount of the fair value of the derivatives on the settlement date of $1,613 proportionately as $124 cost of goods sold, $890 research and development expense and $599 selling, general and administrative expense in the consolidated statement of comprehensive income for the year ended December 31, 2020. The Company did not have any cash flow hedges outstanding as of December 31, 2020 and December 31, 2019.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes Income before the (benefit from) provision for income taxes for the years ended December 31, 2020, 2019 and 2018 consisted of the following: Year Ended December 31, 2020 2019 2018 United States $ (32,755 ) $ (40,055 ) $ 10,527 Foreign 42,504 15,640 55,411 $ 9,749 $ (24,415 ) $ 65,938 The (benefit from) provision for income taxes for the years ended December 31, 2020, 2019 and 2018 consisted of the following: Year Ended December 31, 2020 2019 2018 Current income tax (benefit) provision: Federal $ (24,409 ) $ 4,698 $ (3,457 ) State 228 (121 ) (181 ) Foreign 11,655 (427 ) 8,087 Total current income tax (benefit) provision (12,526 ) 4,150 4,449 Deferred income tax (benefit) provision: Federal 171 18,387 (10,699 ) State 97 5,100 (1,108 ) Foreign (2,794 ) (3,846 ) 290 Total deferred income tax (benefit) provision (2,526 ) 19,641 (11,517 ) Total income tax (benefit) provision $ (15,052 ) $ 23,791 $ (7,068 ) A reconciliation of the U.S. federal statutory rate to the Company’s effective income tax rate for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Federal statutory income tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal tax benefit (6.8 ) 9.8 (0.8 ) Research and development tax credits (37.6 ) 10.3 (15.6 ) Permanent differences (11.5 ) (1.6 ) 1.1 Foreign tax rate differential 7.3 10.2 (6.6 ) Equitable adjustment payments (1.1 ) 1.7 (1.8 ) Stock-based compensation 9.7 3.3 (25.2 ) Foreign taxes withheld 23.1 (9.6 ) 3.3 Rate impact from CARES Act (63.9 ) — — Global intangible low-taxed income 35.7 (4.1 ) 6.7 Withholding tax on repatriation of accumulated earnings of foreign subsidiaries 1.0 (0.1 ) 0.1 Valuation allowance on deferred tax assets (146.9 ) (144.2 ) 6.0 Other, net (3.6 ) 2.3 1.1 Foreign derived intangible income — 3.9 — Research and development costs 20.0 (4.3 ) — Provision to return 2.4 11.1 — Uncertain tax positions (3.2 ) (7.1 ) — Effective income tax rate (154.4 )% (97.4 )% (10.7 )% The income tax effect of each type of temporary difference and carryforward as of December 31, 2020 and 2019 was as follows: December 31, 2020 2019 Deferred tax assets: Stock compensation $ 4,710 $ 3,827 Tax credit carryforwards 13,138 9,900 Capitalized research and development costs 9,710 21,376 Inventory valuation 2,169 1,756 Accrued liabilities and reserves 3,826 5,207 Deferred revenue 796 1,520 Interest expense — 2,149 Intellectual property rights 999 999 Other 2,228 544 Total deferred tax assets 37,576 47,278 Valuation Allowance (24,463 ) (39,124 ) Deferred tax assets, net of valuation allowance 13,113 8,154 Deferred tax liabilities: Depreciation (2,092 ) (1,159 ) Amortization (10,932 ) (12,727 ) Deferred costs (3,444 ) — Withholding tax on unremitted earnings (2,650 ) (2,604 ) Prepaid expenses (127 ) (588 ) Total deferred tax liabilities (19,245 ) (17,078 ) Net deferred tax liabilities $ (6,132 ) $ (8,924 ) The Company has determined that it is more likely than not its net U.S. deferred tax assets will not be realized. As of December 31, 2020, the Company maintains a valuation allowance of $24,463 against its net U.S. deferred tax assets, a decrease of $14,661 during the year ended December 31, 2020. The change in valuation allowance is primarily due to the Company’s ability to carryback U.S. net operating losses under the CARES Act which was enacted during 2020, which resulted in the release of valuation allowance against certain deferred tax assets that could be carried back to prior tax years . T he Company does not anticipate sufficient taxable income or tax liability to utilize its net U.S. deferred tax assets in in the foreseeable future. The Company will continue to monitor the realizability of its net U.S. deferred tax assets and tak e into account multiple factors, including recent operating results, existing taxable temporary differences, future taxable income projections and tax planning strategies. The Company intends to maintain a valuation allowance on its net U.S. deferred tax assets until there is sufficient positive evidence to support the reversal of all or some portion of the valuation allowances. The release of all, or a portion of , the valuation allowance would result in the recognition of certain deferred tax assets and a decrease to income tax expense for the period the release is recorded. On March 27, 2020, the Coronavirus Aid, Relief and Economic Security (“CARES Act”) was signed into law. Among other things, the CARES Act permits net operating loss (“NOL”) carryovers and carrybacks to offset 100 30 50 Effective for taxable years beginning after January 1, 2018, taxpayers are subjected to the GILTI provisions. The GILTI provisions require the Company to currently recognize in U.S. taxable income a deemed dividend inclusion of foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary’s tangible assets. The ability to benefit from a deduction and foreign tax credits against a portion of the GILTI income may be limited under the GILTI rules as a result of the utilization of net operating losses, foreign sourced income, and other potential limitations within the foreign tax credit calculation. The Company made an accounting policy election, as allowed by the SEC and FASB, to recognize the impacts of GILTI within the period incurred. During the years ended December 31, 2020 and 2019, the Company recorded income tax charges of $3,483 and $942, respectively, related to GILTI. As of December 31, 2020, the Company had federal NOL carryforwards of $476 that can be carried forward indefinitely and state NOL carryforwards of $21,714, of which $14,402 will begin to expire in 2030 and $7,312 can be carried forward indefinitely. As of December 31, 2020, the Company had available federal and state research and development tax credit carryforwards of $1,269 and $10,812, respectively, which begin to expire in 2030. Management believes that it is more likely than not that the Company will not realize the benefit of its federal and state net operating losses and research and development tax credits and thus has recorded a valuation allowance against these deferred tax assets. As of December 31, 2020, the Company had foreign net operating loss carryforwards of $1,034 of which $662 will expire in 2024 and $371 can be carried forward indefinitely. As of December 31, 2020, the Company had foreign research and development tax credit carryforwards of $13,875, which do not expire. Management has recorded an uncertain tax position of $11,806 related to these credits. As of December 31, 2020, substantially all of the Company’s unremitted earnings have been taxed through either the deemed repatriation tax or as GILTI income. Of the total amount of undistributed earnings, $26,494 is not indefinitely reinvested and the Company has recorded a $2,649 deferred tax liability related to its withholding taxes associated with such undistributed earnings. The Company records interest and penalties related to uncertain tax positions in its consolidated statements of operations and comprehensive income within other income (expense). Interest and penalties included in the statement of operations were $614, $1,278 and $211 for the years ended December 31, 2020, 2019 and 2018, respectively. The Company recorded a liability for interest and penalties of $2,260 and $1,646 as of December 31, 2020 and 2019, respectively. As of December 31, 2020, the amount of uncertain tax benefits that, if recognized, would impact the effective income tax rate was $17,668. The aggregate changes in the balance of gross uncertain tax positions, which excludes interest and penalties, for the years ended December 31, 2020, 2019 and 2018 were as follows: Balance at December 31, 2017 $ 1,695 Settlement/decreases related to tax positions taken during prior years — Increases related to tax positions taken during prior years 241 Increases related to tax positions taken during the current year 810 Balance at December 31, 2018 2,746 Settlement/decreases related to tax positions taken during prior years (49 ) Increases related to tax positions taken during prior years 18,434 Increases related to tax positions taken during the current year 364 Balance at December 31, 2019 21,495 Expiration of statute of limitations (1,174 ) Decreases related to tax positions taken during prior years (2,815 ) Increases related to tax positions taken during prior years 155 Increases related to tax positions taken during the current year 249 Balance at December 31, 2020 $ 17,910 The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction as well as various states and foreign jurisdictions. The Company and certain subsidiaries have tax years that remain open and are subject to examination by tax authorities in the following major taxing jurisdictions: United States for tax years 2017 through 2020, Ireland for tax years 2016 through 2020, China for tax years 2010 through 2020 and Australia for tax years 2016 through 2020. The Company files income tax returns on a combined, unitary, or stand-alone basis in multiple state and local jurisdictions, which generally have statutes of limitations from three to four years. If any issues addressed in the Company’s tax audits are resolved in a manner not consistent with management’s expectations, the Company would be required to adjust its provision for income tax in the period such resolution occurs. The Company’s unrecognized tax benefits could change up to $4,344 in the next 12 months due to the expiration of the statute of limitations.

Debt

Debt	12 Months Ended
Debt	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	11. Debt The aggregate principal amount of debt outstanding as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Term loans $ 288,000 $ 291,000 Revolving credit facility 6,500 — Mortgage loan — 6,644 Total principal amount of debt outstanding $ 294,500 $ 297,644 Current and non-current debt obligations reflected in the consolidated balance sheets as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Current liabilities: Term loans $ 9,775 $ 3,000 Revolving credit facility 6,500 — Mortgage loan — 6,644 Current portion of principal payment obligations 16,275 9,644 Unamortized debt issuance costs, current portion (1,104 ) (1,120 ) Current portion of long-term debt, net of unamortized debt issuance costs $ 15,171 $ 8,524 Non-current liabilities: Term loans $ 278,225 $ 288,000 Unamortized debt issuance costs, non-current portion (2,140 ) (3,244 ) Long-term debt, net of current portion and unamortized debt issuance costs $ 276,085 $ 284,756 As of December 31, 2020, aggregate minimum future principal payments of the Company’s debt are summarized as follows: Year Ending December 31, 2021 $ 16,275 2022 3,000 2023 275,225 Thereafter — $ 294,500 Term Loan and Revolving Credit Facilities On December 20, 2016, the Company entered into a credit agreement with JPMorgan Chase Bank, N.A., as administrative agent, various lenders and JPMorgan Chase Bank, N.A. and Barclays Bank PLC providing for (i) a term loan facility of $300,000 and (ii) a revolving credit facility of up to $25,000 in revolving credit loans and letters of credit. As of December 31, 2020 and 2019, $288,000 and $291,000 in principal amount, respectively, were outstanding under the term loan facility (the “Term Loans”) and as of December 31, 2020, the Company had outstanding borrowings under the revolving credit facility of $6,500 that were drawn down during the year ended December 31, 2020. As of December 31, 2019, the Company had no outstanding borrowings under the revolving credit facility. As of December 31, 2020 and 2019, the Company had also used $1,454 and $1,343 of availability under the revolving credit facility for two stand-by letters of credit, one which served as collateral to one of the Company’s customers pursuant to a contractual obligation and one which is used as collateral for operating leases in Australia. In addition, the Company may, subject to certain conditions, including the consent of the administrative agent and the institutions providing such increases, increase the facilities by an unlimited amount so long as the Company is in compliance with specified leverage ratios, or otherwise by up to $70,000. Borrowings under the facilities bear interest at a floating rate, which can be either a Eurodollar rate plus an applicable margin or, at the Company’s option, a base rate (defined as the highest of (x) the JPMorgan Chase, N.A. prime rate, (y) the federal funds effective rate, plus one-half percent (0.50%) per annum and (z) a one-month Eurodollar rate plus 1.00% per annum) plus an applicable margin. The applicable margin for borrowings under the term loan facility is 4.00% per annum for Eurodollar rate loans (subject to a 1.00% per annum interest rate floor) and 3.00% per annum for base rate loans. The applicable margin for borrowings under the revolving credit facility is 1.75% per annum for Eurodollar rate loans and 0.75% per annum for base rate loans, subject to reduction based on the Company’s maintaining of specified net leverage ratios. The interest rates payable under the facilities are subject to an increase of 2.00% per annum during the continuance of any payment default. For Eurodollar rate loans, the Company may select interest periods of one, three or six months or, with the consent of all relevant affected lenders, twelve months. Interest will be payable at the end of the selected interest period, but no less frequently than every three months within the selected interest period. Interest on any base rate loan is not set for any specified period and is payable quarterly. The Company has the right to convert Eurodollar rate loans into base rate loans and the right to convert base rate loans into Eurodollar rate loans at its option, subject, in the case of Eurodollar rate loans, to breakage costs if the conversion is effected prior to the end of the applicable interest period. As of December 31, 2020, the interest rate on the Term Loans was 5.00% per annum, which was based on a one-month Eurodollar rate of 1.00% per annum plus the applicable margin of 4.00% per annum for Eurodollar rate loans. As of December 31, 2019, the interest rate on the Term Loans was 5.80% per annum, which was based on a one-month Eurodollar rate of 1.80% per annum plus the applicable margin of 4.00% per annum for Eurodollar rate loans. Upon entering into the term loan facility, the Company incurred debt issuance costs of $7,811, which were initially recorded as a reduction of the debt liability and are being amortized to interest expense using the effective interest method from the issuance date of the Term Loan until the maturity date. The Company made principal payments of $3,000 under the term loan facility during each of the years ended December 31, 2020, 2019 and 2018. Interest expense, including the amortization of debt issuance costs, totaled $16,493, $19,728 and $19,146 for the years ended December 31, 2020, 2019 and 2018, respectively. The revolving credit facility also requires payment of quarterly commitment fees at a rate of 0.25% per annum on the difference between committed amounts and amounts actually borrowed under the facility and customary letter of credit fees. For the years ended December 31, 2020, 2019 and 2018, interest expense related to the fee for the unused amount of the revolving credit facility totaled $52, $59 and $62, respectively. The Term Loans mature on December 20, 2023, and the revolving credit facility matures on December 20, 2021. The Term Loans are subject to amortization in equal quarterly installments, which commenced on March 31, 2017, of principal in an annual aggregate amount equal to 1.0% of the original principal amount of the Term Loans of $300,000, with the remaining outstanding balance payable at the date of maturity. Voluntary prepayments of principal amounts outstanding under the term loan facility are permitted at any time; however, if a prepayment of principal is made with respect to a Eurodollar loan on a date other than the last day of the applicable interest period, the Company is required to compensate the lenders for any funding losses and expenses incurred as a result of the prepayment. Prior to the revolving credit facility maturity date, funds borrowed under the revolving credit facility may be borrowed, repaid and reborrowed, without premium or penalty. In addition, the Company is required to make mandatory prepayments under the facilities with respect to (i) 100% of the net cash proceeds from certain asset dispositions (including casualty and condemnation events) by the Company or certain of its subsidiaries, subject to certain exceptions and reinvestment provisions, (ii) 100% of the net cash proceeds from the issuance or incurrence of any additional debt by the Company or certain of its subsidiaries, subject to certain exceptions, and (iii) 50% of the Company’s excess cash flow, as defined in the credit agreement, subject to reduction upon its achievement of specified performance targets. In accordance with these provisions, a mandatory prepayment of $6.8 million will be required, no later than May 5, 2021. This amount has been included in the current portion of long-term debt, net of unamortized debt issuance costs on the consolidated balance sheet as of December 31, 2020. The facilities are secured by, among other things, a first priority security interest, subject to permitted liens, in substantially all of the Company’s assets and all of the assets of certain of its subsidiaries and a pledge of certain of the stock of certain of its subsidiaries, in each case subject to specified exceptions. The facilities contain customary affirmative and negative covenants, including certain restrictions on the Company’s ability to pay dividends, and, with respect to the revolving credit facility, a financial covenant requiring the Company to maintain a specified total net leverage ratio in the event that on the last day of any fiscal quarter the Company has utilized more than 30% of its borrowing capacity under the facility. The Company was in compliance with all covenants as of December 31, 2020. As of December 31, 2019, the Company’s net leverage ratio exceeded the maximum; however, as the Company’s utilization of the revolving credit facility did not exceed the 30% testing threshold on December 31, 2019, the Company was not in default of the revolving credit facility as a result of the Company’s net leverage ratio exceeding the maximum permitted amount. The Company was in compliance with all other applicable covenants of the facilities as of December 31, 2019 . Commercial Mortgage Loan On July 1, 2015, the Company entered into a commercial mortgage loan agreement in the amount of $7,950 (the “Mortgage Loan”). Borrowings under the Mortgage Loan bore interest at a rate of 3.5% per annum and were repayable in 60 monthly installments of $46, consisting of principal and interest based on a 20-year amortization schedule. The remaining amount of unpaid principal under the Mortgage Loan was paid on the maturity date of July 1, 2020 utilizing the Company’s revolving credit facility. Upon entering into the Mortgage Loan, the Company incurred debt issuance costs of $45, which the Company initially recorded as a direct deduction from the debt liability and amortized to interest expense using the effective interest method from issuance date of the loan until the maturity date. The Company made principal payments under the Mortgage Loan of $6,644, $314 and $303 during the years ended December 31, 2020, 2019 and 2018, respectively. Interest expense, including the amortization of debt issuance costs, totaled $120, $249 and $260 for the years ended December 31, 2020, 2019 and 2018, respectively.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	12. Stockholders’ Equity In December 2017, the Company closed its initial public offering (“IPO”) of 6,900 shares of its common stock at an offering price of $13.00 per share, including 900 shares pursuant to the underwriters’ option to purchase additional shares of the Company’s common stock. The Company received net proceeds of $79,327, after deducting underwriting discounts and commissions of $6,279 and offering costs of $4,094. Upon the closing of the IPO, all 4,038 shares of the Company’s then-outstanding preferred stock automatically converted on a ten-for-one basis into an aggregate of 40,382 shares of the Company’s common stock. Upon conversion of the preferred stock, the Company reclassified $97,439 from temporary equity to additional paid-in capital and $40 from temporary equity to common stock. On April 30, 2018, the Company closed its follow-on public offering in which certain stockholders sold 7,350 shares of the Company’s common stock at a price of $25.00 per share, before deducting underwriting discounts and commissions (the “follow-on offering”). The Company did not sell any common stock in the follow-on offering and did not receive any of the proceeds from the sale of the Company’s common stock by the selling stockholders. In connection with the sale of the Company’s common stock in the follow-on offering, certain of the selling stockholders disgorged $3,770 of profits recognized from the sale, after deducting $41 of offering costs, to the Company in accordance with Section 16(b) of the Securities Exchange Act of 1934, as amended, which was recorded as an increase in additional paid-in capital. The Company incurred $856 of transaction costs in connection with the follow-on offering, of which $815 was recorded in selling, general and administrative expenses in the accompanying consolidated statements of operations. Special Dividends to Holders of Common and Preferred Stock The board of directors, on five separate occasions, declared a special dividend to the holders of common stock and preferred stock of record at that time. The below table details the cash dividends declared to stockholders of each share type for each of the five special dividends, as well as the amount of dividends the Company paid in each of the years ended December 31, 2020, 2019 and 2018, respectively: Cash Dividend Declared Dividends Paid per Share Type During the Year Ended Dividend Declaration Date Common Series B and Series C Convertible Preferred December 31, 2020 December 31, 2019 December 31, 2018 November 30, 2017 $ 0.5802 $ 5.8020 $ — $ — $ 865 May 10, 2017 1.1774 11.7744 — — — December 27, 2016 2.3306 23.3058 — — — June 17, 2016 0.5891 5.8910 — — — November 30, 2014 0.3835 3.8346 — — — Total dividends paid $ — $ — $ 865 No dividend payments were payable as of December 31, 2020 and December 31, 2019. In connection with these special dividends, the board of directors also approved cash payments to be made to holders of the Company’s stock options, SARs and restricted stock units (“RSUs”) as equitable adjustments to the holders of such instruments in accordance with the provisions of the Company’s equity incentive plans. These equitable adjustment payments are equal to an amount per share multiplied by the net number of shares subject to outstanding equity awards after applying the treasury stock method. The below table provides details of these equitable adjustment payments: Equitable Adjustment Payments During the Year Ended Equitable Adjustment Liability(1) Dividend Declaration Dates Equitable Adjustment per share Year of Final Vesting December 31, 2020 December 31, 2019 December 31, 2018 As of December 31, 2020 As of December 31, 2019 November 30, 2017 $ 0.5802 2021 $ 148 $ 426 $ 1,132 $ 30 $ 177 May 10, 2017 1.1774 2021 178 618 1,492 31 182 December 27, 2016 2.3306 2020 303 1,286 3,105 2 335 June 17, 2016 0.5891 2020 54 259 684 — 37 November 30, 2014 0.3835 2018 — 1 43 — — Total $ 683 $ 2,590 $ 6,456 $ 63 $ 731 (1) Net of estimated forfeitures. Amounts are included in accrued expenses and other current liabilities in the accompanying consolidated balance sheets.

Stock-based Compensation

Stock-based Compensation	12 Months Ended
Stock-based Compensation	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	13. Stock-based Compensation 2003 Stock Incentive Plan The Company’s 2003 Stock Incentive Plan, as amended (the “2003 Plan”), provided for the grant of qualified incentive stock options, nonqualified stock options, restricted stock or other stock-based awards to the Company’s employees, officers, directors, advisers and outside consultants. The number of shares authorized for grant under the 2003 Plan was 32,500 shares. The 2003 Plan was administered by the board of directors, or at the discretion of the board of directors, by a committee of the board or by one or more executive officers of the Company. The exercise prices, vesting and other restrictions were determined at the discretion of the board of directors, or a committee of the board or one or more executive officers of the Company, if so delegated. The 2003 Plan was terminated in August 2011, and the remaining 2,140 shares available for issuance under the plan at that time were transferred to the Company’s 2011 Stock Incentive Plan (the “2011 Plan”). The shares of common stock underlying any awards that are forfeited, canceled, repurchased or are otherwise terminated by the Company under the 2003 Plan will be added back to the shares of common stock available for issuance under the Company’s 2017 Stock Incentive Plan (the “2017 Plan”). 2011 Stock Incentive Plan The 2011 Plan provided for the Company to sell or issue common stock or restricted common stock, or to grant qualified incentive stock options, nonqualified stock options, SARs, RSUs or other stock-based awards to the Company’s employees, officers, directors, advisers and outside consultants. The 2011 Plan was administered by the board of directors, or at the discretion of the board of directors, by a committee of the board. The exercise prices, vesting and other restrictions were determined at the discretion of the board of directors, or a committee of the board, if so delegated, except that the exercise price per share of stock options could not be less than 100% of the fair market value of common stock on the date of grant and the term of the stock option could not be greater than ten years. The stock options generally vest over a four-year ten years The 2011 Plan was terminated for the purpose of making new grants in December 2017, and the remaining 2,855 shares available for issuance under the 2011 Plan at that time were transferred to the 2017 Plan. Awards outstanding under the 2011 Plan at the time of the 2011 Plan’s termination will continue to be governed by their existing terms. The shares of common stock underlying any awards that are forfeited, canceled, repurchased or otherwise terminated by the Company under the 2011 Plan will be added back to the shares of common stock available for issuance under the 2017 Plan. 2017 Stock Incentive Plan On November 17, 2017, the Company’s board of directors adopted, and on November 30, 2017, the Company’s stockholders approved, the 2017 Plan, which became effective immediately prior to the effectiveness of the registration statement for the IPO. The 2017 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The number of shares initially reserved for issuance under the 2017 Plan was the sum of 7,161 shares, plus the number of shares (up to 18,746 shares) equal to the sum of (i) the number of shares remaining available for issuance under the 2003 Plan and 2011 Plan upon the effectiveness of the 2017 Plan and (ii) the number of shares of common stock subject to outstanding awards under the 2003 Plan and 2011 Plan that expire, terminate or are otherwise surrendered, canceled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right. The number of shares of common stock that may be issued under the 2017 Plan will automatically increase on each January 1, beginning with the fiscal year ending December 31, 2019 and continuing for each fiscal year until, and including, the fiscal year ending December 31, 2027, equal to the least of (i) 20,000 shares, (ii) 4% of the outstanding shares of common stock on such date and (iii) an amount determined by the Company’s board of directors. The shares of common stock underlying any awards that are forfeited, canceled, repurchased or otherwise terminated by the Company under the 2017 Plan will be added back to the shares of common stock available for issuance under the 2017 Plan. The total number of shares authorized for issuance under the 2017 Plan was 22,981 shares as of December 31, 2020, of which 10,647 shares remained available for future grant. Upon the closing of the IPO on December 19, 2017, the Company filed a restated certificate of incorporation, which authorized the Company to issue 500,000 shares of $0.001 par value common stock. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any, subject to the preferential dividend rights of the preferred stock. Through December 31, 2020, except for the special cash dividends declared on November 30, 2014, June 17, 2016, December 21, 2016, May 10, 2017 and November 30, 2017 (see Note 12), no dividends have been declared by the board of directors. As of December 31, 2020, the Company had reserved 22,981 shares of common stock for the exercise of outstanding stock options, the vesting of outstanding RSUs, and the number of shares remaining available for grant under the Company’s 2017 Plan. Stock Repurchase Program On February 21, 2019, the Company announced a stock repurchase program authorizing it to repurchase up to $75,000 of the Company’s common stock. During the years ended December 31, 2020 and 2019, the Company repurchased 1,227 and 495 shares for $3,031 and $1,795, respectively, including commissions. As of December 31, 2020, $70,208 remained authorized for repurchases of the Company’s common stock under this stock repurchase program. On August 14, 2018, the Company announced a stock repurchase program authorizing it to repurchase up to $75,000 of the Company’s common stock. During the year ended December 31, 2018, the Company repurchased and retired 5,172 shares for $75,000, before commissions. Stock repurchases under this program are now complete. Stock Option Valuation Subsequent to the completion of the IPO, the Company uses the closing price of its common stock as reported on the Nasdaq Global Select Market on the applicable date of grant to determine the fair value of the shares of common stock underlying stock options. The assumptions used in the Black-Scholes option-pricing model were as follows: Year Ended December 31, 2020 2019 2018 Risk-free interest rate 0.4%–0.7% 1.6%–2.5% 2.7%–3.0% Expected term (in years) 6.1 6.1-6.2 6.0–6.2 Expected volatility 29.3%–31.9% 28.8%–30.6% 30.6%–32.6% Expected dividend yield 0.0% 0.0% 0.0% Stock Options A summary of option activity under the 2003 Plan, the 2011 Plan and the 2017 Plan for the year ended December 31, 2020 is as follows: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value (in years) Outstanding at January 1, 2020 8,250 $ 7.73 5.65 $ 4,235 Granted 166 4.55 Exercised (591 ) 2.02 Forfeited (705 ) 8.98 Outstanding at December 31, 2020 7,120 $ 8.01 4.88 $ 9,367 Options exercisable at December 31, 2020 6,492 $ 7.62 4.59 $ 9,026 Vested or expected to vest at December 31, 2020 7,090 $ 8.01 4.87 $ 9,341 The weighted-average grant-date fair value of options granted during the years ended December 31, 2020, 2019 and 2018 was $1.42, $2.13 and $7.59 per share, respectively. Cash proceeds received upon the exercise of options were $1,195, $2,687 and $14,730 during the years ended December 31, 2020, 2019 and 2018, respectively. The intrinsic value of stock options exercised during the years ended December 31, 2020, 2019 and 2018 was $1,746, $6,970 and $105,787, respectively. The aggregate intrinsic value is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. Restricted Stock Units A summary of RSU activity for the year ended December 31, 2020 is as follows: Number of Shares Weighted- Average Grant Date Fair Value Aggregate Fair Value Unvested balance at January 1, 2020 1,653 $ 11.38 Granted 3,270 3.54 Vested (554 ) 11.03 $ 2,321 Forfeited (138 ) 9.60 Unvested balance at December 31, 2020 4,231 $ 5.43 The Company withheld 150, 77 and 1 shares of common stock in settlement of employee tax withholding obligations due upon the vesting of RSUs during the years ended December 31, 2020, 2019 and 2018, respectively. Performance Based Restricted Stock Units The Company granted 983 Performance-based Restricted Stock Units (“PSUs”) in February 2020 to certain employees that vest over a three-year Compensation expense for PSUs is based on the estimated value of the awards on the grant date, and is recognized over the period from the grant date through the expected vest dates of each vesting condition, both of which were estimated based on a Monte Carlo simulation model applying the following key assumptions: Grant Date Assumptions Risk-free interest rate 1.2% Volatility 70.0% Dividend yield 0.0% Cost of equity 11.0% A summary of PSU activity for the year ended December 31, 2020 is as follows: Number of Shares Weighted- Average Grant Date Fair Value Aggregate Fair Value Unvested balance at January 1, 2020 — $ — Granted 983 3.22 Vested (246 ) 3.22 $ 1,516 Forfeited — — Unvested balance at December 31, 2020 737 $ 3.22 Stock Appreciation Rights On three occasions between 2012 and 2017, the Company granted SARs that allow the holder the right, upon exercise, to receive in cash the amount of the difference between the fair market value of the Company’s common stock at the date of exercise and the price of the underlying common stock at the date of grant of each SAR. The SARs vested over a four-year Stock-Based Compensation Expense The Company classified s tock-based compensation expense related to stock options, RSUs and SARs for the years ended December 31, 2020, 2019 and 2018 in the consolidated statements of operations and comprehensive income (loss) as follows: Year Ended December 31, 2020 2019 2018 Cost of revenue $ 153 $ 216 $ 249 Research and development expenses 2,447 1,569 1,864 Selling, general and administrative 10,555 8,036 6,781 $ 13,155 $ 9,821 $ 8,894 The Company recognized s tock-based compensation expense for the years ended December 31, 2020, 2019 and 2018 in the consolidated balance sheet as follows: Year Ended December 31, 2020 2019 2018 Change in fair value of SAR liability $ 229 $ (1,123 ) $ (768 ) Recognized as additional paid-in capital 12,926 10,944 9,662 Total stock-based compensation $ 13,155 $ 9,821 $ 8,894 As of December 31, 2020, there was $20,948 of unrecognized compensation cost related to outstanding stock options, RSUs and SARs, which is expected to be recognized over a weighted-average period of 2.24 years.

Net Income (Loss) per Share

Net Income (Loss) per Share	12 Months Ended
Net Income (Loss) per Share	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Income (Loss) per Share	14. Net Income (Loss) per Share The Company calculated b asic and diluted net income (loss) per share attributable to common stockholders as follows: Year Ended December 31, 2020 2019 2018 Numerator: Net income (loss) attributable to common stockholders, basic and diluted $ 24,801 $ (48,206 ) $ 73,006 Denominator: Weighted-average shares used to compute net income (loss) per share attributable to common stockholders, basic 83,465 83,853 83,539 Dilutive effect of stock options 1,050 — 8,086 Dilutive effect of restricted stock units 763 — 252 Weighted-average shares used to compute net income (loss) per share attributable to common stockholders, diluted 85,278 83,853 91,877 Net income (loss) per share attributable to common stockholders: Basic $ 0.30 $ (0.57 ) $ 0.87 Diluted $ 0.29 $ (0.57 ) $ 0.79 The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net income (loss) per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Year Ended December 31, 2020 2019 2018 Options to purchase common stock 4,119 4,641 2,213 Unvested restricted stock units 1,030 1,516 168 Unvested performance-based stock units 983 — —

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
Revenue from Contracts with Customers	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Revenue from Contracts with Customers	15. Revenue from Contracts with Customers Disaggregation of revenue The Company disaggregates its revenue by product and service in the consolidated statements of operations and comprehensive income (loss). The Company recognizes performance obligations related to product revenue at a point in time, and performance obligations related to service revenue over time. The Company also disaggregates its revenue based on geographic locations of its customers, as determined by the customer’s shipping address, summarized as follows: Year Ended December 31, 2020 2019 2018 North America: United States $ 127,217 $ 103,451 $ 104,124 Canada 38,960 36,466 41,884 Total North America 166,177 139,917 146,008 Latin America 34,926 24,043 32,283 Europe, Middle East and Africa: Germany 5,487 13,773 45,864 Other 30,446 24,381 35,479 Total Europe, Middle East and Africa 35,933 38,154 81,343 Asia-Pacific Australia 116,661 42,218 24,354 Other 39,549 37,965 13,139 Total Asia-Pacific 156,210 80,183 37,493 Total revenue (1) $ 393,246 $ 282,297 $ 297,127 (1) Other than the United States, Canada, Germany and Australia, no individual countries represented 10% or The Company also disaggregates its revenue based on product line summarized as follows: Year Ended December 31, 2020 2019 2018 Product revenue: Wireless $ 111,255 $ 58,234 $ 402 Fixed telco 96,904 38,734 — Cable 137,924 144,409 256,587 Total product revenue 346,083 241,377 256,989 Service revenue Wireless 7,348 1,701 250 Fixed telco 1,924 773 — Cable 37,891 38,446 39,888 Total service revenue 47,163 40,920 40,138 Total revenue $ 393,246 $ 282,297 $ 297,127 Costs to Obtain or Fulfill a Contract As of December 31, 2020 and 2019 and January 1, 2019, the Company had short-term capitalized contract costs of $95, $585 and $209, respectively, which are included in prepaid expenses and other current assets and had long-term capitalized contract costs of $70, $70 and $128, respectively, which are included in other assets in the accompanying consolidated balance sheets. During the year ended December 31, 2020 and 2019, amortization expense associated with capitalized contract costs was $568 and $695, respectively, Contract Balances Contract liabilities consist of deferred revenue and include payments received in advance of performance under the contract. The Company recognizes such amounts as revenue when the Company satisfies its performance obligations. For the year ended December 31, 2020, the Company recognized The Company receives payments from customers based upon contractual billing terms. The Company records a ccounts receivable when the right to consideration becomes unconditional. Contract assets include amounts related to the Company’s contractual right to consideration for both completed and partially completed performance obligations that may not have been invoiced. As of December 31 , 2020 and 2019 and January 1, 2019, the Company recorded contract assets of $ 771 , $50 and $ 28 , respectively, which is netted with deferred revenue in the accompanying consolidated balance sheets . Transaction price allocated to the remaining performance obligations As of December 31, 2020, the aggregate remaining amount of revenue expected to be recognized related to unsatisfied or partially unsatisfied performance obligations is $19,051, which consists of deferred revenue. The Company expects approximately 82% of this amount to be recognized in the next twelve months with the remaining amounts to be recognized over the next two to five years.

Segment Information

Segment Information	12 Months Ended
Segment Information	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Information	16. Segment Information The Company operates as one operating segment. Operating segments are defined as components of an enterprise for which separate financial information is regularly evaluated by the Company’s chief operating decision maker, or decision-making group, in deciding how to allocate resources and assess performance. The Company has determined that its chief operating decision maker is its President and Chief Executive Officer. The Company’s chief operating decision maker reviews the Company’s financial information on a consolidated basis for purposes of allocating resources and assessing financial performance. Since the Company operates as one operating segment, all required financial segment information can be found in these consolidated financial statements. Please refer to Note 15 for the Company’s revenue by geography for the years ended December 31, 2020, 2019 and 2018. The Company’s property and equipment, net by location was as follows: December 31, 2020 2019 United States $ 20,988 $ 25,583 China 2,986 3,277 Australia 2,849 4,041 Other 2,057 3,009 Total property and equipment, net $ 28,880 $ 35,910

Related Parties

Related Parties	12 Months Ended
Related Parties	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Parties	17. Related Parties Transactions Involving Liberty Global Ventures Holding B.V. and its Affiliates Liberty Global Ventures Holding B.V. was a principal stockholder of the Company through its ownership of common stock. Affiliates of Liberty Global Ventures Holding B.V. (“Liberty Global Affiliates”) are customers of the Company. Liberty Global Affiliates ceased being a principal stockholder as of October 19, 2018, when it disposed of a portion of its ownership of the Company’s stock. During the year ended December 31, 2018, the Company recognized revenue of $22,252 from transactions with Liberty Global Affiliates and amounts received in cash from Liberty Global Affiliates totaled $30,432. Employment of Rongke Xie Rongke Xie, who serves as Deputy General Manager of Guangzhou Casa Communication Technology LTD (“Casa China”), a subsidiary of the Company, is the sister of Lucy Xie, the Company’s Senior Vice President of Operations and a member of the Company’s board of directors. Casa China paid Rongke Xie $187, $117 and $143 in total compensation in the years ended December 31, 2020, 2019 and 2018, respectively, for her services as an employee. In addition, during the year s ended December 31, 20 20 and 201 9 , the Company granted to Rongke Xie 90 and 8 RSUs, respectively, which vest in annual installments over a four -year period. The grant-date fair value of the award s totaled $ 200 and $ 100 , respectively, which will be recorded as stock-based compensation expense over the vesting period of the award s . During the year s ended December 31, 20 20 and 201 9 , the Company recognized selling, general and administrative expenses of $ 90 and $ 46 related to th ese award s , respectively .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	18. Commitments and Contingencies Operating Leases The Company leases manufacturing, warehouse and office space in the United States, China, Hong Kong, Spain and Australia under non-cancelable operating leases that expire through 2024. The Company also has a lease in Ireland that expires in 2026. Rent expense for the years ended December 31, 2020, 2019 and 2018 was $3,252, $2,459 and $1,029, respectively. The Company records rent expense on a straight-line basis, and, as a result, as of December 31, 2020 and 2019, the Company had a deferred rent liability of $90 and $212, respectively, which is included in accrued expenses and other current liabilities in the accompanying consolidated balance sheets. Future minimum lease payments under non-cancelable operating leases as of December 31, 2020 were as follows: Year Ending December 31, 2021 $ 2,533 2022 1,500 2023 1,425 2024 536 2025 445 Thereafter 334 $ 6,773 Indemnification The Company has, in the ordinary course of business, agreed to defend and indemnify certain customers against third-party claims asserting infringement of certain intellectual property rights, which may include patents, copyrights, trademarks or trade secrets. As permitted under Delaware law, the Company indemnifies its officers, directors and employees for certain events or occurrences that happen by reason of their relationship with or position held at the Company. As of December 31, 2020 and 2019, the Company had not experienced any losses related to these indemnification obligations and no material claims were outstanding where a continent loss was considered to be probable or reasonably estimable. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related liabilities were recorded in its consolidated financial statements. Litigation On May 29, 2019, John Shen filed a putative shareholder class action complaint in the Massachusetts Superior Court of Essex County, John Shen v Casa Systems, Inc et al., Civil Action No 1977VB00787 Mirza R. Baig v. Casa Systems, Inc, et al., Civil Action No. 1977CV00961 John Shen v. Casa Systems, Inc. et al., Civil Action No. 19-CV-03203-BLS2 Mirza R. Baig v. Casa Systems, Inc., Civil Action No. 19-CV-03204-BLS2 make such statements not misleading and (ii) the individual defendants and Summit Partners acted as controlling persons within the meaning and in violation of Section 15 of the Securities Act. On November 12, 2019, the plaintiffs filed an amended shareholder class action complaint, purportedly on behalf of all purchasers of the Company’s common stock in and/or traceable to the IPO, which contain ed substantially similar allegations and assert ed the same claims as the two initial complaints, described above. Plaintiffs sought, among other things, compensatory damages, costs and expenses, including counsel and expert fees, rescission or a rescissory measure of damages, and equitable and injunctive relief. On January 14, 2020, the defendants filed motions to dismiss the amended complaint, with prejudices . One January 11, 2021, the court granted the motions to dismiss . On August 9, 2019, Donald Hook filed a putative shareholder class action lawsuit in the Supreme Court of the State of New York, County of New York, Donald Hook et al., v. Casa Systems, Inc. et al., Index No. 654548/2019 On August 13, 2019, Panther Partners, Inc. filed a putative shareholder class action lawsuit in the Supreme Court of the State of New York, New York County, Panther Partners, Inc., et al., v. Jerry Guo, et al., Index No. 654585/2019 The Company is generally obligated to indemnify our officers, directors, and the IPO and Follow-on Offering underwriters in each of the matters described above. No amounts have been accrued for any of the putative class action lawsuits referenced above as of December 31, 2020 as the Company does not believe the likelihood of a material loss is probable. Although the ultimate outcome of these matters cannot be predicted with certainty, the resolution of this matter could have a material impact on the Company’s results of operations in the period in which such matter is resolved.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	19. Employee Benefit Plan The Company has a Section 401(k) defined contribution savings plan for its employees. The plan covers substantially all employees in the United States who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis, subject to certain limitations. Company contributions to the plan may be made at the discretion of the board of directors. Effective January 1, 2014, the Company commenced matching contributions in the amount of 50% of the employee’s contributions of up to 6% of eligible wages. The Company made matching contributions to the plan of $1,523, $1,762 and $1,630 in the years ended December 31, 2020, 2019 and 2018, respectively.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and judgments relied upon by management in preparing these consolidated financial statements include revenue recognition, provision for doubtful accounts, reserves for excess and obsolete inventory, valuation of inventory and deferred inventory costs, the expensing and capitalization of software-related research and development costs, amortization and depreciation periods, the recoverability of net deferred tax assets, valuations of uncertain tax positions, warranty allowances, the valuation of equity instruments and stock-based compensation expense. Although the Company regularly reassesses the assumptions underlying these estimates, actual results could differ materially from these estimates. Changes in estimates are recorded in the period in which they become known. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances existing at the time such estimates are made . The emergence of COVID-19 around the world, and particularly in the United States and China, presents various risks to the Company, not all of which the Company is able to fully evaluate or even to foresee at the current time, and could have a material effect upon the estimates and judgments relied upon by management in preparing these consolidated financial statements. While the COVID-19 pandemic did not significantly adversely affect the Company’s financial results and business operations in the year ended December 31, 2020, economic and health conditions in the United States and across most of the globe changed rapidly during the year, and are continuing to change after the end of the year. Globally, all aspects of the Company’s business remain fully operational. However, increasing demand for certain of the Company’s products has increased pressure on its supply chain which could impact continued availability of inventory requirements. The Company will continue to monitor its business very closely for any effects of COVID-19 for as long as necessary on an ongoing basis.
Subsequent Event Considerations	Subsequent Event Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. The Company has evaluated all subsequent events and determined that there are no material recognized or unrecognized subsequent events requiring disclosure in these consolidated financial statements.
Cash and Cash Equivalents, Restricted Cash	Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents include all highly liquid investments maturing within three months from the date of purchase. As of December 31, 2020 and 2019, the Company’s cash and cash equivalents consisted of investments in certificates of deposit and money market mutual funds. Restricted cash, which was included in other assets as of December 31, 2020 and 2019, consisted of a certificate of deposit of $1,006 and $1,019, respectively, in each period pledged as collateral for a stand-by letter of credit required to support a contractual obligation. The following table is a reconciliation of cash, cash equivalents and restricted cash included in the accompanying consolidated balance sheets that sum to the total cash, cash equivalents and restricted cash included in the accompanying consolidated statements of cash flows. December 31, 2020 December 31, 2019 Cash and cash equivalents $ 157,455 $ 113,638 Restricted cash included in other assets 1,006 1,019 $ 158,461 $ 114,657
Accounts Receivable	Accounts Receivable Accounts receivable are presented net of a provision for doubtful accounts, which is an estimate of amounts that may not be collectible. Accounts receivable for arrangements with customary payment terms, which are one year or less, are recorded at invoiced amounts and do not bear interest. The Company generally does not require collateral, but may, in certain instances based on its credit assessment, require full or partial prepayment prior to shipment. The Company may, in limited circumstances, grant payment terms longer than one year. Payments due beyond 12 months from the balance sheet date are recorded as non-current assets. Accounts receivable as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Current portion of accounts receivable, net: Accounts receivable, net $ 93,480 $ 91,273 Accounts receivable, extended payment arrangements 644 1,827 94,124 93,100 Accounts receivable, net of current portion: Accounts receivable, extended payment arrangements 143 575 $ 94,267 $ 93,675 The Company performs ongoing credit evaluations of its customers and, if necessary, provides a provision for doubtful accounts and expected losses. When assessing and recording its provision for doubtful accounts, the Company evaluates the age of its accounts receivable, current economic trends, creditworthiness of customers, customer payment history, and other specific customer and transaction information. The Company writes off accounts receivable against the provision when it determines a balance is uncollectible and no longer actively pursues collection of the receivable. Adjustments to the provision for doubtful accounts are recorded as selling, general and administrative expenses in the consolidated statements of operations and comprehensive income (loss). A summary of changes in the provision for doubtful accounts for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Provision for doubtful accounts at beginning of year $ 20 $ 410 $ 692 Provisions and recoveries 38 560 — Write-offs — (950 ) (282 ) Provision for doubtful accounts at end of year $ 58 $ 20 $ 410 As of December 31, 2020 and 2019, the Company concluded that all amounts due under extended payment term arrangements were collectible and no reserve for credit losses was recorded. During the years ended December 31, 2020, 2019 and 2018, the Company did not provide a reserve for credit losses and did not write off any uncollectible receivables due under extended payment term arrangements.
Inventories	Inventories The Company values inventories at the lower of cost or market value. The Company computes cost using the first-in first-out convention. Inventories are composed of hardware and related component parts of finished goods. The Company establishes provisions for excess and obsolete inventories after evaluating historical sales, future demand, market conditions, expected product life cycles, and current inventory levels to reduce such inventories to their estimated net realizable value. The Company makes such provisions in the normal course of business and charges them to cost of revenue in its consolidated statements of operations and comprehensive income (loss). The Company includes deferred inventory costs within inventory in its consolidated balance sheets. Deferred inventory costs represent the cost of products that have been delivered to the customer for which revenue associated with the arrangement has been deferred as a result of not meeting all of the required revenue recognition criteria, such as receipt of customer acceptance. The Company recognizes deferred inventory costs as cost of revenue in its consolidated statements of operations and comprehensive income (loss) when the related revenue is recognized.
Property and Equipment	Property and Equipment The Company states property and equipment at historical cost less accumulated depreciation. The Company computes depreciation using the straight-line method over the estimated useful lives of the assets. The Company records leasehold improvements at cost with any reimbursement from the landlord being accounted for as deferred rent, which is amortized using the straight-line method over the lease term. The Company also includes costs for trial systems held and used by its customers pursuant to evaluation agreements within property and equipment. The Company depreciates trial systems held and used by its customers over the estimated useful life of such assets, which is two years. Whenever a trial system is sold to a customer and the selling price is recorded as revenue, the Company removes the related net book value of the trial system sold from property and equipment and records it as a cost of revenue. The Company expenses maintenance and repairs expenditures as incurred. Estimated useful lives of the respective property and equipment assets are as follows: Estimated Useful Life Computers and purchased software 3 – 4 years Leasehold improvements Shorter of lease term or 7 years Furniture and fixtures 6 – 8 years Machinery and equipment 3 – 5 years Building 40 years Building improvements 5 – 40 years Trial systems at customers’ sites 2 years Upon retirement or sale, the Company removes the cost of assets disposed of and the related accumulated depreciation from the accounts and any resulting gain or loss is included in income (loss) from operations.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates its long-lived assets, which consist primarily of property and equipment and intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. The Company measures recoverability of assets to be held and used by a comparison of the carrying amount of an asset to the future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the Company measures the impairment to be recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset, less the cost to sell. No events or changes in circumstances existed to require an impairment assessment during the years ended December 31, 2020, 2019 and 2018.
Deferred Offering Costs	Deferred Offering Costs The Company paid deferred offering costs of $1,148 during the year ended December 31, 2018. No deferred offering costs were paid during the years ended December 31, 2020 and 2019.
Concentration of Risks	Concentration of Risks Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. Cash and cash equivalents consist of demand deposits, savings accounts, commercial paper, money market mutual funds, and certificates of deposit with financial institutions, which may exceed Federal Deposit Insurance Corporation limits. The Company has not experienced any losses related to its cash and cash equivalents and does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. We grant credit to customers in the ordinary course of business. Credit evaluations are performed on an ongoing basis to reduce credit risk, and no collateral is required from our customers. An allowance for uncollectible accounts is provided for those accounts receivable considered to be uncollectible based upon historical experience and credit evaluation. Due to these factors, no additional losses beyond the amounts provided for collection losses is believed by management to be probable in the Company’s accounts receivable. Significant customers are those that represent 10% or more of revenue or accounts receivable and are set forth in the following tables: Revenue Accounts Receivable, Net Year Ended December 31, December 31, 2020 2019 2018 2020 2019 Customer A * 14 % 27 % * 11 % Customer B * * 11 % * * Customer C * * 12 % * 14 % Customer D * * 14 % * * Customer E * * * * 19 % Customer F 20 % 12 % * * * Customer G 11 % * * 14 % * * Less than 10% of total Customer B was a related party until October 19, 2018, Liberty Global Affiliates (see Note 17). Certain of the components and subassemblies included in the Company’s products are obtained from a single source or a limited group of suppliers. Although the Company seeks to reduce dependence on those limited sources of suppliers and manufacturers, the partial or complete loss of certain of these sources could have a material adverse effect on the Company’s operating results, financial condition and cash flows and damage its customer relationships.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill represents the excess purchase price over the estimated fair value of net assets acquired as of the acquisition date. Goodwill has been recorded in connection with the acquisition of NetComm on July 1, 2019 (refer to Note 3). The Company tests goodwill for impairment on an annual basis and between annual tests when impairment indicators are identified, and goodwill is written down when impaired. The Company performs its annual goodwill impairment test during its fourth quarter. For its annual goodwill impairment test, the Company operates under one reporting unit and the fair value of its reporting unit has been determined based on the Company’s enterprise value. As part of the annual goodwill impairment test, the Company has the option to perform a qualitative assessment to determine whether further impairment testing is necessary. Examples of events and circumstances that might indicate that the reporting unit’s fair value is less than its carrying amount include macro-economic conditions such as deterioration in the entity’s operating environment or industry or market considerations; entity-specific events such as increasing costs, declining financial performance, or loss of key personnel; or other events such as a sustained decrease in the stock price on either an absolute basis or relative to peers. If, as a result of its qualitative assessment, it is more likely than not (i.e., greater than 50% chance) that the fair value of the Company’s reporting unit is less than its carrying amount, the quantitative impairment test will be required. Otherwise, no further testing will be required. The Company completed its qualitative assessment and concluded that as of December 31, 2020, it is not more likely than not that the fair value of the Company’s reporting unit is less than its carrying amount. The Company amortizes its acquired intangible assets subject to amortization using the straight-line method over their estimated useful lives, ranging from 3 to 10 years. Purchased software licenses are classified as intangible assets and are amortized using the straight-line method over their estimated useful lives, typically ranging from 3 to 4 years. The Company evaluates the recoverability of intangible assets periodically by taking into account events or circumstances that may warrant revised estimates of useful lives or that indicate the asset may be impaired. The Company considered potential impairment indicators of acquired intangible assets at December 31, 2020 and noted no indicators of impairment.
Product Warranties	Product Warranties Substantially all of the Company’s products are covered by a warranty for software and hardware for periods ranging from 90 days to one year. In addition, in conjunction with customers’ renewals of maintenance and support contracts, the Company offers an extended warranty for periods typically of one to three years for agreed-upon fees. In the event of a failure of a hardware product or software covered by these warranties, the Company must repair or replace the software or hardware or, if those remedies are insufficient, and at the discretion of the Company, provide a refund. The Company’s warranty reserve, which is included in accrued expenses and other current liabilities in the consolidated balance sheets, reflects estimated material, labor and other costs related to potential or actual software and hardware warranty claims for which the Company expects to incur an obligation. The Company’s estimates of anticipated rates of warranty claims and the costs associated therewith are primarily based on historical information and future forecasts. The Company periodically assesses the adequacy of the warranty reserve and adjusts the amount as necessary. If the historical data used to calculate the adequacy of the warranty reserve are not indicative of future requirements, additional or reduced warranty reserves may be required. A summary of changes in the amount reserved for warranty costs for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Warranty reserve at beginning of year $ 2,448 $ 926 $ 1,246 Provisions 2,745 3,603 1,886 Acquired warranty reserve — 1,867 — Charges (2,839 ) (3,948 ) (2,206 ) Warranty reserve at end of year $ 2,354 $ 2,448 $ 926 The increase in the warranty charges and reserve for the year ended December 31, 2019 is primarily due to warranty obligations obtained with the acquisition of NetComm on July 1, 2019.
Revenue Recognition	Revenue Recognition Effective January 1, 2019, the Company adopted ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”) using the modified retrospective transition method. This method was applied to contracts that were not complete as of the date of initial application. The following is a summary of new and/or revised significant accounting policies affected by the Company’s adoption of ASC 606, which relate primarily to revenue and cost recognition. Refer to Note 2, Summary of Significant Accounting Policies, in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 for the policies in effect for revenue and cost recognition prior to January 1, 2019. The Company generates revenue from sales of its products, along with associated maintenance, support and extended hardware warranty services, and to a lesser extent, from sales of professional services. The Company also generates revenue from sales of additional line cards and software-based capacity expansions. Maintenance and support services include telephone support, bug fixes and unspecified software upgrades and updates provided on a when-and-if-available basis and/or extended hardware warranty. In its consolidated statements of operations and comprehensive income (loss), the Company classifies revenue from sales of cable products and fixed wireless access and fixed telco devices as product revenue, and revenue from maintenance and support and professional services as service revenue. In accordance with ASC 606, the Company recognizes revenue when a customer obtains control of promised products or services. The amount of revenue recognized reflects the consideration that the Company expects to be entitled to receive in exchange for these products or services. To achieve the core principle of this standard, the Company applies the following five steps: 1) Identify the contract with a customer 2) Identify the performance obligations in the contract 3) Determine the transaction price includes v ariable consideration in the transaction price if, in its judgment, it is probable that no significant future reversal of cumulative revenue under the contract will occur . 4) Allocate the transaction price to performance obligations in the contract 5) Recognize revenue when or as the Company satisfies a performance obligation Performance Obligations The majority of the Company’s contracts with customers contain multiple performance obligations including products and maintenance services, and on a limited basis, professional services. For these contracts, the Company accounts for individual performance obligations separately if they are considered distinct. The Company’s cable, wireless and fixed telco products, maintenance services and professional services are considered distinct performance obligations. When multiple performance obligations exist in a customer contract, the Company allocates the transaction price to the separate performance obligations on a relative SSP basis. The Company determines SSP using its judgment and based on the best evidence available, which may include the selling price of products when sold on a standalone basis to similar customers in similar circumstances, or in the absence of standalone sales, taking into consideration the Company’s historical pricing practices by customer type, selling method (i.e. resellers or direct), and geographic-specific market factors. Product revenue The Company’s cable, wireless and fixed telco products generally have both software and non-software (i.e., hardware) components that function together to deliver the products’ essential functionality. The Company’s hardware generally cannot be used apart from the embedded software and is considered one distinct performance obligation. The Company recognizes revenue for both new and existing customers at a point in time when control of the products is transferred to the customer, which is typically when title and risk of loss have transferred and the right to payment is enforceable. The Company also earns revenue from the sale of perpetual software licenses and/or software-enabled capacity expansions. Revenue on perpetual software licenses and software-enabled capacity expansions for existing customers are also distinct performance obligations as they are separately identifiable and provide additional bandwidth capacity on hardware products already purchased by the customer. The Company recognizes revenue on perpetual software licenses and software-enabled capacity expansions when control is transferred, which is typically as the software entitlements are made available to the customer. When customer contracts require acceptance of product and services, the Company considers the nature of the acceptance provisions to determine if they are substantive or considered perfunctory to determine if these acceptance provisions impact the timing of revenue recognition. When acceptance provisions are considered substantive, the Company will defer revenue on all performance obligations in the contract subject to acceptance until acceptance has been received. The Company does not defer revenue when acceptance provisions are deemed perfunctory. Maintenance and Support Services and Professional Services Revenue The Company generally sells its products with maintenance and support services, a distinct performance obligation that includes the stand-ready obligation to provide telephone support, bug fixes and unspecified software upgrades and updates provided on a when-and-if-available basis and/or extended hardware warranty. After the initial sale, customers may purchase annual renewals of support contracts. The Company’s telephone support and unspecified upgrades and updates are delivered over time and the Company therefore recognizes revenue ratably over the contract term, which is typically one year, but can be as long as five years. The Company also generates revenue from sales of professional services, such as installation, configuration and training. Professional services are a distinct performance obligation since the Company’s products are functional without these services and can generally be performed by the customer or a third party. The Company generally recognizes fee-based professional services delivered at a point in time as the professional services are completed and upon receipt of acceptance if applicable. The sale of the Company’s products generally includes a 90-day warranty on the software and a one-year obligation. The Company records a warranty accrual for the initial software and hardware warranty included with product sales and does not defer revenue . Resellers and Sales Agents The Company markets and sells its products through its direct global sales force, supported by sales agents, and through resellers. The Company’s resellers receive an order from an end customer prior to placing an order with the Company, and the Company confirms the identification of or is aware of the end customer prior to accepting such order. The Company invoices the reseller an amount that reflects a reseller discount and records revenue based on the amount of the discounted transaction value. Aside from wireless and fixed telco hardware products, the Company’s resellers do not stock inventory received from the Company. When the Company transacts with a reseller, the contract is with the reseller and not with the end customer. Whether the Company transacts business with and receives the order directly from the reseller or a customer, its revenue recognition policy and resulting pattern of revenue recognition for the order are the same. The Company has assessed whether it is principal (i.e., reports revenue on a gross basis) or agent (i.e., reports revenues on a net basis) by evaluating whether it has control of the good or service before it is transferred to the reseller. Generally, the Company controls the promised good or service before transferring it to the reseller and acts as the principal in the transaction. Accordingly, the Company reports revenues on a gross basis. The Company also uses sales agents that assist in the sales process with certain customers, primarily located in the Latin America and Asia-Pacific regions. Sales agents are not resellers. If a sales agent is engaged in the sales process, the Company receives the order directly from the end customer and sells the products and services directly to the end customer, and the Company pays a commission to the sales agent, calculated as a percentage of the related transaction value. Accounting considerations related to sales agent commissions are discussed in the “Costs to Obtain or Fulfill a Contract” section below. Costs to Obtain or Fulfill a Contract The Company capitalizes commission expenses paid to internal sales personnel and sales agent commissions that are incremental to obtaining customer contracts, for which the related revenue is recognized over a future period greater than 12 months. These costs are incurred on initial sales of product, professional services and maintenance and support contract renewals. The Company defers these costs and amortizes them over the period of benefit, which is generally considered to be the contract term. The Company has elected to use the practical expedient, allowing the Company to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the entity otherwise would have recognized is one year or less. Commissions paid relating to maintenance and support contract renewals of twelve months or less are expensed as incurred as commissions paid on renewals are commensurate with commissions paid on initial sales transactions. Costs to obtain a contract for professional services contracts are expensed as incurred in accordance with the practical expedient as the contractual period of our professional services contracts are one year or less. The Company periodically reviews the carrying amount of capitalized contract costs to determine whether events or changes in circumstances have occurred that could impact the period of benefit. Deferred Revenue The Company recognizes amounts billed in excess of revenue recognized as deferred revenue. Deferred revenue includes customer deposits, amounts billed for maintenance and support services contracts in advance of services being performed, amounts for trade-in right liabilities and amounts related to contracts that have been deferred as a result of not meeting the required revenue recognition criteria as of the end of the reporting period. The Company reports deferred revenue expected to be recognized as revenue more than one year subsequent to the balance sheet date within long-term liabilities in the consolidated balance sheets. The Company defers recognition of direct costs, such as cost of goods and services, until recognition of the related revenue. The Company classifies such costs as current assets if the related deferred revenue is classified as current and as non-current assets if the related deferred revenue is classified as non-current. Other Revenue Recognition Policies The Company’s customary payment terms are generally 90 days or less. The Company has elected to apply the practical expedient that allows an entity to not adjust the promised amount of consideration in customer contracts for the effect of a significant financing component when the period between the transfer of product and services and payment of the related consideration is less than one year. If the Company provides extended payment terms that represent a significant financing component, the Company adjusts the amount of promised consideration for the time value of money using an appropriate discount rate and recognizes interest income separate from the revenue recognized on contracts with customers. During the year ended December 31, 2020 and 2019, the Company recorded $64 and $160, respectively, in interest income in its consolidated statements of operations and comprehensive income (loss) related to arrangements with customers that were determined to have a significant financing component. In limited instances, the Company has offered future rebates to customers based on a fixed or variable percentage of actual sales volumes over specified periods. The future rebates earned based on the customer’s purchasing from the Company in one period may be used as credits to be applied by them against accounts receivable due to the Company in later periods. The Company accounts for these future rebates as variable consideration and reduces the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will occur when the variable consideration is resolved. The Company estimates the reduction of the transaction price based on historical activity and other relevant factors and recognizes it when the Company recognizes revenue for the transfer of goods and services to the customer on which the future rebate was earned. Other forms of contingent revenue or variable consideration are infrequent. The Company excludes any taxes assessed by a governmental authority that are directly imposed on a revenue-producing transaction (e.g., sales, use and value added taxes) from its transaction price. The Company records billings to customers for reimbursement of out-of-pocket expenses, including travel, lodging and meals, as revenue, and the associated costs incurred by the Company as cost of revenue. Revenue related to the reimbursement of out-of-pocket costs are accounted for as variable consideration. The Company accounts for any shipping and handling activities as a fulfilment cost rather than an additional promised service. The Company records shipping and handling billed to customers as an offset to cost of revenue. Transition Disclosures In accordance with the modified retrospective method transition requirements, the Company has presented the financial statement line items impacted and adjusted to compare to presentation under ASC Topic 605, Revenue Recognition As of December 31, 2019 Balance Sheet As Reported under ASC 606 Adjustments Without adoption of ASC 606 Assets: Accounts receivable $ 93,100 $ 47 $ 93,147 Inventory 93,604 186 93,790 Prepaid expenses and other current assets 4,884 54 4,938 Prepaid income taxes 3,217 330 3,547 Accounts receivable, net of current portion 575 23 598 Deferred tax assets 69 1,757 1,826 Other assets 7,820 (69 ) 7,751 Total assets $ 444,312 $ 2,328 $ 446,640 Liabilities: Accrued expenses and other current liabilities $ 34,567 $ (491 ) $ 34,076 Deferred revenue 25,485 8,194 33,679 Deferred revenue, net of current portion 4,583 1,856 6,439 Total liabilities 405,748 9,559 415,307 Stockholders’ Equity: Accumulated deficit (127,064 ) (7,231 ) (134,295 ) Total stockholders’ equity 38,564 (7,231 ) 31,333 Total liabilities and stockholders’ equity $ 444,312 $ 2,328 $ 446,640 Total reported assets under ASC 606 as of December 31, 2019 were $2,328 less than the total assets without the adoption of ASC 606 largely due to decreases in deferred tax assets, prepaid income taxes and deferred inventory costs related to contracts for which deferred revenue was adjusted to retained earnings, partially offset by increases in prepaid expenses and other current assets and other assets related to contract costs capitalized under ASC 606 that would have been expensed when incurred under ASC 605. Total reported liabilities under ASC 606 as of December 31, 2019 were $9,559 less than the total liabilities without the adoption of ASC 606 primarily driven by the adjustment of deferred revenue related to a customer contract for which revenue was recognized based on receipt of cash payments under ASC 605 that would have been recognized upon product acceptance under ASC 606, offset by an increase in accrued partner commissions in accrued expenses and other current liabilities. These partner commissions were previously being recognized in the period in which cash was received and revenue was recognized. Upon the adoption of ASC 606, partner commissions are reflected as a cost to obtain a contract and they are expensed consistent with the pattern of revenue recognition on this contract. Year Ended December 31, 2019 Statement of Operations and Comprehensive (Loss) Income As Reported under ASC 606 Adjustments Without adoption of ASC 606 Revenue: Product $ 241,377 $ (6,201 ) $ 235,176 Service 40,920 197 41,117 Total revenue 282,297 (6,004 ) 276,293 Cost of revenue: Product 113,059 182 113,241 Gross profit 162,532 (6,186 ) 156,346 Operating expenses: Selling, general and administrative 88,320 231 88,551 Loss from operations (9,119 ) (6,417 ) (15,536 ) Other income (expense): Interest income 4,406 (159 ) 4,247 Loss before provision for (benefit from) income taxes (24,415 ) (6,576 ) (30,991 ) Provision for (benefit from) income taxes 23,791 (1,495 ) 22,296 Net loss (48,206 ) (5,081 ) (53,287 ) Comprehensive loss $ (49,270 ) $ (5,081 ) $ (54,351 ) Net loss per share attributable to common stockholders: Basic $ (0.57 ) $ (0.07 ) $ (0.64 ) Diluted $ (0.57 ) $ (0.07 ) $ (0.64 ) During the year ended December 31, 2019, the adoption of ASC 606 resulted in a net increase to product revenue due to certain contracts for which product revenue was recognized upon delivery that would have been deferred without the adoption of ASC 606 due to the lack of vendor-specific objective evidence. Year Ended December 31, 2019 Statement of Cash Flows As Reported under ASC 606 Adjustments Without adoption of ASC 606 Cash flows used in operating activities: Net loss $ (48,206 ) $ (5,081 ) $ (53,287 ) Deferred income taxes 19,641 (1,166 ) 18,475 Changes in operating assets and liabilities: Accounts receivable 1,881 159 2,040 Inventory (21,276 ) 182 (21,094 ) Prepaid expenses and other assets (3,679 ) (322 ) (4,001 ) Prepaid income taxes 16 (330 ) (314 ) Accrued expenses and other current liabilities (7,827 ) 554 (7,273 ) Deferred revenue (9,498 ) 6,004 (3,494 ) Net cash used in operating activities $ (39,022 ) $ — $ (39,022 ) During the year ended December 31, 2019, the adoption of ASC 606 resulted in offsetting changes in operating assets and liabilities and had no impact on net cash used in operations.
Stock-Based Compensation	Stock-Based Compensation The Company measures stock options and other stock-based awards granted to employees and directors based on the fair value on the date of the grant and recognizes compensation expense of those awards, net of estimated forfeitures, over the requisite service period, which is generally the vesting period of the respective award. Generally, the Company issues stock options with only service-based vesting conditions and records the expense for these awards using the straight-line method. The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive income (loss) in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified. The Company recognizes compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, the Company has considered its historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from the Company’s estimate, the Company may be required to record adjustments to stock-based compensation expense in future periods. The Company estimates the fair value of each stock option grant on the date of grant using the Black-Scholes option pricing model. The Company was a private company until December 14, 2017 and lacks sufficient company-specific historical and implied volatility information for its stock. Therefore, it estimates its expected stock volatility based on the historical volatility of publicly traded peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to non-employees is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company does not have a history of declaring or paying cash dividends, except for the special cash dividends declared in November 2014, June 2016, December 2016, May 2017 and November 2017 and in those circumstances the board of directors approved cash dividends to be paid to holders of the Company’s stock options, stock appreciation rights (“SARs”) and restricted stock units (“RSUs”) upon vesting as an equitable adjustment to the holders of such instruments. The Company has also granted SARs to certain employees, which require the Company to pay in cash upon exercise an amount equal to the product of the excess of the per share fair market value of the Company’s common stock on the date of exercise over the exercise price, multiplied by the number of shares of common stock with respect to which the SAR is exercised. Because these awards may require the Company to settle the awards in cash, the Company accounts for them as a liability in the Company’s consolidated balance sheets. The Company recognizes the liability related to these awards, as well as related compensation expense over the period during which services are rendered until completed. The Company estimates changes in the fair value of the SAR liability using the Black-Scholes option pricing model and records them in the consolidated statements of operations and comprehensive income (loss). After vesting is completed, the Company will continue to remeasure the fair market value of the liability until the award is either exercised or canceled, with changes in the fair value of the liability recorded in the consolidated statements of operations and comprehensive income (loss).
Research and Development Costs	Research and Development Costs The Company expenses research and development costs as incurred. The Company expenses costs incurred to develop software to be licensed to customers prior to the establishment of technological feasibility of the software and capitalizes them thereafter until commercial release of the software. The Company has not historically capitalized software development costs as the establishment of technological feasibility typically occurs shortly before the commercial release of its software, which is embedded in its products. As such, the Company expenses all software development costs related to software to be licensed to customers as incurred and includes such amounts within research and development expense in the accompanying consolidated statements of operations and comprehensive income (loss).
Advertising Costs	Advertising Costs The Company expenses advertising costs as incurred and includes them in selling, general and administrative expense in the accompanying consolidated statements of operations and comprehensive income (loss). Advertising expenses were not significant for any periods presented.
Foreign Currency Translation	Foreign Currency Translation For the Company’s subsidiaries in Ireland and Australia, the U.S. dollar is the functional currency. For each of the Company’s other foreign subsidiaries, the functional currency is its local currency. Assets and liabilities of these foreign subsidiaries are translated into U.S. dollars using period-end exchange rates, and revenues and expenses are translated into U.S. dollars using average exchange rates in effect during each period. The Company includes the effects of these foreign currency translation adjustments in accumulated other comprehensive income (loss), a separate component of stockholders’ equity. The Company includes foreign currency transaction gains (losses) in its consolidated statements of operations and comprehensive income (loss) as a component of other income (expense). They totaled $452, $298 and $(911) for the years ended December 31, 2020, 2019 and 2018, respectively.
Fair Value Measurements	Fair Value Measurements The Company carries certain assets and liabilities at fair value under GAAP. Fair value is defined as the price that would be received for an asset or the exit price that would be paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: Level 1— Quoted prices in active markets for identical assets and liabilities. Level 2— Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities at the measurement date; quoted prices in markets that are not active for identical or similar assets and liabilities; or other inputs that are observable or can be corroborated by observable market data. Level 3— Unobservable inputs that involve management judgment and are supported by little or no market activity, including pricing models, discounted cash flow methodologies and similar techniques. The categorization of a financial instrument within the valuation hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Company carries cash equivalents, marketable securities, foreign currency forward contracts and SARs at fair value, determined according to the fair value hierarchy described above (see Note 7). The fair values of cash equivalents, accounts receivable, accounts payable and accrued expenses and other current liabilities approximate their fair values due to the short-term nature of these assets and liabilities, with the exception of amounts recorded by the Company as “accounts receivable, non-current,” which represent amounts billed to customers for which payment has not yet become due and for which an offsetting amount of deferred revenue has been recorded. The carrying values of the Company’s debt obligations (see Note 11) as of December 31, 2020 and 2019 approximated their fair values because the debt bears interest at rates the Company would be required to pay on the issuance of debt with similar terms, based on an analysis of recent market conditions and other Company-specific factors.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement and tax basis of assets and liabilities, as measured by enacted tax rates anticipated to be in effect when these differences reverse. This method also requires the recognition of future tax benefits to the extent that realization of such benefits is more likely than not. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. The Company evaluates the potential for recovery of deferred tax assets by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. As of December 31, 2020, the Company determined that it is more likely than not that a portion of its net U.S. deferred tax assets will not be realized, and thus has recognized a valuation allowance of $24,463 against its net U.S. deferred tax assets that are not expected to be realized, a decrease of $14,661 during the year ended December 31, 2020 (see Note 10). The Company records a liability for potential payments of taxes to various tax authorities related to uncertain tax positions and other tax matters. The Company bases t he recorded liability on its determination of whether and how much of a tax benefit taken by the Company in its tax filings or positions is “more likely than not” to be realized. The amount of the benefit that may be recognized in the financial statements is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. To the extent that the assessment of such tax positions changes, the Company records the change in estimate in the period in which the determination is made. The Company establishes a liability, which is included in accrued income taxes in the consolidated balance sheets, for tax-related uncertainties based on estimates of whether, and the extent to which, additional taxes will be due. The Company establishes t hese liabilities when the Company believes that certain positions might be challenged despite its belief that the tax return positions are fully supportable. The Company adjusts the recorded liability in light of changing facts and circumstances. The (benefit from) provision for income taxes includes the impact of the recorded liability and changes thereto. The Company recognizes interest and penalties related to uncertain tax positions within other income (expense) in the accompanying consolidated statements of operations and comprehensive income (loss). The Company records accrued interest and penalties in accrued income taxes in the consolidated balance sheets. For taxable years beginning after January 1, 2018, taxpayers are subjected to the global intangible low-taxed income (“GILTI”) provisions. The GILTI provisions require the Company to currently recognize in U.S. taxable income a deemed dividend inclusion of foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary’s tangible assets. The ability to benefit from a deduction and foreign tax credits against a portion of the GILTI income may be limited under the GILTI rules as a result of the utilization of net operating losses, foreign sourced income, and other potential limitations within the foreign tax credit calculation. During the years ended December 31, 2020 and 2019, the Company recorded an income tax charge of $3,483 million and $942 million, respectively related to GILTI. The Company has made an accounting policy election, as allowed by the SEC and FASB, to recognize the impacts of GILTI within the period incurred. Therefore, no U.S. deferred taxes are provided on GILTI inclusions of future foreign subsidiary earnings.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) includes net income (loss) as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. Comprehensive income (loss) for the periods presented consists of net income and the change in the cumulative foreign currency translation adjustment.
Net Income (Loss) per Share	Net Income (Loss) per Share Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, including potential dilutive common shares. For purpose of this calculation, outstanding stock-based awards are considered potential dilutive common shares.
Impact of Recently Adopted and Issued Accounting Standards	Impact of Recently Adopted Accounting Standards In June 2018, the Financial Accounting Standards Board (“FASB”) issued ASU 2018-07, Compensation – Stock Compensation (Topic 718) (“ASU 2018-07”), which expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The Company adopted ASU 2018-07 as of January 1, 2020 and such adoption did not have a material effect on its consolidated financial statements . In May 2014, the FASB issued ASC 606, which supersedes existing revenue recognition guidance under GAAP. The core principle of this standard is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company adopted ASC 606 on January 1, 2019, using the modified retrospective method. Under this method of adoption, the Company recognized the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of accumulated deficit. Comparative prior year periods were not adjusted. As a result of applying the modified retrospective method to adopt ASC 606, the following adjustments were made to the consolidated balance sheet as of January 1, 2019: December 31, 2018 January 1, 2019 As reported Adjustments As adjusted Assets: Accounts receivable $ 81,782 $ (153 ) $ 81,629 Inventory 50,997 (368 ) 50,629 Prepaid expenses and other current assets 3,755 209 3,964 Accounts receivable, net of current portion 2,388 (75 ) 2,313 Deferred tax assets 21,578 (592 ) 20,986 Other assets 3,293 128 3,421 Total assets $ 474,649 $ (851 ) $ 473,798 Liabilities: Accrued expenses and other current liabilities $ 36,992 $ 1,045 $ 38,037 Deferred revenue 31,206 (2,190 ) 29,016 Deferred revenue, net of current portion 12,479 (1,856 ) 10,623 Total liabilities 399,793 (3,001 ) 396,792 Stockholders’ equity: Accumulated deficit (81,008 ) 2,150 (78,858 ) Total stockholders’ equity 74,856 2,150 77,006 Total liabilities and stockholders’ equity $ 474,649 $ (851 ) $ 473,798 Upon adoption of ASC 606 on January 1, 2019, the Company recorded a decrease to accumulated deficit of $2,150 as a result of the transition. The impact of the adoption primarily relates to the cumulative effect of a $4,046 total decrease in deferred revenue and deferred revenue, net of current portion primarily related to a customer contract for which revenue was recognized based on receipt of cash payments under ASC 605 that would have been recognized upon product acceptance under ASC 606; a $1,045 increase in accrued expenses and other current liabilities related to partner commissions that were previously being recognized in the period in which cash was received and revenue was recognized, but would have been reflected as a cost to obtain a contract and expensed consistent with the pattern of revenue recognition on the contract; a $368 decrease in inventory related to the adjustment of deferred cost of goods sold on deferred revenue also adjusted as part of the adoption; a $337 total increase in prepaid expenses and other current assets and other assets for short term and long term capitalized contract costs on open contracts as of the adoption date; a $228 total decrease in accounts receivable and accounts receivable, net of current portion related to a contract with a significant financing component; and a $592 decrease in deferred tax assets related to the above items. Impact of Recently Issued Accounting Standards In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842): Amendments to FASB Accounting Standards Codification (“ASU 2016-02”), which replaces the existing guidance for leases. ASU 2016-02 requires the identification of arrangements that should be accounted for as leases by lessees. In general, for lease arrangements exceeding a twelve-month term, the arrangements must now be recognized as assets and liabilities on the balance sheet of the lessee. Under ASU 2016-02, a right-of-use asset and lease obligation will be recorded for all leases, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization/interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption of ASU 2016-02 must be calculated using the applicable incremental borrowing rate at the date of adoption. This guidance will become effective for private companies, and emerging growth companies that choose to take advantage of the extended transition periods, for annual reporting periods beginning after December 15, 2020, and interim periods within fiscal years beginning after December 15, 2021. The Company has begun planning for adoption by implementing new lease accounting software and by working to establish additional changes to internal processes to comply with all requirements upon adoption. The standard allows for, and the Company plans on using, a modified retrospective approach with comparatives under ASC 840, where entities would recognize a cumulative effect to retained earnings at the date of adoption without restating prior period balances or disclosure. Management is continuing to assess the impact of ASU 2016-02 on the Company’s consolidated financial statements and the accompanying notes thereto. In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This guidance is intended to provide more decision-useful information about expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The main provisions include presenting financial assets measured at amortized cost at the amount expected to be collected, which is net of an allowance for expected credit losses, and recording credit losses related to available-for-sale securities through an allowance for credit losses. The effective dates for the amendments in ASU 2016-13 were updated in ASU 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842), and as such ASU 2016-13 will become effective for private companies, and emerging growth companies that choose to take advantage of the extended transition periods, for fiscal years beginning after December 15, 2022, including interim periods within those fiscal periods, and must be applied using a modified retrospective approach. The Company is currently evaluating the impact ASU 2016-13 will have on its consolidated financial statements .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash in Accompanying Condensed Consolidated Balance Sheets	The following table is a reconciliation of cash, cash equivalents and restricted cash included in the accompanying consolidated balance sheets that sum to the total cash, cash equivalents and restricted cash included in the accompanying consolidated statements of cash flows. December 31, 2020 December 31, 2019 Cash and cash equivalents $ 157,455 $ 113,638 Restricted cash included in other assets 1,006 1,019 $ 158,461 $ 114,657
Schedule of Accounts Receivable	Accounts receivable as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Current portion of accounts receivable, net: Accounts receivable, net $ 93,480 $ 91,273 Accounts receivable, extended payment arrangements 644 1,827 94,124 93,100 Accounts receivable, net of current portion: Accounts receivable, extended payment arrangements 143 575 $ 94,267 $ 93,675
Summary of Changes in Provision for Doubtful Accounts	A summary of changes in the provision for doubtful accounts for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Provision for doubtful accounts at beginning of year $ 20 $ 410 $ 692 Provisions and recoveries 38 560 — Write-offs — (950 ) (282 ) Provision for doubtful accounts at end of year $ 58 $ 20 $ 410
Schedule of Estimated Useful Lives of Property and Equipment Assets	Estimated useful lives of the respective property and equipment assets are as follows: Estimated Useful Life Computers and purchased software 3 – 4 years Leasehold improvements Shorter of lease term or 7 years Furniture and fixtures 6 – 8 years Machinery and equipment 3 – 5 years Building 40 years Building improvements 5 – 40 years Trial systems at customers’ sites 2 years
Schedule of Significant Customers Represent 10% or More of Revenue or Accounts Receivable	Significant customers are those that represent 10% or more of revenue or accounts receivable and are set forth in the following tables: Revenue Accounts Receivable, Net Year Ended December 31, December 31, 2020 2019 2018 2020 2019 Customer A * 14 % 27 % * 11 % Customer B * * 11 % * * Customer C * * 12 % * 14 % Customer D * * 14 % * * Customer E * * * * 19 % Customer F 20 % 12 % * * * Customer G 11 % * * 14 % * * Less than 10% of total
Summary of Changes in Amount Reserved for Warranty Costs	A summary of changes in the amount reserved for warranty costs for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Warranty reserve at beginning of year $ 2,448 $ 926 $ 1,246 Provisions 2,745 3,603 1,886 Acquired warranty reserve — 1,867 — Charges (2,839 ) (3,948 ) (2,206 ) Warranty reserve at end of year $ 2,354 $ 2,448 $ 926
Impact of New Accounting Standards ASC 606 on Financial Statements	In accordance with the modified retrospective method transition requirements, the Company has presented the financial statement line items impacted and adjusted to compare to presentation under ASC Topic 605, Revenue Recognition As of December 31, 2019 Balance Sheet As Reported under ASC 606 Adjustments Without adoption of ASC 606 Assets: Accounts receivable $ 93,100 $ 47 $ 93,147 Inventory 93,604 186 93,790 Prepaid expenses and other current assets 4,884 54 4,938 Prepaid income taxes 3,217 330 3,547 Accounts receivable, net of current portion 575 23 598 Deferred tax assets 69 1,757 1,826 Other assets 7,820 (69 ) 7,751 Total assets $ 444,312 $ 2,328 $ 446,640 Liabilities: Accrued expenses and other current liabilities $ 34,567 $ (491 ) $ 34,076 Deferred revenue 25,485 8,194 33,679 Deferred revenue, net of current portion 4,583 1,856 6,439 Total liabilities 405,748 9,559 415,307 Stockholders’ Equity: Accumulated deficit (127,064 ) (7,231 ) (134,295 ) Total stockholders’ equity 38,564 (7,231 ) 31,333 Total liabilities and stockholders’ equity $ 444,312 $ 2,328 $ 446,640 Total reported liabilities under ASC 606 as of December 31, 2019 were $9,559 less than the total liabilities without the adoption of ASC 606 primarily driven by the adjustment of deferred revenue related to a customer contract for which revenue was recognized based on receipt of cash payments under ASC 605 that would have been recognized upon product acceptance under ASC 606, offset by an increase in accrued partner commissions in accrued expenses and other current liabilities. These partner commissions were previously being recognized in the period in which cash was received and revenue was recognized. Upon the adoption of ASC 606, partner commissions are reflected as a cost to obtain a contract and they are expensed consistent with the pattern of revenue recognition on this contract. Year Ended December 31, 2019 Statement of Operations and Comprehensive (Loss) Income As Reported under ASC 606 Adjustments Without adoption of ASC 606 Revenue: Product $ 241,377 $ (6,201 ) $ 235,176 Service 40,920 197 41,117 Total revenue 282,297 (6,004 ) 276,293 Cost of revenue: Product 113,059 182 113,241 Gross profit 162,532 (6,186 ) 156,346 Operating expenses: Selling, general and administrative 88,320 231 88,551 Loss from operations (9,119 ) (6,417 ) (15,536 ) Other income (expense): Interest income 4,406 (159 ) 4,247 Loss before provision for (benefit from) income taxes (24,415 ) (6,576 ) (30,991 ) Provision for (benefit from) income taxes 23,791 (1,495 ) 22,296 Net loss (48,206 ) (5,081 ) (53,287 ) Comprehensive loss $ (49,270 ) $ (5,081 ) $ (54,351 ) Net loss per share attributable to common stockholders: Basic $ (0.57 ) $ (0.07 ) $ (0.64 ) Diluted $ (0.57 ) $ (0.07 ) $ (0.64 ) During the year ended December 31, 2019, the adoption of ASC 606 resulted in a net increase to product revenue due to certain contracts for which product revenue was recognized upon delivery that would have been deferred without the adoption of ASC 606 due to the lack of vendor-specific objective evidence. Year Ended December 31, 2019 Statement of Cash Flows As Reported under ASC 606 Adjustments Without adoption of ASC 606 Cash flows used in operating activities: Net loss $ (48,206 ) $ (5,081 ) $ (53,287 ) Deferred income taxes 19,641 (1,166 ) 18,475 Changes in operating assets and liabilities: Accounts receivable 1,881 159 2,040 Inventory (21,276 ) 182 (21,094 ) Prepaid expenses and other assets (3,679 ) (322 ) (4,001 ) Prepaid income taxes 16 (330 ) (314 ) Accrued expenses and other current liabilities (7,827 ) 554 (7,273 ) Deferred revenue (9,498 ) 6,004 (3,494 ) Net cash used in operating activities $ (39,022 ) $ — $ (39,022 ) As a result of applying the modified retrospective method to adopt ASC 606, the following adjustments were made to the consolidated balance sheet as of January 1, 2019: December 31, 2018 January 1, 2019 As reported Adjustments As adjusted Assets: Accounts receivable $ 81,782 $ (153 ) $ 81,629 Inventory 50,997 (368 ) 50,629 Prepaid expenses and other current assets 3,755 209 3,964 Accounts receivable, net of current portion 2,388 (75 ) 2,313 Deferred tax assets 21,578 (592 ) 20,986 Other assets 3,293 128 3,421 Total assets $ 474,649 $ (851 ) $ 473,798 Liabilities: Accrued expenses and other current liabilities $ 36,992 $ 1,045 $ 38,037 Deferred revenue 31,206 (2,190 ) 29,016 Deferred revenue, net of current portion 12,479 (1,856 ) 10,623 Total liabilities 399,793 (3,001 ) 396,792 Stockholders’ equity: Accumulated deficit (81,008 ) 2,150 (78,858 ) Total stockholders’ equity 74,856 2,150 77,006 Total liabilities and stockholders’ equity $ 474,649 $ (851 ) $ 473,798

Business Acquisition (Tables)

Business Acquisition (Tables)	12 Months Ended
Business Acquisition (Tables)	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Purchase Price and Valuation, Allocation of Total Purchase Price	Based upon the purchase price and the valuation, the allocation of the total purchase price was as follows: Purchase Price Allocation Assets acquired Fair value of tangible assets: Accounts receivable $ 18,142 Inventory 24,138 Prepaid expenses and other current assets 2,240 Property, plant and equipment 8,010 Deferred tax assets 365 Other assets 13 Goodwill 50,177 Identifiable intangible assets 44,000 Total assets acquired $ 147,085 Liabilities assumed Accounts payable $ (9,719 ) Accrued expenses (13,178 ) Accrued income taxes (140 ) Deferred tax liabilities (10,621 ) Current portion of long-term debt (3,507 ) Other liabilities (489 ) Total liabilities assumed $ (37,654 ) Net assets acquired $ 109,431
Schedule of Purchase Price and Estimated Useful Lives Associated with Certain Assets	The allocation of the purchase price and the estimated useful lives associated with certain assets is as follows : Amount Estimated Useful Life Net tangible assets $ 15,254 — Identifiable intangible assets: Developed technology 25,000 7 years Customer relationships 18,000 10 years Trade name 1,000 3 years Goodwill 50,177 — Total purchase price $ 109,431
Schedule of Unaudited Pro Forma Results	The unaudited pro forma combined results of the Company and NetComm are as follows: Year Ended December 31, 2020 2019 2018 Net revenue $ 393,246 $ 375,306 $ 436,791 Net income (loss) 25,134 (47,898 ) 68,808

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	12 Months Ended
Goodwill and Intangibles (Tables)	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets Net	Intangible assets, net Intangible assets, net consisted of intangible assets resulting from the acquisition of NetComm and purchased software to be used in our products. Intangible assets, net consisted of the following at December 31, 2020 and 2019, respectively: As of December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology 25,000 (5,358 ) 19,642 Customer relationships 18,000 (2,700 ) 15,300 Trade name 1,000 (498 ) 502 Purchased Software 432 (32 ) 400 Totals as of December 31, 2020 $ 44,432 $ (8,588 ) $ 35,844 As of December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology 25,000 (1,786 ) 23,214 Customer relationships 18,000 (900 ) 17,100 Trade name 1,000 (166 ) 834 Totals as of December 31, 2019 $ 44,000 $ (2,852 ) $ 41,148
Schedule of Amortization Expense on Existing Intangible Assets	As of December 31, 2020, amortization expense on existing intangible assets for the next five years and beyond is summarized as follows: Year Ending December 31, 2021 $ 5,849 2022 5,681 2023 5,484 2024 5,372 2025 5,372 Thereafter 8,086 $ 35,844
Summary of Amortization Expense	A Year Ended December 31, 2020 2019 Product cost of revenue $ 3,571 $ 1,786 Research and development 32 — Selling, general and administrative 2,133 1,066 Totals $ 5,736 $ 2,852
Schedule of Carrying Value of Goodwill	The changes in the carrying value of goodwill are as follows: Carrying Value of Goodwill Balance at December 31, 2018 $ — NetComm Acquisition 50,347 Balance at December 31, 2019 50,347 Adjustment recorded to preliminary purchase price allocation (170 ) Balance at December 31, 2020 $ 50,177

Inventory (Tables)

Inventory (Tables)	12 Months Ended
Inventory (Tables)	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Raw materials $ 50,904 $ 19,821 Work in process 19 17 Finished goods: Manufactured finished goods 49,764 69,503 Deferred inventory costs 517 4,263 $ 101,204 $ 93,604

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
Property and Equipment (Tables)	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Summary of Components of Property and Equipment	Property and equipment as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Computers and purchased software $ 24,865 $ 22,294 Leasehold improvements 4,148 4,380 Furniture and fixtures 2,644 2,794 Machinery and equipment 36,701 40,002 Land 3,091 3,091 Building 4,765 4,765 Building improvements 7,244 6,776 Trial systems at customers’ sites 5,300 6,039 88,758 90,141 Less: Accumulated depreciation and amortization (59,878 ) (54,231 ) $ 28,880 $ 35,910

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Dec. 31, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Accrued compensation and related taxes $ 22,722 $ 18,540 Accrued warranty (see Note 2) 2,354 2,448 Dividends and equitable adjustments payable (see Note 12) 63 750 Accrued customer incentives 20 233 Other accrued expenses 14,634 12,596 $ 39,793 $ 34,567

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	The following tables present information about the fair value of the Company’s financial assets and liabilities as of December 31, 2020 and 2019 and indicate the level of the fair value hierarchy utilized to determine such fair values: Fair Value Measurements as of December 31, 2020 Using: Level 1 Level 2 Level 3 Total Assets: Certificates of deposit—restricted cash $ — $ 1,006 $ — $ 1,006 Money market mutual funds 114,404 — — 114,404 $ 114,404 $ 1,006 $ — $ 115,410 Liabilities: SARs $ — $ — $ 493 $ 493 $ — $ — $ 493 $ 493 Fair Value Measurements as of December 31, 2019 Using: Level 1 Level 2 Level 3 Total Assets: Certificates of deposit $ — $ 10,933 $ — $ 10,933 Certificates of deposit—restricted cash — 1,019 — 1,019 Money market mutual funds 53,763 — — 53,763 Foreign currency forward contracts — 23 — 23 $ 53,763 $ 11,975 $ — $ 65,738 Liabilities: SARs $ — $ — $ 264 $ 264 Foreign currency forward contracts — 50 — 50 $ — $ 50 $ 264 $ 314
Summary of Changes in Fair Values of SARs Liability	The following table provides a summary of changes in the fair values of the Company’s SARs liability, for which fair value is determined by Level 3 inputs: Year Ended December 31, 2020 2019 2018 Fair value at beginning of the year $ 264 $ 1,387 $ 2,155 Change in fair value 229 (1,123 ) (768 ) Exercises — — — Fair value at end of year $ 493 $ 264 $ 1,387
Summary of Company's Cash and Cash Equivalents	The Company’s cash, cash equivalents and restricted cash as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Cash $ 43,051 $ 48,942 Cash equivalents and restricted cash: Certificates of deposit — 10,933 Certificates of deposit—restricted cash 1,006 1,019 Money market mutual funds 114,404 53,763 Total cash equivalents and restricted cash 115,410 65,715 Total cash, cash equivalents and restricted cash $ 158,461 $ 114,657

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Income Before (Benefit from) Provision for Income Taxes	Income before the (benefit from) provision for income taxes for the years ended December 31, 2020, 2019 and 2018 consisted of the following: Year Ended December 31, 2020 2019 2018 United States $ (32,755 ) $ (40,055 ) $ 10,527 Foreign 42,504 15,640 55,411 $ 9,749 $ (24,415 ) $ 65,938
Schedule of (Benefit from) Provision for Income Taxes	The (benefit from) provision for income taxes for the years ended December 31, 2020, 2019 and 2018 consisted of the following: Year Ended December 31, 2020 2019 2018 Current income tax (benefit) provision: Federal $ (24,409 ) $ 4,698 $ (3,457 ) State 228 (121 ) (181 ) Foreign 11,655 (427 ) 8,087 Total current income tax (benefit) provision (12,526 ) 4,150 4,449 Deferred income tax (benefit) provision: Federal 171 18,387 (10,699 ) State 97 5,100 (1,108 ) Foreign (2,794 ) (3,846 ) 290 Total deferred income tax (benefit) provision (2,526 ) 19,641 (11,517 ) Total income tax (benefit) provision $ (15,052 ) $ 23,791 $ (7,068 )
Schedule of Reconciliation of U.S. Federal Statutory Rate to Effective Income Tax Rate	A reconciliation of the U.S. federal statutory rate to the Company’s effective income tax rate for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, 2020 2019 2018 Federal statutory income tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal tax benefit (6.8 ) 9.8 (0.8 ) Research and development tax credits (37.6 ) 10.3 (15.6 ) Permanent differences (11.5 ) (1.6 ) 1.1 Foreign tax rate differential 7.3 10.2 (6.6 ) Equitable adjustment payments (1.1 ) 1.7 (1.8 ) Stock-based compensation 9.7 3.3 (25.2 ) Foreign taxes withheld 23.1 (9.6 ) 3.3 Rate impact from CARES Act (63.9 ) — — Global intangible low-taxed income 35.7 (4.1 ) 6.7 Withholding tax on repatriation of accumulated earnings of foreign subsidiaries 1.0 (0.1 ) 0.1 Valuation allowance on deferred tax assets (146.9 ) (144.2 ) 6.0 Other, net (3.6 ) 2.3 1.1 Foreign derived intangible income — 3.9 — Research and development costs 20.0 (4.3 ) — Provision to return 2.4 11.1 — Uncertain tax positions (3.2 ) (7.1 ) — Effective income tax rate (154.4 )% (97.4 )% (10.7 )%
Schedule of Income Tax Effect of Each Type of Temporary Difference and Carryforward	The income tax effect of each type of temporary difference and carryforward as of December 31, 2020 and 2019 was as follows: December 31, 2020 2019 Deferred tax assets: Stock compensation $ 4,710 $ 3,827 Tax credit carryforwards 13,138 9,900 Capitalized research and development costs 9,710 21,376 Inventory valuation 2,169 1,756 Accrued liabilities and reserves 3,826 5,207 Deferred revenue 796 1,520 Interest expense — 2,149 Intellectual property rights 999 999 Other 2,228 544 Total deferred tax assets 37,576 47,278 Valuation Allowance (24,463 ) (39,124 ) Deferred tax assets, net of valuation allowance 13,113 8,154 Deferred tax liabilities: Depreciation (2,092 ) (1,159 ) Amortization (10,932 ) (12,727 ) Deferred costs (3,444 ) — Withholding tax on unremitted earnings (2,650 ) (2,604 ) Prepaid expenses (127 ) (588 ) Total deferred tax liabilities (19,245 ) (17,078 ) Net deferred tax liabilities $ (6,132 ) $ (8,924 )
Schedule of Changes in Balance of Gross Uncertain Tax Positions	The aggregate changes in the balance of gross uncertain tax positions, which excludes interest and penalties, for the years ended December 31, 2020, 2019 and 2018 were as follows: Balance at December 31, 2017 $ 1,695 Settlement/decreases related to tax positions taken during prior years — Increases related to tax positions taken during prior years 241 Increases related to tax positions taken during the current year 810 Balance at December 31, 2018 2,746 Settlement/decreases related to tax positions taken during prior years (49 ) Increases related to tax positions taken during prior years 18,434 Increases related to tax positions taken during the current year 364 Balance at December 31, 2019 21,495 Expiration of statute of limitations (1,174 ) Decreases related to tax positions taken during prior years (2,815 ) Increases related to tax positions taken during prior years 155 Increases related to tax positions taken during the current year 249 Balance at December 31, 2020 $ 17,910

Debt (Tables)

Debt (Tables)	12 Months Ended
Debt (Tables)	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Aggregate Principal Amount of Debt Outstanding	The aggregate principal amount of debt outstanding as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Term loans $ 288,000 $ 291,000 Revolving credit facility 6,500 — Mortgage loan — 6,644 Total principal amount of debt outstanding $ 294,500 $ 297,644
Schedule of Current and Non-Current Debt Obligations	Current and non-current debt obligations reflected in the consolidated balance sheets as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 Current liabilities: Term loans $ 9,775 $ 3,000 Revolving credit facility 6,500 — Mortgage loan — 6,644 Current portion of principal payment obligations 16,275 9,644 Unamortized debt issuance costs, current portion (1,104 ) (1,120 ) Current portion of long-term debt, net of unamortized debt issuance costs $ 15,171 $ 8,524 Non-current liabilities: Term loans $ 278,225 $ 288,000 Unamortized debt issuance costs, non-current portion (2,140 ) (3,244 ) Long-term debt, net of current portion and unamortized debt issuance costs $ 276,085 $ 284,756
Schedule of Aggregate Minimum Future Principal Payments of Debt	As of December 31, 2020, aggregate minimum future principal payments of the Company’s debt are summarized as follows: Year Ending December 31, 2021 $ 16,275 2022 3,000 2023 275,225 Thereafter — $ 294,500

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
Stockholders' Equity (Tables)	Dec. 31, 2020
Equity [Abstract]
Schedule of Cash Dividends Declared and Paid to Stockholders for Special Dividends	The below table details the cash dividends declared to stockholders of each share type for each of the five special dividends, as well as the amount of dividends the Company paid in each of the years ended December 31, 2020, 2019 and 2018, respectively: Cash Dividend Declared Dividends Paid per Share Type During the Year Ended Dividend Declaration Date Common Series B and Series C Convertible Preferred December 31, 2020 December 31, 2019 December 31, 2018 November 30, 2017 $ 0.5802 $ 5.8020 $ — $ — $ 865 May 10, 2017 1.1774 11.7744 — — — December 27, 2016 2.3306 23.3058 — — — June 17, 2016 0.5891 5.8910 — — — November 30, 2014 0.3835 3.8346 — — — Total dividends paid $ — $ — $ 865
Schedule of Equitable Adjustment Payments	The below table provides details of these equitable adjustment payments: Equitable Adjustment Payments During the Year Ended Equitable Adjustment Liability(1) Dividend Declaration Dates Equitable Adjustment per share Year of Final Vesting December 31, 2020 December 31, 2019 December 31, 2018 As of December 31, 2020 As of December 31, 2019 November 30, 2017 $ 0.5802 2021 $ 148 $ 426 $ 1,132 $ 30 $ 177 May 10, 2017 1.1774 2021 178 618 1,492 31 182 December 27, 2016 2.3306 2020 303 1,286 3,105 2 335 June 17, 2016 0.5891 2020 54 259 684 — 37 November 30, 2014 0.3835 2018 — 1 43 — — Total $ 683 $ 2,590 $ 6,456 $ 63 $ 731 (1) Net of estimated forfeitures. Amounts are included in accrued expenses and other current liabilities in the accompanying consolidated balance sheets.

Stock-based Compensation (Table

Stock-based Compensation (Tables)	12 Months Ended
Stock-based Compensation (Tables)	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Assumptions Used in Black-Scholes Option Pricing Model	The assumptions used in the Black-Scholes option-pricing model were as follows: Year Ended December 31, 2020 2019 2018 Risk-free interest rate 0.4%–0.7% 1.6%–2.5% 2.7%–3.0% Expected term (in years) 6.1 6.1-6.2 6.0–6.2 Expected volatility 29.3%–31.9% 28.8%–30.6% 30.6%–32.6% Expected dividend yield 0.0% 0.0% 0.0%
Summary of Option Activity	A summary of option activity under the 2003 Plan, the 2011 Plan and the 2017 Plan for the year ended December 31, 2020 is as follows: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value (in years) Outstanding at January 1, 2020 8,250 $ 7.73 5.65 $ 4,235 Granted 166 4.55 Exercised (591 ) 2.02 Forfeited (705 ) 8.98 Outstanding at December 31, 2020 7,120 $ 8.01 4.88 $ 9,367 Options exercisable at December 31, 2020 6,492 $ 7.62 4.59 $ 9,026 Vested or expected to vest at December 31, 2020 7,090 $ 8.01 4.87 $ 9,341
Summary of RSU Activity	A summary of RSU activity for the year ended December 31, 2020 is as follows: Number of Shares Weighted- Average Grant Date Fair Value Aggregate Fair Value Unvested balance at January 1, 2020 1,653 $ 11.38 Granted 3,270 3.54 Vested (554 ) 11.03 $ 2,321 Forfeited (138 ) 9.60 Unvested balance at December 31, 2020 4,231 $ 5.43
Assumptions of Estimated Based on Monte Carlo Simulation Model	Compensation expense for PSUs is based on the estimated value of the awards on the grant date, and is recognized over the period from the grant date through the expected vest dates of each vesting condition, both of which were estimated based on a Monte Carlo simulation model applying the following key assumptions: Grant Date Assumptions Risk-free interest rate 1.2% Volatility 70.0% Dividend yield 0.0% Cost of equity 11.0%
Summary of PSU Activity	A summary of PSU activity for the year ended December 31, 2020 is as follows: Number of Shares Weighted- Average Grant Date Fair Value Aggregate Fair Value Unvested balance at January 1, 2020 — $ — Granted 983 3.22 Vested (246 ) 3.22 $ 1,516 Forfeited — — Unvested balance at December 31, 2020 737 $ 3.22
Schedule of Stock-based Compensation Expense	The Company classified s tock-based compensation expense related to stock options, RSUs and SARs for the years ended December 31, 2020, 2019 and 2018 in the consolidated statements of operations and comprehensive income (loss) as follows: Year Ended December 31, 2020 2019 2018 Cost of revenue $ 153 $ 216 $ 249 Research and development expenses 2,447 1,569 1,864 Selling, general and administrative 10,555 8,036 6,781 $ 13,155 $ 9,821 $ 8,894 The Company recognized s tock-based compensation expense for the years ended December 31, 2020, 2019 and 2018 in the consolidated balance sheet as follows: Year Ended December 31, 2020 2019 2018 Change in fair value of SAR liability $ 229 $ (1,123 ) $ (768 ) Recognized as additional paid-in capital 12,926 10,944 9,662 Total stock-based compensation $ 13,155 $ 9,821 $ 8,894

Net Income (Loss) per Share (Ta

Net Income (Loss) per Share (Tables)	12 Months Ended
Net Income (Loss) per Share (Tables)	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders	The Company calculated b asic and diluted net income (loss) per share attributable to common stockholders as follows: Year Ended December 31, 2020 2019 2018 Numerator: Net income (loss) attributable to common stockholders, basic and diluted $ 24,801 $ (48,206 ) $ 73,006 Denominator: Weighted-average shares used to compute net income (loss) per share attributable to common stockholders, basic 83,465 83,853 83,539 Dilutive effect of stock options 1,050 — 8,086 Dilutive effect of restricted stock units 763 — 252 Weighted-average shares used to compute net income (loss) per share attributable to common stockholders, diluted 85,278 83,853 91,877 Net income (loss) per share attributable to common stockholders: Basic $ 0.30 $ (0.57 ) $ 0.87 Diluted $ 0.29 $ (0.57 ) $ 0.79
Schedule of Potential Common Shares Excluded from the Computation of Diluted Net Income (Loss) Per Share Attributable to Common Stockholders	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net income (loss) per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Year Ended December 31, 2020 2019 2018 Options to purchase common stock 4,119 4,641 2,213 Unvested restricted stock units 1,030 1,516 168 Unvested performance-based stock units 983 — —

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
Revenue from Contracts with Customers (Tables)	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Summary of Disaggregation of Revenue Based on Geographic Locations Determined by Customer's Shipping Address	The Company also disaggregates its revenue based on geographic locations of its customers, as determined by the customer’s shipping address, summarized as follows: Year Ended December 31, 2020 2019 2018 North America: United States $ 127,217 $ 103,451 $ 104,124 Canada 38,960 36,466 41,884 Total North America 166,177 139,917 146,008 Latin America 34,926 24,043 32,283 Europe, Middle East and Africa: Germany 5,487 13,773 45,864 Other 30,446 24,381 35,479 Total Europe, Middle East and Africa 35,933 38,154 81,343 Asia-Pacific Australia 116,661 42,218 24,354 Other 39,549 37,965 13,139 Total Asia-Pacific 156,210 80,183 37,493 Total revenue (1) $ 393,246 $ 282,297 $ 297,127 (1) Other than the United States, Canada, Germany and Australia, no individual countries represented 10% or
Summary of Disaggregates of Revenue Based on Product Line	The Company also disaggregates its revenue based on product line summarized as follows: Year Ended December 31, 2020 2019 2018 Product revenue: Wireless $ 111,255 $ 58,234 $ 402 Fixed telco 96,904 38,734 — Cable 137,924 144,409 256,587 Total product revenue 346,083 241,377 256,989 Service revenue Wireless 7,348 1,701 250 Fixed telco 1,924 773 — Cable 37,891 38,446 39,888 Total service revenue 47,163 40,920 40,138 Total revenue $ 393,246 $ 282,297 $ 297,127

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
Segment Information (Tables)	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Property and Equipment, Net by Location	The Company’s property and equipment, net by location was as follows: December 31, 2020 2019 United States $ 20,988 $ 25,583 China 2,986 3,277 Australia 2,849 4,041 Other 2,057 3,009 Total property and equipment, net $ 28,880 $ 35,910

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments under Non-cancelable Operating Leases	Future minimum lease payments under non-cancelable operating leases as of December 31, 2020 were as follows: Year Ending December 31, 2021 $ 2,533 2022 1,500 2023 1,425 2024 536 2025 445 Thereafter 334 $ 6,773

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Significant Accounting Policies [Line Items]
Restricted cash	$ 1,006,000	$ 1,019,000
Restricted Cash and Cash Equivalents, Noncurrent, Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Write off of uncollectible receivables		$ 950,000	$ 282,000
Deferred offering costs paid	$ 0	0	1,148,000
Percentage of fair value of reporting unit	50.00%
Intangible assets amortization method	straight-line method
Standard product warranty description	The Company’s products are covered by a warranty for software and hardware for periods ranging from 90 days to one year.
Extended product warranty description	The Company offers an extended warranty for periods typically of one to three years for agreed-upon fees.
Assets	$ 492,966,000	444,312,000	474,649,000
Liabilities	416,592,000	405,748,000	399,793,000
Foreign currency transaction gains (losses)	452,000	298,000	(911,000)
Valuation allowance	24,463,000	39,124,000
Deferred tax asset valuation allowance increase (decrease)	(14,661,000)
Income tax charge	$ (15,052,000)	23,791,000	(7,068,000)
Change in accounting principle, accounting standards update, adopted	true
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201807Member
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
Accumulated deficit	$ (102,263,000)	(127,064,000)	(81,008,000)
Accrued expenses and other current liabilities	39,793,000	34,567,000	36,992,000
Inventory	101,204,000	93,604,000	50,997,000
Accounts receivable, net	94,267,000	93,675,000
Deferred tax assets	1,150,000	69,000	21,578,000
Global Intangible Low Taxed Income
Significant Accounting Policies [Line Items]
Income tax charge	3,483,000,000	942,000,000
Accounting Standards Update 2014-09
Significant Accounting Policies [Line Items]
Assets				$ 473,798,000
Liabilities				396,792,000
Accumulated deficit				(78,858,000)
Accrued expenses and other current liabilities				38,037,000
Inventory				50,629,000
Deferred tax assets				20,986,000
Accounting Standards Update 2014-09 \| Adjustments
Significant Accounting Policies [Line Items]
Assets		2,328,000		(851,000)
Liabilities		9,559,000		(3,001,000)
Income tax charge		(1,495,000)
Accumulated deficit		(7,231,000)		2,150,000
Deferred revenue, net				(4,046,000)
Accrued expenses and other current liabilities		(491,000)		1,045,000
Inventory		186,000		(368,000)
Prepaid expenses and other current assets and other assets				337,000
Accounts receivable, net				(228,000)
Deferred tax assets		1,757,000		$ (592,000)
Interest Income
Significant Accounting Policies [Line Items]
Other revenue	$ 64,000	160,000
Software
Significant Accounting Policies [Line Items]
Warranty period	90 days
Hardware
Significant Accounting Policies [Line Items]
Warranty period	1 year
Minimum
Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives	3 years
Product warranties period for software and hardware	90 days
Extended product warranty period for renewals of maintenance and support contracts	1 year
Maximum
Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives	10 years
Product warranties period for software and hardware	1 year
Extended product warranty period for renewals of maintenance and support contracts	3 years
Maintenance and support services and professional services revenue, recognition period	5 years
IPO
Significant Accounting Policies [Line Items]
Deferred offering costs paid			1,148,000
Trial Systems at Customers' Sites
Significant Accounting Policies [Line Items]
Property and equipment useful life	2 years
Software Licenses
Significant Accounting Policies [Line Items]
Intangible assets amortization method	straight-line method
Software Licenses \| Minimum
Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives	3 years
Software Licenses \| Maximum
Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives	4 years
Accounts Receivable, Extended Payment Arrangements
Significant Accounting Policies [Line Items]
Reserve for credit losses	$ 0	0	0
Write off of uncollectible receivables	0	0	$ 0
Certificates of Deposit
Significant Accounting Policies [Line Items]
Restricted cash	$ 1,006,000	$ 1,019,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash in Accompanying Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018	[1]	Dec. 31, 2017
Accounting Policies [Abstract]
Cash and cash equivalents	$ 157,455		$ 113,638
Restricted cash included in other assets	$ 1,006		$ 1,019
Restricted Cash and Cash Equivalents, Noncurrent, Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent		us-gaap:OtherAssetsNoncurrent
Cash and cash equivalents, restricted cash	$ 158,461	[1]	$ 114,657	[1]	$ 281,606		$ 260,820

[1]	See Note 2 of the accompanying notes for a reconciliation of the ending balance of cash, cash equivalents and restricted cash shown in these consolidated statements of cash flows.

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current portion of accounts receivable, net:
Current portion of accounts receivable, net	$ 94,124	$ 93,100	$ 81,782
Accounts receivable, net of current portion:
Accounts receivable, net of current portion	143	575	$ 2,388
Accounts receivable	94,267	93,675
Accounts Receivable, Net
Current portion of accounts receivable, net:
Current portion of accounts receivable, net	93,480	91,273
Accounts Receivable, Extended Payment Arrangements
Current portion of accounts receivable, net:
Current portion of accounts receivable, net	$ 644	$ 1,827

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Changes in Provision for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Provision for doubtful accounts at beginning of year	$ 20	$ 410	$ 692
Provisions and recoveries	38	560
Write-offs		(950)	(282)
Provision for doubtful accounts at end of year	$ 58	$ 20	$ 410

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Property and Equipment Assets (Details)	12 Months Ended
	Dec. 31, 2020
Computers and Purchased Software \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment useful life	3 years
Computers and Purchased Software \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment useful life	4 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment useful life	7 years
Property and equipment useful life	Shorter of lease term or 7 years
Furniture and Fixtures \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment useful life	6 years
Furniture and Fixtures \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment useful life	8 years
Machinery and Equipment \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment useful life	3 years
Machinery and Equipment \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment useful life	5 years
Building
Property Plant And Equipment [Line Items]
Property and equipment useful life	40 years
Building Improvements \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment useful life	5 years
Building Improvements \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment useful life	40 years
Trial Systems at Customers' Sites
Property Plant And Equipment [Line Items]
Property and equipment useful life	2 years

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Schedule of Significant Customers Represent 10% or More of Revenue or Accounts Receivable (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue \| Customer A
Concentration Risk [Line Items]
Concentration risk percentage		14.00%	27.00%
Revenue \| Customer B
Concentration Risk [Line Items]
Concentration risk percentage			11.00%
Revenue \| Customer C
Concentration Risk [Line Items]
Concentration risk percentage			12.00%
Revenue \| Customer D
Concentration Risk [Line Items]
Concentration risk percentage			14.00%
Revenue \| Customer F
Concentration Risk [Line Items]
Concentration risk percentage	20.00%	12.00%
Revenue \| Customer G
Concentration Risk [Line Items]
Concentration risk percentage	11.00%
Accounts Receivable \| Customer A
Concentration Risk [Line Items]
Concentration risk percentage		11.00%
Accounts Receivable \| Customer C
Concentration Risk [Line Items]
Concentration risk percentage		14.00%
Accounts Receivable \| Customer E
Concentration Risk [Line Items]
Concentration risk percentage		19.00%
Accounts Receivable \| Customer G
Concentration Risk [Line Items]
Concentration risk percentage	14.00%

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Summary of Changes in Amount Reserved for Warranty Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Warranty reserve at beginning of year	$ 2,448	$ 926	$ 1,246
Provisions	2,745	3,603	1,886
Acquired warranty reserve		1,867
Charges	(2,839)	(3,948)	(2,206)
Warranty reserve at end of year	$ 2,354	$ 2,448	$ 926

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Impact of New Accounting Standards ASC 606 on Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Accounts receivable, net of provision for doubtful accounts of $58 and $20 as of December 31, 2020 and 2019, respectively	$ 94,124	$ 93,100		$ 81,782
Inventory	101,204	93,604		50,997
Prepaid expenses and other current assets	3,864	4,884		3,755
Prepaid income taxes	14,087	3,217
Accounts receivable, net of current portion	143	575		2,388
Deferred tax assets	1,150	69		21,578
Other assets	6,038	7,820		3,293
Total assets	492,966	444,312		474,649
Liabilities:
Accrued expenses and other current liabilities	39,793	34,567		36,992
Deferred revenue	15,531	25,485		31,206
Deferred revenue, net of current portion	3,520	4,583		12,479
Total liabilities	416,592	405,748		399,793
Stockholders’ equity:
Accumulated deficit	(102,263)	(127,064)		(81,008)
Total stockholders’ equity	76,374	38,564		74,856	$ 50,156
Total liabilities and stockholders’ equity	$ 492,966	444,312		$ 474,649
Accounting Standards Update 2014-09
Assets
Accounts receivable, net of provision for doubtful accounts of $58 and $20 as of December 31, 2020 and 2019, respectively			$ 81,629
Inventory			50,629
Prepaid expenses and other current assets			3,964
Accounts receivable, net of current portion			2,313
Deferred tax assets			20,986
Other assets			3,421
Total assets			473,798
Liabilities:
Accrued expenses and other current liabilities			38,037
Deferred revenue			29,016
Deferred revenue, net of current portion			10,623
Total liabilities			396,792
Stockholders’ equity:
Accumulated deficit			(78,858)
Total stockholders’ equity			77,006
Total liabilities and stockholders’ equity			473,798
Accounting Standards Update 2014-09 \| Adjustments
Assets
Accounts receivable, net of provision for doubtful accounts of $58 and $20 as of December 31, 2020 and 2019, respectively		47	(153)
Inventory		186	(368)
Prepaid expenses and other current assets		54	209
Prepaid income taxes		330
Accounts receivable, net of current portion		23	(75)
Deferred tax assets		1,757	(592)
Other assets		(69)	128
Total assets		2,328	(851)
Liabilities:
Accrued expenses and other current liabilities		(491)	1,045
Deferred revenue		8,194	(2,190)
Deferred revenue, net of current portion		1,856	(1,856)
Total liabilities		9,559	(3,001)
Stockholders’ equity:
Accumulated deficit		(7,231)	2,150
Total stockholders’ equity		(7,231)	2,150
Total liabilities and stockholders’ equity		2,328	$ (851)
Accounting Standards Update 2014-09 \| Without adoption of ASC 606
Assets
Accounts receivable, net of provision for doubtful accounts of $58 and $20 as of December 31, 2020 and 2019, respectively		93,147
Inventory		93,790
Prepaid expenses and other current assets		4,938
Prepaid income taxes		3,547
Accounts receivable, net of current portion		598
Deferred tax assets		1,826
Other assets		7,751
Total assets		446,640
Liabilities:
Accrued expenses and other current liabilities		34,076
Deferred revenue		33,679
Deferred revenue, net of current portion		6,439
Total liabilities		415,307
Stockholders’ equity:
Accumulated deficit		(134,295)
Total stockholders’ equity		31,333
Total liabilities and stockholders’ equity		$ 446,640

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Impact of New Accounting Standards ASC 606 on Statement of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue	$ 393,246	$ 282,297	$ 297,127
Cost of revenue:
Total cost of revenue	192,647	119,765	79,161
Gross profit	200,599	162,532	217,966
Operating expenses:
Selling, general and administrative	92,016	88,320	68,026
Income (loss) from operations	24,213	(9,119)	78,966
Other income (expense):
Interest income	999	4,406	6,259
Income (loss) before (benefit from) provision for income taxes	9,749	(24,415)	65,938
(Benefit from) provision for income taxes	(15,052)	23,791	(7,068)
Net income (loss)	24,801	(48,206)	73,006
Comprehensive loss	$ 27,360	$ (49,270)	$ 71,654
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.30	$ (0.57)	$ 0.87
Diluted	$ 0.29	$ (0.57)	$ 0.79
Product
Revenue:
Total revenue	$ 346,083	$ 241,377	$ 256,989
Cost of revenue:
Total cost of revenue	187,706	113,059	74,350
Service
Revenue:
Total revenue	47,163	40,920	40,138
Cost of revenue:
Total cost of revenue	$ 4,941	6,706	$ 4,811
Accounting Standards Update 2014-09 \| Adjustments
Revenue:
Total revenue		(6,004)
Cost of revenue:
Gross profit		(6,186)
Operating expenses:
Selling, general and administrative		231
Income (loss) from operations		(6,417)
Other income (expense):
Interest income		(159)
Income (loss) before (benefit from) provision for income taxes		(6,576)
(Benefit from) provision for income taxes		(1,495)
Net income (loss)		(5,081)
Comprehensive loss		$ (5,081)
Net income (loss) per share attributable to common stockholders:
Basic		$ (0.07)
Diluted		$ (0.07)
Accounting Standards Update 2014-09 \| Without adoption of ASC 606
Revenue:
Total revenue		$ 276,293
Cost of revenue:
Gross profit		156,346
Operating expenses:
Selling, general and administrative		88,551
Income (loss) from operations		(15,536)
Other income (expense):
Interest income		4,247
Income (loss) before (benefit from) provision for income taxes		(30,991)
(Benefit from) provision for income taxes		22,296
Net income (loss)		(53,287)
Comprehensive loss		$ (54,351)
Net income (loss) per share attributable to common stockholders:
Basic		$ (0.64)
Diluted		$ (0.64)
Accounting Standards Update 2014-09 \| Product \| Adjustments
Revenue:
Total revenue		$ (6,201)
Cost of revenue:
Total cost of revenue		182
Accounting Standards Update 2014-09 \| Product \| Without adoption of ASC 606
Revenue:
Total revenue		235,176
Cost of revenue:
Total cost of revenue		113,241
Accounting Standards Update 2014-09 \| Service \| Adjustments
Revenue:
Total revenue		197
Accounting Standards Update 2014-09 \| Service \| Without adoption of ASC 606
Revenue:
Total revenue		$ 41,117

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Impact of New Accounting Standards ASC 606 on Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ 24,801	$ (48,206)	$ 73,006
Deferred income taxes	(2,526)	19,641	(11,517)
Changes in operating assets and liabilities:
Accounts receivable	(350)	1,881	34,716
Inventory	(9,774)	(21,276)	(11,051)
Prepaid expenses and other assets	2,837	(3,679)	(1,084)
Prepaid income taxes		16
Accrued expenses and other current liabilities	6,254	(7,827)	6,124
Deferred revenue	(11,061)	(9,498)	(5,087)
Net cash used in operating activities	$ 53,642	(39,022)	$ 98,545
Accounting Standards Update 2014-09 \| Adjustments
Cash flows from operating activities:
Net income (loss)		(5,081)
Deferred income taxes		(1,166)
Changes in operating assets and liabilities:
Accounts receivable		159
Inventory		182
Prepaid expenses and other assets		(322)
Prepaid income taxes		(330)
Accrued expenses and other current liabilities		554
Deferred revenue		6,004
Accounting Standards Update 2014-09 \| Without adoption of ASC 606
Cash flows from operating activities:
Net income (loss)		(53,287)
Deferred income taxes		18,475
Changes in operating assets and liabilities:
Accounts receivable		2,040
Inventory		(21,094)
Prepaid expenses and other assets		(4,001)
Prepaid income taxes		(314)
Accrued expenses and other current liabilities		(7,273)
Deferred revenue		(3,494)
Net cash used in operating activities		$ (39,022)

Business Acquisition - Addition

Business Acquisition - Additional Information (Details) $ in Thousands, $ in Thousands	Jul. 01, 2019USD ($)	Jul. 01, 2019AUD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Business Acquisition [Line Items]
Goodwill			$ 50,177	$ 50,347
Net income (loss)			24,801	$ (48,206)	$ 73,006
NetComm
Business Acquisition [Line Items]
Business combination acquisition of equity interests percentage	100.00%
Cash consideration	$ 112,674	$ 161,963
Exchange rate	0.700
Cash and cash equivalents balance	$ 3,243
Consideration net of cash acquired	109,431
Existing debt	3,507
Fair value of receivables acquired	18,142
Identifiable intangible assets	$ 44,000
Weighted average life of identifiable intangible assets	8 years 2 months 12 days	8 years 2 months 12 days
Goodwill	$ 50,177
Net revenues			75,769
Net income (loss)			1,424
Transaction costs related to acquisition			$ 3,494
Adjustment for amortization of step up of inventory fair value	3,200
NetComm \| Developed Technology
Business Acquisition [Line Items]
Identifiable intangible assets	$ 25,000
Intangible assets, estimated useful lives	7 years	7 years
NetComm \| Customer Relationships
Business Acquisition [Line Items]
Identifiable intangible assets	$ 18,000
Intangible assets, estimated useful lives	10 years	10 years
NetComm \| Trade Name
Business Acquisition [Line Items]
Identifiable intangible assets	$ 1,000
Intangible assets, estimated useful lives	3 years	3 years

Business Acquisition - Schedule

Business Acquisition - Schedule of Purchase Price and Valuation, Allocation of Total Purchase Price (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jul. 01, 2019
Fair value of tangible assets:
Goodwill	$ 50,177	$ 50,347
NetComm
Fair value of tangible assets:
Fair value of receivables acquired			$ 18,142
Inventory			24,138
Prepaid expenses and other current assets			2,240
Property, plant and equipment			8,010
Deferred tax assets			365
Other assets			13
Goodwill			50,177
Identifiable intangible assets			44,000
Total assets acquired			147,085
Liabilities assumed
Accounts payable			(9,719)
Accrued expenses			(13,178)
Accrued income taxes			(140)
Deferred tax liabilities			(10,621)
Current portion of long-term debt			(3,507)
Other liabilities			(489)
Total liabilities assumed			(37,654)
Net assets acquired			$ 109,431

Business Acquisition - Schedu_2

Business Acquisition - Schedule of Purchase Price and Estimated Useful Lives Associated with Certain Assets (Details) - USD ($) $ in Thousands	Jul. 01, 2019	Dec. 31, 2020	Dec. 31, 2019
Identifiable intangible assets:
Goodwill		$ 50,177	$ 50,347
NetComm
Business Acquisition [Line Items]
Net tangible assets	$ 15,254
Identifiable intangible assets:
Identifiable intangible assets	44,000
Goodwill	50,177
Net assets acquired	109,431
NetComm \| Developed Technology
Identifiable intangible assets:
Identifiable intangible assets	$ 25,000
Identifiable intangible assets, Estimated Useful Life	7 years
NetComm \| Customer Relationships
Identifiable intangible assets:
Identifiable intangible assets	$ 18,000
Identifiable intangible assets, Estimated Useful Life	10 years
NetComm \| Trade Name
Identifiable intangible assets:
Identifiable intangible assets	$ 1,000
Identifiable intangible assets, Estimated Useful Life	3 years

Business Acquisition - Schedu_3

Business Acquisition - Schedule of Unaudited Pro Forma Results (Details) - NetComm - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Net revenue	$ 393,246	$ 375,306	$ 436,791
Net income (loss)	$ 25,134	$ (47,898)	$ 68,808

Goodwill and Intangibles - Sche

Goodwill and Intangibles - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Net Carrying Amount	$ 35,844
NetComm
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	44,432	$ 44,000
Accumulated Amortization	(8,588)	(2,852)
Net Carrying Amount	35,844	41,148
Developed Technology \| NetComm
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	25,000	25,000
Accumulated Amortization	(5,358)	(1,786)
Net Carrying Amount	19,642	23,214
Customer Relationships \| NetComm
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	18,000	18,000
Accumulated Amortization	(2,700)	(900)
Net Carrying Amount	15,300	17,100
Trade Name \| NetComm
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	(498)	(166)
Net Carrying Amount	502	$ 834
Purchased Software \| NetComm
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	432
Accumulated Amortization	(32)
Net Carrying Amount	$ 400

Goodwill and Intangibles - Sc_2

Goodwill and Intangibles - Schedule of Amortization Expense on Existing Intangible Assets (Details) $ in Thousands	Dec. 31, 2020USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2021	$ 5,849
2022	5,681
2023	5,484
2024	5,372
2025	5,372
Thereafter	8,086
Net Carrying Amount	$ 35,844

Goodwill and Intangibles - Summ

Goodwill and Intangibles - Summary of Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 5,736	$ 2,852
Product Cost of Revenue
Finite Lived Intangible Assets [Line Items]
Amortization expense	3,571	1,786
Research and Development
Finite Lived Intangible Assets [Line Items]
Amortization expense	32
Selling, General and Administrative Expenses
Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 2,133	$ 1,066

Goodwill and Intangibles - Sc_3

Goodwill and Intangibles - Schedule of Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning Balance	$ 50,347
NetComm Acquisition		$ 50,347
Adjustment recorded to preliminary purchase price allocation	(170)
Ending Balance	$ 50,177	$ 50,347

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 50,904	$ 19,821
Work in process	19	17
Finished goods:
Manufactured finished goods	49,764	69,503
Deferred inventory costs	517	4,263
Total inventory	$ 101,204	$ 93,604	$ 50,997

Property and Equipment - Summar

Property and Equipment - Summary of Components of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 88,758	$ 90,141
Less: Accumulated depreciation and amortization	(59,878)	(54,231)
Property and equipment, net	28,880	35,910
Computers and Purchased Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	24,865	22,294
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	4,148	4,380
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	2,644	2,794
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	36,701	40,002
Land
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,091	3,091
Building
Property Plant And Equipment [Line Items]
Property and equipment, gross	4,765	4,765
Building Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	7,244	6,776
Trial Systems at Customers' Sites
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,300	$ 6,039

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Depreciation and amortization expense on property and equipment	$ 12,234	$ 11,870	$ 9,454
Trial Systems
Property Plant And Equipment [Line Items]
Transfers from inventory into property and equipment	(1,259)	(502)	(357)
Equipment
Property Plant And Equipment [Line Items]
Transfers from inventory into property and equipment	$ (805)	$ (261)	$ 371

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued compensation and related taxes	$ 22,722	$ 18,540
Accrued warranty (see Note 2)	2,354	2,448
Dividends and equitable adjustments payable (see Note 12)	63	750
Accrued customer incentives	20	233
Other accrued expenses	14,634	12,596
Total accrued expenses and other current liabilities	$ 39,793	$ 34,567	$ 36,992

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Assets fair value	$ 115,410	$ 65,738
Liabilities:
Liabilities fair value	493	314
Certificates of Deposit
Assets:
Assets fair value		10,933
Certificates of Deposit—Restricted Cash
Assets:
Assets fair value	1,006	1,019
Money Market Mutual Funds
Assets:
Assets fair value	114,404	53,763
Derivative Financial Instruments, Assets \| Foreign Currency Forward Contracts
Assets:
Assets fair value		23
Derivative Financial Instruments, Liabilities \| Foreign Currency Forward Contracts
Liabilities:
Liabilities fair value		50
SARs \| Share Based Compensation Liability
Liabilities:
Liabilities fair value	493	264
Level 1
Assets:
Assets fair value	114,404	53,763
Level 1 \| Money Market Mutual Funds
Assets:
Assets fair value	114,404	53,763
Level 2
Assets:
Assets fair value	1,006	11,975
Liabilities:
Liabilities fair value		50
Level 2 \| Certificates of Deposit
Assets:
Assets fair value		10,933
Level 2 \| Certificates of Deposit—Restricted Cash
Assets:
Assets fair value	1,006	1,019
Level 2 \| Derivative Financial Instruments, Assets \| Foreign Currency Forward Contracts
Assets:
Assets fair value		23
Level 2 \| Derivative Financial Instruments, Liabilities \| Foreign Currency Forward Contracts
Liabilities:
Liabilities fair value		50
Level 3
Liabilities:
Liabilities fair value	493	264
Level 3 \| SARs \| Share Based Compensation Liability
Liabilities:
Liabilities fair value	$ 493	$ 264

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair value, assets, transfers from Level 1 to Level 2	$ 0	$ 0	$ 0
Fair value, assets, transfers from Level 2 to Level 1	0	0	0
Fair value, liabilities, transfers from Level 1 to Level 2	0	0	0
Fair value, liabilities, transfers from Level 2 to Level 1	0	0	0
Fair value, assets, transfers out of Level 3	0	0	0
Fair value, liabilities, transfers into Level 3	0	0	0
Fair value, liabilities, transfers out of Level 3	$ 0	$ 0	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Changes in Fair Values of SARs Liability (Details) - Level 3 - SARs - Share Based Compensation Liability - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value at beginning of the year	$ 264	$ 1,387	$ 2,155
Change in fair value	229	(1,123)	(768)
Fair value at end of year	$ 493	$ 264	$ 1,387

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Company's Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018	[1]	Dec. 31, 2017
Cash And Cash Equivalents [Line Items]
Cash	$ 43,051		$ 48,942
Cash equivalents and restricted cash:
Certificates of deposit			10,933
Money market mutual funds	114,404		53,763
Total cash equivalents and restricted cash	115,410		65,715
Cash and cash equivalents, restricted cash	158,461	[1]	114,657	[1]	$ 281,606		$ 260,820
Certificates of Deposit
Cash equivalents and restricted cash:
Restricted cash	$ 1,006		$ 1,019

[1]	See Note 2 of the accompanying notes for a reconciliation of the ending balance of cash, cash equivalents and restricted cash shown in these consolidated statements of cash flows.

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2020AUD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2019USD ($)	Dec. 31, 2019EUR (€)
Australian Subsidiary
Derivatives Fair Value [Line Items]
Fair value of derivatives amount recognized	$ 1,613,000
Australian Subsidiary \| Cost of Goods Sold
Derivatives Fair Value [Line Items]
Fair value of derivatives amount recognized	124,000
Australian Subsidiary \| Research and Development Expense
Derivatives Fair Value [Line Items]
Fair value of derivatives amount recognized	890,000
Australian Subsidiary \| Selling, General and Administrative Expenses
Derivatives Fair Value [Line Items]
Fair value of derivatives amount recognized	599,000
Australian Subsidiary \| Cash Flow Hedges
Derivatives Fair Value [Line Items]
Amount of gain reclassified from other comprehensive income (loss)	752,000
Foreign Currency Forward Contracts \| Prepaid Expenses and Other Current Assets
Derivatives Fair Value [Line Items]
Derivatives asset fair value	0			$ 23,000
Foreign Currency Forward Contracts \| Accrued Expenses And Other Current Liabilities
Derivatives Fair Value [Line Items]
Liability derivatives	0			50,000
Foreign Currency Forward Contracts \| Australian Subsidiary
Derivatives Fair Value [Line Items]
Outstanding notional amounts	0		€ 0	900,000	€ 500,000
Foreign Currency Forward Contracts \| Australian Subsidiary \| Cash Flow Hedges
Derivatives Fair Value [Line Items]
Outstanding notional amounts	$ 0			$ 0
Foreign Currency Forward Contracts One \| Australian Subsidiary \| Cash Flow Hedges
Derivatives Fair Value [Line Items]
Derivative notional amounts settled		$ 8,500
Foreign Currency Forward Contracts Two \| Australian Subsidiary \| Cash Flow Hedges
Derivatives Fair Value [Line Items]
Derivative notional amounts settled		$ 5,000

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Before (Benefit from) Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States	$ (32,755)	$ (40,055)	$ 10,527
Foreign	42,504	15,640	55,411
Income (loss) before (benefit from) provision for income taxes	$ 9,749	$ (24,415)	$ 65,938

Income Taxes - Schedule of (Ben

Income Taxes - Schedule of (Benefit from) Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current income tax (benefit) provision:
Federal	$ (24,409)	$ 4,698	$ (3,457)
State	228	(121)	(181)
Foreign	11,655	(427)	8,087
Total current income tax (benefit) provision	(12,526)	4,150	4,449
Deferred income tax (benefit) provision:
Federal	171	18,387	(10,699)
State	97	5,100	(1,108)
Foreign	(2,794)	(3,846)	290
Total deferred income tax (benefit) provision	(2,526)	19,641	(11,517)
Total income tax (benefit) provision	$ (15,052)	$ 23,791	$ (7,068)

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of U.S. Federal Statutory Rate to Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	21.00%	21.00%
State taxes, net of federal tax benefit	(6.80%)	9.80%	(0.80%)
Research and development tax credits	(37.60%)	10.30%	(15.60%)
Permanent differences	(11.50%)	(1.60%)	1.10%
Foreign tax rate differential	7.30%	10.20%	(6.60%)
Equitable adjustment payments	(1.10%)	1.70%	(1.80%)
Stock-based compensation	9.70%	3.30%	(25.20%)
Foreign taxes withheld	23.10%	(9.60%)	3.30%
Rate impact from CARES Act	(63.90%)
Global intangible low-taxed income	35.70%	(4.10%)	6.70%
Withholding tax on repatriation of accumulated earnings of foreign subsidiaries	1.00%	(0.10%)	0.10%
Valuation allowance on deferred tax assets	(146.90%)	(144.20%)	6.00%
Other, net	(3.60%)	2.30%	1.10%
Foreign derived intangible income		3.90%
Research and development costs	20.00%	(4.30%)
Provision to return	2.40%	11.10%
Uncertain tax positions	(3.20%)	(7.10%)
Effective income tax rate	(154.40%)	(97.40%)	(10.70%)

Income Taxes - Schedule of In_2

Income Taxes - Schedule of Income Tax Effect of Each Type of Temporary Difference and Carryforward (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Stock compensation	$ 4,710	$ 3,827
Tax credit carryforwards	13,138	9,900
Capitalized research and development costs	9,710	21,376
Inventory valuation	2,169	1,756
Accrued liabilities and reserves	3,826	5,207
Deferred revenue	796	1,520
Interest expense		2,149
Intellectual property rights	999	999
Other	2,228	544
Total deferred tax assets	37,576	47,278
Valuation Allowance	(24,463)	(39,124)
Deferred tax assets, net of valuation allowance	13,113	8,154
Deferred tax liabilities:
Depreciation	(2,092)	(1,159)
Amortization	(10,932)	(12,727)
Deferred costs	(3,444)
Withholding tax on unremitted earnings	(2,650)	(2,604)
Prepaid expenses	(127)	(588)
Total deferred tax liabilities	(19,245)	(17,078)
Net deferred tax liabilities	$ (6,132)	$ (8,924)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	Mar. 27, 2020	Mar. 26, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes Disclosure [Line Items]
Valuation Allowance			$ 24,463	$ 39,124
Deferred tax asset valuation allowance increase (decrease)			14,661
Percentage of taxable income offset by NOL carryovers and carrybacks	100.00%
Tax benefit of due to the revaluation of deferred tax assets due to the carryback of U.S. net operating loss			23,518
Interest expense deduction, percentage of adjusted taxable income	50.00%	30.00%
Income tax charges related to global intangible low taxed income			3,483	942
Undistributed earnings amount			26,494
Deferred tax liability			2,649
Foreign withholding taxes on unremitted earnings			135,384
Liability recorded for potential penalties and interest				2,260	$ 1,646
Unrecognized tax benefits			17,910	21,495	2,746	$ 1,695
Unrecognized tax benefits that would impact effective tax rate			17,668
Unrecognized tax benefits change in next 12 months due to the expiration of the statute of limitations			$ 4,344
Minimum
Income Taxes Disclosure [Line Items]
Statute of limitation year			3 years
Maximum
Income Taxes Disclosure [Line Items]
Statute of limitation year			4 years
Other Income (Expense)
Income Taxes Disclosure [Line Items]
Interest and penalties related to uncertain tax positions			$ 614	$ 1,278	$ 211
Start Year \| United States
Income Taxes Disclosure [Line Items]
Examination tax year			2017
Start Year \| Ireland
Income Taxes Disclosure [Line Items]
Examination tax year			2016
Start Year \| China
Income Taxes Disclosure [Line Items]
Examination tax year			2010
Start Year \| Australia
Income Taxes Disclosure [Line Items]
Examination tax year			2016
End Year \| United States
Income Taxes Disclosure [Line Items]
Examination tax year			2020
End Year \| Ireland
Income Taxes Disclosure [Line Items]
Examination tax year			2020
End Year \| China
Income Taxes Disclosure [Line Items]
Examination tax year			2020
End Year \| Australia
Income Taxes Disclosure [Line Items]
Examination tax year			2020
Federal
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards			$ 476
Research and development tax credit carryforwards			$ 1,269
Research and development tax credit carryforwards expiration year			2030
State
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards			$ 21,714
Research and development tax credit carryforwards			$ 10,812
Research and development tax credit carryforwards expiration year			2030
State \| Tax Year 2030
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards			$ 14,402
Net operating loss carryforwards, expiration year			2030
State \| Indefinite Tax Year
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards			$ 7,312
Foreign
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards			1,034
Research and development tax credit carryforwards			13,875
Uncertain tax positions credits			11,806
Foreign \| Indefinite Tax Year
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards			371
Foreign \| Tax Year 2024
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards			$ 662
Net operating loss carryforwards, expiration year			2024

Income Taxes - Schedule of Chan

Income Taxes - Schedule of Changes in Balance of Gross Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Balance	$ 21,495	$ 2,746	$ 1,695
Settlement/decreases related to tax positions taken during prior years		(49)
Expiration of statute of limitations	(1,174)
Decreases related to tax positions taken during prior years	(2,815)
Increases related to tax positions taken during prior years	155	18,434	241
Increases related to tax positions taken during the current year	249	364	810
Balance	$ 17,910	$ 21,495	$ 2,746

Debt - Schedule of Aggregate Pr

Debt - Schedule of Aggregate Principal Amount of Debt Outstanding (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total principal amount of debt outstanding	$ 294,500	$ 297,644
Revolving Credit Facility
Debt Instrument [Line Items]
Total principal amount of debt outstanding	6,500
Term Loans
Debt Instrument [Line Items]
Total principal amount of debt outstanding	$ 288,000	291,000
Mortgage Loan
Debt Instrument [Line Items]
Total principal amount of debt outstanding		$ 6,644

Debt - Schedule of Current and

Debt - Schedule of Current and Non-Current Debt Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current liabilities:
Current portion of principal payment obligations	$ 16,275	$ 9,644
Revolving credit facility	6,500
Unamortized debt issuance costs, current portion	(1,104)	(1,120)
Current portion of long-term debt, net of unamortized debt issuance costs	15,171	8,524
Non-current liabilities:
Unamortized debt issuance costs, non-current portion	(2,140)	(3,244)
Long-term debt, net of current portion and unamortized debt issuance costs	276,085	284,756
Term Loans
Current liabilities:
Current portion of principal payment obligations	9,775	3,000
Non-current liabilities:
Non-current portion of principal payment obligations	$ 278,225	288,000
Mortgage Loan
Current liabilities:
Current portion of principal payment obligations		$ 6,644

Debt - Schedule of Aggregate Mi

Debt - Schedule of Aggregate Minimum Future Principal Payments of Debt (Details) $ in Thousands	Dec. 31, 2020USD ($)
Debt Disclosure [Abstract]
2021	$ 16,275
2022	3,000
2023	275,225
Aggregate minimum future principal payments of debt	$ 294,500

Debt - Additional Information (

Debt - Additional Information (Details)	Dec. 20, 2016USD ($)	Jul. 01, 2015USD ($)Installment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	May 05, 2021USD ($)
Debt Instrument [Line Items]
Outstanding borrowings			$ 294,500,000
Outstanding borrowings			6,500,000
JPMorgan Chase Bank, N.A. and Barclays Bank PLC and Various Lenders \| Maximum
Debt Instrument [Line Items]
Maximum amount of increase in facilities			$ 70,000,000
JPMorgan Chase Bank, N. A.
Debt Instrument [Line Items]
Debt instrument, interest rate description			Borrowings under the facilities bear interest at a floating rate, which can be either a Eurodollar rate plus an applicable margin or, at the Company’s option, a base rate (defined as the highest of (x) the JPMorgan Chase, N.A. prime rate, (y) the federal funds effective rate, plus one-half percent (0.50%) per annum and (z) a one-month Eurodollar rate plus 1.00% per annum) plus an applicable margin. The applicable margin for borrowings under the term loan facility is 4.00% per annum for Eurodollar rate loans (subject to a 1.00% per annum interest rate floor) and 3.00% per annum for base rate loans. The applicable margin for borrowings under the revolving credit facility is 1.75% per annum for Eurodollar rate loans and 0.75% per annum for base rate loans, subject to reduction based on the Company’s maintaining of specified net leverage ratios. The interest rates payable under the facilities are subject to an increase of 2.00% per annum during the continuance of any payment default.
Debt instrument prepayment description			In addition, the Company is required to make mandatory prepayments under the facilities with respect to (i) 100% of the net cash proceeds from certain asset dispositions (including casualty and condemnation events) by the Company or certain of its subsidiaries, subject to certain exceptions and reinvestment provisions, (ii) 100% of the net cash proceeds from the issuance or incurrence of any additional debt by the Company or certain of its subsidiaries, subject to certain exceptions, and (iii) 50% of the Company’s excess cash flow, as defined in the credit agreement, subject to reduction upon its achievement of specified performance targets. In accordance with these provisions, a mandatory prepayment of $6.8 million will be required, no later than May 5, 2021. This amount has been included in the current portion of long-term debt, net of unamortized debt issuance costs on the consolidated balance sheet as of December 31, 2020.
Percentage of net proceeds from asset dispositions to be used for mandatory prepayment	100.00%
Percentage of net cash proceeds from issuances or incurrence of additional Debt to be used for mandatory prepayment	100.00%
Percentage on excess cash flow for mandatory prepayments of debt	50.00%
Line of credit facility, covenant terms			The facilities are secured by, among other things, a first priority security interest, subject to permitted liens, in substantially all of the Company’s assets and all of the assets of certain of its subsidiaries and a pledge of certain of the stock of certain of its subsidiaries, in each case subject to specified exceptions. The facilities contain customary affirmative and negative covenants, including certain restrictions on the Company’s ability to pay dividends, and, with respect to the revolving credit facility, a financial covenant requiring the Company to maintain a specified total net leverage ratio in the event that on the last day of any fiscal quarter the Company has utilized more than 30% of its borrowing capacity under the facility.
Line of credit facility, Covenant compliance			As of December 31, 2019, the Company’s net leverage ratio exceeded the maximum; however, as the Company’s utilization of the revolving credit facility did not exceed the 30% testing threshold on December 31, 2019, the Company was not in default of the revolving credit facility as a result of the Company’s net leverage ratio exceeding the maximum permitted amount. The Company was in compliance with all other applicable covenants of the facilities as of December 31, 2019.
JPMorgan Chase Bank, N. A. \| Scenario, Forecast
Debt Instrument [Line Items]
Debt instrument, mandatory prepayment of debt payable						$ 6,800,000
JPMorgan Chase Bank, N. A. \| Minimum
Debt Instrument [Line Items]
Line of credit facility borrowing capacity utilized percentage			30.00%
Line of credit facility borrowing capacity not utilized percentage				30.00%
Term Loan Facility \| JPMorgan Chase Bank, N.A. and Barclays Bank PLC and Various Lenders
Debt Instrument [Line Items]
Maximum borrowing amount under facility	$ 300,000,000
Outstanding borrowings			$ 288,000,000	$ 291,000,000
Term Loan Facility \| JPMorgan Chase Bank, N. A.
Debt Instrument [Line Items]
Debt instrument, interest rate stated percentage	4.00%
Debt instrument, interest rate description			As of December 31, 2020, the interest rate on the Term Loans was 5.00% per annum, which was based on a one-month Eurodollar rate of 1.00% per annum plus the applicable margin of 4.00% per annum for Eurodollar rate loans. As of December 31, 2019, the interest rate on the Term Loans was 5.80% per annum, which was based on a one-month Eurodollar rate of 1.80% per annum plus the applicable margin of 4.00% per annum for Eurodollar rate loans.
Debt instrument, effective interest rate percentage			5.00%	5.80%
Debt issuance costs	$ 7,811,000
Debt instrument, principal payment			$ 3,000,000	$ 3,000,000	$ 3,000,000
Interest expense, including amortization of debt issuance costs			$ 16,493,000	$ 19,728,000	19,146,000
Debt instrument, maturity date	Dec. 20, 2023
Original principal amount of term loan amortization percentage	1.00%
Principal amount of loan	$ 300,000,000
Term Loan Facility \| JPMorgan Chase Bank, N. A. \| Eurodollar Rate
Debt Instrument [Line Items]
Debt instrument, variable interest rate percentage			4.00%	4.00%
Debt instrument, effective interest rate percentage			1.00%	1.80%
Term Loan Facility \| JPMorgan Chase Bank, N. A. \| Floor Rate
Debt Instrument [Line Items]
Debt instrument, interest rate stated percentage	1.00%
Term Loan Facility \| JPMorgan Chase Bank, N. A. \| Base Rate
Debt Instrument [Line Items]
Debt instrument, interest rate stated percentage	3.00%
Commercial Mortgage Loan
Debt Instrument [Line Items]
Debt instrument, interest rate stated percentage		3.50%
Debt instrument, principal payment			$ 6,644,000	$ 314,000	303,000
Interest expense, including amortization of debt issuance costs			120,000	249,000	260,000
Debt instrument, maturity date		Jul. 1, 2020
Principal amount of loan		$ 7,950,000
Debt instrument, number of periodic payment installments \| Installment		60
Debt instrument, principal and interest payment		$ 46,000
Debt instrument payment, amortization period		20 years
Debt issuance costs		$ 45,000
Revolving Credit Facility \| JPMorgan Chase Bank, N.A. and Barclays Bank PLC and Various Lenders
Debt Instrument [Line Items]
Maximum borrowing amount under facility	$ 25,000,000
Outstanding borrowings			$ 6,500,000	0
Revolving Credit Facility \| JPMorgan Chase Bank, N. A.
Debt Instrument [Line Items]
Debt instrument, interest rate increase	2.00%
Payment of quarterly commitment fees percentage			0.25%
Interest expense related to the fee for the unused amount			$ 52,000	59,000	$ 62,000
Debt instrument, maturity date	Dec. 20, 2021
Revolving Credit Facility \| JPMorgan Chase Bank, N. A. \| Federal Funds Effective Rate
Debt Instrument [Line Items]
Debt instrument, variable interest rate percentage	0.50%
Revolving Credit Facility \| JPMorgan Chase Bank, N. A. \| Eurodollar Rate
Debt Instrument [Line Items]
Debt instrument, variable interest rate percentage	1.00%
Debt instrument, interest rate stated percentage	1.75%
Revolving Credit Facility \| JPMorgan Chase Bank, N. A. \| Base Rate
Debt Instrument [Line Items]
Debt instrument, interest rate stated percentage	0.75%
Stand-by Letter of Credit \| JPMorgan Chase Bank, N.A. and Barclays Bank PLC and Various Lenders
Debt Instrument [Line Items]
Line of credit facility, used as collateral amount			$ 1,454,000	$ 1,343,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	Apr. 30, 2018	Dec. 19, 2017	Dec. 31, 2020
Class Of Stock [Line Items]
Initial public offering of common stock		6,900,000
Common stock offering price per share		$ 13
Additional shares of common stock		900,000
Net proceeds after deducting underwriting discounts		$ 79,327,000
Underwriting discounts and commission amount		6,279,000
Offering costs		$ 4,094,000
Convertible outstanding preferred stock		4,038,000
Aggregate shares of common stock		40,382,000
Temporary equity to additional paid-in capital		$ 97,439,000
Temporary equity to common stock		$ 40,000
Follow-on Offering
Class Of Stock [Line Items]
Initial public offering of common stock	0
Net proceeds after deducting underwriting discounts	$ 0
Offering costs	$ 41,000
Number of shares sold by selling stockholders	7,350,000
Sale of stock, price per share	$ 25
Profit after offering cost amount disgorged by selling shareholders in connection with sale of shares	$ 3,770,000
Transaction costs incurred on behalf of selling stockholders	856,000
Follow-on Offering \| Selling, General and Administrative Expenses
Class Of Stock [Line Items]
Transaction costs incurred on behalf of selling stockholders	$ 815,000
Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Conversion of preferred stock, description			ten-for-one

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Cash Dividends Declared and Paid to Stockholders for Special Dividends (Details) - USD ($)	May 10, 2017	Dec. 27, 2016	Jun. 17, 2016	Nov. 30, 2014	Nov. 30, 2017	Dec. 31, 2018
Class Of Stock [Line Items]
Cash Dividend Declared per Share						$ 865,000
November 30, 2017
Class Of Stock [Line Items]
Dividend Declaration Date					Nov. 30, 2017
Cash Dividend Declared per Share						$ 865,000
November 30, 2017 \| Series B and Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Cash Dividend Declared per Share					$ 5,802
May 10, 2017
Class Of Stock [Line Items]
Dividend Declaration Date	May 10, 2017
May 10, 2017 \| Series B and Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Cash Dividend Declared per Share	$ 11,774.4000
December 27, 2016
Class Of Stock [Line Items]
Dividend Declaration Date		Dec. 27, 2016
December 27, 2016 \| Series B and Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Cash Dividend Declared per Share		$ 23,305.8000
June 17, 2016
Class Of Stock [Line Items]
Dividend Declaration Date			Jun. 17, 2016
June 17, 2016 \| Series B and Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Cash Dividend Declared per Share			$ 5,891
November 30, 2014
Class Of Stock [Line Items]
Dividend Declaration Date				Nov. 30, 2014
November 30, 2014 \| Series B and Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Cash Dividend Declared per Share				$ 3,834.6000
Common Stock \| November 30, 2017
Class Of Stock [Line Items]
Cash Dividend Declared per Share					$ 0.5802
Common Stock \| May 10, 2017
Class Of Stock [Line Items]
Cash Dividend Declared per Share	$ 1.1774
Common Stock \| December 27, 2016
Class Of Stock [Line Items]
Cash Dividend Declared per Share		$ 2.3306
Common Stock \| June 17, 2016
Class Of Stock [Line Items]
Cash Dividend Declared per Share			$ 0.5891
Common Stock \| November 30, 2014
Class Of Stock [Line Items]
Cash Dividend Declared per Share				$ 0.3835

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Equitable Adjustment Payments (Details) - USD ($) $ / shares in Units, $ in Thousands	May 10, 2017	Dec. 27, 2016	Jun. 17, 2016	Nov. 30, 2014	Nov. 30, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class Of Stock [Line Items]
Dividends Paid								$ 865
Vested Equity Awards
Class Of Stock [Line Items]
Dividends Paid						$ 683	$ 2,590	6,456
Vested Equity Awards \| Accrued Expenses And Other Current Liabilities
Class Of Stock [Line Items]
Equitable Adjustment Liability						63	731
November 30, 2017
Class Of Stock [Line Items]
Dividend Declaration Date					Nov. 30, 2017
Dividends Paid								865
November 30, 2017 \| Vested Equity Awards
Class Of Stock [Line Items]
Dividend Declaration Date					Nov. 30, 2017
Equitable Adjustment per share					$ 0.5802
Year of Final Vesting					2021
Dividends Paid						148	426	1,132
November 30, 2017 \| Vested Equity Awards \| Accrued Expenses And Other Current Liabilities
Class Of Stock [Line Items]
Equitable Adjustment Liability						30	177
May 10, 2017
Class Of Stock [Line Items]
Dividend Declaration Date	May 10, 2017
May 10, 2017 \| Vested Equity Awards
Class Of Stock [Line Items]
Dividend Declaration Date	May 10, 2017
Equitable Adjustment per share	$ 1.1774
Year of Final Vesting	2021
Dividends Paid						178	618	1,492
May 10, 2017 \| Vested Equity Awards \| Accrued Expenses And Other Current Liabilities
Class Of Stock [Line Items]
Equitable Adjustment Liability						31	182
December 27, 2016
Class Of Stock [Line Items]
Dividend Declaration Date		Dec. 27, 2016
December 27, 2016 \| Vested Equity Awards
Class Of Stock [Line Items]
Dividend Declaration Date		Dec. 27, 2016
Equitable Adjustment per share		$ 2.3306
Year of Final Vesting		2020
Dividends Paid						303	1,286	3,105
December 27, 2016 \| Vested Equity Awards \| Accrued Expenses And Other Current Liabilities
Class Of Stock [Line Items]
Equitable Adjustment Liability						2	335
June 17, 2016
Class Of Stock [Line Items]
Dividend Declaration Date			Jun. 17, 2016
June 17, 2016 \| Vested Equity Awards
Class Of Stock [Line Items]
Dividend Declaration Date			Jun. 17, 2016
Equitable Adjustment per share			$ 0.5891
Year of Final Vesting			2020
Dividends Paid						$ 54	259	684
June 17, 2016 \| Vested Equity Awards \| Accrued Expenses And Other Current Liabilities
Class Of Stock [Line Items]
Equitable Adjustment Liability							37
November 30, 2014
Class Of Stock [Line Items]
Dividend Declaration Date				Nov. 30, 2014
November 30, 2014 \| Vested Equity Awards
Class Of Stock [Line Items]
Dividend Declaration Date				Nov. 30, 2014
Equitable Adjustment per share				$ 0.3835
Year of Final Vesting				2018
Dividends Paid							$ 1	$ 43

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 21, 2019	Aug. 14, 2018	Dec. 19, 2017	Nov. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares authorized		500,000,000	500,000,000				500,000,000
Common stock, par value		$ 0.001	$ 0.001				$ 0.001
Cash proceeds received upon the exercise of options		$ 1,195,000	$ 2,687,000	$ 14,730,000
Fair value of SAR liability		493,000	$ 314,000
Unrecognized compensation cost		$ 20,948,000
Weighted-average period of unrecognized compensation cost expected to be recognized		2 years 2 months 26 days
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program, common stock remaining authorized to be repurchased		$ 70,208,000
Stock repurchase program, stock repurchased, shares		1,227,000	495,000
Stock repurchase program, stock repurchased, value		$ 3,031,000	$ 1,795,000
Stock repurchase program, common stock repurchased and retired, shares				5,172,000
Stock repurchased and retired during period value before commissions				$ 75,000,000
November 2014 Special Dividend
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividends, declared date		Nov. 30, 2014
June 2016 Special Dividend
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividends, declared date		Jun. 17, 2016
December 2016 Special Dividend
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividends, declared date		Dec. 21, 2016
May 2017 Special Dividend
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividends, declared date		May 10, 2017
November 2017 Special Dividend
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividends, declared date		Nov. 30, 2017
Board of Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock cash dividends declared		$ 0
Maximum \| Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program, common stock authorized to be repurchased					$ 75,000,000	$ 75,000,000
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value per share of options		$ 1.42	$ 2.13	$ 7.59
Cash proceeds received upon the exercise of options		$ 1,195,000	$ 2,687,000	$ 14,730,000
Intrinsic value of stock options exercised		$ 1,746,000	$ 6,970,000	$ 105,787,000
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted		3,270,000
Number of award outstanding		4,231,000	1,653,000
Performance Based Restricted Stock Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		3 years
Number of shares granted		983,000
Number of award outstanding		737,000
Performance Based Restricted Stock Units (PSUs) \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares earned upon vesting		983,000
Stock Appreciation Rights
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period	4 years
Award expiration period	10 years
Number of award outstanding		220,000
Fair value of SAR		$ 2.24
Stock Appreciation Rights \| Accrued Expenses And Other Current Liabilities
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of SAR liability		$ 493,000	$ 264,000
2003 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for grant		32,500,000
Award termination period		2011-08
Number of remaining shares available for grant		2,140,000
2011 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award termination period		2017-12
Number of remaining shares available for grant		2,855,000
2011 Stock Incentive Plan \| Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award expiration period		10 years
2011 Stock Incentive Plan \| Stock Options \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage on fair market value of common stock on the date of grant		100.00%
Award vesting period		4 years
2011 Stock Incentive Plan \| Stock Options \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award grant period		10 years
2017 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for grant		22,981,000						18,746,000
Number of remaining shares available for grant		10,647,000
Common stock, initially reserved for future issuance		22,981,000						7,161,000
2017 Stock Incentive Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued in period		20,000,000
Percentage of number of shares issued in period		4.00%
2011 and 2017 Stock Incentive Plan \| Restricted Stock Units (RSUs) \| Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock in settlement of employee tax withholding obligations		150,000	77,000	1,000

Stock-based Compensation - Assu

Stock-based Compensation - Assumptions Used in Black-Scholes Option Pricing Model (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days
Expected volatility, Minimum	29.30%	28.80%	30.60%
Expected volatility, Maximum	31.90%	30.60%	32.60%
Expected dividend yield	0.00%	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	0.40%	1.60%	2.70%
Expected term (in years)		6 years 1 month 6 days	6 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	0.70%	2.50%	3.00%
Expected term (in years)		6 years 2 months 12 days	6 years 2 months 12 days

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Option Activity (Details) - 2003, 2011 and 2017 Stock Incentive Plan - Stock Options - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning Balance	8,250
Number of Shares, Granted	166
Number of Shares, Exercised	(591)
Number of Shares, Forfeited	(705)
Number of Shares, Outstanding, Ending Balance	7,120	8,250
Number of Shares, Options exercisable at December 31, 2020	6,492
Number of Shares, Vested or expected to vest at December 31, 2020	7,090
Weighted-Average Exercise Price, Outstanding, Beginning Balance	$ 7.73
Weighted-Average Exercise Price, Granted	4.55
Weighted-Average Exercise Price, Exercised	2.02
Weighted-Average Exercise Price, Forfeited	8.98
Weighted-Average Exercise Price, Outstanding, Ending Balance	8.01	$ 7.73
Weighted-Average Exercise Price, Options exercisable at December 31, 2020	7.62
Weighted-Average Exercise Price, Vested or expected to vest at December 31, 2020	$ 8.01
Weighted-Average Remaining Contractual Term, Outstanding	4 years 10 months 17 days	5 years 7 months 24 days
Weighted-Average Remaining Contractual Term, Options exercisable at December 31, 2020	4 years 7 months 2 days
Weighted-Average Remaining Contractual Term, Vested or expected to vest at December 31, 2020	4 years 10 months 13 days
Aggregate Intrinsic Value, Outstanding	$ 9,367	$ 4,235
Aggregate Intrinsic Value, Options exercisable at December 31, 2020	9,026
Aggregate Intrinsic Value, Vested or expected to vest at December 31, 2020	$ 9,341

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of RSU Activity (Details) - Restricted Stock Units (RSUs) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Unvested, Beginning Balance \| shares	1,653
Number of Shares, Granted \| shares	3,270
Number of Shares, Vested \| shares	(554)
Number of Shares, Forfeited \| shares	(138)
Number of Shares, Unvested, Ending Balance \| shares	4,231
Weighted-Average Grant Date Fair Value, Unvested, Beginning Balance \| $ / shares	$ 11.38
Weighted-Average Grant Date Fair Value, Granted \| $ / shares	3.54
Weighted-Average Grant Date Fair Value, Vested \| $ / shares	11.03
Weighted-Average Grant Date Fair Value, Forfeited \| $ / shares	9.60
Weighted-Average Grant Date Fair Value, Unvested, Ending Balance \| $ / shares	$ 5.43
Aggregate Fair Value, Vested \| $	$ 2,321

Stock-based Compensation - As_2

Stock-based Compensation - Assumptions of Estimated Based on Monte Carlo Simulation Model (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Performance Based Restricted Stock Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	1.20%
Volatility	70.00%
Dividend yield	0.00%
Cost of equity	11.00%

Stock-based Compensation - Su_3

Stock-based Compensation - Summary of PSU Activity (Details) - Performance Based Restricted Stock Units (PSUs) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted \| shares	983
Number of Shares, Vested \| shares	(246)
Number of Shares, Unvested, Ending Balance \| shares	737
Weighted-Average Grant Date Fair Value, Granted \| $ / shares	$ 3.22
Weighted-Average Grant Date Fair Value, Vested \| $ / shares	3.22
Weighted-Average Grant Date Fair Value, Unvested, Ending Balance \| $ / shares	$ 3.22
Aggregate Fair Value, Vested \| $	$ 1,516

Stock-based Compensation - Sche

Stock-based Compensation - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 13,155	$ 9,821	$ 8,894
Product Cost of Revenue
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	153	216	249
Research and Development Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	2,447	1,569	1,864
Selling, General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 10,555	$ 8,036	$ 6,781

Stock-based Compensation - Su_4

Stock-based Compensation - Summary of Stock-based Compensation Expense Recognized in the Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Change in fair value of SAR liability	$ 229	$ (1,123)	$ (768)
Recognized as additional paid-in capital	12,926	10,944	9,662
Total stock-based compensation	$ 13,155	$ 9,821	$ 8,894

Net Income (Loss) per Share - S

Net Income (Loss) per Share - Schedule of Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income (loss) attributable to common stockholders, basic and diluted	$ 24,801	$ (48,206)	$ 73,006
Denominator:
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders, basic	83,465	83,853	83,539
Dilutive effect of stock options	1,050		8,086
Dilutive effect of restricted stock units	763		252
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders, diluted	85,278	83,853	91,877
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.30	$ (0.57)	$ 0.87
Diluted	$ 0.29	$ (0.57)	$ 0.79

Net Income (Loss) per Share -_2

Net Income (Loss) per Share - Schedule of Potential Common Shares Excluded from the Computation of Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares excluded from computation of diluted net income per share	4,119	4,641	2,213
Unvested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares excluded from computation of diluted net income per share	1,030	1,516	168
Unvested Performance-Based Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares excluded from computation of diluted net income per share	983

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Summary of Disaggregation of Revenue Based on Geographic Locations Determined by Customer's Shipping Address (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 393,246	$ 282,297	$ 297,127
North America - United States
Disaggregation Of Revenue [Line Items]
Total revenue	127,217	103,451	104,124
North America - Canada
Disaggregation Of Revenue [Line Items]
Total revenue	38,960	36,466	41,884
North America
Disaggregation Of Revenue [Line Items]
Total revenue	166,177	139,917	146,008
Latin America
Disaggregation Of Revenue [Line Items]
Total revenue	34,926	24,043	32,283
Europe, Middle East and Africa - Germany
Disaggregation Of Revenue [Line Items]
Total revenue	5,487	13,773	45,864
Europe, Middle East and Africa - Other
Disaggregation Of Revenue [Line Items]
Total revenue	30,446	24,381	35,479
Europe, Middle East and Africa
Disaggregation Of Revenue [Line Items]
Total revenue	35,933	38,154	81,343
Asia-Pacific - Australia
Disaggregation Of Revenue [Line Items]
Total revenue	116,661	42,218	24,354
Asia-Pacific - Other
Disaggregation Of Revenue [Line Items]
Total revenue	39,549	37,965	13,139
Asia-Pacific
Disaggregation Of Revenue [Line Items]
Total revenue	$ 156,210	$ 80,183	$ 37,493

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Summary of Disaggregation of Revenue Based on Geographic Locations Determined by Customer's Shipping Address (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2020Country
Other than United States and Australia
Disaggregation Of Revenue [Line Items]
Number of countries represents 10% or more of total revenue	0
Revenue \| Geographic Concentration Risk
Disaggregation Of Revenue [Line Items]
Concentration risk percentage	10.00%

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Summary of Disaggregates of Revenue Based on Product Line (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 393,246	$ 282,297	$ 297,127
Product - Wireless
Disaggregation Of Revenue [Line Items]
Total revenue	111,255	58,234	402
Product - Fixed Telco
Disaggregation Of Revenue [Line Items]
Total revenue	96,904	38,734
Product - Cable
Disaggregation Of Revenue [Line Items]
Total revenue	137,924	144,409	256,587
Product
Disaggregation Of Revenue [Line Items]
Total revenue	346,083	241,377	256,989
Service - Wireless
Disaggregation Of Revenue [Line Items]
Total revenue	7,348	1,701	250
Service - Fixed Telco
Disaggregation Of Revenue [Line Items]
Total revenue	1,924	773
Service - Cable
Disaggregation Of Revenue [Line Items]
Total revenue	37,891	38,446	39,888
Service
Disaggregation Of Revenue [Line Items]
Total revenue	$ 47,163	$ 40,920	$ 40,138

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Disaggregation Of Revenue [Line Items]
Revenue remaining performance obligation amount	$ 19,051
Prepaid Expenses and Other Current Assets
Disaggregation Of Revenue [Line Items]
Short-term capitalized contract costs	95	$ 585	$ 209
Other Assets
Disaggregation Of Revenue [Line Items]
Long-term capitalized contract costs	70	70	128
Deferred Revenue
Disaggregation Of Revenue [Line Items]
Revenue	23,048	22,273
Contract assets	771	50	$ 28
Selling, General and Administrative Expenses
Disaggregation Of Revenue [Line Items]
Amortization of capitalized contract costs	$ 568	$ 695

Revenue from Contracts with C_7

Revenue from Contracts with Customers - Additional Information (Details1)	Dec. 31, 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Disaggregation Of Revenue [Line Items]
Revenue remaining performance obligation, percentage	82.00%
Revenue, remaining performance obligation, expected timing of satisfaction period	12 months
Minimum \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction period	2 years
Maximum \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction period	5 years

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
Segment Information - Additional Information (Details)	Dec. 31, 2020Segment
Segment Reporting [Abstract]
Number of operating segments	1

Segment Information - Schedule

Segment Information - Schedule of Property and Equipment, Net by Location (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Property and equipment, net	$ 28,880	$ 35,910
United States
Segment Reporting Information [Line Items]
Property and equipment, net	20,988	25,583
China
Segment Reporting Information [Line Items]
Property and equipment, net	2,986	3,277
Australia
Segment Reporting Information [Line Items]
Property and equipment, net	2,849	4,041
Other
Segment Reporting Information [Line Items]
Property and equipment, net	$ 2,057	$ 3,009

Related Parties - Additional In

Related Parties - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted Stock Units (RSUs)
Related Party Transaction [Line Items]
Aggregate fair value vested	$ 2,321
Number of shares granted	3,270,000
Liberty Global Affiliates
Related Party Transaction [Line Items]
Revenue from transactions with Liberty Global Affiliates			$ 22,252
Amounts received in cash from Liberty Global Affiliates			30,432
Rongke Xie
Related Party Transaction [Line Items]
Compensation paid	$ 187	$ 117	$ 143
Rongke Xie \| Restricted Stock Units (RSUs)
Related Party Transaction [Line Items]
Aggregate fair value vested	$ 200	100
Vesting period	4 years
Selling, general and administrative expenses recognized	$ 90	$ 46
Number of shares granted	90	8

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies Disclosure [Line Items]
Rent expense	$ 3,252,000	$ 2,459,000	$ 1,029,000
Deferred rent liability	90,000	212,000
Indemnification obligations material claims, outstanding	0	$ 0
Accrued contingency	$ 0
United States
Commitments And Contingencies Disclosure [Line Items]
Non-cancelable operating leases expiration year	2024
China
Commitments And Contingencies Disclosure [Line Items]
Non-cancelable operating leases expiration year	2024
Hong Kong
Commitments And Contingencies Disclosure [Line Items]
Non-cancelable operating leases expiration year	2024
Spain
Commitments And Contingencies Disclosure [Line Items]
Non-cancelable operating leases expiration year	2024
Australia
Commitments And Contingencies Disclosure [Line Items]
Non-cancelable operating leases expiration year	2024
Ireland
Commitments And Contingencies Disclosure [Line Items]
Non-cancelable operating leases expiration year	2026

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments under Non-cancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2020USD ($)
Commitments And Contingencies Disclosure [Abstract]
2021	$ 2,533
2022	1,500
2023	1,425
2024	536
2025	445
Thereafter	334
Total	$ 6,773

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details) - USD ($) $ in Thousands	Jan. 01, 2014	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Percentage by which employer contribution matches up to 6% of employee's contribution	50.00%
Employer matching contributions made to plan		$ 1,523	$ 1,762	$ 1,630
Maximum
Defined Contribution Plan Disclosure [Line Items]
Percentage of employee's contributions eligible for employer contribution match	6.00%