Penumbra (PEN) 10-Q 4 May 21 2021 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2021	Apr. 12, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-37557
Entity Registrant Name	Penumbra, Inc
Entity Address, Address Description	One Penumbra Place
Entity Address, City or Town	Alameda
Entity Address, State or Province	CA
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	05-0605598
Entity Address, Postal Zip Code	94502
City Area Code	510
Local Phone Number	748-3200
Title of 12(b) Security	Common Stock, Par value $0.001 per share
Trading Symbol	PEN
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		36,482,357
Entity Central Index Key	0001321732
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 55,632	$ 69,670
Marketable investments	186,977	195,162
Accounts receivable, net of allowance for credit losses of $2,137 and $2,198 at March 31, 2021 and December 31, 2020, respectively	126,415	114,608
Inventories	245,321	219,527
Prepaid expenses and other current assets	20,782	18,735
Total current assets	635,127	617,702
Property and equipment, net	50,314	48,169
Operating lease right-of-use assets	40,691	41,192
Finance lease right-of-use assets	37,697	38,065
Intangible assets, net	10,097	10,639
Goodwill	8,006	8,372
Deferred taxes	48,978	50,139
Other non-current assets	9,914	8,705
Total assets	840,824	822,983
Current liabilities:
Accounts payable	15,389	14,109
Accrued liabilities	90,214	85,795
Current operating lease liabilities	4,822	4,697
Current finance lease liabilities	1,437	1,331
Total current liabilities	111,862	105,932
Non-current operating lease liabilities	43,525	44,183
Non-current finance lease liabilities	27,000	27,066
Other non-current liabilities	7,966	8,014
Total liabilities	190,353	185,195
Commitments and contingencies
Stockholders’ equity:
Common stock	36	36
Additional paid-in capital	603,022	598,299
Accumulated other comprehensive (loss) income	(425)	2,541
Retained earnings	52,458	40,622
Total Penumbra, Inc. stockholders’ equity	655,091	641,498
Non-controlling interest	(4,620)	(3,710)
Total stockholders’ equity	650,471	637,788
Total liabilities and stockholders’ equity	$ 840,824	$ 822,983

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for credit losses	$ 2,137	$ 2,198

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 169,204	$ 137,329
Cost of revenue	57,867	49,320
Gross profit	111,337	88,009
Operating expenses:
Research and development	18,076	12,946
Sales, general and administrative	79,798	74,453
Total operating expenses	97,874	87,399
Income from operations	13,463	610
Interest income, net	480	299
Other expense, net	(1,476)	(1,655)
Income (loss) before income taxes	12,467	(746)
Provision for (benefit from) income taxes	1,541	(1,634)
Consolidated net income	10,926	888
Net loss attributable to non-controlling interest	(910)	(537)
Net income attributable to Penumbra, Inc.	$ 11,836	$ 1,425
Net income attributable to Penumbra, Inc. per share:
Basic (in dollars per share)	$ 0.32	$ 0.04
Diluted (in dollars per share)	$ 0.32	$ 0.04
Weighted average shares outstanding:
Basic (in shares)	36,455,712	35,042,912
Diluted (in shares)	37,533,520	36,362,726

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Consolidated net income	$ 10,926	$ 888
Other comprehensive loss, net of tax:
Foreign currency translation adjustments, net of tax	(2,695)	(1,634)
Net change in unrealized losses on available-for-sale securities, net of tax	(271)	(617)
Total other comprehensive loss, net of tax	(2,966)	(2,251)
Consolidated comprehensive income (loss)	7,960	(1,363)
Net loss attributable to non-controlling interest	(910)	(537)
Comprehensive income (loss) attributable to Penumbra, Inc.	$ 8,870	$ (826)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit)Cumulative Effect, Period of Adoption, Adjustment	Total Penumbra, Inc. Stockholders’ Equity	Total Penumbra, Inc. Stockholders’ EquityCumulative Effect, Period of Adoption, Adjustment	Non-controlling Interest
Beginning balance (in shares) at Dec. 31, 2019			35,001,581
Beginning balance at Dec. 31, 2019	$ 485,613	$ (1,198)	$ 35	$ 430,659	$ (2,324)	$ 57,522	$ (1,198)	$ 485,892	$ (1,198)	$ (279)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			81,485
Issuance of common stock	396		$ 0	396				396
Shares held for tax withholdings (in shares)			(12,058)
Shares held for tax withholdings	(2,105)			(2,105)				(2,105)
Stock-based compensation	(6,774)			(6,774)		0		(6,774)		0
Other comprehensive income (loss)	(2,251)				(2,251)			(2,251)
Net income (loss)	1,425					1,425		1,425
Net loss attributable to non-controlling interest	(537)									(537)
Consolidated net income	888
Ending balance (in shares) at Mar. 31, 2020			35,071,008
Ending balance at Mar. 31, 2020	488,117		$ 35	435,724	(4,575)	57,749		488,933		(816)
Beginning balance (in shares) at Dec. 31, 2020			36,414,732
Beginning balance at Dec. 31, 2020	637,788		$ 36	598,299	2,541	40,622		641,498		(3,710)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			79,080
Issuance of common stock	666		$ 0	666				666
Shares held for tax withholdings (in shares)			(11,955)
Shares held for tax withholdings	(3,036)			(3,036)				(3,036)
Stock-based compensation	7,093			7,093				7,093
Other comprehensive income (loss)	(2,966)				(2,966)			(2,966)
Net income (loss)	11,836					11,836		11,836
Net loss attributable to non-controlling interest	(910)									(910)
Consolidated net income	10,926
Ending balance (in shares) at Mar. 31, 2021			36,481,857
Ending balance at Mar. 31, 2021	$ 650,471		$ 36	$ 603,022	$ (425)	$ 52,458		$ 655,091		$ (4,620)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Cash Flows [Abstract]
Consolidated net income	$ 10,926	$ 888
Adjustments to reconcile consolidated net income to net cash used in operating activities:
Depreciation and amortization	3,471	2,959
Stock-based compensation	6,395	5,689
Inventory write-downs	991	1,097
Deferred taxes	1,223	(1,502)
Other	886	168
Changes in operating assets and liabilities:
Accounts receivable	(12,943)	(238)
Inventories	(31,608)	(15,090)
Prepaid expenses and other current and non-current assets	(3,463)	(1,544)
Accounts payable	1,272	921
Accrued expenses and other non-current liabilities	8,482	732
Net cash provided by (used in) operating activities	(14,368)	(5,920)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable investments	(12,266)	0
Proceeds from sales of marketable investments	0	7,188
Proceeds from maturities of marketable investments	19,497	12,980
Purchases of property and equipment	(3,991)	(10,131)
Other	(150)	0
Net cash provided by (used in) investing activities	3,090	10,037
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercises of stock options	666	396
Payment of employee taxes related to vested stock	(3,036)	(2,105)
Payments of finance lease obligations	(337)	(1,958)
Payment of acquisition-related obligations	0	(683)
Other	93	0
Net cash used in financing activities	(2,614)	(4,350)
Effect of foreign exchange rate changes on cash and cash equivalents	(146)	(90)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(14,038)	(323)
CASH AND CASH EQUIVALENTS—Beginning of period	69,670	72,779
CASH AND CASH EQUIVALENTS—End of period	55,632	72,456
NONCASH INVESTING AND FINANCING ACTIVITIES:
Right-of-use assets obtained in exchange for lease obligations	803	325
Right-of-use assets obtained in exchange for finance lease obligations	428	0
Purchase of property and equipment funded through accounts payable and accrued liabilities	$ 2,184	$ 1,702

Organization and Description of

Organization and Description of Business	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying condensed consolidated balance sheet as of March 31, 2021, the condensed consolidated statements of operations, the condensed consolidated statements of comprehensive income (loss), and the condensed consolidated statements of stockholders’ equity for the three months ended March 31, 2021 and 2020, and the condensed consolidated statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited. The unaudited condensed consolidated financial statements included herein have been prepared by the Company in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and the applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) for interim financial information. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. The condensed consolidated balance sheet data as of December 31, 2020 was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments of a normal recurring nature considered necessary to state fairly the Company’s financial position as of March 31, 2021, the results of its operations for the three months ended March 31, 2021 and 2020, the changes in comprehensive income (loss) and stockholders’ equity for the three months ended March 31, 2021 and 2020, and the cash flows for the three months ended March 31, 2021 and 2020. The results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021 or for any other future annual or interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2020, included in the Company’s Annual Report on Form 10-K. There have been no changes to the Company’s significant accounting policies during the three months ended March 31, 2021, as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020. The condensed consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and its majority-owned subsidiary. The portion of equity and consolidated net income not attributable to the Company is considered non-controlling interest and is classified separately in the condensed consolidated financial statements. Any subsequent changes in the Company’s ownership interest while the Company retains its controlling interest in its majority-owned subsidiary will be accounted for as equity transactions. All intercompany balances and transactions have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and equity accounts; disclosure of contingent assets and liabilities at the date of the financial statements; and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to marketable investments, allowances for credit losses, the amount of variable consideration included in the transaction price, warranty reserve, valuation of inventories, useful lives of property and equipment, operating and financing lease right-of-use (“ROU”) assets and liabilities, income taxes, contingent consideration and other contingencies, among others. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other data. Actual results could differ from those estimates. Segments The Company determined its operating segment on the same basis that it uses to evaluate its performance internally. The Company has one business activity: the design, development, manufacturing and marketing of innovative medical devices, and operates as one operating segment. The Company’s chief operating decision-maker, its Chief Executive Officer, reviews its consolidated operating results for the purpose of allocating resources and evaluating financial performance. Recently Adopted Accounting Standards On January 1, 2021, the Company adopted ASU No. 2019-12, Income Taxes— Simplifying the Accounting for Income Taxes (“ASU 2019-12”). This new standard removes certain exceptions for recognizing deferred taxes of foreign investments, the incremental approach to performing intraperiod allocation, and calculating income taxes for year-to-date interim period losses when such losses exceed anticipated full year losses. The standard also adds guidance to reduce complexity in certain areas, including accounting for franchise taxes that are partially based on income, transactions with a government that result in a step up in goodwill tax basis, enacted tax law changes impact during interim periods, and allocation of taxes to members of a consolidated group which are not subject to tax. The adoption of ASU 2019-12 did not have a material impact on the consolidated financial statements during the three months ended March 31, 2021.

Investments and Fair Value of F

Investments and Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Investments and Fair Value of Financial Instruments	3. Investments and Fair Value of Financial Instruments Marketable Investments The Company’s marketable investments have been classified and accounted for as available-for-sale. The following table presents the Company’s marketable investments as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 Securities with net gains or losses in accumulated other comprehensive income (loss) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance Fair Value Commercial paper $ 4,247 $ 2 $ — $ — $ 4,249 U.S. agency and government sponsored securities 4,548 7 — — 4,555 U.S. states and municipalities 47,283 148 (6) — 47,425 Corporate bonds 130,411 396 (59) — 130,748 Total $ 186,489 $ 553 $ (65) $ — $ 186,977 December 31, 2020 Securities with net gains or losses in accumulated other comprehensive income (loss) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance Fair Value Commercial paper $ 4,242 $ 4 $ — $ — $ 4,246 U.S. agency and government sponsored securities 7,846 11 — — 7,857 U.S. states and municipalities 47,934 162 (1) — 48,095 Corporate bonds 134,298 669 (3) — 134,964 Total $ 194,320 $ 846 $ (4) $ — $ 195,162 As of March 31, 2021, the total amortized cost basis of the Company’s impaired available-for-sale securities exceeded its fair value by a nominal amount. The Company reviewed its impaired available-for-sale securities and concluded that the decline in fair value was not related to credit losses and is recoverable. Accordingly, during the three months ended March 31, 2021 no allowance for credit losses was recorded and instead the unrealized losses are reported as a component of accumulated other comprehensive loss. The following tables present the gross unrealized losses and the fair value for those marketable investments that were in an unrealized loss position for less than twelve months or for twelve months or more as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 Less than 12 months 12 months or more Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. states and municipalities $ 3,590 $ (6) $ — $ — $ 3,590 $ (6) Corporate bonds 32,127 (59) — — 32,127 (59) Total $ 35,717 $ (65) $ — $ — $ 35,717 $ (65) December 31, 2020 Less than 12 months 12 months or more Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. states and municipalities 1,408 (1) — — 1,408 (1) Corporate bonds $ 12,552 $ (3) $ — $ — $ 12,552 $ (3) Total $ 13,960 $ (4) $ — $ — $ 13,960 $ (4) The following table presents the contractual maturities of the Company’s marketable investments as of March 31, 2021 (in thousands): March 31, 2021 Amortized Cost Fair Value Due in less than one year $ 100,191 $ 100,403 Due in one to five years 86,298 86,574 Total $ 186,489 $ 186,977 Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value: Level 1 - Quoted prices in active markets for identical assets or liabilities. Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. 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 classifies its cash equivalents and marketable investments within Level 1 and Level 2, as it uses quoted market prices or alternative pricing sources and models utilizing market observable inputs. The Company determined the fair value of its Level 1 financial instruments, which are traded in active markets, using quoted market prices for identical instruments. Marketable investments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, historical pricing trends of a security as relative to its peers. To validate the fair value determination provided by its investment managers, the Company reviews the pricing movement in the context of overall market trends and trading information from its investment managers. In addition, the Company assesses the inputs and methods used in determining the fair value in order to determine the classification of securities in the fair value hierarchy. The Company did not hold any Level 3 marketable investments as of March 31, 2021 or December 31, 2020. During the three months ended March 31, 2021 and 2020, the Company did not have any transfers between Level 1, Level 2 or Level 3 of the fair value hierarchy. Additionally, the Company did not have any financial assets and liabilities measured at fair value on a non-recurring basis as of March 31, 2021 or December 31, 2020. The following tables set forth the Company’s financial assets measured at fair value by level within the fair value hierarchy as of March 31, 2021 and December 31, 2020 (in thousands): As of March 31, 2021 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds $ 11,056 $ — $ — $ 11,056 Marketable investments: Commercial paper — 4,249 — 4,249 U.S. agency and government sponsored securities — 4,555 — 4,555 U.S. states and municipalities — 47,425 — 47,425 Corporate bonds — 130,748 — 130,748 Total $ 11,056 $ 186,977 $ — $ 198,033 As of December 31, 2020 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds 33,054 — — 33,054 Marketable investments: Commercial paper — 4,246 — 4,246 U.S. agency and government sponsored securities — 7,857 — 7,857 U.S. states and municipalities — 48,095 — 48,095 Corporate bonds — 134,964 — 134,964 Total $ 33,054 $ 195,162 $ — $ 228,216 Contingent Consideration Obligations As of March 31, 2021 and December 31, 2020, there were no contingent consideration liabilities classified as Level 3. The Company had a contingent consideration liability balance of $1.2 million related to milestone payments due in connection with the 2017 acquisition of Crossmed S.p.a. (“Crossmed”) and was based on actual revenue performance for the year ended December 31, 2019 and not based on unobservable inputs. The Company made this payment during the three months ended March 31, 2020 of which $0.5 million is presented in operating activities and $0.7 million is presented in financing activities in the condensed consolidated statement of cash flows. The following table summarizes the changes in fair value of the contingent consideration obligation for the three months ended March 31, 2020 (in thousands): Fair Value of Contingent Consideration Balance at December 31, 2019 $ 1,206 Payments of contingent consideration liabilities (1,186) Changes in fair value — Foreign currency remeasurement (20) Balance at March 31, 2020 $ —

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	4. Balance Sheet Components Inventories The following table shows the components of inventories as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 December 31, 2020 Raw materials $ 58,816 $ 45,341 Work in process 20,853 22,099 Finished goods 165,652 152,087 Inventories $ 245,321 $ 219,527 Accrued Liabilities The following table shows the components of accrued liabilities as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 December 31, 2020 Payroll and employee-related cost $ 57,234 $ 50,083 Accrued expenses 13,213 9,246 Sales return provision 1,470 9,812 Product warranty 3,314 2,896 Other acquisition-related costs (1) 3,000 3,000 Other accrued liabilities 11,983 10,758 Total accrued liabilities $ 90,214 $ 85,795 (1) Amount consists of a contingent liability related to an anti-dilution provision from the asset acquisition of MVI Health Inc. (“MVI”) in 2018. The following table shows the changes in the Company’s estimated product warranty accrual, included in accrued liabilities, as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 December 31, 2020 Balance at the beginning of the period $ 2,896 $ 2,318 Accruals of warranties issued 775 1,589 Settlements of warranty claims (357) (1,011) Balance at the end of the period $ 3,314 $ 2,896

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2021
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangible Assets	5. Intangible Assets Acquired Intangible Assets The following tables present details of the Company’s acquired finite-lived intangible assets, as of March 31, 2021 and December 31, 2020 (in thousands, except weighted-average amortization period): As of March 31, 2021 Weighted-Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Customer relationships 15.0 years $ 6,991 $ (1,748) $ 5,243 Trade secrets and processes 20.0 years 5,256 (854) 4,402 Other 5.0 years 1,803 (1,351) 452 Total intangible assets 16.7 years $ 14,050 $ (3,953) $ 10,097 As of December 31, 2020 Weighted-Average Gross Carrying Amount Accumulated Amortization Net Customer relationships 15.0 years $ 7,311 $ (1,706) $ 5,605 Trade secrets and processes 20.0 years 5,256 (788) 4,468 Other 5.0 years 1,885 (1,319) 566 Total intangible assets 16.6 years $ 14,452 $ (3,813) $ 10,639 The customer relationships and other intangible assets subject to amortization relate to the acquisition of Crossmed during the third quarter of 2017. The gross carrying amount and accumulated amortization of these intangible assets are subject to foreign currency translation effects. The Company’s $5.3 million trade secrets and processes intangible asset was recognized in connection with a royalty buyout agreement entered into during the first quarter of 2018. The following table presents the amortization expense recorded related to the Company’s finite-lived intangible assets for the three months ended March 31, 2021 and March 31, 2020 (in thousands): Three Months Ended March 31, 2021 2020 Cost of revenue $ 66 $ 66 Sales, general and administrative 212 194 Total $ 278 $ 260

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	6. Goodwill The following table presents the changes in goodwill during the three months ended March 31, 2021 (in thousands): Total Company Balance as of December 31, 2020 $ 8,372 Foreign currency translation (366) Balance as of March 31, 2021 $ 8,006

Debt

Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Indebtedness	7. Indebtedness Credit Agreement On April 24, 2020, the Company entered into a Credit Agreement (the “Credit Agreement”) with JPMorgan Chase Bank, N.A., as administrative agent and lender, and Bank of America, N.A. and Citibank, N.A. as lenders. The Credit Agreement is secured and provides for up to $100 million in available revolving borrowing capacity with an option, subject to certain conditions, for the Company to increase the aggregate borrowing capacity to up to $150 million, and was set to mature on April 23, 2021. The Company entered into an amended one-year credit agreement with JPMorgan Chase Bank, N.A., as administrative agent and lender, and Bank of America, N.A. and Citibank, N.A. as lenders during the three months ended March 31, 2021. The amended Credit Agreement extended the maturity date from April 23, 2021 to February 21, 2022 and has substantially the same terms and conditions as the prior credit agreement with certain changes including the exclusion of certain one-time charges and expenses incurred during the fiscal quarters ended September 30, 2020 and December 31, 2020 from the calculation of the financial covenants, reductions in interest rate floors applicable to revolving loans and other changes to borrowing mechanics under the Credit Agreement. The Credit Agreement requires the Company to maintain a minimum fixed charge coverage ratio and to not exceed a maximum leverage ratio. As of March 31, 2021, the Company was in compliance with these requirements. As of March 31, 2021 and December 31, 2020, there were no borrowings outstanding under the amended Credit Agreement.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Royalty Obligations In March 2005, the Company entered into a license agreement that requires the Company to make minimum royalty payments to the licensor on a quarterly basis. In July 2019, the Company amended the license agreement to extend its term for an additional ten years and to increase the required minimum annual royalty payments by $0.2 million. As of both March 31, 2021 and December 31, 2020, the amended license agreement required minimum quarterly royalty payments of $0.3 million. On each January 1, the quarterly calendar year minimum royalty shall be adjusted to equal the prior year’s minimum royalty adjusted by a percentage equal to the percentage change in the “consumer price index for all urban consumers” for the prior calendar year as reported by the U.S. Department of Labor. Unless terminated earlier, the term of the amended license agreement shall expire June 30, 2029. In April 2012, the Company entered into an agreement that requires the Company to pay, on a quarterly basis, a 5% royalty on sales of products covered under applicable patents. The first commercial sale of covered products occurred in April 2014. Unless terminated earlier, the royalty term for each applicable product shall continue for fifteen years following the first commercial sale of such patented product, or when the applicable patent covering such product has expired, whichever is sooner. Royalty expense included in cost of revenue for the three months ended March 31, 2021 and 2020, was $0.5 million and $0.7 million, respectively. Contingencies From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. Refer to Note “3. Investments and Fair Value of Financial Instruments” for more information on contingent liabilities recorded on the condensed consolidated balance sheet. Indemnification The Company enters into standard indemnification arrangements in the ordinary course of business. In many such arrangements, the Company agrees to indemnify, hold harmless, and reimburse the indemnified parties for losses suffered or incurred by the indemnified parties in connection with any trade secret, copyright, patent or other intellectual property infringement claim by any third-party with respect to the Company’s technology. The Company also agrees to indemnify many indemnified parties for product defect and similar claims. The term of these indemnification agreements is generally perpetual. The maximum potential amount of future payments the Company could be required to make under these agreements is not determinable because it involves claims that may be made against the Company in the future, but have not yet been made. The Company has entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers, other than liabilities arising from willful misconduct of the individual. The Company has not incurred costs to defend lawsuits or settle claims related to these indemnification agreements. No liability associated with any of these indemnification requirements has been recorded to date. Litigation From time to time, the Company is subject to other claims and assessments in the ordinary course of business. On January 15, 2021, a putative securities class action complaint was filed against the Company and its CEO, Adam Elsesser, and Executive Vice President, Global Marketing and Public Relations, Gita Barry, on behalf of a single shareholder in the U.S. District Court for the Northern District of California, asserting claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. The complaint sought unspecified damages on behalf of a purported class that would comprise all individuals who purchased or otherwise acquired the Company's common stock between August 3, 2020 and December 15, 2020. The complaint alleged securities law violations based on allegedly misleading statements and/or omissions made in connection with the Company’s JET 7 Xtra Flex product. On March 16, 2021, the plaintiff voluntarily dismissed the complaint without prejudice. The Company is not currently a party to any litigation matter that, individually or in the aggregate, is expected to have a material adverse effect on the Company’s business, financial condition, results of operations or cash flows.

Stockholder's Equity

Stockholder's Equity	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Stockholder's Equity	9. Stockholders’ Equity Equity Incentive Plans Stock Options Activity of stock options under the 2005 Plan, 2011 Plan and 2014 Plan (collectively, the "Plans") is set forth below: Number of Shares Weighted-Average Balance at December 31, 2020 1,020,978 $ 23.38 Exercised (42,408) 15.70 Canceled/Forfeited — — Balance at March 31, 2021 978,570 23.71 Restricted Stock and Restricted Stock Units Activity of unvested restricted stock awards and restricted stock units under the Plans during the three months ended March 31, 2021 is set forth below: Number of Shares Weighted -Average Unvested at December 31, 2020 369,629 $ 163.03 Granted 53,080 255.00 Released/Vested - Restricted Stock/RSUs (36,672) 140.42 Canceled/Forfeited (4,182) 175.99 Unvested at March 31, 2021 381,855 177.84 As of March 31, 2021, 364,777 restricted stock awards and restricted stock units are expected to vest. Stock-based Compensation The following table sets forth the stock-based compensation expense included in the Company’s condensed consolidated statements of operations for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 Cost of revenue $ 798 $ 648 Research and development 1,062 874 Sales, general and administrative 4,535 4,167 Total $ 6,395 $ 5,689 As of March 31, 2021, total unrecognized compensation cost was $55.6 million related to unvested share-based compensation arrangements which is expected to be recognized over a weighted average period of 2.9 years. The total stock-based compensation cost capitalized in inventory was $1.3 million and $1.2 million as of March 31, 2021 and December 31, 2020, respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Accumulated Other Comprehensive Loss	10. Accumulated Other Comprehensive (Loss) Income Other comprehensive loss consists of two components: unrealized gains or losses on the Company’s available-for-sale marketable investments and gains or losses from foreign currency translation adjustments. Until realized and reported as a component of consolidated net (loss) income, these comprehensive (loss) income items accumulate and are included within accumulated other comprehensive income (loss). Unrealized gains and losses on the Company’s marketable investments are reclassified from accumulated other comprehensive income (loss) into earnings when realized upon sale, and are determined based on specific identification of securities sold. Gains and losses from the translation of assets and liabilities denominated in non-U.S. dollar functional currencies are included in accumulated other comprehensive income (loss). The following table summarizes the changes in the accumulated balances during the period and includes information regarding the manner in which the reclassifications out of accumulated other comprehensive income (loss) into earnings affect the Company’s condensed consolidated statements of operations and consolidated statements of comprehensive (loss) income (in thousands): Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Marketable Currency Translation Total Marketable Currency Translation Total Balance, beginning of the period $ 647 $ 1,894 $ 2,541 $ 238 $ (2,562) $ (2,324) Other comprehensive (loss) income before reclassifications: Unrealized (loss) gain — marketable investments (353) — (353) (689) — (689) Foreign currency translation (losses) gains — (2,695) (2,695) — (1,634) (1,634) Income tax effect — expense 82 — 82 72 — 72 Net of tax (271) (2,695) (2,966) (617) (1,634) (2,251) Amounts reclassified from accumulated other comprehensive income (loss) to consolidated net (loss) income: Realized gain (loss) — marketable investments — — — — — — Income tax effect — expense (benefit) — — — — — — Net of tax — — — — — — Net current-year other comprehensive (loss) income (271) (2,695) (2,966) (617) (1,634) (2,251) Balance, end of the period $ 376 $ (801) $ (425) $ (379) $ (4,196) $ (4,575)

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes The Company’s income tax expense, deferred tax assets and liabilities, and reserves for unrecognized tax benefits reflect management’s best assessment of estimated current and future taxes to be paid. The Company is subject to income taxes in both the United States and foreign jurisdictions. Significant judgment and estimates are required in determining the consolidated income tax expense. During interim periods, the Company generally utilizes the estimated annual effective tax rate (“AETR”) method which involves the use of forecasted information. Under the AETR method, the provision is calculated by applying the estimated AETR for the full fiscal year to “ordinary” income or loss (pretax income or loss excluding unusual or infrequently occurring discrete items) for the reporting period. Jurisdictions with tax assets for which the Company believes a tax benefit cannot be realized are excluded from the computation of its AETR. The Company’s provision for income taxes was $1.5 million for the three months ended March 31, 2021, which was primarily due to tax expenses attributable to its worldwide profits offset by excess tax benefits from stock-based compensation attributable to its U.S. jurisdiction. The Company’s benefit from income taxes was $1.6 million for the three months ended March 31, 2020, which was primarily due to tax benefits attributable to its worldwide losses as a result of the COVID-19 pandemic impact combined with excess tax benefits from stock-based compensation attributable to its U.S. jurisdiction. The Company’s effective tax rate changed to 12.4% for the three months ended March 31, 2021, compared to 219.0% for the three months ended March 31, 2020. The Company’s change in effective tax rate was primarily attributable to small tax expenses over relatively large worldwide profits for the three months ended March 31, 2021, when compared to large tax benefits over relatively small worldwide losses for the three months ended March 31, 2020. Significant domestic deferred tax assets (“DTAs”) were generated in recent years, primarily due to excess tax benefits from stock option exercises and vesting of restricted stock. The Company evaluates all available positive and negative evidence, objective and subjective in nature, in each reporting period to determine if sufficient taxable income will be generated to realize the benefits of its DTAs and, if not, a valuation allowance to reduce the DTAs is recorded. As of March 31, 2021 and 2020, the Company maintains a valuation allowance against its Federal Research and Development Tax Credit and California DTAs as the Company could not conclude at the required more-likely-than-not level of certainty, that the benefit of these tax attributes would be realized prior to expiration. As of March 31, 2021 and 2020, the Company also maintains a valuation allowance against DTAs acquired from MVI which are subject to Separate Return Limitation Year (“SRLY”) rules that limit the utilization of the pre-acquisition tax attributes to offset future taxable income solely generated by MVI. The Company maintains that all foreign earnings, with the exception of a portion of the earnings of its German subsidiary, are permanently reinvested outside the United States and therefore deferred taxes attributable to such are not provided for in the Company’s condensed consolidated financial statements as of March 31, 2021. The Company will repatriate foreign earnings only to the extent doing so will not result in any material U.S. tax consequences. Thus, deferred taxes on any potential future repatriation of a portion of the earnings of its German subsidiary were not reflected in the Company’s condensed consolidated financial statements as of March 31, 2021.

Net (Loss) Income Attributable

Net (Loss) Income Attributable to Penumbra, Inc. Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Net (Loss) Income Attributable to Penumbra, Inc. Per Share	12. Net Income Attributable to Penumbra, Inc. Per Share The Company computed basic net income attributable to Penumbra, Inc. per share based on the weighted average number of shares of common stock outstanding during the period. The Company computed diluted net income attributable to Penumbra, Inc. per share based on the weighted average number of shares of common stock outstanding plus potentially dilutive common stock equivalents outstanding during the period using the treasury stock method. For the purposes of this calculation, stock options, restricted stock, restricted stock units and stock sold through the Company’s employee stock purchase plan are considered common stock equivalents. A reconciliation of the numerator and denominator used in the calculation of the basic and diluted net income attributable to Penumbra, Inc. per share is as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2021 2020 Numerator: Net income attributable to Penumbra, Inc. $ 11,836 $ 1,425 Denominator: Weighted average shares used to compute net income attributable to common stockholders: Basic 36,455,712 35,042,912 Potential dilutive stock-based options and awards 1,077,808 1,319,814 Diluted 37,533,520 36,362,726 Net income attributable to Penumbra, Inc. per share: Basic $ 0.32 $ 0.04 Diluted $ 0.32 $ 0.04 For the three months ended March 31, 2021 and 2020, outstanding stock-based awards of 22 thousand and 18 thousand shares, respectively, were excluded from the computation of diluted net income attributable to Penumbra, Inc. per share because their effect would have been anti-dilutive.

Revenues

Revenues	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenues	13. Revenues Revenue Recognition Revenue is recognized in an amount that reflects the consideration the Company expects to be entitled to in exchange for goods or services. All revenue recognized in the condensed consolidated statements of operations is considered to be revenue from contracts with customers. The following table presents the Company’s revenues disaggregated by geography, based on the destination to which the Company ships its products, for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 United States $ 120,070 $ 95,774 International 49,134 41,555 Total $ 169,204 $ 137,329 The following table presents the Company’s revenues disaggregated by product category, for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 Vascular $ 89,165 $ 59,253 Neuro 80,039 78,076 Total $ 169,204 $ 137,329 China Distribution and Technology Licensing Agreement In December 2020, the Company entered into a distribution and technology licensing arrangement with its existing distribution partner in China. In addition to modifying the Company’s standard distribution agreement with its Chinese partner, the Company agreed to license the technology for certain products to its Chinese partner to permit the manufacturing and commercialization of such products in China as well as provide certain regulatory support. Apart from the standard distribution agreement, the Company will receive fixed payments upon transferring its distinct licensed technology and providing related regulatory support and receive royalty payments on the downstream sales of the licensed products. Performance Obligations Delivery of products - The Company’s contracts with customers typically contain a single performance obligation, delivery of the Company’s products. Satisfaction of that performance obligation occurs when control of the promised goods transfers to the customer, which is generally upon shipment for non-consignment sale agreements and upon utilization for consignment sale agreements. Payment terms - Our payment terms vary by the type and location of our customer. The timing between fulfillment of performance obligations and when payment is due is not significant and does not give rise to financing transactions. The Company did not have any contracts with significant financing components as of March 31, 2021. Product returns - The Company may allow customers to return products purchased at the Company’s discretion. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period in which the related product revenue is recognized. The Company currently estimates product return liabilities using its own historic sales information, trends, industry data, and other relevant data points. Warranties - The Company offers its standard warranty to all customers and it is not available for sale on a standalone basis. The Company’s standard warranty represents its guarantee that its products function as intended, are free from defects, and comply with agreed-upon specifications and quality standards. This assurance does not constitute a service and is not a separate performance obligation. Transaction Price Revenue is recorded at the net sales price, which includes estimates of variable consideration such as product returns utilizing historical return rates, rebates, discounts, and other adjustments to net revenue. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price. When determining if variable consideration should be constrained, management considers whether there are factors that could result in a significant reversal of revenue and the likelihood of a potential reversal. Variable consideration is included in revenue only to the extent that it is probable that a significant reversal of the revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. These estimates are reassessed each reporting period as required. During the three months ended March 31, 2021, the Company made no material changes in estimates for variable consideration. When the Company performs shipping and handling activities after control of goods is transferred to the customer, they are considered as fulfillment activities, and costs are accrued for when the related revenue is recognized. Taxes collected from customers relating to product sales and remitted to governmental authorities are excluded from revenues.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation and Consolidation The accompanying condensed consolidated balance sheet as of March 31, 2021, the condensed consolidated statements of operations, the condensed consolidated statements of comprehensive income (loss), and the condensed consolidated statements of stockholders’ equity for the three months ended March 31, 2021 and 2020, and the condensed consolidated statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited. The unaudited condensed consolidated financial statements included herein have been prepared by the Company in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and the applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) for interim financial information. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. The condensed consolidated balance sheet data as of December 31, 2020 was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments of a normal recurring nature considered necessary to state fairly the Company’s financial position as of March 31, 2021, the results of its operations for the three months ended March 31, 2021 and 2020, the changes in comprehensive income (loss) and stockholders’ equity for the three months ended March 31, 2021 and 2020, and the cash flows for the three months ended March 31, 2021 and 2020. The results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021 or for any other future annual or interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2020, included in the Company’s Annual Report on Form 10-K. There have been no changes to the Company’s significant accounting policies during the three months ended March 31, 2021, as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020.
Consolidation	The condensed consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and its majority-owned subsidiary. The portion of equity and consolidated net income not attributable to the Company is considered non-controlling interest and is classified separately in the condensed consolidated financial statements. Any subsequent changes in the Company’s ownership interest while the Company retains its controlling interest in its majority-owned subsidiary will be accounted for as equity transactions. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of EstimatesThe preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and equity accounts; disclosure of contingent assets and liabilities at the date of the financial statements; and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to marketable investments, allowances for credit losses, the amount of variable consideration included in the transaction price, warranty reserve, valuation of inventories, useful lives of property and equipment, operating and financing lease right-of-use (“ROU”) assets and liabilities, income taxes, contingent consideration and other contingencies, among others. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other data. Actual results could differ from those estimates.
Segments	Segments The Company determined its operating segment on the same basis that it uses to evaluate its performance internally. The Company has one business activity: the design, development, manufacturing and marketing of innovative medical devices, and
Recently Adopted Accounting Standards and Recently Issued Accounting Standards	Recently Adopted Accounting Standards On January 1, 2021, the Company adopted ASU No. 2019-12, Income Taxes— Simplifying the Accounting for Income Taxes (“ASU 2019-12”). This new standard removes certain exceptions for recognizing deferred taxes of foreign investments, the incremental approach to performing intraperiod allocation, and calculating income taxes for year-to-date interim period losses when such losses exceed anticipated full year losses. The standard also adds guidance to reduce complexity in certain areas, including accounting for franchise taxes that are partially based on income, transactions with a government that result in a step up in goodwill tax basis, enacted tax law changes impact during interim periods, and allocation of taxes to members of a consolidated group which are not subject to tax. The adoption of ASU 2019-12 did not have a material impact on the consolidated financial statements during the three months ended March 31, 2021.
Marketable Investments	Marketable InvestmentsThe Company’s marketable investments have been classified and accounted for as available-for-sale.

Investments and Fair Value of_2

Investments and Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Marketable Investments	The following table presents the Company’s marketable investments as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 Securities with net gains or losses in accumulated other comprehensive income (loss) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance Fair Value Commercial paper $ 4,247 $ 2 $ — $ — $ 4,249 U.S. agency and government sponsored securities 4,548 7 — — 4,555 U.S. states and municipalities 47,283 148 (6) — 47,425 Corporate bonds 130,411 396 (59) — 130,748 Total $ 186,489 $ 553 $ (65) $ — $ 186,977 December 31, 2020 Securities with net gains or losses in accumulated other comprehensive income (loss) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance Fair Value Commercial paper $ 4,242 $ 4 $ — $ — $ 4,246 U.S. agency and government sponsored securities 7,846 11 — — 7,857 U.S. states and municipalities 47,934 162 (1) — 48,095 Corporate bonds 134,298 669 (3) — 134,964 Total $ 194,320 $ 846 $ (4) $ — $ 195,162
Schedule of the Fair Value of Marketable Investments in an Unrealized Loss Position for Less than Twelve Months	The following tables present the gross unrealized losses and the fair value for those marketable investments that were in an unrealized loss position for less than twelve months or for twelve months or more as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 Less than 12 months 12 months or more Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. states and municipalities $ 3,590 $ (6) $ — $ — $ 3,590 $ (6) Corporate bonds 32,127 (59) — — 32,127 (59) Total $ 35,717 $ (65) $ — $ — $ 35,717 $ (65) December 31, 2020 Less than 12 months 12 months or more Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. states and municipalities 1,408 (1) — — 1,408 (1) Corporate bonds $ 12,552 $ (3) $ — $ — $ 12,552 $ (3) Total $ 13,960 $ (4) $ — $ — $ 13,960 $ (4)
Schedule of Contractual Maturities of Marketable Investments	The following table presents the contractual maturities of the Company’s marketable investments as of March 31, 2021 (in thousands): March 31, 2021 Amortized Cost Fair Value Due in less than one year $ 100,191 $ 100,403 Due in one to five years 86,298 86,574 Total $ 186,489 $ 186,977
Schedule of Fair Value of Assets and Liabilities	The following tables set forth the Company’s financial assets measured at fair value by level within the fair value hierarchy as of March 31, 2021 and December 31, 2020 (in thousands): As of March 31, 2021 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds $ 11,056 $ — $ — $ 11,056 Marketable investments: Commercial paper — 4,249 — 4,249 U.S. agency and government sponsored securities — 4,555 — 4,555 U.S. states and municipalities — 47,425 — 47,425 Corporate bonds — 130,748 — 130,748 Total $ 11,056 $ 186,977 $ — $ 198,033 As of December 31, 2020 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds 33,054 — — 33,054 Marketable investments: Commercial paper — 4,246 — 4,246 U.S. agency and government sponsored securities — 7,857 — 7,857 U.S. states and municipalities — 48,095 — 48,095 Corporate bonds — 134,964 — 134,964 Total $ 33,054 $ 195,162 $ — $ 228,216
Schedule of Fair Value of Contingent Consideration Obligation	The following table summarizes the changes in fair value of the contingent consideration obligation for the three months ended March 31, 2020 (in thousands): Fair Value of Contingent Consideration Balance at December 31, 2019 $ 1,206 Payments of contingent consideration liabilities (1,186) Changes in fair value — Foreign currency remeasurement (20) Balance at March 31, 2020 $ —

Balance Sheet Components Balanc

Balance Sheet Components Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Inventories	The following table shows the components of inventories as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 December 31, 2020 Raw materials $ 58,816 $ 45,341 Work in process 20,853 22,099 Finished goods 165,652 152,087 Inventories $ 245,321 $ 219,527
Schedule of Accrued Liabilities	The following table shows the components of accrued liabilities as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 December 31, 2020 Payroll and employee-related cost $ 57,234 $ 50,083 Accrued expenses 13,213 9,246 Sales return provision 1,470 9,812 Product warranty 3,314 2,896 Other acquisition-related costs (1) 3,000 3,000 Other accrued liabilities 11,983 10,758 Total accrued liabilities $ 90,214 $ 85,795
Schedule of Estimated Product Warranty Accrual	The following table shows the changes in the Company’s estimated product warranty accrual, included in accrued liabilities, as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 December 31, 2020 Balance at the beginning of the period $ 2,896 $ 2,318 Accruals of warranties issued 775 1,589 Settlements of warranty claims (357) (1,011) Balance at the end of the period $ 3,314 $ 2,896

Intangible Assets Intangible As

Intangible Assets Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2021
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Schedule of indefinite-lived intangible assets	The following tables present details of the Company’s acquired finite-lived intangible assets, as of March 31, 2021 and December 31, 2020 (in thousands, except weighted-average amortization period): As of March 31, 2021 Weighted-Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Customer relationships 15.0 years $ 6,991 $ (1,748) $ 5,243 Trade secrets and processes 20.0 years 5,256 (854) 4,402 Other 5.0 years 1,803 (1,351) 452 Total intangible assets 16.7 years $ 14,050 $ (3,953) $ 10,097 As of December 31, 2020 Weighted-Average Gross Carrying Amount Accumulated Amortization Net Customer relationships 15.0 years $ 7,311 $ (1,706) $ 5,605 Trade secrets and processes 20.0 years 5,256 (788) 4,468 Other 5.0 years 1,885 (1,319) 566 Total intangible assets 16.6 years $ 14,452 $ (3,813) $ 10,639
Finite-lived Intangible Assets Amortization Expense	The following table presents the amortization expense recorded related to the Company’s finite-lived intangible assets for the three months ended March 31, 2021 and March 31, 2020 (in thousands): Three Months Ended March 31, 2021 2020 Cost of revenue $ 66 $ 66 Sales, general and administrative 212 194 Total $ 278 $ 260

Goodwill Goodwill (Tables)

Goodwill Goodwill (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	6. Goodwill The following table presents the changes in goodwill during the three months ended March 31, 2021 (in thousands): Total Company Balance as of December 31, 2020 $ 8,372 Foreign currency translation (366) Balance as of March 31, 2021 $ 8,006 Goodwill Impairment Review The Company reviews goodwill for impairment annually during the fourth quarter or more frequently if events or circumstances indicate that an impairment loss may have occurred. The Company determined that there was no impairment of goodwill as of March 31, 2021.

Stockholder's Equity (Tables)

Stockholder's Equity (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Activity	Activity of stock options under the 2005 Plan, 2011 Plan and 2014 Plan (collectively, the "Plans") is set forth below: Number of Shares Weighted-Average Balance at December 31, 2020 1,020,978 $ 23.38 Exercised (42,408) 15.70 Canceled/Forfeited — — Balance at March 31, 2021 978,570 23.71
Summary of Unvested Restricted Stock and Restricted Stock Unit Activity	Activity of unvested restricted stock awards and restricted stock units under the Plans during the three months ended March 31, 2021 is set forth below: Number of Shares Weighted -Average Unvested at December 31, 2020 369,629 $ 163.03 Granted 53,080 255.00 Released/Vested - Restricted Stock/RSUs (36,672) 140.42 Canceled/Forfeited (4,182) 175.99 Unvested at March 31, 2021 381,855 177.84
Schedule of Stock-based Compensation Expense	The following table sets forth the stock-based compensation expense included in the Company’s condensed consolidated statements of operations for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 Cost of revenue $ 798 $ 648 Research and development 1,062 874 Sales, general and administrative 4,535 4,167 Total $ 6,395 $ 5,689

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in the accumulated balances during the period and includes information regarding the manner in which the reclassifications out of accumulated other comprehensive income (loss) into earnings affect the Company’s condensed consolidated statements of operations and consolidated statements of comprehensive (loss) income (in thousands): Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Marketable Currency Translation Total Marketable Currency Translation Total Balance, beginning of the period $ 647 $ 1,894 $ 2,541 $ 238 $ (2,562) $ (2,324) Other comprehensive (loss) income before reclassifications: Unrealized (loss) gain — marketable investments (353) — (353) (689) — (689) Foreign currency translation (losses) gains — (2,695) (2,695) — (1,634) (1,634) Income tax effect — expense 82 — 82 72 — 72 Net of tax (271) (2,695) (2,966) (617) (1,634) (2,251) Amounts reclassified from accumulated other comprehensive income (loss) to consolidated net (loss) income: Realized gain (loss) — marketable investments — — — — — — Income tax effect — expense (benefit) — — — — — — Net of tax — — — — — — Net current-year other comprehensive (loss) income (271) (2,695) (2,966) (617) (1,634) (2,251) Balance, end of the period $ 376 $ (801) $ (425) $ (379) $ (4,196) $ (4,575)

Net (Loss) Income Attributabl_2

Net (Loss) Income Attributable to Penumbra, Inc. Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Reconciliation of the Numerator and Denominator used in the Calculation of the Basic and Diluted Earnings per Share	A reconciliation of the numerator and denominator used in the calculation of the basic and diluted net income attributable to Penumbra, Inc. per share is as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2021 2020 Numerator: Net income attributable to Penumbra, Inc. $ 11,836 $ 1,425 Denominator: Weighted average shares used to compute net income attributable to common stockholders: Basic 36,455,712 35,042,912 Potential dilutive stock-based options and awards 1,077,808 1,319,814 Diluted 37,533,520 36,362,726 Net income attributable to Penumbra, Inc. per share: Basic $ 0.32 $ 0.04 Diluted $ 0.32 $ 0.04

Revenues Revenues (Tables)

Revenues Revenues (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents the Company’s revenues disaggregated by geography, based on the destination to which the Company ships its products, for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 United States $ 120,070 $ 95,774 International 49,134 41,555 Total $ 169,204 $ 137,329 The following table presents the Company’s revenues disaggregated by product category, for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 Vascular $ 89,165 $ 59,253 Neuro 80,039 78,076 Total $ 169,204 $ 137,329

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Disclosures (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)activitysegment	Dec. 31, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of business activities | activity	1
Number of operating segments | segment	1
Adjustment to retained earnings	$ (650,471)	$ (637,788)	$ (488,117)	$ (485,613)
Accounts receivable, net	126,415	114,608
Allowance for credit losses	2,137	2,198
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to retained earnings				1,198
Retained Earnings (Accumulated Deficit)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to retained earnings	$ (52,458)	$ (40,622)	$ (57,749)	(57,522)
Retained Earnings (Accumulated Deficit) | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to retained earnings				$ 1,198

Investments and Fair Value of_3

Investments and Fair Value of Financial Instruments - Gains and Losses of Marketable Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 186,489	$ 194,320
Gross Unrealized Gains	553	846
Gross Unrealized Losses	(65)	(4)
Allowance for Credit Loss	0	0
Fair Value	186,977	195,162
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,247	4,242
Gross Unrealized Gains	2	4
Gross Unrealized Losses	0	0
Allowance for Credit Loss	0	0
Fair Value	4,249	4,246
U.S. agency and government sponsored securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,548	7,846
Gross Unrealized Gains	7	11
Gross Unrealized Losses	0	0
Allowance for Credit Loss	0	0
Fair Value	4,555	7,857
U.S. states and municipalities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	47,283	47,934
Gross Unrealized Gains	148	162
Gross Unrealized Losses	(6)	(1)
Allowance for Credit Loss	0	0
Fair Value	47,425	48,095
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	130,411	134,298
Gross Unrealized Gains	396	669
Gross Unrealized Losses	(59)	(3)
Allowance for Credit Loss	0	0
Fair Value	$ 130,748	$ 134,964

Investments and Fair Value of_4

Investments and Fair Value of Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Gross Unrealized Losses	$ (65,000)	$ (4,000)
Allowance for credit losses	$ 0

Investments and Fair Value of_5

Investments and Fair Value of Financial Instruments - Marketable Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Less than 12 months: Fair Value	$ 35,717	$ 13,960
Less than 12 months: Gross Unrealized Losses	(65)	(4)
12 Months of more: Fair Value	0	0
12 months or more: Gross Unrealized Losses	0	0
Total: Fair Value	35,717	13,960
Total: Gross Unrealized Losses	(65)	(4)
U.S. states and municipalities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months: Fair Value	3,590	1,408
Less than 12 months: Gross Unrealized Losses	(6)	(1)
12 Months of more: Fair Value	0	0
12 months or more: Gross Unrealized Losses	0	0
Total: Fair Value	3,590	1,408
Total: Gross Unrealized Losses	(6)	(1)
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 months: Fair Value	32,127	12,552
Less than 12 months: Gross Unrealized Losses	(59)	(3)
12 Months of more: Fair Value	0	0
12 months or more: Gross Unrealized Losses	0	0
Total: Fair Value	32,127	12,552
Total: Gross Unrealized Losses	$ (59)	$ (3)

Investments and Fair Value of_6

Investments and Fair Value of Financial Instruments - Contractual Maturities of Marketable Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Amortized Cost
Due in less than one year	$ 100,191
Due in one to five years	86,298
Total	186,489
Fair Value
Due in less than one year	100,403
Due in one to five years	86,574
Total	$ 186,977	$ 195,162

Investments and Fair Value of_7

Investments and Fair Value of Financial Instruments - Financial Assets and Liabilities Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financial Assets
Total	$ 198,033	$ 228,216
Commercial paper
Financial Assets
Marketable investments	4,249	4,246
U.S. agency and government sponsored securities
Financial Assets
Marketable investments	4,555	7,857
U.S. states and municipalities
Financial Assets
Marketable investments	47,425	48,095
Corporate bonds
Financial Assets
Marketable investments	130,748	134,964
Money market funds
Financial Assets
Cash equivalents	11,056	33,054
Level 1
Financial Assets
Total	11,056	33,054
Level 1 | Commercial paper
Financial Assets
Marketable investments	0	0
Level 1 | U.S. agency and government sponsored securities
Financial Assets
Marketable investments	0	0
Level 1 | U.S. states and municipalities
Financial Assets
Marketable investments	0	0
Level 1 | Corporate bonds
Financial Assets
Marketable investments	0	0
Level 1 | Money market funds
Financial Assets
Cash equivalents	11,056	33,054
Level 2
Financial Assets
Total	186,977	195,162
Level 2 | Commercial paper
Financial Assets
Marketable investments	4,249	4,246
Level 2 | U.S. agency and government sponsored securities
Financial Assets
Marketable investments	4,555	7,857
Level 2 | U.S. states and municipalities
Financial Assets
Marketable investments	47,425	48,095
Level 2 | Corporate bonds
Financial Assets
Marketable investments	130,748	134,964
Level 2 | Money market funds
Financial Assets
Cash equivalents	0	0
Level 3
Financial Assets
Total	0	0
Level 3 | Commercial paper
Financial Assets
Marketable investments	0	0
Level 3 | U.S. agency and government sponsored securities
Financial Assets
Marketable investments	0	0
Level 3 | U.S. states and municipalities
Financial Assets
Marketable investments	0	0
Level 3 | Corporate bonds
Financial Assets
Marketable investments	0	0
Level 3 | Money market funds
Financial Assets
Cash equivalents	$ 0	$ 0

Investments and Fair Value of_8

Investments and Fair Value of Financial Instruments - Contingent Consideration (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Payments of contingent consideration liabilities	$ (1,186)
Foreign currency remeasurement	(20)
Ending balance	0
Fair Value of Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payment for contingent consideration, operating activities	500
Payment for contingent consideration, financing activities	700
Fair Value of Contingent Consideration | Measurement Input, Actual Revenue Results
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability balance		$ 1,200
Monte Carlo Simulation | Level 3 | Fair Value of Contingent Consideration
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,206
Sales, general and administrative | Fair Value of Contingent Consideration
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in fair value	$ 0

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 58,816	$ 45,341
Work in process	20,853	22,099
Finished goods	165,652	152,087
Inventories	$ 245,321	$ 219,527

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Payroll and employee-related cost	$ 57,234	$ 50,083
Accrued expenses	13,213	9,246
Sales return provision	1,470	9,812
Product warranty	3,314	2,896
Other acquisition-related costs	3,000	3,000
Other accrued liabilities	11,983	10,758
Total accrued liabilities	$ 90,214	$ 85,795

Balance Sheet Components - Prod

Balance Sheet Components - Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2021	Jun. 30, 2020
Product Warranty, Increase (Decrease) [Roll Forward]
Balance at the beginning of the period	$ 2,896	$ 2,318
Accruals of warranties issued	775	1,589
Settlements of warranty claims	(357)	$ (1,011)
Balance at the end of the period	$ 3,314

Intangible Assets - Intangible

Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2020	Mar. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Amortization Period	16 years 8 months 12 days		16 years 7 months 6 days
Finite lived intangible assets: gross carrying amount	$ 14,050			$ 14,452
Accumulated amortization	(3,953)			(3,813)
Finite lived intangible assets: net	10,097			10,639
Total amortization of finite lived intangible assets	$ 278	$ 260
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Amortization Period	15 years		15 years
Finite lived intangible assets: gross carrying amount	$ 6,991			7,311
Accumulated amortization	(1,748)			(1,706)
Finite lived intangible assets: net	$ 5,243			5,605
Trade secrets and processes
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Amortization Period	20 years		20 years
Finite lived intangible assets: gross carrying amount	$ 5,256			5,256	$ 5,300
Accumulated amortization	(854)			(788)
Finite lived intangible assets: net	$ 4,402			4,468
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Amortization Period	5 years		5 years
Finite lived intangible assets: gross carrying amount	$ 1,803			1,885
Accumulated amortization	(1,351)			(1,319)
Finite lived intangible assets: net	452			$ 566
Cost of revenue
Finite-Lived Intangible Assets [Line Items]
Total amortization of finite lived intangible assets	66	66
Sales, general and administrative
Finite-Lived Intangible Assets [Line Items]
Total amortization of finite lived intangible assets	$ 212	$ 194

Goodwill (Details)

Goodwill (Details)	3 Months Ended
	Mar. 31, 2021USD ($)
Goodwill [Roll Forward]
Goodwill	$ 8,372,000
Foreign currency translation	(366,000)
Goodwill	8,006,000
Goodwill impairment	$ 0

Debt (Details)

Debt (Details) - Revolving Credit Facility - USD ($)	3 Months Ended
	Mar. 31, 2021	Apr. 24, 2020
Line of Credit Facility [Line Items]
Borrowing capacity		$ 100,000,000
Line of credit, increase limit		$ 150,000,000
Borrowings outstanding	$ 0
Bank Of America And Citibank | Line of Credit
Line of Credit Facility [Line Items]
Debt instrument, term (in years)	1 year

Commitments and Contingencies -

Commitments and Contingencies - Royalty Obligations (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jul. 31, 2019	Mar. 31, 2021	Mar. 31, 2020
Cost of revenue
Other Commitments [Line Items]
Royalty expense		$ 0.5	$ 0.7
Royalty Agreement, March 2005
Other Commitments [Line Items]
Extended term of agreement	10 years
Increase in minimum annual royalty payments	$ 0.2
Minimum quarterly royalty payments		$ 0.3
Royalty Agreement, April 2012
Other Commitments [Line Items]
Term of agreement		15 years
Royalty as a percent of sales		5.00%

Stockholder's Equity - Stock Op

Stockholder's Equity - Stock Option Activity (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	1,020,978
Options exercised (in shares) | shares	(42,408)
Options cancelled (in shares) | shares	0
Ending balance (in shares) | shares	978,570
Weighted-Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 23.38
Options exercised (in dollars per share) | $ / shares	15.70
Options cancelled (in dollars per share) | $ / shares	0
Ending balance (in dollars per share) | $ / shares	$ 23.71

Stockholder's Equity - Restrict

Stockholder's Equity - Restricted Stock and Restricted Stock Units Activity (Details) - Restricted stock and restricted stock units	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Number of Shares
Unvested beginning balance (in shares)	369,629
Granted (in shares)	53,080
Vested (in shares)	(36,672)
Canceled/Forfeited (in shares)	(4,182)
Unvested and expected to vest ending balance (in shares)	381,855
Weighted -Average Grant Date Fair Value
Unvested beginning balance (in dollars per share) | $ / shares	$ 163.03
Granted (in dollars per share) | $ / shares	255
Vested (in dollars per share) | $ / shares	140.42
Canceled/Forfeited (in dollars per share) | $ / shares	175.99
Unvested and expected to vest ending balance (in dollars per share) | $ / shares	$ 177.84
Restricted stock and RSUs expected to vest (shares)	364,777

Stockholder's Equity - Stock-ba

Stockholder's Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 6,395	$ 5,689
Unrecognized compensation cost related to unvested share-based compensation arrangements	$ 55,600
Unrecognized compensation cost, expected recognition period	2 years 10 months 24 days
Share-based compensation expense, capitalized in inventory	$ 1,300		$ 1,200
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	798	648
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	1,062	874
Sales, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 4,535	$ 4,167

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 641,498
Amounts reclassified from accumulated other comprehensive income (loss) to consolidated net (loss) income:
Total other comprehensive (loss) income, net of tax	(2,966)	$ (2,251)
Ending balance	655,091
Marketable Investments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	647	238
Other comprehensive (loss) income before reclassifications:
Other comprehensive income before reclassifications	(353)	(689)
Income tax effect — expense	82	72
Net of tax	(271)	(617)
Amounts reclassified from accumulated other comprehensive income (loss) to consolidated net (loss) income:
Realized gain (loss) — marketable investments	0	0
Income tax effect — expense (benefit)	0	0
Net of tax	0	0
Total other comprehensive (loss) income, net of tax	(271)	(617)
Ending balance	376	(379)
Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	1,894	(2,562)
Other comprehensive (loss) income before reclassifications:
Other comprehensive income before reclassifications	(2,695)	(1,634)
Income tax effect — expense	0	0
Net of tax	(2,695)	(1,634)
Amounts reclassified from accumulated other comprehensive income (loss) to consolidated net (loss) income:
Realized gain (loss) — marketable investments	0	0
Income tax effect — expense (benefit)	0	0
Net of tax	0	0
Total other comprehensive (loss) income, net of tax	(2,695)	(1,634)
Ending balance	(801)	(4,196)
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	2,541	(2,324)
Other comprehensive (loss) income before reclassifications:
Income tax effect — expense	82	72
Net of tax	(2,966)	(2,251)
Amounts reclassified from accumulated other comprehensive income (loss) to consolidated net (loss) income:
Realized gain (loss) — marketable investments	0	0
Income tax effect — expense (benefit)	0	0
Net of tax	0	0
Total other comprehensive (loss) income, net of tax	(2,966)	(2,251)
Ending balance	$ (425)	$ (4,575)

Income Taxes Income Taxes (Deta

Income Taxes Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Benefit from income taxes	$ (1,541)	$ 1,634
Effective tax rate (benefit) expense	12.40%	(219.00%)

Net (Loss) Income Attributabl_3

Net (Loss) Income Attributable to Penumbra, Inc. Per Share - Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income attributable to Penumbra, Inc.	$ 11,836	$ 1,425
Weighted average shares used to compute net income attributable to common stockholders:
Basic (in shares)	36,455,712	35,042,912
Potential dilutive stock-based options and awards (in shares)	1,077,808	1,319,814
Diluted (in shares)	37,533,520	36,362,726
Net income attributable to Penumbra, Inc. per share:
Basic (in dollars per share)	$ 0.32	$ 0.04
Diluted (in dollars per share)	$ 0.32	$ 0.04

Net (Loss) Income Attributabl_4

Net (Loss) Income Attributable to Penumbra, Inc. Per Share - Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Antidilutive securities excluded from the computation of earnings per share (in shares)	22	18

Revenues - Disaggregation of Re

Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 169,204	$ 137,329
United States
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	120,070	95,774
International
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	49,134	41,555
Neuro
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	80,039	78,076
Vascular
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 89,165	$ 59,253