Abiomed (ABMD) 10-K 21 May 21 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2021	May 14, 2021	Sep. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Trading Symbol	ABMD
Entity Registrant Name	ABIOMED, Inc.
Entity Central Index Key	0000815094
Current Fiscal Year End Date	--03-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		45,295,979
Entity Public Float			$ 12,155,296,841
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	true
Entity File Number	001-09585
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-2743260
Entity Address, Address Line One	22 Cherry Hill Drive
Entity Address, City or Town	Danvers
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01923
City Area Code	978
Local Phone Number	646-1400
Title of 12(b) Security	Common Stock, $0.01 par value
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	Portions of the registrant’s definitive Proxy Statement relating to the 2021 Annual Meeting of Stockholders are incorporated by reference into Part III (Items 10, 11, 12, 13 and 14) of this Annual Report on Form 10-K. Such Proxy Statement will be filed with the Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Current assets:
Cash and cash equivalents	$ 232,710	$ 192,341
Short-term marketable securities	350,985	250,775
Accounts receivable, net	97,179	84,650
Inventories	81,059	90,088
Prepaid expenses and other current assets	26,032	18,009
Total current assets	787,965	635,863
Long-term marketable securities	264,085	207,795
Property and equipment, net	197,129	164,931
Goodwill	78,568	31,969
Other intangibles, net	42,150	14,913
Deferred tax assets	11,380	43,336
Other assets	113,082	117,655
Total assets	1,494,359	1,216,462
Current liabilities:
Accounts payable	34,842	32,774
Accrued expenses	66,046	75,107
Deferred revenue	24,322	19,147
Other current liabilities	3,759	4,857
Total current liabilities	128,969	131,885
Other long-term liabilities	10,162	9,305
Contingent consideration	24,706	9,000
Deferred tax liabilities	847	806
Total liabilities	164,684	150,996
Commitments and contingencies (Note 16)
Stockholders' equity:
Class B Preferred stock, $.01 par value Authorized - 1,000,000 shares; Issued and outstanding - none
Common stock, $.01 par value Authorized - 100,000,000 shares; Issued - 47,542,061 shares at March 31, 2020 and 47,026,226 shares at March 31, 2019; Outstanding - 45,008,687 shares at March 31, 2020 and 45,122,985 shares at March 31, 2019	453	451
Additional paid in capital	800,690	739,133
Retained earnings	828,007	602,482
Treasury stock at cost 2,658,454 shares as of March 31, 2021 and 2,533,374 shares as of March 31, 2020	(288,030)	(265,411)
Accumulated other comprehensive loss	(11,445)	(11,189)
Total stockholders' equity	1,329,675	1,065,466
Total liabilities and stockholders' equity	$ 1,494,359	$ 1,216,462

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Mar. 31, 2020
Statement Of Financial Position [Abstract]
Class B Preferred Stock, par value	$ 0.01	$ 0.01
Class B Preferred Stock, Authorized	1,000,000	1,000,000
Class B Preferred Stock, Issued	0	0
Class B Preferred Stock, outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, Authorized	100,000,000	100,000,000
Common stock, Issued	47,929,402	47,542,061
Common stock, Outstanding	45,270,948	45,008,687
Treasury stock, shares	2,658,454	2,533,374

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2021		Mar. 31, 2020		Mar. 31, 2019
Income Statement [Abstract]
Revenue	$ 847,522		$ 840,883		$ 769,432
Costs and expenses:
Cost of revenue	161,907		151,305		129,567
Research and development	121,875		98,759		93,503
Selling, general and administrative	334,183		341,600		321,550
Costs and Expenses, Total	617,965		591,664		544,620
Income from operations	229,557		249,219		224,812
Other income:
Investment income, net	6,717		12,167		8,166
Other income (expense), net	51,946		(4,561)		30,382
Nonoperating Income (Expense), Total	58,663	[1]	7,606	[1]	38,548
Income before income taxes	288,220		256,825		263,360
Income tax provision	62,695	[2]	53,816	[2]	4,344
Net income	$ 225,525		$ 203,009		$ 259,016
Basic net income per share	$ 5		$ 4.49		$ 5.77
Basic weighted average shares outstanding	45,140		45,179		44,911
Diluted net income per share	$ 4.94		$ 4.43		$ 5.61
Diluted weighted average shares outstanding	45,674		45,816		46,151
[1]	In fiscal year 2019, the Company invested $25.0 million in medical device company Shockwave Medical. The fair value of this investment as of March 31, 2021 was $38.7 million. The Company recognized a pre-tax gain of $50.8 million for the year ended March 31, 2021 and a pre-tax loss of $0.5 million for the year ended March 31, 2020 in other income (expense), net.
[2]	The income tax provision for the years ended March 31, 2021 and 2020 included excess tax benefits of $12.1 million and $14.8 million, respectively. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during the years ended March 31, 2021 and 2020.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 225,525	$ 203,009	$ 259,016
Other comprehensive (loss) income:
Foreign currency translation gain (loss)	2,142	(1,832)	(11,431)
Unrealized (loss) gain on derivative instrument	(2,095)	3,999
Net unrealized (loss) gain on marketable securities	(303)	1,333	946
Other comprehensive (loss) income	(256)	3,500	(10,485)
Comprehensive income	$ 225,269	$ 206,509	$ 248,531

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Mar. 31, 2018	$ 689,524	$ 444	$ (67,078)	$ 619,905	$ 140,457	$ (4,204)
Beginning Balance (in shares) at Mar. 31, 2018		44,375,337	1,725,312
Restricted stock units issued		$ 4		(4)
Restricted stock units issued (in shares)		427,431
Stock options exercised	12,949	$ 5		12,944
Stock options exercised (in shares)		485,363
Stock issued under employee stock purchase plan	3,052			3,052
Stock issued under employee stock purchase plan (in shares)		12,467
Stock issued to directors	116			116
Stock issued to directors (in shares)		316
Return of common stock to pay withholding taxes on restricted stock	(71,776)	$ (2)	$ (71,774)
Return of common stock to pay withholding taxes on restricted stock (in shares)		177,929	(177,929)
Stock compensation expense	54,494			54,494
Other comprehensive income (loss)	(10,485)					(10,485)
Net income	259,016				259,016
Ending Balance at Mar. 31, 2019	936,890	$ 451	$ (138,852)	690,507	399,473	(14,689)
Ending Balance (in shares) at Mar. 31, 2019		45,122,985	1,903,241
Restricted stock units issued		$ 4		(4)
Restricted stock units issued (in shares)		392,872
Stock options exercised	3,748	$ 2		3,747
Stock options exercised (in shares)		85,136
Stock issued under employee stock purchase plan	5,103			5,103
Stock issued under employee stock purchase plan (in shares)		37,827
Return of common stock to pay withholding taxes on restricted stock	(41,687)	$ (2)	$ (41,685)
Return of common stock to pay withholding taxes on restricted stock (in shares)		164,446	(164,446)
Stock compensation expense	39,781			39,781
Stock repurchase program	$ (84,879)	$ (5)	$ (84,874)
Stock repurchase program, (in shares)	(465,687)	(465,687)	465,687
Other comprehensive income (loss)	$ 3,500					3,500
Net income	203,009				203,009
Ending Balance at Mar. 31, 2020	$ 1,065,466	$ 451	$ (265,411)	739,133	602,482	(11,189)
Ending Balance (in shares) at Mar. 31, 2020	45,008,687	45,008,687	2,533,374
Restricted stock units issued	$ 1	$ 2		(1)
Restricted stock units issued (in shares)		140,159
Stock options exercised	$ 9,075	$ 2		9,073
Stock options exercised (in shares)	215,000	215,262
Stock issued under employee stock purchase plan	$ 5,479			5,479
Stock issued under employee stock purchase plan (in shares)		31,920
Return of common stock to pay withholding taxes on restricted stock	(11,311)	$ (1)	$ (11,310)
Return of common stock to pay withholding taxes on restricted stock (in shares)		57,431	(57,431)
Stock compensation expense	47,006			47,006
Stock repurchase program	$ (11,310)	$ (1)	$ (11,309)
Stock repurchase program, (in shares)	(67,649)	(67,649)	67,649
Other comprehensive income (loss)	$ (256)					(256)
Net income	225,525				225,525
Ending Balance at Mar. 31, 2021	$ 1,329,675	$ 453	$ (288,030)	$ 800,690	$ 828,007	$ (11,445)
Ending Balance (in shares) at Mar. 31, 2021	45,270,948	45,270,948	2,658,454

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net income	$ 225,525	$ 203,009	$ 259,016
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	24,097	20,430	14,121
Bad debt (recoveries) expense	(126)	487	720
Stock-based compensation	47,006	39,781	54,494
Write-down of inventory and other	8,518	4,249	4,252
Accretion on marketable securities	1,977	(2,731)	(2,744)
Change in fair value of other investments	(50,983)	5,184	(30,161)
Deferred tax provision	29,380	32,953	(7,745)
Change in fair value of contingent consideration	2,406	(575)	(915)
Other non-cash operating activities	4,164	4,108
Changes in assets and liabilities:
Accounts receivable	(12,059)	5,551	(22,023)
Inventories	2,535	(13,237)	(37,181)
Prepaid expenses and other assets	(1,032)	(5,333)	(2,527)
Accounts payable	2,629	2,581	7,976
Accrued expenses and other liabilities	(14,632)	15,676	13,406
Deferred revenue	5,173	2,787	1,508
Net cash provided by operating activities	274,578	314,920	252,197
Investing activities:
Purchases of marketable securities	(556,199)	(611,280)	(361,602)
Proceeds from the sale and maturity of marketable securities and other	396,643	550,788	331,886
Acquisition of Breethe Inc., net of cash acquired	52,183
Purchases of other investments and intangible assets	(26,104)	(20,957)	(42,735)
Proceeds from sale of Shockwave Medical Investment	67,882
Purchases of property and equipment	(53,383)	(44,006)	(44,004)
Net cash used for investing activities	(223,344)	(125,455)	(116,455)
Financing activities:
Proceeds from the exercise of stock options	9,075	3,748	12,949
Taxes paid related to net share settlement upon vesting of stock awards	(11,311)	(41,687)	(71,776)
Repurchase of common stock	(11,310)	(84,879)
Proceeds from the issuance of stock under employee stock purchase plan	5,479	5,103	3,052
Net cash used for financing activities	(8,067)	(117,715)	(55,775)
Effect of exchange rate changes on cash	(2,798)	(430)	(1,921)
Net increase in cash and cash equivalents	40,369	71,320	78,046
Cash and cash equivalents at beginning of year	192,341	121,021	42,975
Cash and cash equivalents at end of year	232,710	192,341	121,021
Supplemental disclosure of cash flow information:
Cash paid for income taxes	48,693	9,685	5,290
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment in accounts payable and accrued expenses	1,638	2,977	$ 4,787
Right-of-use assets obtained in exchange for lease liabilities	$ 2,592	$ 15,650

Nature of Operations

Nature of Operations	12 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Nature of Operations	Note 1. Nature of Operations ABIOMED, Inc. (the “Company” or “ABIOMED”) is a provider of mechanical circulatory support devices and offers a continuum of care to heart failure patients. The Company develops, manufactures and markets proprietary products that are designed to enable the heart to rest, heal and recover by improving blood flow and/or performing the pumping function of the heart. The Company’s products are used in the cardiac catheterization lab, or cath lab, by interventional cardiologists and in the heart surgery suite by cardiac surgeons for patients who are in need of hemodynamic support prophylactically or emergently before, during or after angioplasty or heart surgery procedures.

Basis of Preparation and Summar

Basis of Preparation and Summary of Significant Accounting Policies	12 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Preparation and Summary of Significant Accounting Policies	Note 2. Basis of Preparation and Summary of Significant Accounting Policies The accompanying consolidated financial statements Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. COVID-19 Pandemic The Company is subject to risks and uncertainties as a result of the ongoing COVID-19 pandemic. The ongoing COVID-19 pandemic has adversely impacted and is likely to further adversely impact the Company’s business and markets, including the Company’s workforce and the operations of its customers, suppliers, and business partners. The full extent to which the pandemic will directly or indirectly impact the Company's business, results of operations and financial condition, including sales, expenses, manufacturing, clinical trials, research and development costs, reserves and allowances, fair value measurements, asset impairment charges, contingent consideration obligations, and the effectiveness of the Company's hedging instruments, will depend on future developments that are highly uncertain and difficult to predict. These developments include, but are not limited to: the duration and spread of the ongoing COVID-19 pandemic (including new variants of COVID-19), its severity, the actions to contain the virus or address its impact, the timing, distribution, and efficacy of vaccines and other treatments, U.S. and foreign government actions to respond to the reduction in global economic activity, and how quickly and to what extent normal economic and operating conditions can resume. Beginning in mid-March 2020, the Company experienced a decline in patient utilization in its main markets in the U.S., Europe and Japan as healthcare systems diverted resources to meet the increasing demands of managing COVID-19. The Company’s business was most impacted in the first quarter of fiscal year 2021, in terms of the decline in patients and revenue from the shelter-in-place restrictions in a majority of countries and limitations on procedures in hospitals. The Company experienced sequential quarterly improvement during the second quarter of fiscal year 2021 as patient procedure volume trends and availability of healthcare resources improved as certain restrictions were lifted and limitations eased during the summer of 2020. During the third quarter of fiscal year 2021, a broad resurgence of COVID-19 cases throughout the U.S. and Europe slowed the Company’s continued recovery in patient utilization. Despite these challenges, the Company experienced increased recovery in patient utilization and revenue during the fourth quarter of fiscal year 2021 due to the high-risk nature of the patient population that are treated with the Company’s Impella devices. While the COVID-19 pandemic remains fluid and continues to evolve differently across various geographies, the Company believes it is likely to continue to experience variable impacts on its business. Hospitals are generally managing the pandemic better currently than they have in the earlier part of the pandemic due to more testing, improved protocols, more experience with the effects of COVID-19 and a greater number of vaccinated caregivers. During these challenging times, the Company’s priorities have been to support its clinician partners, protect the well-being of its employees and maintain continuous access to its life-saving technologies while offering front-line in-hospital support. The Company has established onsite COVID-19 testing for its employees in both Danvers, Massachusetts and Aachen, Germany, set up temperature-taking stations, administered thousands of COVID-19 tests to date and provided personal protective equipment for its employees in order to maintain a safe working environment. The Company’s proactive testing program has reduced exposure with early detection, reduced employee anxiety and enabled its manufacturing facilities to operate at full capacity in line with local social distancing requirements. The Company also took proactive actions in the first half of fiscal year 2021 in order to mitigate the business impact of COVID-19 on its financial operations and it continues to monitor closely in order the business impact of COVID-19. Despite the ongoing challenges posed by COVID-19, including the recent global resurgence, the Company continues to invest strategically in engineering, regulatory, clinical trials and manufacturing in order to support its future growth initiatives and sales and marketing activities, with a particular focus on training and education initiatives to drive utilization of its products and recovery awareness for acute heart failure patients. The Company continues to closely monitor the impact of COVID-19 on all aspects of its business and geographies, including its impact on its customers, employees, suppliers, vendors, business partners and distribution channels. The extent to which the COVID-19 pandemic impacts the Company’s business, results of operations, and financial condition will depend on future developments, which are highly uncertain and are difficult to predict. Even after the ongoing COVID-19 pandemic has subsided, the Company may continue to experience materially adverse impacts on its financial condition and results of operations. 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 and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The Company bases its estimates on historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition, collectability of receivables, realizability of inventory, property and equipment, goodwill, intangible and other long-lived assets, other investments, accrued expenses, stock-based compensation, income taxes including deferred tax assets and liabilities, contingencies and litigation. Provisions for depreciation are based on their estimated useful lives using the straight-line method. Some of these estimates can be subjective and complex and, consequently, actual results may differ from these estimates under different assumptions or conditions. Cash Equivalents and Marketable Securities The Company classifies any marketable security with an original maturity date of 90 days or less at the time of purchase as a cash equivalent. Cash equivalents are carried on the balance sheet at fair market value. The Company classifies any marketable security with a maturity date of greater than 90 days at the time of purchase as marketable securities and classifies marketable securities with a maturity date of greater than one year from the balance sheet date as long-term marketable securities. The Company’s marketable securities, consisting of U.S. Treasury securities, government-back securities, corporate debt securities, and commercial paper, are classified as available-for-sale securities and, accordingly, are recorded at fair value. The difference between amortized cost and fair value is included in stockholders’ equity. Marketable securities that the Company has the positive intent and ability to hold to maturity are reported at amortized cost and classified as held-to-maturity marketable securities. If the Company does not have the intent and ability to hold a marketable security to maturity, it reports the investment as available-for-sale marketable securities. The Company includes unrealized gains and, to the extent deemed temporary, unrealized losses in stockholders’ equity. If any adjustment to fair value reflects a decline in the value of the investment, the Company considers available evidence to evaluate whether the decline is “other than temporary” and, if so, marks the marketable security to market through a charge reflected on the consolidated statements of operations. Major Customers and Concentrations of Credit Risk The Company primarily sells its products to hospitals and distributors. No individual customer accounted for more than 10% of total revenues in fiscal years ended March 31, 2021, 2020 or 2019. No individual customer had an accounts receivable balance greater than 10% of total accounts receivable as of March 31, 2021 and 2020. Credit is extended based on an evaluation of a customer’s historical financial condition and generally collateral is not required. The Company’s history of credit losses has not been significant and the Company maintains an allowance for doubtful accounts based on its assessment of the collectability of accounts receivable. Accounts receivables are geographically dispersed, primarily throughout the U.S., as well as in Europe and other foreign countries where formal distributor agreements exist in certain countries. The Company's exposure to credit losses may increase if its customers are adversely affected by changes in healthcare laws, coverage, and reimbursement, economic pressures or uncertainty associated with local or global economic recessions, or other customer-specific factors. Financial instruments which potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents, marketable securities, short and long-term marketable securities and accounts receivable. Management mitigates credit risk by limiting the investment type and maturity to securities that preserve capital, maintain liquidity and have a high credit quality. Financial Instruments The Company’s financial instruments are comprised of cash and cash equivalents, derivative instruments, marketable securities, accounts receivable, accounts payable and contingent consideration. The carrying amounts of accounts receivable and accounts payable are considered reasonable estimates of their fair value, due to the short maturity of these investments. Derivative Instruments The Company uses a foreign-exchange-related derivative instrument to manage its exposure related to changes in the exchange rate on its intercompany loan. The Company does not enter into derivative instruments for any purpose other than cash flow hedging. The Company does not speculate using derivative instruments. The Company recognizes all derivative instruments as either assets or liabilities in the balance sheet at their respective fair values. For more information, see “Note 5. Financial Instruments—Derivative Instruments.” Inventories Inventories are stated at the lower of cost or market. Cost is based on the first in, first out method. The Company regularly reviews inventory quantities on hand and writes down to its net realizable value any inventory that it believes to be impaired. Management considers forecast demand in relation to the inventory on hand, competitiveness of product offerings, market conditions and product life cycles when determining excess and obsolescence and net realizable value adjustments. Once inventory is written down and a new cost basis is established, it is not written back up if demand increases. Property and Equipment Property and equipment is recorded at cost less accumulated depreciation. Land is carried at cost and is not depreciated. Depreciation is computed using the straight-line method based on estimated useful lives of three to five years for machinery and equipment, computer software, and furniture and fixtures. Building and building improvements are depreciated using the straight-line method over estimated useful lives of seven to thirty-three years. Leasehold improvements are amortized using the straight-line method over the shorter of the lease term or the estimated useful lives of the related assets. Expenditures for maintenance and repairs are expensed as incurred. Upon retirement or other disposition of assets, the costs and related accumulated depreciation are eliminated from the accounts and the resulting gain or loss is reflected in operating expenses. Property and equipment is reviewed for impairment losses whenever events or changes in circumstances indicate the carrying amount may not be recoverable. An impairment loss would be recognized based on the amount by which the carrying value of the asset or asset group exceeds its fair value. Fair value is determined primarily using the estimated future cash flows associated with the asset or asset group under review discounted at a rate commensurate with the risk involved and other valuation techniques. Other Investments The Company periodically makes investments in medical device companies that focus on heart failure and heart pumps and other medical device technologies. For investments that do not have readily determinable market values, the Company measures these investments at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment. The Company monitors any events or changes in circumstances that may have a significant effect on the fair value of investments, either due to impairment or based on observable price changes, and makes any necessary adjustments. Leases On April 1, 2019, the Company adopted ASU 2016-02, “Leases.” This new guidance required that the Company’s lease commitments to be recognized as operating lease liabilities and right-of-use assets, which increased total assets and total liabilities that the Company reported on its consolidated balance sheet. For a discussion on the impact of this accounting policy adoption, including key accounting policies and elections, see “Note 11. Leases.” Goodwill Goodwill is recorded when consideration for an acquisition exceeds the fair value of the net tangible and intangible assets acquired. Goodwill is not amortized. The Company evaluates goodwill for impairment at least annually at October 31, as well as whenever events or changes in circumstances suggest that the carrying amount may not be recoverable. In applying the goodwill impairment test, the Company assesses qualitative factors to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying value. Qualitative factors may include, but are not limited to, macroeconomic conditions, industry conditions, the competitive environment, changes in the market for the Company’s products and services, regulatory and political developments, cost factors, and entity specific factors such as strategies and overall financial performance. If, after assessing these qualitative factors, the Company determines it is more likely than not that the fair value of a reporting unit is less than its carrying value, then the Company performs a quantitative impairment test. The Company determined, after performing the qualitative review, that it is more likely than not that the fair value of each of its reporting units substantially exceeds the respective carrying amounts. Indefinite-Lived Intangibles and In-process research and development, or IPR&D, assets are considered to be indefinite-lived until the completion or abandonment of the associated research and development projects. IPR&D assets represent the fair value assigned to technologies that are acquired, which at the time of acquisition have not reached technological feasibility and have no alternative future use. During the period that the IPR&D assets are considered indefinite-lived, they are tested for impairment on an annual basis on October 31, or more frequently if the Company becomes aware of any events occurring or changes in circumstances that indicate that the fair value of the IPR&D assets are less than their carrying values. If and when development is complete, which generally occurs upon regulatory approval and the Company is able to commercialize products associated with the IPR&D assets, these assets are then deemed definite-lived and are amortized based on their estimated useful lives at that point in time. If development is terminated or abandoned, the Company may have a full or partial impairment charge related to the IPR&D assets, calculated as the excess of carrying value of the IPR&D assets over fair value. The Company performed its annual impairment review for fiscal year 2021 as of October 31, 2020 and concluded that it was more likely than not that the fair value of the IPR&D assets is not less than its carrying value. Finite-Lived Intangible Assets The Company records finite-lived intangible assets at historical cost and amortizes over their estimated useful lives. The Company uses a straight-line method of amortization, unless a method that better reflects the pattern in which the economic benefits of the intangible asset are consumed or otherwise used up can be reliably determined. The approximate useful live for amortization of the Company’s intangible assets is 15 years for the OXY-1 System amortizable technology from the acquisition of Breethe. The Company reviews finite-lived intangible assets subject to amortization quarterly to determine if any adverse conditions exist or a change in circumstances has occurred that would indicate impairment or a change in the remaining useful life. Conditions that may indicate impairment include, but are not limited to, a significant adverse change in legal factors or business climate that could affect the value of an asset, a product recall or an adverse action or assessment by a regulator. If the Company determines it is more likely than not that the asset is impaired based on its qualitative assessment of impairment indicators, the Company tests the intangible asset for recoverability. Contingent Consideration Contingent consideration represents potential milestones that the Company could pay as additional consideration for a business acquisition and is recorded as a liability and is measured at fair value using a combination of (1) an income approach, based on various revenue and cost assumptions and applying a probability to each outcome and (2) a Monte-Carlo valuation model that simulates outcomes based on management estimates. With the income approach, p robabilities were applied to each potential scenario and the resulting values were discounted using a rate that considers the weighted average cost of capital, the related projections, and the overall business. The Monte-Carlo valuation model simulates estimated future revenues during the earn out-period using management's best estimates. Accrued Expenses As part of the process of preparing its financial statements, the Company is required to estimate accrued expenses. This process includes identifying services that third parties have performed and estimating the level of service performed and the associated cost incurred on these services as of each balance sheet date in its financial statements. Examples of estimated accrued expenses include estimates for certain payroll costs, such as bonuses and commissions; contract service fees, such as amounts due to clinical research organizations and investigators in conjunction with clinical trials; professional service fees, such as attorneys and accountants, and third-party expenses relating to marketing efforts associated with commercialization of the Company’s products. The dates in which certain services commence and end, the level of services performed on or before a given date and the cost of services is often subject to the Company’s judgment. The Company makes these judgments and estimates based upon known facts and circumstances. Revenue Recognition See “Note 4. Revenue Recognition” for a discussion of key accounting policies and elections related to revenue recognition. Product Warranty The Company generally provides a one-year Accumulated Other Comprehensive Income (Loss) Comprehensive income (loss) is comprised of net income, plus all changes in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources, including any foreign currency translation adjustments. These changes in equity are recorded as adjustments to accumulated other comprehensive income (loss) in the Company’s consolidated balance sheet. The components of accumulated other comprehensive income (loss) consist of foreign currency translation adjustments, unrealized gains (losses) on marketable securities, and unrealized gains (losses) on derivative instruments. There were no reclassifications out of accumulated other comprehensive income (loss) during the fiscal years ended March 31, 2021, 2020 and 2019. Translation of Foreign Currencies The functional currency of the Company’s foreign subsidiaries is their local currency. The assets and liabilities of the Company’s foreign subsidiaries are translated into U.S. dollars at exchange rates in effect at the balance sheet date. Income and expense items in the Company’s consolidated statement of operations are translated at the average exchange rates prevailing during the period. The cumulative translation effect for subsidiaries using a functional currency other than the U.S. dollar is included in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity. The Company’s intercompany accounts are denominated in the functional currency of the foreign subsidiary. Gains and losses resulting from the remeasurement of intercompany transactions that the Company considers to be of a long-term investment nature are recorded in accumulated other comprehensive income or loss as a separate component of stockholders’ equity, while gains and losses resulting from the remeasurement of intercompany transactions from those foreign subsidiaries for which the Company anticipates settlement in the foreseeable future are recorded in the consolidated statement of operations. The net foreign currency translation gains and losses recorded in the consolidated statements of operations for the fiscal years ended March 31, 2021, 2020 and 2019 were not significant. Net Income Per Share Basic net income per share is computed by dividing net income by the weighted average number of common shares outstanding during the fiscal year. Diluted net income per share is computed using the treasury stock method by dividing net income by the weighted average number of dilutive common shares outstanding during the fiscal year. Diluted shares outstanding is calculated by adding to the weighted average shares outstanding any potential dilutive securities outstanding for the fiscal year. Potential dilutive securities include stock options, restricted stock units, performance-based stock awards and shares to be purchased under the Company’s employee stock purchase plan. The Company’s basic and diluted net income per share were as follows (figures in tables are in thousands, except per share data): Fiscal Years Ended March 31, Basic Net Income Per Share 2021 2020 2019 Net income $ 225,525 $ 203,009 $ 259,016 Weighted average shares - basic 45,140 45,179 44,911 Net income per share - basic $ 5.00 $ 4.49 $ 5.77 Fiscal Years Ended March 31, Diluted Net Income Per Share 2021 2020 2019 Net income $ 225,525 $ 203,009 $ 259,016 Weighted average shares - basic 45,140 45,179 44,911 Effect of dilutive securities 534 637 1,240 Weighted average shares - diluted 45,674 45,816 46,151 Net income per share - diluted $ 4.94 $ 4.43 $ 5.61 For the fiscal years ended March 31, 2021, 2020 and 2019, approximately 168,000, 232,000 and 64,000 shares of common stock underlying outstanding securities related to out-of-the-money stock options and performance-based awards where milestones were not met were not included in the computation of diluted earnings per share because their inclusion would be anti-dilutive. Stock-Based Compensation The Company’s stock-based compensation cost is measured at the grant date based on the fair value of the award and is recognized as an expense over the requisite service period. The fair value of stock option grants is estimated using the Black-Scholes option pricing model. Use of the valuation model requires management to make certain assumptions with respect to selected model inputs. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for a term consistent with the expected life of the stock options. Volatility assumptions are calculated based on historical volatility of the Company’s stock. The Company estimates the expected term of options based on historical exercise experience and estimates of future exercises of unexercised options. In addition, an expected dividend yield of zero is used in the option valuation model because the Company does not pay cash dividends and does not expect to pay any cash dividends in the foreseeable future. Forfeitures are recorded as they occur instead of estimating forfeitures that are expected to occur. For awards with service conditions only, the Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period. For awards with service and performance-based conditions, the Company recognizes stock-based compensation expense using the graded vesting method over the requisite service period. Estimates of stock-based compensation expense for an award with performance conditions are based on the probable outcome of the performance conditions and the cumulative effect of any changes in the probability outcomes are recorded in the period in which the changes occur. Income Taxes The Company’s provision for income taxes is comprised of a current and deferred provision. The current income tax provision is calculated as the estimated taxes payable or refundable on income tax returns for the current fiscal year. The deferred income tax provision is calculated for the estimated future income tax effects attributable to temporary differences and carryforwards using expected tax rates in effect in the years during which the temporary differences are expected to reverse. Deferred income taxes are recognized for the tax consequences in future years as the differences between the tax bases of assets and liabilities and their financial reporting amounts at each fiscal year end based on enacted tax laws and statutory tax rates applicable to the periods in which the differences are expected to impact taxable income. The Company regularly assesses its ability to realize its deferred tax assets. Assessing the realization of deferred tax assets requires significant management judgment. Valuation allowances are established when necessary to reduce net deferred tax assets to the amount that is more likely than not to be realized. The Company recognizes and measures uncertain tax positions using a two-step approach. The first step is to evaluate the tax position for recognition by determining if, based on the technical merits, it is more likely than not that the position will be sustained upon audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit at the largest amount that is more likely than not of being realized upon ultimate settlement. The Company reevaluates these uncertain tax positions on an ongoing basis, when applicable. This evaluation is based on factors including, but not limited to, changes in facts or circumstances, new information and technical insights, and changes in tax laws. Any changes in these factors could result in the recognition of a tax benefit or an additional charge to the tax provision. Refer to “ Note 15. Income Taxes ” for further information related to the Tax Reform Act and its impact on the Company’s financial statements. When applicable, the Company accrues for the effects of uncertain tax positions and the related potential penalties and interest through income tax expense. Recently Adopted Accounting Pronouncements Effective April 1, 2019, the Company adopted the Financial Accounting Standards Board (“FASB”) standard update ASU 2016-02 “Leases,” which requires lessees to identify arrangements that should be accounted for as leases. Under this guidance, for lease arrangements exceeding a one-year term, a right-of-use asset and lease obligation is recorded by the lessee for all leases on the balance sheet, whether operating or financing, while the statement of operations includes lease expense for operating leases and amortization and interest expense for financing leases. ASU 2016-02 was adopted using a modified retrospective approach for all leases existing at or entered into after the April 1, 2019. Additional information and disclosures required by this new standard are contained in “ Note 11. Leases .” In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326).” This guidance will require financial instruments to be measured at amortized cost, and accounts receivables to be presented at the net amount expected to be collected. The new model requires an entity to estimate credit losses based on historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments. ASU 2016-13 is effective for annual reporting periods beginning after December 31, 2019. This update did not have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350).” This new standard simplifies the accounting for goodwill impairment by removing Step 2 of the goodwill impairment test, which required companies to estimate the implied fair value of goodwill and recognize an impairment charge by the amount in which the carrying value exceeds the implied fair value. Under the new guidance, if the carrying value of a reporting unit exceeds its fair value, a goodwill impairment charge will be recorded, even if the difference is attributable to the fair value of other assets in the reporting unit. The Company adopted this standard in the first quarter of fiscal 2021, and it did not have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820).” Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosure requirements on fair value measurements. This ASU is effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. The Company adopted this standard in the first quarter of fiscal year 2021 and did not have a material impact on its consolidated financial statements . Recently Issued Accounting Pronouncements Not Yet Effective In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740).” This amendment to the guidance on income taxes is intended to simplify the accounting for income taxes. The amendment eliminates certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, and the recognition of deferred tax liabilities for outside basis differences. The amendment also clarifies existing guidance related to the evaluation of a step up in the tax basis of goodwill, and the effects of enacted changes in tax laws or rates in the effective tax rate computation, among other clarifications. ASU 2019-12 will become effective for the Company in fiscal year 2022. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. In January 2020, the FASB issued ASU 2020-01, “Investments—Equity Securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815),” an amendment clarifying the interaction between accounting standards related to equity securities, equity method investments, and certain derivative instruments. The guidance is effective for fiscal years beginning after December 15, 2020. ASU 2020-01 will become effective for the Company in fiscal year 2022. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. No other new accounting pronouncements, issued or effective, during the period had, or are expected to have, a material impact on our consolidated financial statements.

Acquisition

Acquisition	12 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
Acquisition	Note 3. Acquisition Acquisition of Breethe The Company acquired Breethe, a Maryland corporation on April 24, 2020. Breethe is engaged in research and development of an ECMO system that we aim to complement and expand the Company’s product portfolio to more comprehensively serve the needs of patients whose lungs can no longer provide sufficient oxygenation, including patients suffering from cardiogenic shock, or respiratory failure. The Company acquired Breethe for $55.0 million in cash, with additional potential payouts up to a maximum of $55.0 million payable based on the achievement of certain technical, regulatory and commercial milestones. Purchase Price Allocation The acquisition of Breethe was accounted for as a business combination. The purchase price for the acquisition has been allocated to the assets acquired and liabilities assumed based on their estimated fair values. The acquisition-date fair value of the consideration transferred is as follows: Total Acquisition Date Fair Value (in thousands) Cash and other considerations $ 57,850 Contingent consideration 13,300 Total consideration transferred $ 71,150 The following table summarizes the estimated fair values of the assets acquired and liabilities assumed on the date of acquisition (in thousands): Acquired assets: Cash and cash equivalents $ 3,404 Property and equipment 744 Goodwill 44,485 In-process research and development 27,000 Other assets acquired 895 Total assets acquired 76,528 Liabilities assumed: Accounts payable and other liabilities 1,562 Deferred tax liabilities 3,816 Net assets acquired $ 71,150 Goodwill is calculated as the difference between the acquisition-date fair value of the consideration transferred and the fair values of the assets acquired and liabilities assumed. The goodwill is not deductible for income tax purposes. IPR&D from the acquisition of Breethe represents the estimated fair value of the Breethe ECMO technology which had not reached commercial technological feasibility nor had alternative future use at the time of the acquisition. During the third quarter of fiscal year 2021, upon receiving FDA 510(k) clearance of the OXY-1 System, in October 2020, the Company reclassified the IPR&D asset of $27 million from the acquisition of Breethe to a finite-lived developed technology intangible asset and began amortizing on a straight-line basis over an estimated useful life of 15 years (see Note 8). The Company believes the amount of purchased IPR&D assets represent fair value for these intangible assets as of the acquisition date. Transaction costs such as legal, insurance and other costs related to the acquisition, aggregating approximately $0.9 million, have been expensed as incurred and are included in selling, general and administrative expenses in the Company’s condensed consolidated statements of operations. The Company’s consolidated financial statements include the operating results of Breethe from the acquisition date. Separate post-acquisition operating results and pro forma results of operations for this acquisition have not been presented as the effect is not material to the Company’s financial results.

Revenue Recognition

Revenue Recognition	12 Months Ended
	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Revenue Recognition	Note 4. Revenue Recognition The Company adopted Topic 606 on April 1, 2018, using the modified retrospective method for all revenue contracts not completed as of the date of adoption. The reported results for fiscal years 2021, 2020 and 2019 reflect the application of Topic 606 guidance. The Company has made the following accounting policy elections and elected to use certain practical expedients, as permitted by the FASB, in applying Topic 606: (1) the Company accounts for amounts collected from customers for sales and other taxes, net of related amounts remitted to tax authorities; (2) the Company does not adjust the promised amount of consideration for the effects of a significant financing component because, at contract inception, the Company expects the period between the time when the Company transfers a promised good or service to the customer and the time when the customer pays for that good or service will be one year or less; (3) the Company expenses costs to obtain a contract as they are incurred if the expected period of benefit, and therefore the amortization period, is one year or less; (4) the Company accounts for shipping and handling activities that occur after control transfers to the customer as a fulfillment cost rather than an additional promised service and these fulfillment costs are recorded as selling, general and administrative expenses; (5) the Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract with the customer; and (6) the Company does not disclose the transaction price allocated to unsatisfied performance obligations when the original expected contract duration is one year or less. The Company generates revenue primarily from the sale of Impella 2.5, Impella CP, Impella 5.0, Impella LD, Impella RP, Impella 5.5, Impella AIC and the OXY-1 System products and related accessories. The Company also earns revenue from preventative maintenance service contracts and maintenance calls. The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer • Identification of the performance obligation in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligation in the contract • Recognition of revenue when, or as, a performance obligation is satisfied Identification of contracts and performance obligations The Company accounts for a contract with a customer when there is an approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of the consideration is probable. The Company's performance obligations consist mainly of transferring control of products and services identified in the contracts, purchase orders or invoices. For each contract, the Company considers the obligation to transfer products and services to the customer, each of which are distinct, to be performance obligations. Transaction price and allocation to performance obligations Transaction prices of products or services are typically based on contracted rates with customers and there is only variable consideration in limited instances. To the extent that the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing the expected value method or the most likely amount, depending on the circumstances, to which the Company expects to be entitled. An expected value method may be an appropriate estimate of the amount of variable consideration if an entity has a large number of contracts with similar characteristics whereas the most likely amount method may be an appropriate estimate of the amount of variable consideration if the contract has only two possible outcomes. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of the Company’s anticipated performance and all information (historical, current and forecasted) that is reasonably available. Sales and other taxes collected on behalf of third parties are excluded from revenue. Consistent with industry practice, the Company generally offers customers a limited right of return for its products. Product returns are typically not significant because returns are generally not allowed unless there are product order errors or the product is damaged at time of receipt. Customers typically have a limited time frame to notify the Company of any defective or non-conforming products. The Company’s limited warranty provision is accounted for using the cost accrual method and is recognized as expense when products are sold and is not considered a separate performance obligation. If a contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price based on the estimated relative standalone selling prices of the promised products or services underlying each performance obligation. The Company determines standalone selling prices based on the price at which the performance obligation is sold separately. Revenue Recognition Revenue is recognized when, or as, obligations under the terms of a contract are satisfied, which occurs when control of the promised products or services is transferred to customers. Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products or services to a customer. Product revenue is generally recognized when the customer obtains control of the Company’s product, which occurs at a point in time, and may be upon shipment or upon delivery based on the contractual shipping terms of a contract. Service revenue is generally recognized over time as the services are rendered to the customer based on the extent of progress towards completion of the performance obligation. The Company recognizes service revenue over the term of the service contract. Services are expected to be transferred to the customer throughout the term of the contract and the Company believes recognizing revenue ratably over the term of the contract best depicts the transfer of value to the customer. Revenue generated from preventative maintenance calls is recognized at a point in time when the services are provided to the customer. Revenue from the sale of products and services are evidenced by either a contract with the customer or a valid purchase order and an invoice which includes all relevant terms of sale and shipment of product or service provided has been incurred. The Company performs a review of each specific customer's credit worthiness and ability to pay prior to acceptance as a customer. Further, the Company performs periodic reviews of its customers' creditworthiness prospectively. Disaggregation of Revenue Revenue is disaggregated from contracts between product revenue and service and other revenue and by geography, which the Company believes best depicts how the nature, amount, timing, and uncertainty of revenues and cash flows are affected by economic factors. The Company generally sells its products and services through a direct sales force in the U.S. and Germany and through direct sales and distribution agreements in other international markets outside (e.g., Japan, Europe, Canada, Latin America, Asia-Pacific, Middle East). The following table disaggregates the Company’s revenue by products and services: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Impella product revenue $ 806,322 $ 806,824 $ 741,699 Service and other revenue 41,200 34,059 27,733 Total revenue $ 847,522 $ 840,883 $ 769,432 The following table disaggregates the Company’s revenue by geographical location: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) U.S. $ 691,579 $ 705,409 $ 665,082 Europe 105,320 94,266 57,460 Japan 42,868 35,215 17,502 Other international 7,755 5,993 29,388 Total revenue $ 847,522 $ 840,883 $ 769,432 Variable Consideration Returns Reserve The Company estimates an allowance for future sales returns based on historical return experience, which requires judgment. 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 the related product revenue is recognized. The Company estimates product return liabilities using the expected value method based on its historical sales information and other factors that it believes could significantly impact its expected returns, including product discontinuations, product recalls and expirations, of which it becomes aware. The Company’s cost of replacing defective products has not been material and is accounted for at the time of replacement. The Company’s returns reserve was not material as of March 31, 2021 and March 31, 2020. Rebates and Discounts The Company provides certain customers with rebates and discounts that are defined in the Company’s contract arrangements with customers and are recorded as a reduction of revenue in the period the related revenue is recognized, resulting in a reduction to revenue and the establishment of a liability, which are all included in accrued expenses in the accompanying consolidated balance sheet. Rebates normally result from performance-based offers that are primarily based on attaining contractually specified sales volumes as well as product usage. Discounts are normally from early payment incentives. The Company estimates the amount of rebates and discounts based on an estimate of the third-party’s sales and the respective rebate or discount defined in the customer contractual arrangement. Revenue adjustments that relate to performance obligations satisfied in prior periods during the twelve months ended March 31, 2021 and 2020, were not material. Contract Balances Deferred Revenue The Company’s deferred revenue balance was $24.3 million and $19.1 million as of March 31, 2021 and March 31, 2020, respectively. The deferred revenue balance is comprised of product shipments in which the Company recognizes revenue when the customer obtains control of the product, and preventative maintenance service contracts in which revenue is recognized ratably over the term of the service contract. During the fiscal year ended March 31, 2021, the Company recognized $19.0 million of revenue that was included in the deferred revenue balance as of March 31, 2020. During the fiscal year ended March 31, 2020, the Company recognized $15.6 million of revenue that was included in the deferred revenue balance as of March 31, 2019. Costs to Obtain or Fulfill a Customer Contract The Company has certain costs to obtain and fulfill a customer contract, such as commissions and shipping costs. The Company recognizes the incremental costs of obtaining contracts as an expense when incurred if the amortization period of the assets that the Company otherwise would have recognized is one year or less. The Company accounts for shipping and handling activities related to contracts with customers as costs to fulfill the promise to transfer the associated products. These costs are included in selling, general, and administrative expenses.

Financial Instruments

Financial Instruments	12 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Financial Instruments	Note 5. Financial Instruments Cash Equivalents and Marketable Securities The Company’s cash equivalents and marketable securities are invested in the following: Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value March 31, 2021: (in $000's) Money market funds $ 124,297 $ — $ — $ 124,297 Repurchase agreements 33,000 — — 33,000 Total cash equivalents 157,297 — — 157,297 Short-term U.S. Treasury mutual fund securities 72,221 28 — 72,249 Short-term government-backed securities 128,668 13 (12 ) 128,669 Short-term corporate debt securities 104,253 581 (2 ) 104,832 Short-term commercial paper 45,237 1 (3 ) 45,235 Total short-term marketable securities 350,379 623 (17 ) 350,985 Long-term government-backed securities 225,231 190 (37 ) 225,384 Long-term corporate debt securities 38,091 630 (20 ) 38,701 Total long-term marketable securities 263,322 820 (57 ) 264,085 $ 770,998 $ 1,443 $ (74 ) $ 772,367 Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value March 31, 2020: (in $000's) Money market funds $ 115,019 $ — $ — $ 115,019 Repurchase agreements 20,000 — — 20,000 Total cash equivalents 135,019 — — 135,019 Short-term U.S. Treasury securities 42,236 412 — 42,648 Short-term government-backed securities 67,594 401 — 67,995 Short-term corporate debt securities 107,290 94 (83 ) 107,301 Short-term commercial paper 32,757 74 — 32,831 Total short-term marketable securities 249,877 981 (83 ) 250,775 Long-term government-backed securities 90,911 153 — 91,064 Long-term corporate debt securities 116,110 851 (230 ) 116,731 Total long-term marketable securities 207,021 1,004 (230 ) 207,795 $ 591,917 $ 1,985 $ (313 ) $ 593,589 Derivative Instruments In October 2019, the Company entered into an intercompany agreement in which it loaned 85.0 million Euro to Abiomed Europe GMBH, its German subsidiary. In conjunction with this intercompany loan agreement, the Company entered into a cross-currency swap agreement to convert a notional amount of 85.0 million Euro equivalent to a $93.5 million denominated intercompany loan into U.S. dollars. The objective of this cross-currency swap is to hedge the variability of cash flows related to the forecasted interest and principal payments on the Euro denominated fixed rate loan against changes in the exchange rate between the U.S. dollar and the Euro. Under the terms of this cross-currency swap contract, which has been designated as a cash flow hedge, the Company will make interest payments in Euro and receive interest in U.S. dollars. Upon the maturity of this contract, the Company will pay the principal amount of the loan in Euro and receive U.S. dollars from the counterparty. The cross-currency swap is carried on the consolidated balance sheet at fair value, and changes in the fair values are recorded as unrealized gains or losses in accumulated other comprehensive income (loss). The Company does not enter into derivative instruments for any purpose other than cash flow hedging. The following table summarizes the terms of the cross-currency swap agreement as of March 31, 2021 (dollar amounts in thousands): Effective Date Maturity Fixed Rate Aggregate Notional Amount (in $000's) Pay EUR October 15, October 15, 2.75% EUR 85,000 Receive U.S.$ 2019 2024 4.64% USD 93,457 The following table presents the fair value of the Company’s derivative instrument as follows: March 31, 2021 March 31, 2020 Derivatives designated as hedging instruments under ASC 815 Balance sheet classification (in $000's) Cross-currency swap (Long-term liabilities) other assets $ (4,298 ) $ 3,786 The Company has structured its cross-currency swap agreement to be 100% effective and, as a result, there was no net impact to earnings resulting from hedge ineffectiveness. Changes in the fair value of the cross-currency swap are designated as a hedging instrument that effectively offsets the variability of cash flows are reported in accumulated other comprehensive income (loss). These amounts subsequently are reclassified into the consolidated income statement in the same period in which the related hedged item affects earnings. The change of fair value of the cross-currency swap during the fiscal year 2021 was solely due to the appreciation of the Euro against the U.S. dollar. For the fiscal year 2021 and 2020, the Company recorded income related to the interest rate differential of the cross-currency swaps of $1.6 million and $0.8 million, respectively, in other income (expense), net, included in the consolidated statements of operations. Contingent Consideration Contingent consideration represents potential milestones that the Company may pay as additional consideration related to acquired businesses. The Company has contingent consideration potentially payable related to the acquisition of ECP Entwicklungsgesellschaft mbH (“ECP”) in July 2014 and the acquisition of Breethe in April 2020. The fair value of the contingent consideration at each reporting date is updated by reflecting the changes in fair value reflected within research and development expenses in the Company’s consolidated statement of operations. Significant increases or decreases in any valuation assumptions, including probabilities of success or changes in expected timelines for achievement of any of these milestones, could result in a significantly higher or lower fair value of the contingent consideration liability. There is no assurance that any of the conditions for the milestone payments will be met. The components of contingent consideration liability are as follows: March 31, 2021 March 31, 2020 (in $000's) ECP $ 10,306 $ 9,000 Breethe 14,400 — $ 24,706 $ 9,000 ECP In July 2014, the Company acquired ECP and AIS GmbH Aachen Innovative Solutions (“AIS”) for $13.0 million in cash, with additional potential payouts totaling $15.0 million based on the achievement of CE Mark approval in the European Union and a revenue-based milestone related to the development of the future Impella ECP TM The Company used a combination of an income approach, based on various revenue and cost assumptions and applying a probability to each outcome and a Monte-Carlo valuation model, both of which consider significant unobservable inputs. For the clinical and regulatory milestone, probabilities were applied to each potential scenario and the resulting values were discounted using a rate that considers weighted average cost of capital as well as a specific risk premium associated with the riskiness of the earn out itself, the related projections, and the overall business. The revenue-based milestone is valued using a Monte-Carlo valuation model, which simulates estimated future revenues during the earn out-period using management’s best estimates. Key unobservable inputs include the discount rate used to present value the projected revenues and cash flows (ranging from 1.2% to 17%), the mean probability of achieving the various technical, regulatory and commercial milestones of 69% and projected revenues, which are based on the Company’s operational forecasts and long-range strategic plans. Breethe In April 2020, the Company acquired Breethe for $55.0 million in cash, with additional potential payouts up to a maximum of $55.0 million payable based on the achievement of certain technical, regulatory and commercial milestones. The Company used a combination of an income approach, based on various revenue and cost assumptions and applying a probability to each outcome and a Monte-Carlo valuation model, both of which consider significant unobservable inputs. For the regulatory milestones, probabilities were applied to each potential scenario and the resulting values were discounted using a rate that considers weighted average cost of capital as well as a specific risk premium associated with the earn out itself, the related projections, and the overall business. The commercial milestones are valued using a Monte-Carlo valuation model, which simulates estimated future revenues during the earn out-period using management’s best estimates. Key unobservable inputs include the discount rates used to present value the projected revenues and cash flows (ranging from 1.4% to 2%), the probability of achieving the various technical, regulatory and commercial milestones (estimated to range from 25% to 75%) and projected revenues, which are based on the Company’s operational forecasts and long-range strategic plans. Fair Value Hierarchy Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three categories: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data. Level 1 primarily consists of financial instruments whose values are based on quoted market prices such as exchange-traded instruments and listed equities. Level 2 includes financial instruments that are valued using models or other valuation methodologies. These models are primarily industry-standard models that consider various assumptions, including time value, yield curve, volatility factors, prepayment speeds, default rates, loss severity, current market and contractual prices for the underlying financial instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace, can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace. Level 3 is comprised of unobservable inputs that are supported by little or no market activity. Financial assets are considered Level 3 when their fair values are determined using pricing models, discounted cash flows or similar techniques and at least one significant model assumption or input is unobservable. The following table presents the Company’s fair value hierarchy for its financial instruments measured at fair value: Level 1 Level 2 Level 3 Total March 31, 2021: (in $000's) Assets Money market funds $ 124,297 $ — $ — $ 124,297 Repurchase agreements — 33,000 — 33,000 Short-term U.S. Treasury securities — 72,249 — 72,249 Short-term government-backed securities — 128,669 — 128,669 Short-term corporate debt securities — 104,832 — 104,832 Short-term commercial paper — 45,235 — 45,235 Long-term government-backed securities — 225,384 — 225,384 Long-term corporate debt securities — 38,701 — 38,701 Investment in Shockwave Medical 38,655 — — 38,655 Liabilities Cross currency swap agreement — 4,298 — 4,298 Contingent consideration — — 24,706 24,706 Level 1 Level 2 Level 3 Total March 31, 2020: (in $000's) Assets Money market funds $ 115,019 $ — $ — $ 115,019 Repurchase agreements — 20,000 — 20,000 Short-term U.S. Treasury securities — 42,648 — 42,648 Short-term government-backed securities — 67,995 — 67,995 Short-term corporate debt securities — 107,301 — 107,301 Short-term commercial paper — 32,831 — 32,831 Long-term government-backed securities — 91,064 — 91,064 Long-term corporate debt securities — 116,731 — 116,731 Cross currency swap agreement — 3,786 — 3,786 Investment in Shockwave Medical 55,704 — — 55,704 Liabilities Contingent consideration — — 9,000 9,000 The Company has determined that the estimated fair value of its money market funds and its investment in Shockwave Medical, a publicly traded medical device company, are reported as Level 1 financial assets as they are valued at quoted market prices in active markets. The investment in Shockwave Medical is classified within other assets in the consolidated balance sheet. The Company has determined that the estimated fair value of its repurchase agreements, U.S. Treasury mutual fund securities, government-backed securities, corporate debt securities and commercial paper and cross-currency swap agreement are reported as Level 2 financial assets as they are based on model-driven valuations in which all significant inputs are observable, or can be derived from or corroborated by observable market data for substantially the full term of the asset. Level 3 Financial Liabilities This contingent consideration liability is reported as Level 3 as the estimated fair value of the contingent consideration related to the acquisitions of ECP and Breethe require significant management judgment or estimation. Quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements are described above. This contingent consideration liability is reported as Level 3 as the estimated fair value of the contingent consideration related to the acquisitions of ECP and Breethe require significant management judgment or estimation and is calculated as described above. The following table summarizes the change in fair value, as determined by Level 3 inputs, of the contingent consideration: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Level 3 liabilities, beginning balance $ 9,000 $ 9,575 $ 10,490 Additions 13,300 — — Payments — — — Change in fair value 2,406 (575 ) (915 ) Level 3 liabilities, ending balance $ 24,706 $ 9,000 $ 9,575 The change in fair value of the contingent consideration was primarily due to the addition of contingent consideration related to the Breethe acquisition and the passage of time impact on fair value measurements. Information About Uncertainty of Level 3 Fair Value Measurements The significant unobservable inputs used in the fair value of the Company’s contingent consideration are the discount rate and forecasted financial information. Significant increases (decreases) in the discount rate would have resulted in a significantly lower (higher) fair value measurement. Significant increases (decreases) in the forecasted financial information would have resulted in a significantly higher (lower) fair value measurement. As of March 31, 2021 and 2020, the present value of expected payments related to the Company’s contingent consideration was $24.7 million and $9.0 million, respectively. The undiscounted value of the payments, assuming that all contingencies are met, would be $70.0 million and $15.0 million, respectively.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Mar. 31, 2021
Receivables [Abstract]
Accounts Receivable	Note 6. Accounts Receivable The components of accounts receivable are as follows: March 31, 2021 March 31, 2020 (in $000's) Trade receivables $ 97,953 $ 85,852 Allowance for doubtful accounts (774 ) (1,202 ) $ 97,179 $ 84,650 The following table summarizes activity in the allowance for doubtful accounts: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Balance at beginning of year $ 1,202 $ 1,040 $ 320 Additions (recoveries) (127 ) 487 720 Write-offs (301 ) (325 ) — Balance at end of year $ 774 $ 1,202 $ 1,040

Inventories

Inventories	12 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Inventories	Note 7. Inventories The components of inventories are as follows: March 31, 2021 March 31, 2020 (in $000's) Raw materials and supplies $ 27,782 $ 31,411 Work-in-progress $ 35,187 35,008 Finished goods $ 18,090 23,669 $ 81,059 $ 90,088 The Company’s inventories relate to its Impella® and OXY-1 System product platform. Finished goods and work-in-process inventories consist of direct material, labor and overhead.

Property and Equipment

Property and Equipment	12 Months Ended
	Mar. 31, 2021
Property Plant And Equipment [Abstract]
Property and Equipment	Note 8. Property and Equipment The components of property and equipment are as follows: March 31, 2021 March 31, 2020 (in $000's) Land $ 10,875 $ 7,179 Building and building improvements 148,870 100,176 Leasehold improvements 439 14,546 Machinery and equipment 91,784 71,636 Furniture and fixtures 15,608 14,600 Construction in progress 10,906 15,075 Total cost 278,482 223,212 Less accumulated depreciation (81,353 ) (58,281 ) $ 197,129 $ 164,931 In March 2021, the Company acquired the building adjacent to its corporate headquarters that it had been leasing in Danvers, Massachusetts. The total acquisition cost for the land and building was approximately $17.5 million, with $3.4 million being recorded to land and $13.8 million being recorded to building and building improvements. In addition, the Company reclassified $11.0 million in leasehold improvements and $4.7 million in right-of-use assets and recorded a $0.5 million adjustment to remove the prior lease liability due to the termination of the lease agreement upon the property acquisition. Depreciation expense related to property and equipment was $23.1 million, $20.1 million, and $13.9 million for the fiscal years ending March 31, 2021, 2020 and 2019, respectively.

Goodwill, In-Process Research &

Goodwill, In-Process Research & Development and Other Assets	12 Months Ended
	Mar. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, In-Process Research and Development and Other Assets	Note 9. Goodwill, In-Process Research & Development and Other Assets Goodwill The carrying amount of goodwill as of March 31, 2021 and 2020 was $78.6 million and $32.0 million, respectively, and has been recorded in connection with the Company’s acquisition of Impella Cardiosystems AG, in May 2005, ECP in July 2014 and Breethe in April 2020. The goodwill activity is as follows: (in $000's) Balance, March 31, 2019 $ 32,601 Foreign currency translation impact (632 ) Balance, March 31, 2020 $ 31,969 Breethe acquisition 44,485 Foreign currency translation impact 2,114 Balance, March 31, 2021 $ 78,568 The Company evaluates goodwill at least annually on October 31, as well as whenever events or changes in circumstances suggest that the carrying amount may not be recoverable. The Company has no accumulated impairment losses on goodwill. Other Intangible Assets, net Other intangible assets consist of the following: March 31, 2021 March 31, 2020 Weighted Average Useful Life (in years) Cost Accumulated Amortization Net Carrying Value Cost Accumulated Amortization Net Carrying Value (in $000's) Finite-lived intangible assets Developed technology 14.6 $ 27,000 $ (750 ) $ 26,250 — — — Indefinite-lived intangible assets In-process research and development 15,900 — 15,900 14,913 — 14,913 Total $ 42,900 $ (750 ) $ 42,150 $ 14,913 — $ 14,913 The Company’s finite-lived intangible asset represents developed technology associated with the estimated fair value of the OXY-1 System. Upon receiving FDA 510(k) clearance of the OXY-1 System in October 2020, the Company reclassified the IPR&D asset of $27.0 million during the quarter ended December 31, 2020 from the acquisition of Breethe (see Note 3) to finite-lived developed technology intangible assets and began amortizing the intangible asset on a straight-line basis over an estimated useful life of 15 years. The estimated fair value of developed technology was determined using a probability-weighted income approach, which discounts expected future cash flows to present value. The projected cash flow estimates for the OXY-1 System were based on certain key assumptions, including estimates of future revenue and expenses, the stage of development of the technology at the acquisition date and the time and resources needed to complete development. The Company’s IPR&D assets represents the estimated fair value of the Impella ECP TM TM The Company evaluates the other intangible assets at least annually on October 31, as well as whenever events or changes in circumstances suggest that the carrying amount may not be recoverable. The Company has no accumulated impairment losses on other intangible assets. The change in the indefinite-lived intangible assets balance for the fiscal year ended March 31, 2021 was related to foreign currency translation impact.

Other Assets

Other Assets	12 Months Ended
	Mar. 31, 2021
Other Assets [Abstract]
Other Assets	Note 10. Other Assets The components of other assets are as follows: Fiscal Years Ended March 31, 2021 2020 (in $000's) Investment in Shockwave Medical $ 38,655 $ 55,704 Other investments 62,995 38,741 Operating lease right-of-use assets (Note 11) 6,109 11,760 Cross-currency swap (Note 5) — 3,786 Other intangible assets and other assets 5,323 7,664 Total other assets $ 113,082 $ 117,655 Investment in Shockwave Medical In fiscal year 2019, the Company invested $25.0 million in Shockwave Medical, a publicly traded medical device company. During the fiscal year ended March 31, 2021, the Company sold approximately 1.4 million of its shares for cash proceeds of $67.9 million in which it realized a gain of $47.3 million. The Company held 0.3 million shares of Shockwave Medical as of March 31, 2021. Other Investments The Company periodically makes investments in medical device companies that focus on heart failure and heart pumps and other medical device technologies. The carrying value of the Company’s portfolio of other investments and the changes in the balance were as follows: Fiscal Years Ended March 31, 2021 2020 (in $000's) Beginning balance $ 38,741 $ 24,584 Additions 26,104 19,599 Reclassification (2,000 ) - Impairment (800 ) (750 ) Change in fair value, net 950 (4,692 ) Ending balance $ 62,995 $ 38,741 Other Intangible Assets and Other Assets The Company’s other intangible assets and other assets is comprised primarily of license manufacturing rights to certain technology from third parties and other long-term assets such as prepaid expenses.

Leases

Leases	12 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Leases	Note 11. Leases Lessee The Company has lease agreements for real estate including corporate offices and warehouse space, vehicles and certain office equipment. At the inception of a contractual arrangement, the Company determines whether it contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company calculates the associated lease liability and corresponding right-of-use asset upon lease commencement. Operating lease assets and liabilities are recognized based on the present value of minimum lease payments over the lease term using an appropriate discount rate. Right-of-use assets also include any lease payments made at or before lease commencement and any initial direct costs incurred and exclude any lease incentives received. The discount rate used is the rate that the Company would have to pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments in a similar economic environment. At the lease commencement date, the discount rate implicit in the lease is used to discount the lease liability, if readily determinable. If not readily determinable or lease do not contain an implicit rate, the Company’s incremental borrowing rate is used as the discount rate. Discount rates are updated when there is a new lease or a modification to an existing lease, and the methodology is reassessed annually. The Company records operating lease liabilities within current liabilities or long-term liabilities based upon the length of time associated with the lease payments. The Company records its operating lease right-of-use assets as long-term assets. Leases with an initial term of 12 months or less are not recognized on the consolidated balance sheet. The Company have elected the practical expedient where lease agreements with lease and non-lease components are accounted for as a single lease component for all assets. The Company’s financing leases are not material to our financial statements. The Company adopted ASC Topic 842 on April 1, 2019 using the optional transition method. As such, the disclosures required under ASC Topic 842 are not presented for periods before the date of adoption. The Company elected the package of transitional practical expedients for leases existing prior to the adoption date. The Company did not reassess whether existing contracts are or contain leases, leases retained their historical lease classification and initial direct costs were not reassessed for capitalization under the new standard. Operating lease assets and liabilities were recognized based on the present value of minimum lease payments over the remaining lease term as of the adoption date. The following table presents supplemental balance sheet information related to the Company’s operating leases: March 31, 2021 March 31, 2020 (in $000's) Assets Operating lease right-of-use assets in other assets $ 6,109 $ 11,760 Liabilities Operating lease liabilities in other current liabilities 2,459 3,671 Operating lease liabilities in other long-term liabilities 3,657 8,549 Total operating lease liabilities $ 6,116 $ 12,220 In March 2021, the Company acquired the building adjacent to its corporate headquarters that it had been leasing in Danvers, Massachusetts. The total acquisition cost for the land and building was approximately $17.5 million, with $3.4 million being recorded to land and $13.8 million being recorded to building and building improvements. In addition, the Company reclassified $11.0 million in leasehold improvements and $4.7 million in right-of-use assets and recorded a $0.5 million adjustment to remove the prior lease liability due to the termination of the lease agreement upon the property acquisition. Expense charged to operations under operating leases was $4.1 million and $3.7 million during the fiscal years ended March 31, 2021 and 2020, respectively. Short-term lease expenses were not material. Maturities of operating lease liabilities as of March 31, 2021 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2022 $ 2,574 2023 1,404 2024 1,165 2025 617 2026 77 Thereafter 599 Total minimum lease payments 6,436 Less: imputed interest (320 ) Present value of operating lease liabilities $ 6,116 Weighted average remaining lease term 4.02 Weighted average discount rate 1.96 % Lessor In March 2021, as part of the $17.5 million purchase of a building located in Danvers, Massachusetts, we assumed existing leases with third parties for a portion of the building which are classified as operating leases. The leases have annual escalating payments and the latest expires in March 2025 in accordance with the terms and conditions of the existing agreement. For the year ended March 31, 2021, operating lease income was not material.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Mar. 31, 2021
Payables And Accruals [Abstract]
Accrued Expenses	Note 12. Accrued Expenses Accrued expenses consisted of the following: March 31, 2021 March 31, 2020 (in $000's) Employee compensation $ 40,954 $ 32,273 Research and development 6,983 5,749 Sales and income taxes 5,914 21,641 Marketing 3,674 1,705 Warranty 2,053 1,818 Professional, legal and accounting fees 1,957 6,880 Other 4,511 5,041 $ 66,046 $ 75,107 Employee compensation consists primarily of accrued bonuses, accrued commissions and accrued employee benefits as of March 31, 2021 and 2020.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity	Note 13. Stockholders’ Equity Class B Preferred Stock The Company has authorized 1,000,000 shares of Class B Preferred Stock, $.01 par value, of which the board of directors can set the designation, rights and privileges. No shares of Class B Preferred Stock have been issued or are outstanding. Stock Repurchase Program In August 2019, the Company’s Board of Directors authorized a stock repurchase program for up to $200.0 million of shares of its common stock. Under this stock repurchase program, the Company is authorized to repurchase shares through open market purchases, privately negotiated transactions or otherwise in accordance with applicable federal securities laws, including through Rule 10b5-1 trading plans and under Rule 10b-18 of the Exchange Act. The stock repurchase program has no time limit and may be suspended for periods or discontinued at any time. The Company is funding the stock repurchase program with its available cash and marketable securities. Through fiscal year 2021 and 2020, the Company has repurchased a total of 67,649 and 465,687 shares, respectively, at an aggregate cost of $11.3 million and $84.9 million, respectively. The remaining authorization under the stock repurchase program was $103.8 million as of March 31, 2021. The following table provides stock repurchase activities: For the Year Ended March 31, 2021 2020 Shares repurchased 67,649 465,687 Average price per share $ 167.19 $ 182.27 Value of shares repurchased (in millions) $ 11.3 $ 84.9 Accumulated Other Comprehensive Income (Loss) The components of accumulated other comprehensive income (loss), are as follows (in thousands): Foreign Currency Translation Gains (Losses) Unrealized Gains (Losses) on Investments Unrealized Gains (Losses) on Derivative Instruments Total (in $000's) Balance, April 1, 2018 (3,597 ) (607 ) — (4,204 ) Other comprehensive (loss) income (11,431 ) 946 — (10,485 ) Balance, March 31, 2019 (15,028 ) 339 — (14,689 ) Other comprehensive income (loss) (1,832 ) 1,333 3,999 3,500 Balance, March 31, 2020 (16,860 ) 1,672 3,999 (11,189 ) Other comprehensive (loss) income 2,142 (303 ) (2,095 ) (256 ) Balance, March 31, 2021 $ (14,718 ) $ 1,369 $ 1,904 (11,445 )

Stock Award Plans and Stock-Bas

Stock Award Plans and Stock-Based Compensation	12 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Award Plans and Stock-Based Compensation	Note 14. Stock Award Plans and Stock-Based Compensation Stock Award Plans The Company grants stock options and restricted stock awards to employees and others. All outstanding stock options of the Company as of March 31, 2021 were granted with an exercise price equal to the fair market value on the date of grant. Outstanding stock options, if not exercised, expire 10 years from the date of grant. 2015 Stock Incentive Plan The Company’s 2015 Amended and Restated Omnibus Incentive Plan (the “2015 Plan”) authorizes the grant of a variety of equity awards to the Company’s officers, directors, employees, consultants and advisers, including awards of unrestricted and restricted stock, restricted stock units, incentive and nonqualified stock options to purchase shares of common stock, performance share awards and stock appreciation rights. The 2015 Plan provides that options may only be granted at the current market value on the date of grant. Each share of stock issued pursuant to a stock option or stock appreciation right counts as one share against the maximum number of shares issuable under the 2015 Plan, while each share of stock issued pursuant to any other type of award counts as 1.8 shares against the maximum number of shares issuable under the 2015 Plan. The Company’s policy for issuing shares upon exercise of stock options or the vesting of its restricted stock awards and restricted stock units is to issue shares of common stock at the time of exercise or conversion. As of March 31, 2021, a total of approximately 3,334,890 shares were available for future issuance under the 2015 Plan. Stock-Based Compensation The following table summarizes stock-based compensation expense by financial statement line item in the Company’s consolidated statements of operations: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Cost of revenue $ 3,760 $ 2,641 $ 2,643 Research and development 6,941 5,534 9,312 Selling, general and administrative 36,305 31,606 42,539 $ 47,006 $ 39,781 $ 54,494 The components of stock-based compensation were as follows: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Restricted stock units $ 36,347 $ 28,895 $ 45,998 Stock options 8,982 9,006 7,445 Employee stock purchase plan 1,677 1,880 1,051 $ 47,006 $ 39,781 $ 54,494 Stock Options The following table summarizes stock option activity for the fiscal year ended March 31, 2021: Weighted Weighted Average Aggregate Average Remaining Intrinsic Options Exercise Contractual Value (in thousands) Price Term (years) (in thousands) Outstanding at beginning of period 869 $ 112.03 5.30 Granted 70 225.60 Exercised (215 ) 42.16 Cancelled and expired (13 ) 248.42 Outstanding at end of period 711 $ 141.87 5.46 $ 129,912 Exercisable at end of period 537 $ 104.55 4.51 $ 117,880 Options vested and expected to vest at end of period 711 $ 141.87 5.46 $ 129,912 Stock options generally vest and become exercisable annually over three years. The remaining unrecognized stock-based compensation expense for unvested stock option awards as of March 31, 2021 was approximately $8.9 million and the weighted-average period over which this cost will expected to be recognized is 1.6 years. The aggregate intrinsic value of options exercised for fiscal years 2021, 2020 and 2019 was $54.9 million, $15.0 million and $174.0 million, respectively. The total cash received as a result of employee stock option exercises during the fiscal years ended March 31, 2021, 2020 and 2019 was approximately $9.1 million, $3.7 million and $12.9 million, respectively. The Company estimates the fair value of each stock option granted at the grant date using the Black-Scholes option valuation model. The weighted average grant-date fair values and weighted average assumptions used in the calculation of fair value of options granted were as follows: Fiscal Years Ended March 31, 2021 2020 2019 Valuation assumptions: Weighted average grant-date fair value $ 77.82 $ 93.05 $ 141.47 Risk-free interest rate 0.32 % 1.97 % 2.91 % Expected option life (years) 4.22 4.14 4.04 Expected volatility 42.9 % 42.3 % 42.8 % The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for a term consistent with the expected life of the stock options. Volatility assumptions are calculated based on the historical volatility of the Company’s stock. The Company estimates the expected term of options based on historical exercise experience and estimates of future exercises of unexercised options. An expected dividend yield of zero is used in the option valuation model because the Company does not pay cash dividends and does not expect to pay any cash dividends in the foreseeable future. Forfeitures are recorded as they occur instead of estimating forfeitures that are expected to occur. Restricted Stock Units The following table summarizes restricted stock unit activity for the fiscal year ended March 31, 2021: Number of Shares Weighted Average Grant Date Fair Value (in thousands) (per share) Restricted stock units at beginning of period 320 $ 263.92 Granted 230 254.78 Vested (139 ) 227.32 Forfeited (109 ) 266.57 Restricted stock units at end of period 301 $ 273.57 Restricted stock units generally vest annually over three years. The remaining unrecognized compensation expense for outstanding restricted stock units, including performance-based awards, as of March 31, 2021 was $51.9 million and the weighted-average period over which this cost will expected to be recognized is 1.8 years. The weighted average grant-date fair value for restricted stock units granted during the fiscal years ended March 31, 2021, 2020 and 2019 was $254.78, $258.59 and $376.95 per share, respectively. The total fair value of restricted stock units vested in fiscal years 2021, 2020 and 2019 was $27.9 million, $99.3 million and $171.3 million, respectively. Performance Awards Restricted stock units include certain awards that vest subject to certain performance. The remaining unrecognized compensation expense for outstanding performance restricted stock units as of March 31, 2021 was $24.2 million and the weighted-average period over which this cost will be recognized is 1.8 years. In November 2020, performance-based awards of restricted stock units for the potential issuance of up to 66,000 shares of common stock were issued to certain executive officers, which vest upon achievement of prescribed service milestones by the award recipients and the achievement of prescribed performance milestones by the Company. In May 2020, performance-based awards of restricted stock units for the potential issuance of up to 62,000 shares of common stock were issued to certain executive officers and employees, which vest upon achievement of prescribed service milestones by the award recipients and the achievement of prescribed performance milestones by the Company. In May 2019, performance-based awards of restricted stock units for the potential issuance of up to 196,580 shares of common stock were issued to certain executive officers and employees, which vest upon achievement of prescribed service milestones by the award recipients and the achievement of prescribed performance milestones by the Company. The Company did not meet the prescribed performance milestones in fiscal year 2020 and therefore no shares vested for these performance-based awards and the Company reversed all previously recorded stock stock-based compensation expense related to this award in the three months ended March 31, 2020. In May 2018, performance-based awards of restricted stock units for the potential issuance of 114,000 shares of common stock were issued to certain executive officers and employees, which vest upon achievement of prescribed service milestones by the award recipients and performance milestones by the Company. The Company met the prescribed performance milestones in fiscal year 2019 such that the remaining outstanding 22,000 shares of common stock as of March 31, 2021 will vest subject to service requirements for vesting for these employees and stock-based compensation expense is being recognized accordingly over the employee’s service term. Market-Based Awards In May 2020, the Company awarded certain executive officers and employees a total of up to 61,762 market-based restricted stock units. These restricted stock units will vest and result in the issuance of shares of common stock based on continuing employment and the relative ranking of the total shareholder return (“TSR”) of the Company’s common stock in relation to the TSR of 20 peer companies over a two-year and three-year performance period based on a comparison of average closing stock prices during the 20 trading days prior to the first day of the performance period, reinstated dividends during each performance period and the average closing stock prices during the final 20 trading days of each performance period. The actual number of market-based restricted stock units that may be earned can range from 0% to 200% of the target number of shares. Additionally, the payout percentage is further adjusted based on the Company’s performance relative to the constituents of the S&P 500 Index on the first day of the performance period that are still actively trading on the last day of each performance period. The restricted stock units will vest following the end of the two-year and three-year performance period, respectively. The Company used a Monte-Carlo simulation model to estimate the grant-date fair value of the TSR restricted stock units. The fair value related to these awards are recorded as compensation expense over the period from date of grant to May 2022 and May 2023, respectively, regardless of the actual TSR outcome reached. The table below sets forth the assumptions used to value the awards and the estimated grant-date fair value: Risk-free interest rate 0.2 % Expected volatility 35.5 % Dividend yield — Remaining performance period (years) 1.9 - 2.9 Estimated grant date fair value per share $347.05 - $349.28 Target performance (number of shares) 30,881 Employee Stock Purchase Plan The Company has an employee stock purchase plan, or ESPP. Under the ESPP, eligible employees, including officers and directors, who have completed at least three months of employment with the Company or its subsidiaries who elect to participate in the purchase plan instruct the Company to withhold a specified amount of the employee’s income each payroll period during a six-month payment period (the periods April 1—September 30 and October 1—March 31). On the last business day of each six-month payment period, the amount withheld is used to purchase shares of the Company’s common stock at an exercise price equal to 85% of the lower of its market price on the first business day or the last business day of the payment period.

Income Taxes

Income Taxes	12 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 15. Income Taxes The Company’s income tax provision was $62.7 million, $53.8 million and $4.3 million for fiscal years 2021, 2020 and 2019, respectively. The Company’s effective tax rate was 21.8%, 21.0% and 1.6% for fiscal years 2021, 2020 and 2019, respectively. The components of the Company’s income tax provision are as follows: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Income before provision for income taxes: United States $ 249,204 $ 214,825 $ 223,340 Foreign 39,016 42,000 40,020 Income before income taxes 288,220 256,825 263,360 Current tax expense: Federal 8,624 — — State 12,379 6,563 564 Foreign 12,312 14,300 11,525 33,315 20,863 12,089 Deferred tax expense (benefit): Federal 30,413 33,239 (7,153 ) State (2,382 ) 1,584 (1,503 ) Foreign 1,349 (1,870 ) 911 29,380 32,953 (7,745 ) Total income tax provision $ 62,695 $ 53,816 $ 4,344 The components of the Company’s net deferred taxes were as follows: March 31, 2021 March 31, 2020 (in $000's) Deferred tax assets Net operating loss and tax credit carryforwards $ 27,893 $ 50,604 Stock-based compensation 13,790 13,607 Nondeductible reserves and accruals 12,097 9,570 Foreign net operating loss carryforwards 6,856 6,778 Deferred revenue 5,522 4,404 Depreciation and amortization 51 114 Other, net 312 949 $ 66,521 $ 86,026 Deferred tax liabilities Goodwill (7,897 ) (7,843 ) In-process research and development (12,496 ) (4,564 ) Depreciation (11,747 ) (9,211 ) Basis differences on other investments (7,766 ) (6,124 ) Domestic deferred tax liability on foreign net operating loss carryforwards (415 ) (584 ) (40,321 ) (28,326 ) Net deferred tax assets 26,200 57,700 Valuation allowance (15,667 ) (15,170 ) Net deferred tax assets $ 10,533 $ 42,530 Reported as: Deferred tax assets $ 11,380 $ 43,336 Deferred tax liabilities (847 ) (806 ) Net deferred tax assets $ 10,533 $ 42,530 The significant differences between the statutory and effective income tax rate consist of the following items: Fiscal Years Ended March 31, 2021 2020 2019 Statutory income tax rate 21.0 % 21.0 % 21.0 % Increase (decrease) resulting from: Credits (6.0 ) (10.8 ) (1.5 ) Rate differential on foreign operations 4.1 3.2 0.2 Excess tax benefits from stock-based awards (3.3 ) (5.2 ) (24.1 ) State taxes, net 3.2 3.1 0.1 Permanent differences 2.4 5.0 1.8 Change in valuation allowance 0.3 5.3 (0.4 ) Foreign taxes — — 4.1 Other 0.1 (0.6 ) 0.4 Effective tax rate 21.8 % 21.0 % 1.6 % The Company regularly assesses its ability to realize its deferred tax assets. Assessing the realization of deferred tax assets requires significant management judgment. In determining whether its deferred tax assets are more likely than not realizable, the Company evaluates all available positive and negative evidence, and weights the evidence based on its objectivity. As of March 31, 2021 and 2020, respectively, the Company maintained a valuation allowance of $15.7 million and $15.2 million for deferred tax assets primarily related to foreign tax credits that are expected not to be utilizable in the foreign branch basket. Based on the review of all available evidence, the Company recorded a valuation allowance to reduce these deferred tax assets to the amount that is more likely than not to be realizable as of March 31, 2021 and 2020. Changes in the valuation allowance for deferred tax assets were as follows: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Balance at beginning of year $ 15,170 $ 1,302 $ 1,652 Increase 497 13,868 — Decrease — — (350 ) Balance at end of year $ 15,667 $ 15,170 $ 1,302 ASU 2016-09 requires excess tax benefits and shortfalls to be recognized in the income tax provision as discrete items in the period when restricted stock units vest or stock option exercises occur, whereas previously such income tax effects were recorded as part of additional paid-in capital only when the related tax deduction resulted in a reduction of current income taxes payable. The Company recognized excess tax benefits associated with stock-based awards of $12.1 million, $14.8 million and $69.3 million as an income tax benefit for fiscal years 2021, 2020 and 2019, respectively. The amount of future excess tax benefits or shortfalls will likely fluctuate from period to period based on the price of the Company’s stock, the number of restricted stock units that vest or stock options that are exercised, and the fair value assigned to such stock-based awards under U.S. GAAP. As of March 31, 2021, the Company had foreign net-operating losses (“NOLs”) of approximately $27.2 million. As of March 31, 2021, the Company had foreign tax credits of $13.8 million which expire in varying years from fiscal year 2029 through fiscal year 2031. In addition, as of March 31, 2021, the Company had federal and state research and development credit carryforwards of approximately $0.4 million and $12.8 million, respectively, which expire in varying years from fiscal year 2022 through fiscal year 2041. The Company’s operating income outside the U.S. is deemed to be permanently reinvested in foreign jurisdictions. The Tax Reform Act allows for a 100% deduction for the repatriation of foreign subsidiary earnings with minimal U.S. income tax consequences other than a one-time deemed repatriation toll charge. Since most of the Company’s cash and cash equivalents are held by foreign subsidiaries which are disregarded entities for domestic tax purposes, any repatriation of such funds to the U.S. would likely have a nominal tax impact, if any. As of March 31, 2021 and 2020, the Company has no material uncertain tax positions, and no interest and penalties on uncertain tax positions were recognized during fiscal years 2021, 2020 and 2019, respectively. The Company is subject to the examination of its income tax returns by the IRS and other tax authorities. The outcome of these audits cannot be predicted with certainty. The Company’s management regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of the Company’s provision for income taxes. If any issues addressed in the Company’s tax audits are resolved in a manner not consistent with management’s expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs. The Company’s most recent completed income tax audits were in the U.S. relating to fiscal year 2016 and in Germany, which covered fiscal years 2012 through 2015. These tax audits did not materially impact the Company’s financial statements. In October 2020, the Company was notified by the German tax authorities that they will be conducting an income tax audit on Abiomed Europe GmbH and ECP for fiscal years 2016 through 2019 beginning in January 2021. All other tax years remain subject to examination by the IRS, state and foreign tax authorities.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 16. Commitments and Contingencies From time to time, the Company is involved in legal and administrative proceedings and claims of various types. In some actions, the claimants seek damages, as well as other relief, which, if granted, would require significant expenditures. The Company records a liability in its consolidated financial statements for these matters when a loss is known or considered probable and the amount can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If a matter is both probable to result in liability and the amount of loss can be reasonably estimated, the Company estimates and discloses the possible loss or range of loss. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in its consolidated financial statements. Thoratec Matters Thoratec Corporation (“ Thoratec ”), a subsidiary of Abbott Laboratories (“Abbott”) , has challenged a number of Company-owned patents in Europe in connection with the launch of Thoratec’s HeartMate PHP™ medical device (“PHP”) in Europe and the Company has counterclaimed for infringement in the District Court in Düsseldorf. The litigation was stayed pending the highest Court’s ruling on the validity and scope of the litigated patents. In September 2019, the Federal Court of Justice in Germany upheld the Company’s patents that are the subject of the patent infringement action for the sales and marketing of Thoratec’s PHP pump in Germany. Subsequently, the District Court in Düsseldorf lifted the stay, re-opened the litigation proceedings, and ruled in favor of Abiomed. The Court acknowledged that Thoratec’s PHP product infringes two of ABIOMED patents related to the key features of Impella ® intravascular pump and future expandable heart pump, known as Impella ECP®. Abbott appealed and the oral hearing is set for August 2 6 , 2021 . If upheld, the verdict is provisionally enforceable, which means that ABIOMED will be able to seek a court ordered injunction preventing the sale and marketing of PHP, should Thoratec attempt to launch HeartMate PHP in Germany . These actions relate solely to Thoratec’s ability to manufacture and sell its PHP product in Europe and have no impact on the Company's ability to manufacture or sell its Impella® line of medical devices. The actions do not expose the Company to liability risk, except under local German law that requires a losing party in a proceeding to pay a portion of the other party’s legal fees. Maquet Matters In December 2015, the Company received a letter from Maquet Cardiovascular LLC (“Maquet”), a subsidiary of Getinge AB, asserting that the Company’s Impella ® In August 2016, Maquet sent a letter to the Company identifying four new Maquet U.S. continuation patent filings with claims that Maquet alleges are infringed by the Company’s Impella devices. The four U.S. continuation applications have been issued as patents of Maquet but expired on September 1, 2020. In September 2016, Maquet filed a response to the Company’s suit in D. Mass., including various counterclaims alleging that the Company’s Impella 2.5 ® ® ® ® In November 2017, Maquet filed a second action in D. Mass (the “2017 Action”) alleging that the Company’s Impella 2.5®, Impella CP®, and Impella 5.0® heart pumps infringe certain claims of the fourth additional U.S. continuation patent mentioned above (the seventh patent overall). Discovery in the 2017 Action is ongoing. In a series of letters during January and February 2019, Maquet informed the Company of seven new patent applications filed from the patents in the 2016 Action and 2017 Action with claims Maquet alleges would be infringed by the Impella® products if the new applications were to issue as patents. One of the newly issued patents has been added to the 2017 Action. A Markman hearing for the newly-added patent was held on November 18, 2019. A Markman order has not been issued yet. The asserted patent in this case expired on September 1, 2020. Discovery remains ongoing. In the 2016 Action and 2017 Action, Maquet seeks injunctive relief and monetary damages in the form of a reasonable royalty, with three times the amount for alleged willful infringement. In its responses to the Company’s counterclaims, Maquet admits that its current commercially available products do not embody the claims of the asserted patents. The Company is unable to estimate the potential liability with respect to the legal matters noted above. There are numerous factors that make it difficult to meaningfully estimate possible loss or range of loss at this stage of the legal proceedings, including the significant number of legal and factual issues still to be resolved in the Maquet and Thoratec patent disputes. Securities Class Action Litigation On or about August 6, 2019, the Company received a securities class action complaint filed on behalf of a single shareholder in the U.S. District Court for the Southern District of New York (“SDNY”), on behalf of himself and persons or entities that purchased or acquired the Company’s securities between January 31, 2019 through July 31, 2019. On October 7, 2019, a similar purported class action complaint was filed by a different shareholder on behalf of himself and persons or entities that purchased or acquired the Company’s securities between November 1, 2018 and July 31, 2019. Also, on October 7, 2019, four shareholders filed applications to be appointed lead plaintiff and for their counsel to be appointed lead counsel for the class. Two of those shareholders also filed motions to consolidate the two cases and two of the shareholders have withdrawn their applications to be lead plaintiff. The complaints allege that the Company violated Sections 10(b) and 20(a) of and Rule 10b-5 under the Exchange Act, in connection with allegedly misleading disclosures made by the Company regarding its financial condition and results of operations. The Company believes that the allegations are without merit and plans to defend itself vigorously. On June 29, 2020, the Court issued an order consolidating the two cases and appointed Local 705 International Brotherhood of Teamsters Pension Fund as the lead plaintiff and the Labaton Sucharow firm as lead counsel. On September 17, 2020, the lead plaintiff filed an amended complaint in which it proposed a new class period of May 3, 2018 to July 31, 2019. As prescribed by a scheduling order, the Company filed a motion to dismiss on November 16, 2020, lead plaintiff filed its opposition to that motion on January 15, 2021, and the Company filed its reply on February 24, 2021. Shareholder Derivative Litigation On November 6 and 7, 2019, two shareholders filed derivative actions in SDNY that were subsequently consolidated. On November 8, 2019, another shareholder filed a derivative action in Massachusetts Suffolk County Superior Court. On January 7, 2020, another shareholder derivative action was filed in the U.S. District Court for the District of Delaware. The complaints in these actions rely on many of the same allegations as in the securities class actions, and assert that, between November 1, 2018 and July 31, 2019, the directors of the Company made or allowed to be made misleading public statements regarding the Company’s growth, ultimately harming the Company. The Company has agreed with the plaintiffs in all three actions to stay the cases pending resolution of a motion to dismiss in the securities class actions. As a result of the stay, the Delaware action has been administratively closed. Litigation Demand On March 3, 2020, a shareholder sent a letter to the Board of Directors asserting that the directors of the Company made or allowed to be made misleading public statements regarding the Company’s growth. The letter relies on many of the same allegations as the securities class actions and derivative actions, and demands that the Board (i) undertake an independent investigation of the directors, (ii) bring suit against the directors on behalf of the Company, and (iii) take a number of additional affirmative actions to redress the purported wrongs. On March 30, 2020, the Company, after discussions with the Board of Directors, sent a written response to the shareholder’s counsel which they responded to on June 1, 2020. The Company then sent a further response to the shareholder’s counsel on June 15, 2020, affirming the decision to defer consideration of the litigation demand pending further developments in the securities class action suit. Following the filing of the amended complaint in the securities class action, described above, the same shareholder renewed their demand on September 29, 2020. The Company responded on October 9, 2020 and once again affirmed that it will defer consideration of the demand pending further substantive developments in the securities class action suit. On November 5, 2020, a second shareholder sent a letter to the Board of Directors that made essentially the same demands as the September 29, 2020 letter from the first shareholder. The Company responded on November 23, 2020, noting that it will defer consideration of the demand pending further substantive developments in the securities class action suit. The Company is unable to estimate the potential liability with respect to the various legal matters noted above. There are numerous factors that make it difficult to estimate reasonably possible loss or range of loss at this stage of the legal proceedings, including the significant number of legal and factual issues still to be resolved in the securities class action litigation, as well as in the shareholder derivative litigations.

Segment and Enterprise Wide Dis

Segment and Enterprise Wide Disclosures	12 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Segment and Enterprise Wide Disclosures	Note 17. Segment and Enterprise Wide Disclosures The Company operates in one business segment—the research, development and sale of medical devices to assist or replace the pumping function of the failing heart. The Company’s chief operating decision maker (determined to be the Chief Executive Officer) does not manage any part of the Company separately, and the allocation of resources and assessment of performance are based on the Company’s consolidated operating results. International sales (sales outside the U.S. and primarily in Europe) accounted for 18%, 16% and 14% of total revenue during the fiscal years ended March 31, 2021, 2020 and 2019, respectively. As of March 31, 2021 and 2020, most of the Company’s long-lived assets are located in the U.S. except for $56.4 million and $46.7 million as of March 31, 2021 and 2020, respectively, which are located primarily in Germany.

Quarterly Results of Operation

Quarterly Results of Operation	12 Months Ended
	Mar. 31, 2021
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operation	Note 18. Quarterly Results of Operation (Unaudited) The following is a summary of the Company’s unaudited quarterly results of operations: Fiscal Year Ended March 31, 2021 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Total Year (in $000's) Revenue $ 164,850 $ 209,764 $ 231,663 $ 241,246 $ 847,522 Cost of revenue 35,983 38,736 41,110 46,078 161,907 Other operating expenses 94,801 109,692 119,202 132,364 456,058 Other income (1) 27,010 11,579 9,384 10,690 58,663 Income before income taxes 61,076 72,915 80,735 73,494 288,220 Income tax provision (2) 16,488 10,702 18,867 16,638 62,695 Net income $ 44,588 $ 62,213 $ 61,868 $ 56,856 $ 225,525 Basic net income per share $ 0.99 $ 1.38 $ 1.37 $ 1.26 $ 5.00 Diluted net income per share $ 0.98 $ 1.36 $ 1.35 $ 1.24 $ 4.94 Fiscal Year Ended March 31, 2020 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Total Year (in $000's) Revenue $ 207,666 $ 204,974 $ 221,584 $ 206,658 $ 840,883 Cost of revenue 37,073 34,867 39,996 39,369 151,305 Other operating expenses 109,868 109,925 111,329 109,237 440,359 Other income (expense) (1) 42,413 (42,824 ) 26,757 (18,739 ) 7,606 Income before income taxes 103,138 17,358 97,016 39,313 256,825 Income tax provision (2) 14,215 4,287 27,799 7,515 53,816 Net income $ 88,923 $ 13,071 $ 69,217 $ 31,798 $ 203,009 Basic net income per share $ 1.97 $ 0.29 $ 1.53 $ 0.71 $ 4.49 Diluted net income per share $ 1.93 $ 0.28 $ 1.51 $ 0.70 $ 4.43 (1) In fiscal year 2019, the Company invested $25.0 million in medical device company Shockwave Medical. The fair value of this investment as of March 31, 2021 was $38.7 million. The Company recognized a pre-tax gain of $50.8 million for the year ended March 31, 2021 and a pre-tax loss of $0.5 million for the year ended March 31, 2020 in other income (expense), net. (2) The income tax provision for the years ended March 31, 2021 and 2020 included excess tax benefits of $12.1 million and $14.8 million, respectively. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during the years ended March 31, 2021 and 2020.

Basis of Preparation and Summ_2

Basis of Preparation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
COVID-19 Pandemic	COVID-19 Pandemic The Company is subject to risks and uncertainties as a result of the ongoing COVID-19 pandemic. The ongoing COVID-19 pandemic has adversely impacted and is likely to further adversely impact the Company’s business and markets, including the Company’s workforce and the operations of its customers, suppliers, and business partners. The full extent to which the pandemic will directly or indirectly impact the Company's business, results of operations and financial condition, including sales, expenses, manufacturing, clinical trials, research and development costs, reserves and allowances, fair value measurements, asset impairment charges, contingent consideration obligations, and the effectiveness of the Company's hedging instruments, will depend on future developments that are highly uncertain and difficult to predict. These developments include, but are not limited to: the duration and spread of the ongoing COVID-19 pandemic (including new variants of COVID-19), its severity, the actions to contain the virus or address its impact, the timing, distribution, and efficacy of vaccines and other treatments, U.S. and foreign government actions to respond to the reduction in global economic activity, and how quickly and to what extent normal economic and operating conditions can resume. Beginning in mid-March 2020, the Company experienced a decline in patient utilization in its main markets in the U.S., Europe and Japan as healthcare systems diverted resources to meet the increasing demands of managing COVID-19. The Company’s business was most impacted in the first quarter of fiscal year 2021, in terms of the decline in patients and revenue from the shelter-in-place restrictions in a majority of countries and limitations on procedures in hospitals. The Company experienced sequential quarterly improvement during the second quarter of fiscal year 2021 as patient procedure volume trends and availability of healthcare resources improved as certain restrictions were lifted and limitations eased during the summer of 2020. During the third quarter of fiscal year 2021, a broad resurgence of COVID-19 cases throughout the U.S. and Europe slowed the Company’s continued recovery in patient utilization. Despite these challenges, the Company experienced increased recovery in patient utilization and revenue during the fourth quarter of fiscal year 2021 due to the high-risk nature of the patient population that are treated with the Company’s Impella devices. While the COVID-19 pandemic remains fluid and continues to evolve differently across various geographies, the Company believes it is likely to continue to experience variable impacts on its business. Hospitals are generally managing the pandemic better currently than they have in the earlier part of the pandemic due to more testing, improved protocols, more experience with the effects of COVID-19 and a greater number of vaccinated caregivers. During these challenging times, the Company’s priorities have been to support its clinician partners, protect the well-being of its employees and maintain continuous access to its life-saving technologies while offering front-line in-hospital support. The Company has established onsite COVID-19 testing for its employees in both Danvers, Massachusetts and Aachen, Germany, set up temperature-taking stations, administered thousands of COVID-19 tests to date and provided personal protective equipment for its employees in order to maintain a safe working environment. The Company’s proactive testing program has reduced exposure with early detection, reduced employee anxiety and enabled its manufacturing facilities to operate at full capacity in line with local social distancing requirements. The Company also took proactive actions in the first half of fiscal year 2021 in order to mitigate the business impact of COVID-19 on its financial operations and it continues to monitor closely in order the business impact of COVID-19. Despite the ongoing challenges posed by COVID-19, including the recent global resurgence, the Company continues to invest strategically in engineering, regulatory, clinical trials and manufacturing in order to support its future growth initiatives and sales and marketing activities, with a particular focus on training and education initiatives to drive utilization of its products and recovery awareness for acute heart failure patients. The Company continues to closely monitor the impact of COVID-19 on all aspects of its business and geographies, including its impact on its customers, employees, suppliers, vendors, business partners and distribution channels. The extent to which the COVID-19 pandemic impacts the Company’s business, results of operations, and financial condition will depend on future developments, which are highly uncertain and are difficult to predict. Even after the ongoing COVID-19 pandemic has subsided, the Company may continue to experience materially adverse impacts on its financial condition and results of operations.
Use of Estimates	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 and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The Company bases its estimates on historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition, collectability of receivables, realizability of inventory, property and equipment, goodwill, intangible and other long-lived assets, other investments, accrued expenses, stock-based compensation, income taxes including deferred tax assets and liabilities, contingencies and litigation. Provisions for depreciation are based on their estimated useful lives using the straight-line method. Some of these estimates can be subjective and complex and, consequently, actual results may differ from these estimates under different assumptions or conditions.
Cash Equivalents and Marketable Securities	Cash Equivalents and Marketable Securities The Company classifies any marketable security with an original maturity date of 90 days or less at the time of purchase as a cash equivalent. Cash equivalents are carried on the balance sheet at fair market value. The Company classifies any marketable security with a maturity date of greater than 90 days at the time of purchase as marketable securities and classifies marketable securities with a maturity date of greater than one year from the balance sheet date as long-term marketable securities. The Company’s marketable securities, consisting of U.S. Treasury securities, government-back securities, corporate debt securities, and commercial paper, are classified as available-for-sale securities and, accordingly, are recorded at fair value. The difference between amortized cost and fair value is included in stockholders’ equity. Marketable securities that the Company has the positive intent and ability to hold to maturity are reported at amortized cost and classified as held-to-maturity marketable securities. If the Company does not have the intent and ability to hold a marketable security to maturity, it reports the investment as available-for-sale marketable securities. The Company includes unrealized gains and, to the extent deemed temporary, unrealized losses in stockholders’ equity. If any adjustment to fair value reflects a decline in the value of the investment, the Company considers available evidence to evaluate whether the decline is “other than temporary” and, if so, marks the marketable security to market through a charge reflected on the consolidated statements of operations.
Major Customers and Concentrations of Credit Risk	Major Customers and Concentrations of Credit Risk The Company primarily sells its products to hospitals and distributors. No individual customer accounted for more than 10% of total revenues in fiscal years ended March 31, 2021, 2020 or 2019. No individual customer had an accounts receivable balance greater than 10% of total accounts receivable as of March 31, 2021 and 2020. Credit is extended based on an evaluation of a customer’s historical financial condition and generally collateral is not required. The Company’s history of credit losses has not been significant and the Company maintains an allowance for doubtful accounts based on its assessment of the collectability of accounts receivable. Accounts receivables are geographically dispersed, primarily throughout the U.S., as well as in Europe and other foreign countries where formal distributor agreements exist in certain countries. The Company's exposure to credit losses may increase if its customers are adversely affected by changes in healthcare laws, coverage, and reimbursement, economic pressures or uncertainty associated with local or global economic recessions, or other customer-specific factors. Financial instruments which potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents, marketable securities, short and long-term marketable securities and accounts receivable. Management mitigates credit risk by limiting the investment type and maturity to securities that preserve capital, maintain liquidity and have a high credit quality.
Financial Instruments	Financial Instruments The Company’s financial instruments are comprised of cash and cash equivalents, derivative instruments, marketable securities, accounts receivable, accounts payable and contingent consideration. The carrying amounts of accounts receivable and accounts payable are considered reasonable estimates of their fair value, due to the short maturity of these investments.
Derivative Instruments	Derivative Instruments The Company uses a foreign-exchange-related derivative instrument to manage its exposure related to changes in the exchange rate on its intercompany loan. The Company does not enter into derivative instruments for any purpose other than cash flow hedging. The Company does not speculate using derivative instruments. The Company recognizes all derivative instruments as either assets or liabilities in the balance sheet at their respective fair values. For more information, see “Note 5. Financial Instruments—Derivative Instruments.”
Inventories	Inventories Inventories are stated at the lower of cost or market. Cost is based on the first in, first out method. The Company regularly reviews inventory quantities on hand and writes down to its net realizable value any inventory that it believes to be impaired. Management considers forecast demand in relation to the inventory on hand, competitiveness of product offerings, market conditions and product life cycles when determining excess and obsolescence and net realizable value adjustments. Once inventory is written down and a new cost basis is established, it is not written back up if demand increases.
Property and Equipment	Property and Equipment Property and equipment is recorded at cost less accumulated depreciation. Land is carried at cost and is not depreciated. Depreciation is computed using the straight-line method based on estimated useful lives of three to five years for machinery and equipment, computer software, and furniture and fixtures. Building and building improvements are depreciated using the straight-line method over estimated useful lives of seven to thirty-three years. Leasehold improvements are amortized using the straight-line method over the shorter of the lease term or the estimated useful lives of the related assets. Expenditures for maintenance and repairs are expensed as incurred. Upon retirement or other disposition of assets, the costs and related accumulated depreciation are eliminated from the accounts and the resulting gain or loss is reflected in operating expenses. Property and equipment is reviewed for impairment losses whenever events or changes in circumstances indicate the carrying amount may not be recoverable. An impairment loss would be recognized based on the amount by which the carrying value of the asset or asset group exceeds its fair value. Fair value is determined primarily using the estimated future cash flows associated with the asset or asset group under review discounted at a rate commensurate with the risk involved and other valuation techniques.
Other Investments	Other Investments The Company periodically makes investments in medical device companies that focus on heart failure and heart pumps and other medical device technologies. For investments that do not have readily determinable market values, the Company measures these investments at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment. The Company monitors any events or changes in circumstances that may have a significant effect on the fair value of investments, either due to impairment or based on observable price changes, and makes any necessary adjustments.
Leases	Leases On April 1, 2019, the Company adopted ASU 2016-02, “Leases.” This new guidance required that the Company’s lease commitments to be recognized as operating lease liabilities and right-of-use assets, which increased total assets and total liabilities that the Company reported on its consolidated balance sheet. For a discussion on the impact of this accounting policy adoption, including key accounting policies and elections, see “Note 11. Leases.”
Goodwill	Goodwill Goodwill is recorded when consideration for an acquisition exceeds the fair value of the net tangible and intangible assets acquired. Goodwill is not amortized. The Company evaluates goodwill for impairment at least annually at October 31, as well as whenever events or changes in circumstances suggest that the carrying amount may not be recoverable. In applying the goodwill impairment test, the Company assesses qualitative factors to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying value. Qualitative factors may include, but are not limited to, macroeconomic conditions, industry conditions, the competitive environment, changes in the market for the Company’s products and services, regulatory and political developments, cost factors, and entity specific factors such as strategies and overall financial performance. If, after assessing these qualitative factors, the Company determines it is more likely than not that the fair value of a reporting unit is less than its carrying value, then the Company performs a quantitative impairment test. The Company determined, after performing the qualitative review, that it is more likely than not that the fair value of each of its reporting units substantially exceeds the respective carrying amounts.
Indefinite-Lived Intangibles and In-Process Research and Development	Indefinite-Lived Intangibles and In-process research and development, or IPR&D, assets are considered to be indefinite-lived until the completion or abandonment of the associated research and development projects. IPR&D assets represent the fair value assigned to technologies that are acquired, which at the time of acquisition have not reached technological feasibility and have no alternative future use. During the period that the IPR&D assets are considered indefinite-lived, they are tested for impairment on an annual basis on October 31, or more frequently if the Company becomes aware of any events occurring or changes in circumstances that indicate that the fair value of the IPR&D assets are less than their carrying values. If and when development is complete, which generally occurs upon regulatory approval and the Company is able to commercialize products associated with the IPR&D assets, these assets are then deemed definite-lived and are amortized based on their estimated useful lives at that point in time. If development is terminated or abandoned, the Company may have a full or partial impairment charge related to the IPR&D assets, calculated as the excess of carrying value of the IPR&D assets over fair value. The Company performed its annual impairment review for fiscal year 2021 as of October 31, 2020 and concluded that it was more likely than not that the fair value of the IPR&D assets is not less than its carrying value.
Finite-lived Intangible Assets	Finite-Lived Intangible Assets The Company records finite-lived intangible assets at historical cost and amortizes over their estimated useful lives. The Company uses a straight-line method of amortization, unless a method that better reflects the pattern in which the economic benefits of the intangible asset are consumed or otherwise used up can be reliably determined. The approximate useful live for amortization of the Company’s intangible assets is 15 years for the OXY-1 System amortizable technology from the acquisition of Breethe. The Company reviews finite-lived intangible assets subject to amortization quarterly to determine if any adverse conditions exist or a change in circumstances has occurred that would indicate impairment or a change in the remaining useful life. Conditions that may indicate impairment include, but are not limited to, a significant adverse change in legal factors or business climate that could affect the value of an asset, a product recall or an adverse action or assessment by a regulator. If the Company determines it is more likely than not that the asset is impaired based on its qualitative assessment of impairment indicators, the Company tests the intangible asset for recoverability.
Contingent Consideration	Contingent Consideration Contingent consideration represents potential milestones that the Company could pay as additional consideration for a business acquisition and is recorded as a liability and is measured at fair value using a combination of (1) an income approach, based on various revenue and cost assumptions and applying a probability to each outcome and (2) a Monte-Carlo valuation model that simulates outcomes based on management estimates. With the income approach, p robabilities were applied to each potential scenario and the resulting values were discounted using a rate that considers the weighted average cost of capital, the related projections, and the overall business. The Monte-Carlo valuation model simulates estimated future revenues during the earn out-period using management's best estimates.
Accrued Expenses	Accrued Expenses As part of the process of preparing its financial statements, the Company is required to estimate accrued expenses. This process includes identifying services that third parties have performed and estimating the level of service performed and the associated cost incurred on these services as of each balance sheet date in its financial statements. Examples of estimated accrued expenses include estimates for certain payroll costs, such as bonuses and commissions; contract service fees, such as amounts due to clinical research organizations and investigators in conjunction with clinical trials; professional service fees, such as attorneys and accountants, and third-party expenses relating to marketing efforts associated with commercialization of the Company’s products. The dates in which certain services commence and end, the level of services performed on or before a given date and the cost of services is often subject to the Company’s judgment. The Company makes these judgments and estimates based upon known facts and circumstances.
Revenue Recognition	Revenue Recognition See “Note 4. Revenue Recognition” for a discussion of key accounting policies and elections related to revenue recognition.
Product Warranty	Product Warranty The Company generally provides a one-year
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Comprehensive income (loss) is comprised of net income, plus all changes in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources, including any foreign currency translation adjustments. These changes in equity are recorded as adjustments to accumulated other comprehensive income (loss) in the Company’s consolidated balance sheet. The components of accumulated other comprehensive income (loss) consist of foreign currency translation adjustments, unrealized gains (losses) on marketable securities, and unrealized gains (losses) on derivative instruments. There were no reclassifications out of accumulated other comprehensive income (loss) during the fiscal years ended March 31, 2021, 2020 and 2019.
Translation of Foreign Currencies	Translation of Foreign Currencies The functional currency of the Company’s foreign subsidiaries is their local currency. The assets and liabilities of the Company’s foreign subsidiaries are translated into U.S. dollars at exchange rates in effect at the balance sheet date. Income and expense items in the Company’s consolidated statement of operations are translated at the average exchange rates prevailing during the period. The cumulative translation effect for subsidiaries using a functional currency other than the U.S. dollar is included in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity. The Company’s intercompany accounts are denominated in the functional currency of the foreign subsidiary. Gains and losses resulting from the remeasurement of intercompany transactions that the Company considers to be of a long-term investment nature are recorded in accumulated other comprehensive income or loss as a separate component of stockholders’ equity, while gains and losses resulting from the remeasurement of intercompany transactions from those foreign subsidiaries for which the Company anticipates settlement in the foreseeable future are recorded in the consolidated statement of operations. The net foreign currency translation gains and losses recorded in the consolidated statements of operations for the fiscal years ended March 31, 2021, 2020 and 2019 were not significant.
Net Income Per Share	Net Income Per Share Basic net income per share is computed by dividing net income by the weighted average number of common shares outstanding during the fiscal year. Diluted net income per share is computed using the treasury stock method by dividing net income by the weighted average number of dilutive common shares outstanding during the fiscal year. Diluted shares outstanding is calculated by adding to the weighted average shares outstanding any potential dilutive securities outstanding for the fiscal year. Potential dilutive securities include stock options, restricted stock units, performance-based stock awards and shares to be purchased under the Company’s employee stock purchase plan. The Company’s basic and diluted net income per share were as follows (figures in tables are in thousands, except per share data): Fiscal Years Ended March 31, Basic Net Income Per Share 2021 2020 2019 Net income $ 225,525 $ 203,009 $ 259,016 Weighted average shares - basic 45,140 45,179 44,911 Net income per share - basic $ 5.00 $ 4.49 $ 5.77 Fiscal Years Ended March 31, Diluted Net Income Per Share 2021 2020 2019 Net income $ 225,525 $ 203,009 $ 259,016 Weighted average shares - basic 45,140 45,179 44,911 Effect of dilutive securities 534 637 1,240 Weighted average shares - diluted 45,674 45,816 46,151 Net income per share - diluted $ 4.94 $ 4.43 $ 5.61 For the fiscal years ended March 31, 2021, 2020 and 2019, approximately 168,000, 232,000 and 64,000 shares of common stock underlying outstanding securities related to out-of-the-money stock options and performance-based awards where milestones were not met were not included in the computation of diluted earnings per share because their inclusion would be anti-dilutive.
Stock-Based Compensation	Stock-Based Compensation The Company’s stock-based compensation cost is measured at the grant date based on the fair value of the award and is recognized as an expense over the requisite service period. The fair value of stock option grants is estimated using the Black-Scholes option pricing model. Use of the valuation model requires management to make certain assumptions with respect to selected model inputs. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for a term consistent with the expected life of the stock options. Volatility assumptions are calculated based on historical volatility of the Company’s stock. The Company estimates the expected term of options based on historical exercise experience and estimates of future exercises of unexercised options. In addition, an expected dividend yield of zero is used in the option valuation model because the Company does not pay cash dividends and does not expect to pay any cash dividends in the foreseeable future. Forfeitures are recorded as they occur instead of estimating forfeitures that are expected to occur. For awards with service conditions only, the Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period. For awards with service and performance-based conditions, the Company recognizes stock-based compensation expense using the graded vesting method over the requisite service period. Estimates of stock-based compensation expense for an award with performance conditions are based on the probable outcome of the performance conditions and the cumulative effect of any changes in the probability outcomes are recorded in the period in which the changes occur.
Income Taxes	Income Taxes The Company’s provision for income taxes is comprised of a current and deferred provision. The current income tax provision is calculated as the estimated taxes payable or refundable on income tax returns for the current fiscal year. The deferred income tax provision is calculated for the estimated future income tax effects attributable to temporary differences and carryforwards using expected tax rates in effect in the years during which the temporary differences are expected to reverse. Deferred income taxes are recognized for the tax consequences in future years as the differences between the tax bases of assets and liabilities and their financial reporting amounts at each fiscal year end based on enacted tax laws and statutory tax rates applicable to the periods in which the differences are expected to impact taxable income. The Company regularly assesses its ability to realize its deferred tax assets. Assessing the realization of deferred tax assets requires significant management judgment. Valuation allowances are established when necessary to reduce net deferred tax assets to the amount that is more likely than not to be realized. The Company recognizes and measures uncertain tax positions using a two-step approach. The first step is to evaluate the tax position for recognition by determining if, based on the technical merits, it is more likely than not that the position will be sustained upon audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit at the largest amount that is more likely than not of being realized upon ultimate settlement. The Company reevaluates these uncertain tax positions on an ongoing basis, when applicable. This evaluation is based on factors including, but not limited to, changes in facts or circumstances, new information and technical insights, and changes in tax laws. Any changes in these factors could result in the recognition of a tax benefit or an additional charge to the tax provision. Refer to “ Note 15. Income Taxes ” for further information related to the Tax Reform Act and its impact on the Company’s financial statements. When applicable, the Company accrues for the effects of uncertain tax positions and the related potential penalties and interest through income tax expense.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Effective April 1, 2019, the Company adopted the Financial Accounting Standards Board (“FASB”) standard update ASU 2016-02 “Leases,” which requires lessees to identify arrangements that should be accounted for as leases. Under this guidance, for lease arrangements exceeding a one-year term, a right-of-use asset and lease obligation is recorded by the lessee for all leases on the balance sheet, whether operating or financing, while the statement of operations includes lease expense for operating leases and amortization and interest expense for financing leases. ASU 2016-02 was adopted using a modified retrospective approach for all leases existing at or entered into after the April 1, 2019. Additional information and disclosures required by this new standard are contained in “ Note 11. Leases .” In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326).” This guidance will require financial instruments to be measured at amortized cost, and accounts receivables to be presented at the net amount expected to be collected. The new model requires an entity to estimate credit losses based on historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments. ASU 2016-13 is effective for annual reporting periods beginning after December 31, 2019. This update did not have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350).” This new standard simplifies the accounting for goodwill impairment by removing Step 2 of the goodwill impairment test, which required companies to estimate the implied fair value of goodwill and recognize an impairment charge by the amount in which the carrying value exceeds the implied fair value. Under the new guidance, if the carrying value of a reporting unit exceeds its fair value, a goodwill impairment charge will be recorded, even if the difference is attributable to the fair value of other assets in the reporting unit. The Company adopted this standard in the first quarter of fiscal 2021, and it did not have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820).” Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosure requirements on fair value measurements. This ASU is effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. The Company adopted this standard in the first quarter of fiscal year 2021 and did not have a material impact on its consolidated financial statements .
Recently Issued Accounting Pronouncements Not Yet Effective	Recently Issued Accounting Pronouncements Not Yet Effective In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740).” This amendment to the guidance on income taxes is intended to simplify the accounting for income taxes. The amendment eliminates certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, and the recognition of deferred tax liabilities for outside basis differences. The amendment also clarifies existing guidance related to the evaluation of a step up in the tax basis of goodwill, and the effects of enacted changes in tax laws or rates in the effective tax rate computation, among other clarifications. ASU 2019-12 will become effective for the Company in fiscal year 2022. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. In January 2020, the FASB issued ASU 2020-01, “Investments—Equity Securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815),” an amendment clarifying the interaction between accounting standards related to equity securities, equity method investments, and certain derivative instruments. The guidance is effective for fiscal years beginning after December 15, 2020. ASU 2020-01 will become effective for the Company in fiscal year 2022. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. No other new accounting pronouncements, issued or effective, during the period had, or are expected to have, a material impact on our consolidated financial statements.

Basis of Preparation and Summ_3

Basis of Preparation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Computation of Basic and Diluted Net Income Per Share	The Company’s basic and diluted net income per share were as follows (figures in tables are in thousands, except per share data): Fiscal Years Ended March 31, Basic Net Income Per Share 2021 2020 2019 Net income $ 225,525 $ 203,009 $ 259,016 Weighted average shares - basic 45,140 45,179 44,911 Net income per share - basic $ 5.00 $ 4.49 $ 5.77 Fiscal Years Ended March 31, Diluted Net Income Per Share 2021 2020 2019 Net income $ 225,525 $ 203,009 $ 259,016 Weighted average shares - basic 45,140 45,179 44,911 Effect of dilutive securities 534 637 1,240 Weighted average shares - diluted 45,674 45,816 46,151 Net income per share - diluted $ 4.94 $ 4.43 $ 5.61

Acquisition (Tables)

Acquisition (Tables)	12 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
Schedule of Business Acquisitions Date Fair Value of Consideration Transferred	The acquisition-date fair value of the consideration transferred is as follows: Total Acquisition Date Fair Value (in thousands) Cash and other considerations $ 57,850 Contingent consideration 13,300 Total consideration transferred $ 71,150
Schedule of Estimated Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed on the date of acquisition (in thousands): Acquired assets: Cash and cash equivalents $ 3,404 Property and equipment 744 Goodwill 44,485 In-process research and development 27,000 Other assets acquired 895 Total assets acquired 76,528 Liabilities assumed: Accounts payable and other liabilities 1,562 Deferred tax liabilities 3,816 Net assets acquired $ 71,150

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Schedule of Disaggregated Revenue by Major Business Line and Geographical Location	The following table disaggregates the Company’s revenue by products and services: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Impella product revenue $ 806,322 $ 806,824 $ 741,699 Service and other revenue 41,200 34,059 27,733 Total revenue $ 847,522 $ 840,883 $ 769,432 The following table disaggregates the Company’s revenue by geographical location: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) U.S. $ 691,579 $ 705,409 $ 665,082 Europe 105,320 94,266 57,460 Japan 42,868 35,215 17,502 Other international 7,755 5,993 29,388 Total revenue $ 847,522 $ 840,883 $ 769,432

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Cash Equivalents and Marketable Securities	The Company’s cash equivalents and marketable securities are invested in the following: Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value March 31, 2021: (in $000's) Money market funds $ 124,297 $ — $ — $ 124,297 Repurchase agreements 33,000 — — 33,000 Total cash equivalents 157,297 — — 157,297 Short-term U.S. Treasury mutual fund securities 72,221 28 — 72,249 Short-term government-backed securities 128,668 13 (12 ) 128,669 Short-term corporate debt securities 104,253 581 (2 ) 104,832 Short-term commercial paper 45,237 1 (3 ) 45,235 Total short-term marketable securities 350,379 623 (17 ) 350,985 Long-term government-backed securities 225,231 190 (37 ) 225,384 Long-term corporate debt securities 38,091 630 (20 ) 38,701 Total long-term marketable securities 263,322 820 (57 ) 264,085 $ 770,998 $ 1,443 $ (74 ) $ 772,367 Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value March 31, 2020: (in $000's) Money market funds $ 115,019 $ — $ — $ 115,019 Repurchase agreements 20,000 — — 20,000 Total cash equivalents 135,019 — — 135,019 Short-term U.S. Treasury securities 42,236 412 — 42,648 Short-term government-backed securities 67,594 401 — 67,995 Short-term corporate debt securities 107,290 94 (83 ) 107,301 Short-term commercial paper 32,757 74 — 32,831 Total short-term marketable securities 249,877 981 (83 ) 250,775 Long-term government-backed securities 90,911 153 — 91,064 Long-term corporate debt securities 116,110 851 (230 ) 116,731 Total long-term marketable securities 207,021 1,004 (230 ) 207,795 $ 591,917 $ 1,985 $ (313 ) $ 593,589
Schedule of Cross-Currency Rate Swap Derivatives Agreement	The following table summarizes the terms of the cross-currency swap agreement as of March 31, 2021 (dollar amounts in thousands): Effective Date Maturity Fixed Rate Aggregate Notional Amount (in $000's) Pay EUR October 15, October 15, 2.75% EUR 85,000 Receive U.S.$ 2019 2024 4.64% USD 93,457
Schedule of Fair Value of Company's Derivative Instrument	The following table presents the fair value of the Company’s derivative instrument as follows: March 31, 2021 March 31, 2020 Derivatives designated as hedging instruments under ASC 815 Balance sheet classification (in $000's) Cross-currency swap (Long-term liabilities) other assets $ (4,298 ) $ 3,786
Components of Contingent Consideration Liabilities	The components of contingent consideration liability are as follows: March 31, 2021 March 31, 2020 (in $000's) ECP $ 10,306 $ 9,000 Breethe 14,400 — $ 24,706 $ 9,000
Financial Instruments Measured at Fair Value	The following table presents the Company’s fair value hierarchy for its financial instruments measured at fair value: Level 1 Level 2 Level 3 Total March 31, 2021: (in $000's) Assets Money market funds $ 124,297 $ — $ — $ 124,297 Repurchase agreements — 33,000 — 33,000 Short-term U.S. Treasury securities — 72,249 — 72,249 Short-term government-backed securities — 128,669 — 128,669 Short-term corporate debt securities — 104,832 — 104,832 Short-term commercial paper — 45,235 — 45,235 Long-term government-backed securities — 225,384 — 225,384 Long-term corporate debt securities — 38,701 — 38,701 Investment in Shockwave Medical 38,655 — — 38,655 Liabilities Cross currency swap agreement — 4,298 — 4,298 Contingent consideration — — 24,706 24,706 Level 1 Level 2 Level 3 Total March 31, 2020: (in $000's) Assets Money market funds $ 115,019 $ — $ — $ 115,019 Repurchase agreements — 20,000 — 20,000 Short-term U.S. Treasury securities — 42,648 — 42,648 Short-term government-backed securities — 67,995 — 67,995 Short-term corporate debt securities — 107,301 — 107,301 Short-term commercial paper — 32,831 — 32,831 Long-term government-backed securities — 91,064 — 91,064 Long-term corporate debt securities — 116,731 — 116,731 Cross currency swap agreement — 3,786 — 3,786 Investment in Shockwave Medical 55,704 — — 55,704 Liabilities Contingent consideration — — 9,000 9,000
Change in Fair Value of Contingent Consideration as Determined by Level 3 Inputs	The following table summarizes the change in fair value, as determined by Level 3 inputs, of the contingent consideration: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Level 3 liabilities, beginning balance $ 9,000 $ 9,575 $ 10,490 Additions 13,300 — — Payments — — — Change in fair value 2,406 (575 ) (915 ) Level 3 liabilities, ending balance $ 24,706 $ 9,000 $ 9,575

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Mar. 31, 2021
Receivables [Abstract]
Components of Accounts Receivable	The components of accounts receivable are as follows: March 31, 2021 March 31, 2020 (in $000's) Trade receivables $ 97,953 $ 85,852 Allowance for doubtful accounts (774 ) (1,202 ) $ 97,179 $ 84,650
Summary of Allowance for Doubtful Accounts Receivable	The following table summarizes activity in the allowance for doubtful accounts: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Balance at beginning of year $ 1,202 $ 1,040 $ 320 Additions (recoveries) (127 ) 487 720 Write-offs (301 ) (325 ) — Balance at end of year $ 774 $ 1,202 $ 1,040

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Components of Inventories	The components of inventories are as follows: March 31, 2021 March 31, 2020 (in $000's) Raw materials and supplies $ 27,782 $ 31,411 Work-in-progress $ 35,187 35,008 Finished goods $ 18,090 23,669 $ 81,059 $ 90,088

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Mar. 31, 2021
Property Plant And Equipment [Abstract]
Components of Property and Equipment	The components of property and equipment are as follows: March 31, 2021 March 31, 2020 (in $000's) Land $ 10,875 $ 7,179 Building and building improvements 148,870 100,176 Leasehold improvements 439 14,546 Machinery and equipment 91,784 71,636 Furniture and fixtures 15,608 14,600 Construction in progress 10,906 15,075 Total cost 278,482 223,212 Less accumulated depreciation (81,353 ) (58,281 ) $ 197,129 $ 164,931

Goodwill, In-Process Research_2

Goodwill, In-Process Research & Development and Other Assets (Tables)	12 Months Ended
	Mar. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill Activity	The goodwill activity is as follows: (in $000's) Balance, March 31, 2019 $ 32,601 Foreign currency translation impact (632 ) Balance, March 31, 2020 $ 31,969 Breethe acquisition 44,485 Foreign currency translation impact 2,114 Balance, March 31, 2021 $ 78,568
Other Intangible Assets, net	Other intangible assets consist of the following: March 31, 2021 March 31, 2020 Weighted Average Useful Life (in years) Cost Accumulated Amortization Net Carrying Value Cost Accumulated Amortization Net Carrying Value (in $000's) Finite-lived intangible assets Developed technology 14.6 $ 27,000 $ (750 ) $ 26,250 — — — Indefinite-lived intangible assets In-process research and development 15,900 — 15,900 14,913 — 14,913 Total $ 42,900 $ (750 ) $ 42,150 $ 14,913 — $ 14,913

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
	Mar. 31, 2021
Other Assets [Abstract]
Summary of Components of Other Assets	The components of other assets are as follows: Fiscal Years Ended March 31, 2021 2020 (in $000's) Investment in Shockwave Medical $ 38,655 $ 55,704 Other investments 62,995 38,741 Operating lease right-of-use assets (Note 11) 6,109 11,760 Cross-currency swap (Note 5) — 3,786 Other intangible assets and other assets 5,323 7,664 Total other assets $ 113,082 $ 117,655
Schedule Of Portfolio Of Equity Method and Other Investments and Change in Balance	The Company periodically makes investments in medical device companies that focus on heart failure and heart pumps and other medical device technologies. The carrying value of the Company’s portfolio of other investments and the changes in the balance were as follows: Fiscal Years Ended March 31, 2021 2020 (in $000's) Beginning balance $ 38,741 $ 24,584 Additions 26,104 19,599 Reclassification (2,000 ) - Impairment (800 ) (750 ) Change in fair value, net 950 (4,692 ) Ending balance $ 62,995 $ 38,741

Leases (Tables)

Leases (Tables)	12 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Supplemental Balance Sheet Information Related to Operating Leases	The following table presents supplemental balance sheet information related to the Company’s operating leases: March 31, 2021 March 31, 2020 (in $000's) Assets Operating lease right-of-use assets in other assets $ 6,109 $ 11,760 Liabilities Operating lease liabilities in other current liabilities 2,459 3,671 Operating lease liabilities in other long-term liabilities 3,657 8,549 Total operating lease liabilities $ 6,116 $ 12,220
Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities as of March 31, 2021 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2022 $ 2,574 2023 1,404 2024 1,165 2025 617 2026 77 Thereafter 599 Total minimum lease payments 6,436 Less: imputed interest (320 ) Present value of operating lease liabilities $ 6,116 Weighted average remaining lease term 4.02 Weighted average discount rate 1.96 %

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Mar. 31, 2021
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses consisted of the following: March 31, 2021 March 31, 2020 (in $000's) Employee compensation $ 40,954 $ 32,273 Research and development 6,983 5,749 Sales and income taxes 5,914 21,641 Marketing 3,674 1,705 Warranty 2,053 1,818 Professional, legal and accounting fees 1,957 6,880 Other 4,511 5,041 $ 66,046 $ 75,107

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Schedule of Stock Repurchase Activity	The following table provides stock repurchase activities: For the Year Ended March 31, 2021 2020 Shares repurchased 67,649 465,687 Average price per share $ 167.19 $ 182.27 Value of shares repurchased (in millions) $ 11.3 $ 84.9
Schedule of Accumulated Other Comprehensive Income (Loss)	The components of accumulated other comprehensive income (loss), are as follows (in thousands): Foreign Currency Translation Gains (Losses) Unrealized Gains (Losses) on Investments Unrealized Gains (Losses) on Derivative Instruments Total (in $000's) Balance, April 1, 2018 (3,597 ) (607 ) — (4,204 ) Other comprehensive (loss) income (11,431 ) 946 — (10,485 ) Balance, March 31, 2019 (15,028 ) 339 — (14,689 ) Other comprehensive income (loss) (1,832 ) 1,333 3,999 3,500 Balance, March 31, 2020 (16,860 ) 1,672 3,999 (11,189 ) Other comprehensive (loss) income 2,142 (303 ) (2,095 ) (256 ) Balance, March 31, 2021 $ (14,718 ) $ 1,369 $ 1,904 (11,445 )

Stock Award Plans and Stock-B_2

Stock Award Plans and Stock-Based Compensation (Tables)	12 Months Ended
	Mar. 31, 2021
Stock-Based Compensation Recognized	The following table summarizes stock-based compensation expense by financial statement line item in the Company’s consolidated statements of operations: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Cost of revenue $ 3,760 $ 2,641 $ 2,643 Research and development 6,941 5,534 9,312 Selling, general and administrative 36,305 31,606 42,539 $ 47,006 $ 39,781 $ 54,494
Components of Stock-Based Compensation	The components of stock-based compensation were as follows: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Restricted stock units $ 36,347 $ 28,895 $ 45,998 Stock options 8,982 9,006 7,445 Employee stock purchase plan 1,677 1,880 1,051 $ 47,006 $ 39,781 $ 54,494
Summary of Stock Option Activity	The following table summarizes stock option activity for the fiscal year ended March 31, 2021: Weighted Weighted Average Aggregate Average Remaining Intrinsic Options Exercise Contractual Value (in thousands) Price Term (years) (in thousands) Outstanding at beginning of period 869 $ 112.03 5.30 Granted 70 225.60 Exercised (215 ) 42.16 Cancelled and expired (13 ) 248.42 Outstanding at end of period 711 $ 141.87 5.46 $ 129,912 Exercisable at end of period 537 $ 104.55 4.51 $ 117,880 Options vested and expected to vest at end of period 711 $ 141.87 5.46 $ 129,912
Summary of Weighted Average Grant-Date Fair Values And Weighted Average Assumptions Used to Calculate Fair Value of Options Granted	The weighted average grant-date fair values and weighted average assumptions used in the calculation of fair value of options granted were as follows: Fiscal Years Ended March 31, 2021 2020 2019 Valuation assumptions: Weighted average grant-date fair value $ 77.82 $ 93.05 $ 141.47 Risk-free interest rate 0.32 % 1.97 % 2.91 % Expected option life (years) 4.22 4.14 4.04 Expected volatility 42.9 % 42.3 % 42.8 %
Restricted Stock Units
Summary of Restricted Stock Units Activity	The following table summarizes restricted stock unit activity for the fiscal year ended March 31, 2021: Number of Shares Weighted Average Grant Date Fair Value (in thousands) (per share) Restricted stock units at beginning of period 320 $ 263.92 Granted 230 254.78 Vested (139 ) 227.32 Forfeited (109 ) 266.57 Restricted stock units at end of period 301 $ 273.57
Summary of Assumptions Used To Value Awards And Estimated Grant-Date Fair Value	The table below sets forth the assumptions used to value the awards and the estimated grant-date fair value: Risk-free interest rate 0.2 % Expected volatility 35.5 % Dividend yield — Remaining performance period (years) 1.9 - 2.9 Estimated grant date fair value per share $347.05 - $349.28 Target performance (number of shares) 30,881

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Components of Income Tax Provision	The components of the Company’s income tax provision are as follows: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Income before provision for income taxes: United States $ 249,204 $ 214,825 $ 223,340 Foreign 39,016 42,000 40,020 Income before income taxes 288,220 256,825 263,360 Current tax expense: Federal 8,624 — — State 12,379 6,563 564 Foreign 12,312 14,300 11,525 33,315 20,863 12,089 Deferred tax expense (benefit): Federal 30,413 33,239 (7,153 ) State (2,382 ) 1,584 (1,503 ) Foreign 1,349 (1,870 ) 911 29,380 32,953 (7,745 ) Total income tax provision $ 62,695 $ 53,816 $ 4,344
Components of Net Deferred Taxes	The components of the Company’s net deferred taxes were as follows: March 31, 2021 March 31, 2020 (in $000's) Deferred tax assets Net operating loss and tax credit carryforwards $ 27,893 $ 50,604 Stock-based compensation 13,790 13,607 Nondeductible reserves and accruals 12,097 9,570 Foreign net operating loss carryforwards 6,856 6,778 Deferred revenue 5,522 4,404 Depreciation and amortization 51 114 Other, net 312 949 $ 66,521 $ 86,026 Deferred tax liabilities Goodwill (7,897 ) (7,843 ) In-process research and development (12,496 ) (4,564 ) Depreciation (11,747 ) (9,211 ) Basis differences on other investments (7,766 ) (6,124 ) Domestic deferred tax liability on foreign net operating loss carryforwards (415 ) (584 ) (40,321 ) (28,326 ) Net deferred tax assets 26,200 57,700 Valuation allowance (15,667 ) (15,170 ) Net deferred tax assets $ 10,533 $ 42,530 Reported as: Deferred tax assets $ 11,380 $ 43,336 Deferred tax liabilities (847 ) (806 ) Net deferred tax assets $ 10,533 $ 42,530
Differences Between Statutory and Effective Income Tax Rate	The significant differences between the statutory and effective income tax rate consist of the following items: Fiscal Years Ended March 31, 2021 2020 2019 Statutory income tax rate 21.0 % 21.0 % 21.0 % Increase (decrease) resulting from: Credits (6.0 ) (10.8 ) (1.5 ) Rate differential on foreign operations 4.1 3.2 0.2 Excess tax benefits from stock-based awards (3.3 ) (5.2 ) (24.1 ) State taxes, net 3.2 3.1 0.1 Permanent differences 2.4 5.0 1.8 Change in valuation allowance 0.3 5.3 (0.4 ) Foreign taxes — — 4.1 Other 0.1 (0.6 ) 0.4 Effective tax rate 21.8 % 21.0 % 1.6 %
Changes in Valuation Allowance for Deferred Tax Assets	Changes in the valuation allowance for deferred tax assets were as follows: Fiscal Years Ended March 31, 2021 2020 2019 (in $000's) Balance at beginning of year $ 15,170 $ 1,302 $ 1,652 Increase 497 13,868 — Decrease — — (350 ) Balance at end of year $ 15,667 $ 15,170 $ 1,302

Quarterly Results of Operation

Quarterly Results of Operation (Tables)	12 Months Ended
	Mar. 31, 2021
Quarterly Financial Information Disclosure [Abstract]
Summary of Unaudited Quarterly Results of Operations	The following is a summary of the Company’s unaudited quarterly results of operations: Fiscal Year Ended March 31, 2021 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Total Year (in $000's) Revenue $ 164,850 $ 209,764 $ 231,663 $ 241,246 $ 847,522 Cost of revenue 35,983 38,736 41,110 46,078 161,907 Other operating expenses 94,801 109,692 119,202 132,364 456,058 Other income (1) 27,010 11,579 9,384 10,690 58,663 Income before income taxes 61,076 72,915 80,735 73,494 288,220 Income tax provision (2) 16,488 10,702 18,867 16,638 62,695 Net income $ 44,588 $ 62,213 $ 61,868 $ 56,856 $ 225,525 Basic net income per share $ 0.99 $ 1.38 $ 1.37 $ 1.26 $ 5.00 Diluted net income per share $ 0.98 $ 1.36 $ 1.35 $ 1.24 $ 4.94 Fiscal Year Ended March 31, 2020 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Total Year (in $000's) Revenue $ 207,666 $ 204,974 $ 221,584 $ 206,658 $ 840,883 Cost of revenue 37,073 34,867 39,996 39,369 151,305 Other operating expenses 109,868 109,925 111,329 109,237 440,359 Other income (expense) (1) 42,413 (42,824 ) 26,757 (18,739 ) 7,606 Income before income taxes 103,138 17,358 97,016 39,313 256,825 Income tax provision (2) 14,215 4,287 27,799 7,515 53,816 Net income $ 88,923 $ 13,071 $ 69,217 $ 31,798 $ 203,009 Basic net income per share $ 1.97 $ 0.29 $ 1.53 $ 0.71 $ 4.49 Diluted net income per share $ 1.93 $ 0.28 $ 1.51 $ 0.70 $ 4.43 (1) In fiscal year 2019, the Company invested $25.0 million in medical device company Shockwave Medical. The fair value of this investment as of March 31, 2021 was $38.7 million. The Company recognized a pre-tax gain of $50.8 million for the year ended March 31, 2021 and a pre-tax loss of $0.5 million for the year ended March 31, 2020 in other income (expense), net. (2) The income tax provision for the years ended March 31, 2021 and 2020 included excess tax benefits of $12.1 million and $14.8 million, respectively. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during the years ended March 31, 2021 and 2020.

Basis of Preparation and Summ_4

Basis of Preparation and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2021Customershares	Mar. 31, 2020Customershares	Mar. 31, 2019Customershares
Summary Of Significant Accounting Policy [Line Items]
Expected dividend yield	0.00%
Net Income Per Share - Anti-dilutive securities
Summary Of Significant Accounting Policy [Line Items]
Shares excluded from the calculation of diluted weighted average shares outstanding | shares	168,000	232,000	64,000
Customer Concentration Risk | Total Revenues
Summary Of Significant Accounting Policy [Line Items]
Number of customers that accounted for more than 10% of total revenues / receivables	0	0	0
Customer Concentration Risk | Total Accounts Receivable
Summary Of Significant Accounting Policy [Line Items]
Number of customers that accounted for more than 10% of total revenues / receivables	0	0

Basis of Preparation and Summ_5

Basis of Preparation and Summary of Significant Accounting Policies - Property and Equipment - Useful Lives - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2021
Leasehold Improvements
Summary Of Significant Accounting Policy [Line Items]
Leasehold improvements, useful life	shorter of the lease term or the estimated useful lives
Minimum | Machinery and Equipment
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	3 years
Minimum | Computer Software
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	3 years
Minimum | Furniture and Fixtures
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	3 years
Minimum | Building and Building Improvements
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	7 years
Maximum | Machinery and Equipment
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	5 years
Maximum | Computer Software
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	5 years
Maximum | Furniture and Fixtures
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	5 years
Maximum | Building and Building Improvements
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	33 years

Basis of Preparation and Summ_6

Basis of Preparation and Summary of Significant Accounting Policies - Finite lived Intangible Assets - Useful Lives - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Oct. 31, 2020	Mar. 31, 2021
Accounting Policies [Abstract]
Finite-Lived Intangible Asset, Useful Life	15 years	15 years

Basis of Preparation and Summ_7

Basis of Preparation and Summary of Significant Accounting Policies - Product Warranty - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Product warranty period	1 year

Basis of Preparation and Summ_8

Basis of Preparation and Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income (Loss) - Additional Information (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Accounting Policies [Abstract]
Reclassifications out of accumulated other comprehensive income (loss)	$ 0	$ 0	$ 0

Computation of Basic and Dilute

Computation of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Basic Net Income Per Share
Net income	$ 56,856	$ 61,868	$ 62,213	$ 44,588	$ 31,798	$ 69,217	$ 13,071	$ 88,923	$ 225,525	$ 203,009	$ 259,016
Weighted average shares - basic									45,140	45,179	44,911
Net income per share - basic	$ 1.26	$ 1.37	$ 1.38	$ 0.99	$ 0.71	$ 1.53	$ 0.29	$ 1.97	$ 5	$ 4.49	$ 5.77
Diluted Net Income Per Share
Net income	$ 56,856	$ 61,868	$ 62,213	$ 44,588	$ 31,798	$ 69,217	$ 13,071	$ 88,923	$ 225,525	$ 203,009	$ 259,016
Weighted average shares - basic									45,140	45,179	44,911
Effect of dilutive securities									534	637	1,240
Weighted average shares - diluted									45,674	45,816	46,151
Net income per share - diluted	$ 1.24	$ 1.35	$ 1.36	$ 0.98	$ 0.70	$ 1.51	$ 0.28	$ 1.93	$ 4.94	$ 4.43	$ 5.61

Acquisition - Additional Inform

Acquisition - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 24, 2020	Oct. 31, 2020	Mar. 31, 2021
Restructuring Cost And Reserve [Line Items]
Payments to acquire businesses, cash paid	$ 55,000
In-process research and development	27,000	$ 27,000
Intangible asset, amortized useful life		15 years	15 years
Business acquisition, transaction costs			$ 900
Maximum
Restructuring Cost And Reserve [Line Items]
Potential payouts payments	$ 55,000

Schedule of Business Acquisitio

Schedule of Business Acquisitions Date Fair Value of Consideration Transferred (Detail) $ in Thousands	Apr. 24, 2020USD ($)
Business Combinations [Abstract]
Cash and other considerations	$ 57,850
Contingent consideration	13,300
Total consideration transferred	$ 71,150

Schedule of Estimated Fair Valu

Schedule of Estimated Fair Value of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 24, 2020
Business Combinations [Abstract]
Cash and cash equivalents		$ 3,404
Property and equipment		744
Goodwill		44,485
In-process research and development	$ 27,000	27,000
Other assets acquired		895
Total assets acquired		76,528
Accounts payable and other liabilities		1,562
Deferred tax liabilities		3,816
Net assets acquired		$ 71,150

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Disaggregated Revenue by Major Business Line (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Disaggregation Of Revenue [Line Items]
Total revenue	$ 241,246	$ 231,663	$ 209,764	$ 164,850	$ 206,658	$ 221,584	$ 204,974	$ 207,666	$ 847,522	$ 840,883	$ 769,432
U S [Member]
Disaggregation Of Revenue [Line Items]
Total revenue									691,579	705,409	665,082
Europe [Member]
Disaggregation Of Revenue [Line Items]
Total revenue									105,320	94,266	57,460
Japan [Member]
Disaggregation Of Revenue [Line Items]
Total revenue									42,868	35,215	17,502
Other international [Member]
Disaggregation Of Revenue [Line Items]
Total revenue									7,755	5,993	29,388
Impella Product
Disaggregation Of Revenue [Line Items]
Total revenue									806,322	806,824	741,699
Service and Other
Disaggregation Of Revenue [Line Items]
Total revenue									$ 41,200	$ 34,059	$ 27,733

Revenue Recognition - Returns R

Revenue Recognition - Returns Reserve - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Mar. 31, 2020
Revenue From Contract With Customer [Abstract]
Sales return reserve	$ 0	$ 0

Revenue Recognition - Deferred

Revenue Recognition - Deferred Revenue - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue From Contract With Customer [Abstract]
Deferred revenue	$ 24,322	$ 19,147
Deferred Revenue, Revenue Recognized	$ 19,000	$ 15,600

Investable Cash Equivalents and

Investable Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$ 770,998	$ 591,917
Gross Unrealized Gains	1,443	1,985
Gross Unrealized Losses	(74)	(313)
Fair Market Value	772,367	593,589
Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	157,297	135,019
Fair Market Value	157,297	135,019
Repurchase Agreement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Market Value	33,000	20,000
Repurchase Agreement | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	33,000	20,000
Fair Market Value	33,000	20,000
Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	350,379	249,877
Gross Unrealized Gains	623	981
Gross Unrealized Losses	(17)	(83)
Fair Market Value	350,985	250,775
Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	263,322	207,021
Gross Unrealized Gains	820	1,004
Gross Unrealized Losses	(57)	(230)
Fair Market Value	264,085	207,795
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Market Value	124,297	115,019
Money Market Funds | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	124,297	115,019
Fair Market Value	124,297	115,019
Commercial Paper | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	45,237	32,757
Gross Unrealized Gains	1	74
Gross Unrealized Losses	(3)
Fair Market Value	45,235	32,831
U.S. Treasury mutual fund securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	72,221	42,236
Gross Unrealized Gains	28	412
Fair Market Value	72,249	42,648
Government-backed securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	128,668	67,594
Gross Unrealized Gains	13	401
Gross Unrealized Losses	(12)
Fair Market Value	128,669	67,995
Government-backed securities | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	225,231	90,911
Gross Unrealized Gains	190	153
Gross Unrealized Losses	(37)
Fair Market Value	225,384	91,064
Corporate Debt Securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	104,253	107,290
Gross Unrealized Gains	581	94
Gross Unrealized Losses	(2)	(83)
Fair Market Value	104,832	107,301
Corporate Debt Securities | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	38,091	116,110
Gross Unrealized Gains	630	851
Gross Unrealized Losses	(20)	(230)
Fair Market Value	$ 38,701	$ 116,731

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) € in Millions, $ in Millions	Apr. 24, 2020USD ($)	Apr. 30, 2020USD ($)	Jul. 31, 2014USD ($)	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2021EUR (€)	Oct. 30, 2019EUR (€)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other income (expense), net				$ 1.6	$ 0.8
Payments to acquire businesses, cash paid	$ 55
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Present value of expected payments related to contingent consideration				24.7	9
Undiscounted value of payments				$ 70	$ 15
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Potential payouts payments	$ 55
ECP and AIS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire businesses, cash paid			$ 13
Potential payouts payments			$ 15
Commercial Milestones				69.00%
ECP and AIS | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate				1.20%		1.20%
ECP and AIS | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate				17.00%		17.00%
Breethe
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire businesses, cash paid		$ 55
Breethe | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate				1.40%		1.40%
Commercial Milestones				25.00%
Breethe | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Potential payouts payments		$ 55
Discount rate				2.00%		2.00%
Commercial Milestones				75.00%
Intercompany Agreement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans to subsidiaries | €							€ 85
Cross Currency Interest Rate Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative notional amount				$ 93.5		€ 85

Schedule of Cross-Currency Rate

Schedule of Cross-Currency Rate Swap Derivatives (Detail) € in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2021EUR (€)
Pay EUR
Effective Date	Oct. 15, 2019
Maturity	Oct. 15, 2024
Fixed Rate	2.75%	2.75%
Derivative notional amount | €		€ 85,000
Receive U.S $
Effective Date	Oct. 15, 2019
Maturity	Oct. 15, 2024
Fixed Rate	4.64%	4.64%
Derivative notional amount | $	$ 93,457

Schedule of Fair Value of Compa

Schedule of Fair Value of Company's Derivative Instrument (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Cross Currency Interest Rate Contract | Other Assets
Fair Value	$ (4,298)	$ 3,786

Schedule of Components of Conti

Schedule of Components of Contingent Consideration Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Contingent consideration liabilities	$ 24,706	$ 9,000
ECP
Contingent consideration liabilities	10,306	$ 9,000
Breethe
Contingent consideration liabilities	$ 14,400

Financial Instruments Measured

Financial Instruments Measured at Fair Value (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	$ 772,367	$ 593,589
Contingent consideration	24,706	9,000
Cross Currency Interest Rate Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative fair value	4,298	3,786
Repurchase Agreement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	33,000	20,000
Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	350,985	250,775
Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	264,085	207,795
Shockwave Medical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	38,655	55,704
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	124,297	115,019
Commercial Paper | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	45,235	32,831
U.S. Treasury mutual fund securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	72,249	42,648
Government-backed securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	128,669	67,995
Government-backed securities | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	225,384	91,064
Corporate Debt Securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	104,832	107,301
Corporate Debt Securities | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	38,701	116,731
Level 1 | Shockwave Medical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	38,655	55,704
Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	124,297	115,019
Level 2 | Cross Currency Interest Rate Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative fair value	4,298	3,786
Level 2 | Repurchase Agreement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	33,000	20,000
Level 2 | Commercial Paper | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	45,235	32,831
Level 2 | U.S. Treasury mutual fund securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	72,249	42,648
Level 2 | Government-backed securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	128,669	67,995
Level 2 | Government-backed securities | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	225,384	91,064
Level 2 | Corporate Debt Securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	104,832	107,301
Level 2 | Corporate Debt Securities | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	38,701	116,731
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ 24,706	$ 9,000

Change in Fair Value of Conting

Change in Fair Value of Contingent Consideration as Determined by Level 3 Inputs (Detail) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Level 3 liabilities, beginning balance	$ 9,000
Level 3 liabilities, ending balance	24,700	$ 9,000
Contingent Consideration | Ecp Entwickslungsgesellschaft Mbh
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Level 3 liabilities, beginning balance	9,000	9,575	$ 10,490
Additions	13,300
Change in fair value	2,406	(575)	(915)
Level 3 liabilities, ending balance	$ 24,706	$ 9,000	$ 9,575

Components of Accounts Receivab

Components of Accounts Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Receivables [Abstract]
Trade receivables	$ 97,953	$ 85,852
Allowance for doubtful accounts	(774)	(1,202)	$ (1,040)	$ (320)
Accounts receivable, net	$ 97,179	$ 84,650

Summary of Allowance for Doubtf

Summary of Allowance for Doubtful Accounts Receivable (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Receivables [Abstract]
Balance at beginning of year	$ 1,202	$ 1,040	$ 320
Additions (recoveries)	127	487	720
Write-offs	(301)	(325)
Balance at end of year	$ 774	$ 1,202	$ 1,040

Components of Inventories (Deta

Components of Inventories (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 27,782	$ 31,411
Work-in-progress	35,187	35,008
Finished goods	18,090	23,669
Inventories	$ 81,059	$ 90,088

Components of Property and Equi

Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Property Plant And Equipment [Abstract]
Land	$ 10,875	$ 7,179
Building and building improvements	148,870	100,176
Leasehold improvements	439	14,546
Machinery and equipment	91,784	71,636
Furniture and fixtures	15,608	14,600
Construction in progress	10,906	15,075
Total cost	278,482	223,212
Less accumulated depreciation	(81,353)	(58,281)
Property and equipment, net	$ 197,129	$ 164,931

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Property Plant And Equipment [Line Items]
Land	$ 10,875	$ 7,179
Leasehold improvements	439	14,546
Right of Use Asset	6,109	11,760
Adjustment to Remove The Prior Lease Liability	500
Depreciation expense	23,100	$ 20,100	$ 13,900
Lease Agreement Termination [Member]
Property Plant And Equipment [Line Items]
Right of Use Asset	4,700
Land and Building [Member]
Property Plant And Equipment [Line Items]
Acquisition Costs	17,500
Land	3,400
Investment Building and Building Improvements	13,800
Leasehold Improvements
Property Plant And Equipment [Line Items]
Acquisition Costs	11,000
Leasehold improvements	$ 11,000

Goodwill, In-Process Research_3

Goodwill, In-Process Research & Development and Other Assets - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Goodwill [Line Items]
Goodwill		$ 78,568,000	$ 31,969,000	$ 32,601,000
Accumulated impairment loss, goodwill		0
Gross carrying amount. infinite lived intangible assets, cost		$ 27,000,000
Intangible asset, amortized useful life	15 years	15 years
Accumulated impairment losses on IPR&D assets		$ 0
Other Intangible Assets
Goodwill [Line Items]
Intangible asset, amortized useful life		15 years
Impella Cardiosystems AG [Member]
Goodwill [Line Items]
Goodwill		$ 78,600,000	$ 32,000,000

Goodwill Activity (Detail)

Goodwill Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Goodwill [Line Items]
Beginning balance	$ 31,969	$ 32,601
Foreign currency translation impact	2,114	(632)
Ending balance	78,568	$ 31,969
Breethe
Goodwill [Line Items]
Breethe acquisition	$ 44,485

Other Intangible Assets, net (D

Other Intangible Assets, net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Indefinite-lived intangible assets
Gross carrying amount. infinite lived intangible assets, cost	$ 27,000
Other intangible assets, Total cost	42,900	$ 14,913
Other Intangible Assets, Gross, accumulated amortization	(750)
Other intangibles, net	42,150	14,913
Developed Technology [Member]
Finite-lived intangible assets
Gross carrying amount. finite lived intangible assets, cost	$ 27,000
Indefinite-lived intangible assets
Gross carrying amount. finite lived intangible assets, weighted average useful life	14 years 7 months 6 days
Gross carrying amount. finite lived intangible assets, Accumulated amortization	$ (750)
Gross carrying amount, finite lived intangible assets net carrying value	26,250
In Process Research and Development
Indefinite-lived intangible assets
Gross carrying amount. infinite lived intangible assets, cost	15,900	14,913
Gross carrying amount, indefinite lived intangible assets net carrying value	$ 15,900	$ 14,913

Summary of Components of Other

Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Goodwill [Line Items]
Other investments	$ 62,995	$ 38,741	$ 24,584
Operating lease right-of-use assets (Note 11)	6,109	11,760
Cross-currency swap (Note 5)		3,786
Other intangible assets and other assets	5,323	7,664
Other assets	113,082	117,655
Shockwave Medical
Goodwill [Line Items]
Fair value of investment	$ 38,655	$ 55,704

Other Assets - Additional Infor

Other Assets - Additional Information (Detail) - Shockwave Medical - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Goodwill [Line Items]
Investment in affiliate			$ 25,000
Fair value of investment	$ 38,655	$ 55,704
Sale of stock	1.4
Cash proceeds from sale of stock	$ 67,900
Total realized gain (loss) from sale of stock	$ 47,300
Investments In And Advances To Affiliates Balance Shares	0.3
Other Income (Expense)
Goodwill [Line Items]
Gain (loss) recorded in other income (expense)	$ 50,800	$ 500

Carrying value of Other Investm

Carrying value of Other Investments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 38,741	$ 24,584
Additions	26,104	19,599
Reclassification	(2,000)
Impairment	(800)	(750)
Change in fair value, net	950	(4,692)
Ending balance	$ 62,995	$ 38,741

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information Related to Operating Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Right of Use Asset	$ 6,109	$ 11,760
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherCurrentLiabilitiesMember	us-gaap:OtherCurrentLiabilitiesMember
Operating lease liabilities in other current liabilities	$ 2,459	$ 3,671
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherNoncurrentLiabilitiesMember	us-gaap:OtherNoncurrentLiabilitiesMember
Operating lease liabilities in other long-term liabilities	$ 3,657	$ 8,549
Total operating lease liabilities	$ 6,116	$ 12,220

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Property Plant And Equipment [Line Items]
Operating lease expense	$ 4.1	$ 3.7
Gain (loss) on termination of lease	0.5
Land and Building [Member]
Property Plant And Equipment [Line Items]
Acquisition Costs	17.5
Land [Member]
Property Plant And Equipment [Line Items]
Acquisition Costs	3.4
Building Improvements [Member]
Property Plant And Equipment [Line Items]
Acquisition Costs	13.8
Leasehold Improvements
Property Plant And Equipment [Line Items]
Acquisition Costs	11
Right Of Use Assets And Building Improvements [Member]
Property Plant And Equipment [Line Items]
Acquisition Costs	4.7
Building
Property Plant And Equipment [Line Items]
Lessor operating lease	$ 17.5

Maturities of Operating Lease L

Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
2022	$ 2,574
2023	1,404
2024	1,165
2025	617
2026	77
Thereafter	599
Total minimum lease payments	6,436
Less: imputed interest	(320)
Present value of operating lease liabilities	$ 6,116	$ 12,220
Weighted average remaining lease term	4 years 7 days
Weighted average discount rate	1.96%

Accrued Expenses (Detail)

Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Payables and Accruals [Abstract]
Employee compensation	$ 40,954	$ 32,273
Research and development	6,983	5,749
Sales and income taxes	5,914	21,641
Marketing	3,674	1,705
Warranty	2,053	1,818
Professional, legal and accounting fees	1,957	6,880
Other	4,511	5,041
Accrued expenses	$ 66,046	$ 75,107

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Aug. 31, 2019
Stockholders Equity Note [Abstract]
Class B Preferred Stock, par value	$ 0.01	$ 0.01
Class B Preferred Stock, Authorized	1,000,000	1,000,000
Class B Preferred Stock, Issued	0	0
Class B Preferred Stock, outstanding	0	0
Stock repurchase program, authorized amount			$ 200,000
Shares repurchased (in shares)	67,649	465,687
Shares repurchased, value	$ 11,310	$ 84,879
Stock repurchase program, remaining authorized repurchase amount	$ 103,800

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Stock Repurchase Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stockholders Equity Note [Abstract]
Shares repurchased	67,649	465,687
Average price per share	$ 167.19	$ 182.27
Value of shares repurchased (in millions)	$ 11,310	$ 84,879

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Shareholders Equity [Line Items]
Beginning Balance	$ 1,065,466	$ 936,890	$ 689,524
Ending Balance	1,329,675	1,065,466	936,890
Foreign Currency Translation Gains (Losses)
Shareholders Equity [Line Items]
Beginning Balance	(16,860)	(15,028)	(3,597)
Other comprehensive (loss) income	2,142	(1,832)	(11,431)
Ending Balance	(14,718)	(16,860)	(15,028)
Unrealized Gains (Losses) on Investments
Shareholders Equity [Line Items]
Beginning Balance	1,672	339	(607)
Other comprehensive (loss) income	(303)	1,333	946
Ending Balance	1,369	1,672	339
Unrealized Gains (Losses) on Derivative Instruments
Shareholders Equity [Line Items]
Beginning Balance	3,999
Other comprehensive (loss) income	(2,095)	3,999
Ending Balance	1,904	3,999
Accumulated Other Comprehensive Income (Loss)
Shareholders Equity [Line Items]
Beginning Balance	(11,189)	(14,689)	(4,204)
Other comprehensive (loss) income	(256)	3,500	(10,485)
Ending Balance	$ (11,445)	$ (11,189)	$ (14,689)

Stock Award Plans and Stock-B_3

Stock Award Plans and Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Nov. 30, 2020shares	May 31, 2020peercompanyshares	May 31, 2019shares	May 31, 2018shares	Mar. 31, 2021USD ($)$ / sharesshares	Mar. 31, 2020USD ($)$ / sharesshares	Mar. 31, 2019USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options exercised in period | $					$ 54,900	$ 15,000	$ 174,000
Proceeds from the exercise of stock options | $					$ 9,075	$ 3,748	$ 12,949
Expected dividend yield					0.00%
Restricted share unit issued					30,881,000
2015 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option conversion description					Each share of stock issued pursuant to a stock option or stock appreciation right counts as one share against the maximum number of shares issuable under the 2015 Plan, while each share of stock issued pursuant to any other type of award counts as 1.8 shares against the maximum number of shares issuable under the 2015 Plan.
Shares available for future issuance under the Plan					3,334,890
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock award plans, outstanding stock options expiration period					10 years
Vesting period					3 years
Unrecognized stock-based compensation expense | $					$ 8,900
Unrecognized stock-based compensation expense, weighted-average recognition period					1 year 7 months 6 days
Expected dividend yield					0.00%
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					3 years
Unrecognized stock-based compensation expense | $					$ 51,900
Unrecognized stock-based compensation expense, weighted-average recognition period					1 year 9 months 18 days
Weighted average grant-date fair value | $ / shares					$ 254.78	$ 258.59	$ 376.95
Fair value of units vested | $					$ 27,900	$ 99,300	$ 171,300
Restricted share unit issued					230,000
Non-vested shares, outstanding					301,000	320,000
Performance and Market-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense | $					$ 24,200
Unrecognized stock-based compensation expense, weighted-average recognition period					1 year 9 months 18 days
Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share unit issued			196,580	114,000
Performance Based Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share unit issued	66,000
Performance Based Restricted Stock Units Issued in May 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested shares, outstanding					22,000
Performance Based Restricted Stock Units Issued in May 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share unit issued		62,000
Performance Based Restricted Stock Units Issued in May 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested shares, outstanding						0
Market-Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share unit issued		61,762
Stock units minimum range percent		0.00%
Stock units maximum range percent		200.00%
Number of peer companies for ranking in TSR Comparison | peercompany		20
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP, exercise price as a percentage of its market price					85.00%

Stock-Based Compensation Recogn

Stock-Based Compensation Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 47,006	$ 39,781	$ 54,494
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	3,760	2,641	2,643
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	6,941	5,534	9,312
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 36,305	$ 31,606	$ 42,539

Components of Stock-Based Compe

Components of Stock-Based Compensation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 47,006	$ 39,781	$ 54,494
Restricted Stock Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	36,347	28,895	45,998
Employee Stock Option
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	8,982	9,006	7,445
Employee Stock Purchase Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,677	$ 1,880	$ 1,051

Summary of Stock Option Activit

Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Options
Outstanding at beginning of period	869
Granted	70
Exercised	(215)
Cancelled and expired	(13)
Outstanding at end of period	711	869
Exercisable at end of period	537
Options vested and expected to vest at end of period	711
Weighted Average Exercise Price
Outstanding at beginning of period	$ 112.03
Granted	225.60
Exercised	42.16
Cancelled and expired	248.42
Outstanding at end of period	141.87	$ 112.03
Exercisable at end of period	104.55
Options vested and expected to vest at end of period	$ 141.87
Weighted Average Remaining Contractual Term (years)
Outstanding	5 years 5 months 16 days	5 years 3 months 19 days
Exercisable at end of period	4 years 6 months 3 days
Options vested and expected to vest at end of period	5 years 5 months 16 days
Aggregate Intrinsic Value
Outstanding at end of period	$ 129,912
Exercisable at end of period	117,880
Options vested and expected to vest at end of period	$ 129,912

Summary of Weighted Average Gra

Summary of Weighted Average Grant-Date Fair Values And Weighted Average Assumptions Used to Calculate Fair Value of Options Granted (Detail) - $ / shares	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Valuation assumptions:
Risk-free interest rate	0.20%
Expected volatility	35.50%
Employee Stock Option
Valuation assumptions:
Weighted average grant-date fair value	$ 77.82	$ 93.05	$ 141.47
Risk-free interest rate	0.32%	1.97%	2.91%
Expected option life (years)	4 years 2 months 19 days	4 years 1 month 20 days	4 years 15 days
Expected volatility	42.90%	42.30%	42.80%

Summary of Restricted Stock Uni

Summary of Restricted Stock Units Activity (Detail) - $ / shares shares in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Number of Shares
Granted	30,881
Restricted Stock Units
Number of Shares
Beginning Balance	320
Granted	230
Vested	(139)
Forfeited	(109)
Ending Balance	301	320
Weighted Average Grant Date Fair Value
Beginning Balance	$ 263.92
Granted	254.78	$ 258.59	$ 376.95
Vested	227.32
Forfeited	266.57
Ending Balance	$ 273.57	$ 263.92

Summary of Assumptions Used To

Summary of Assumptions Used To Value Awards And Estimated Grant-Date Fair Value (Detail) shares in Thousands	12 Months Ended
	Mar. 31, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.20%
Expected volatility	35.50%
Restricted share unit issued | shares	30,881
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining performance period (years)	1 year 10 months 25 days
Estimated grant date fair value per share	$ 347.05
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining performance period (years)	2 years 10 months 25 days
Estimated grant date fair value per share	$ 349.28

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended																12 Months Ended
	Mar. 31, 2021		Dec. 31, 2020	[1]	Sep. 30, 2020	[1]	Jun. 30, 2020	[1]	Mar. 31, 2020		Dec. 31, 2019	[1]	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2021		Mar. 31, 2020		Dec. 31, 2019	Mar. 31, 2019
Income Taxes [Line Items]
Income tax provision	$ 16,638,000	[1]	$ 18,867,000		$ 10,702,000		$ 16,488,000		$ 7,515,000	[1]	$ 27,799,000		$ 4,287,000		$ 14,215,000		$ 62,695,000	[1]	$ 53,816,000	[1]		$ 4,344,000
Effective income tax rate																	21.80%		21.00%			1.60%
Valuation allowance	15,667,000								$ 15,170,000								$ 15,667,000		$ 15,170,000
Excess tax benefits from stock-based awards																	12,100,000		14,800,000		$ 69,300,000
Foreign tax credits																	$ 13,800,000
Potential repatriation of foreign subsidiary earnings																	100.00%
Interest and penalties on uncertain tax positions																	$ 0		$ 0		$ 0
Earliest Tax Year
Income Taxes [Line Items]
Foreign tax credits carry forwards expiration period																	2029
Federal and state research and development credit carry forwards year of expiration																	2022
Latest Tax Year
Income Taxes [Line Items]
Foreign tax credits carry forwards expiration period																	2031
Federal and state research and development credit carry forwards year of expiration																	2041
Foreign
Income Taxes [Line Items]
Net operating loss carry forwards	27,200,000																$ 27,200,000
Federal
Income Taxes [Line Items]
Research and development credit carry forwards	400,000																400,000
State
Income Taxes [Line Items]
Research and development credit carry forwards	$ 12,800,000																$ 12,800,000
[1]	The income tax provision for the years ended March 31, 2021 and 2020 included excess tax benefits of $12.1 million and $14.8 million, respectively. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during the years ended March 31, 2021 and 2020.

Components of Income Tax Provis

Components of Income Tax Provision (Detail) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Mar. 31, 2021	[1]	Dec. 31, 2020	[1]	Sep. 30, 2020	[1]	Jun. 30, 2020	[1]	Mar. 31, 2020	[1]	Dec. 31, 2019	[1]	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2021		Mar. 31, 2020		Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income (loss) before income taxes																	$ 249,204		$ 214,825		$ 223,340
Income (loss) before income taxes, foreign																	39,016		42,000		40,020
Income (loss) before income taxes																	288,220		256,825		263,360
Current income tax provision, Federal																	8,624
Current income tax provision, State																	12,379		6,563		564
Current income tax provision, Foreign																	12,312		14,300		11,525
Current income tax provision																	33,315		20,863		12,089
Deferred income tax provision, Federal																	30,413		33,239		(7,153)
Deferred income tax provision, State																	(2,382)		1,584		(1,503)
Deferred income tax provision, Foreign																	1,349		(1,870)		911
Deferred income tax provision																	29,380		32,953		(7,745)
Total income tax provision	$ 16,638		$ 18,867		$ 10,702		$ 16,488		$ 7,515		$ 27,799		$ 4,287		$ 14,215		$ 62,695	[1]	$ 53,816	[1]	$ 4,344
[1]	The income tax provision for the years ended March 31, 2021 and 2020 included excess tax benefits of $12.1 million and $14.8 million, respectively. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during the years ended March 31, 2021 and 2020.

Components of Net Deferred Taxe

Components of Net Deferred Taxes (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Deferred tax assets
Net operating loss and tax credit carryforwards	$ 27,893	$ 50,604
Stock-based compensation	13,790	13,607
Nondeductible reserves and accruals	12,097	9,570
Foreign net operating loss carryforwards	6,856	6,778
Deferred revenue	5,522	4,404
Depreciation and amortization	51	114
Other, net	312	949
Deferred Tax Assets, Gross, Total	66,521	86,026
Deferred tax liabilities
Goodwill	(7,897)	(7,843)
In-process research and development	(12,496)	(4,564)
Depreciation	(11,747)	(9,211)
Basis differences on other investments	(7,766)	(6,124)
Domestic deferred tax liability on foreign net operating loss carryforwards	(415)	(584)
Deferred Tax Liabilities, Net	(40,321)	(28,326)
Net deferred tax assets	26,200	57,700
Valuation allowance	(15,667)	(15,170)
Net deferred tax assets	10,533	42,530
Deferred tax assets	11,380	43,336
Deferred tax liabilities	(847)	(806)
Net deferred tax assets	$ 10,533	$ 42,530

Differences Between Statutory a

Differences Between Statutory and Effective Income Tax Rate (Detail)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Statutory income tax rate	21.00%	21.00%	21.00%
Credits	(6.00%)	(10.80%)	(1.50%)
Rate differential on foreign operations	4.10%	3.20%	0.20%
Excess tax benefits from stock-based awards	(3.30%)	(5.20%)	(24.10%)
State taxes, net	3.20%	3.10%	0.10%
Permanent differences	2.40%	5.00%	1.80%
Change in valuation allowance	0.30%	5.30%	(0.40%)
Foreign taxes			4.10%
Other	0.10%	(0.60%)	0.40%
Effective tax rate	21.80%	21.00%	1.60%

Changes in Valuation Allowance

Changes in Valuation Allowance for Deferred Tax Assets (Detail) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Valuation Allowance [Line Items]
Balance at beginning of year	$ 15,170	$ 1,302	$ 1,652
Increase	497	13,868
Decrease			(350)
Balance at end of year	$ 15,667	$ 15,170	$ 1,302

Segment and Enterprise Wide D_2

Segment and Enterprise Wide Disclosures - Additional Information (Detail) $ in Millions	12 Months Ended
	Mar. 31, 2021USD ($)Segment	Mar. 31, 2020USD ($)	Mar. 31, 2019
Segment Reporting Information [Line Items]
Number of business segments | Segment	1
International
Segment Reporting Information [Line Items]
Long-lived assets | $	$ 56.4	$ 46.7
Customer Concentration Risk | Revenue | International
Segment Reporting Information [Line Items]
Percentage of revenue accounted	18.00%	16.00%	14.00%

Summary of Unaudited Quarterly

Summary of Unaudited Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Mar. 31, 2021		Dec. 31, 2020		Sep. 30, 2020		Jun. 30, 2020		Mar. 31, 2020		Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2021		Mar. 31, 2020		Mar. 31, 2019
Disclosure Unaudited Quarterly Financial Information [Abstract]
Revenue	$ 241,246		$ 231,663		$ 209,764		$ 164,850		$ 206,658		$ 221,584		$ 204,974		$ 207,666		$ 847,522		$ 840,883		$ 769,432
Cost of revenue	46,078		41,110		38,736		35,983		39,369		39,996		34,867		37,073		161,907		151,305		129,567
Other operating expenses	132,364		119,202		109,692		94,801		109,237		111,329		109,925		109,868		456,058		440,359
Other income (expense)	10,690	[1]	9,384	[1]	11,579	[1]	27,010	[1]	(18,739)	[1]	26,757	[1]	(42,824)	[1]	42,413	[1]	58,663	[1]	7,606	[1]	38,548
Income before income taxes	73,494		80,735		72,915		61,076		39,313		97,016		17,358		103,138		288,220		256,825		263,360
Income tax provision	16,638	[2]	18,867	[2]	10,702	[2]	16,488	[2]	7,515	[2]	27,799	[2]	4,287	[2]	14,215	[2]	62,695	[2]	53,816	[2]	4,344
Net income	$ 56,856		$ 61,868		$ 62,213		$ 44,588		$ 31,798		$ 69,217		$ 13,071		$ 88,923		$ 225,525		$ 203,009		$ 259,016
Basic net income per share	$ 1.26		$ 1.37		$ 1.38		$ 0.99		$ 0.71		$ 1.53		$ 0.29		$ 1.97		$ 5		$ 4.49		$ 5.77
Diluted net income per share	$ 1.24		$ 1.35		$ 1.36		$ 0.98		$ 0.70		$ 1.51		$ 0.28		$ 1.93		$ 4.94		$ 4.43		$ 5.61
Income tax provision	$ 16,638	[2]	$ 18,867	[2]	$ 10,702	[2]	$ 16,488	[2]	$ 7,515	[2]	$ 27,799	[2]	$ 4,287	[2]	$ 14,215	[2]	$ 62,695	[2]	$ 53,816	[2]	$ 4,344
[1]	In fiscal year 2019, the Company invested $25.0 million in medical device company Shockwave Medical. The fair value of this investment as of March 31, 2021 was $38.7 million. The Company recognized a pre-tax gain of $50.8 million for the year ended March 31, 2021 and a pre-tax loss of $0.5 million for the year ended March 31, 2020 in other income (expense), net.
[2]	The income tax provision for the years ended March 31, 2021 and 2020 included excess tax benefits of $12.1 million and $14.8 million, respectively. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during the years ended March 31, 2021 and 2020.

Summary of Unaudited Quarterl_2

Summary of Unaudited Quarterly Results of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

[1]

Sep. 30, 2020

[1]

Jun. 30, 2020

[1]

Mar. 31, 2020

[1]

Dec. 31, 2019

[1]

Sep. 30, 2019

[1]

Jun. 30, 2019

[1]

Mar. 31, 2021

Mar. 31, 2020

Mar. 31, 2019

Schedule Of Quarterly Financial Data [Line Items]

Income tax provision

$ 16,638

[1]

$ 18,867

$ 10,702

$ 16,488

$ 7,515

$ 27,799

$ 4,287

$ 14,215

$ 62,695

[1]

$ 53,816

[1]

$ 4,344

Vested Restricted Stock Units or Stock Options

Schedule Of Quarterly Financial Data [Line Items]

Income tax provision

12,100

14,800

Shockwave Medical, Inc.

Schedule Of Quarterly Financial Data [Line Items]

Investments

$ 25,000

Fair value of investment

$ 38,700

38,700

Shockwave Medical, Inc. | Other Expense

Schedule Of Quarterly Financial Data [Line Items]

Gain (loss) recorded in other income (expense)

$ 50,800

Shockwave Medical, Inc. | Other Income (Expense)

Schedule Of Quarterly Financial Data [Line Items]

Gain (loss) recorded in other income (expense)

$ 500

[1]

The income tax provision for the years ended March 31, 2021 and 2020 included excess tax benefits of $12.1 million and $14.8 million, respectively. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during the years ended March 31, 2021 and 2020.