Abiomed (ABMD) 10-Q 6 Nov 20 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Sep. 30, 2020	Oct. 22, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Trading Symbol	ABMD
Entity Registrant Name	ABIOMED, INC.
Entity Central Index Key	0000815094
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--03-31
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		45,189,883
Entity File Number	001-09585
Entity Tax Identification Number	04-2743260
Title of 12(b) Security	Common Stock, $0.01 par value
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
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

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Current assets:
Cash and cash equivalents	$ 202,241	$ 192,341
Short-term marketable securities	330,843	250,775
Accounts receivable, net	80,909	84,650
Inventories	83,209	90,088
Prepaid expenses and other current assets	19,419	18,009
Total current assets	716,621	635,863
Long-term marketable securities	202,613	207,795
Property and equipment, net	175,582	164,931
Goodwill	78,122	31,969
In-process research and development	42,895	14,913
Deferred tax assets	29,547	43,336
Other assets	82,594	117,655
Total assets	1,327,974	1,216,462
Current liabilities:
Accounts payable	21,734	32,774
Accrued expenses	57,227	75,107
Deferred revenue	21,314	19,147
Other current liabilities	4,938	4,857
Total current liabilities	105,213	131,885
Contingent consideration	24,417	9,000
Deferred tax liabilities	4,251	806
Other long-term liabilities	11,684	9,305
Total liabilities	145,565	150,996
Commitments and contingencies (Note 14)
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 - 47,435,945 shares at June 30, 2019 and 47,026,226 shares at March 31, 2019 Outstanding - 45,374,278 shares at June 30, 2019 and 45,122,985 shares at March 31, 2019	452	451
Additional paid in capital	767,527	739,133
Retained earnings	709,283	602,482
Treasury stock at cost - 2,657,140 shares at September 30, 2020 and 2,533,374 shares at March 31, 2020	(287,654)	(265,411)
Accumulated other comprehensive loss	(7,199)	(11,189)
Total stockholders' equity	1,182,409	1,065,466
Total liabilities and stockholders' equity	$ 1,327,974	$ 1,216,462

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	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	47,847,023	47,542,061
Common stock, Outstanding	45,189,883	45,008,687
Treasury stock, shares	2,657,140	2,533,374

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 209,764	$ 204,974	$ 374,614	$ 412,640
Costs and expenses:
Cost of revenue	38,736	34,867	74,719	71,940
Research and development	30,525	23,969	56,882	47,759
Selling, general and administrative	79,167	85,956	147,611	172,034
Costs and Expenses, Total	148,428	144,792	279,212	291,733
Income from operations	61,336	60,182	95,402	120,907
Other income (expense):
Investment income, net	1,822	2,932	4,219	5,981
Other income (expense), net	9,757	(45,756)	34,370	(6,392)
Nonoperating Income (Expense), Total	11,579	(42,824)	38,589	(411)
Income before income taxes	72,915	17,358	133,991	120,496
Income tax provision	10,702	4,287	27,190	18,502
Net income	$ 62,213	$ 13,071	$ 106,801	$ 101,994
Basic net income per share	$ 1.38	$ 0.29	$ 2.37	$ 2.25
Basic weighted average shares outstanding	45,104	45,319	45,057	45,267
Diluted net income per share	$ 1.36	$ 0.28	$ 2.34	$ 2.22
Diluted weighted average shares outstanding	45,661	45,912	45,609	46,031

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 62,213	$ 13,071	$ 106,801	$ 101,994
Other comprehensive income (loss):
Foreign currency translation gains (losses)	2,416	(5,716)	3,776	(3,382)
Unrealized losses on derivative instrument	(266)		(726)
Net unrealized (losses) gains on marketable securities	(814)	(85)	940	515
Other comprehensive income	1,336	(5,801)	3,990	(2,867)
Comprehensive income	$ 63,549	$ 7,270	$ 110,791	$ 99,127

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance at Mar. 31, 2019	$ 936,890	$ 451	$ (138,852)	$ 690,507	$ 399,473	$ (14,689)
Beginning 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)		373,430
Stock options exercised	1,261	$ 1		1,260
Stock options exercised (in shares)		36,289
Return of common stock to pay withholding taxes on restricted stock	(40,536)	$ (2)	$ (40,534)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(158,426)	158,426
Stock compensation expense	13,121			13,121
Other comprehensive income (loss)	2,934					2,934
Net income	88,923				88,923
Ending Balance at Jun. 30, 2019	1,002,593	$ 454	$ (179,386)	704,884	488,396	(11,755)
Ending Balance (in shares) at Jun. 30, 2019		45,374,278	2,061,667
Beginning Balance at Mar. 31, 2019	936,890	$ 451	$ (138,852)	690,507	399,473	(14,689)
Beginning Balance (in shares) at Mar. 31, 2019		45,122,985	1,903,241
Stock repurchase program	$ (34,900)
Stock repurchase program, Shares	(180,929)
Other comprehensive income (loss)	$ (2,867)
Net income	101,994
Ending Balance at Sep. 30, 2019	991,457	$ 452	$ (214,926)	722,020	501,467	(17,556)
Ending Balance (in shares) at Sep. 30, 2019		45,238,952	2,245,959
Beginning Balance at Jun. 30, 2019	1,002,593	$ 454	$ (179,386)	704,884	488,396	(11,755)
Beginning Balance (in shares) at Jun. 30, 2019		45,374,278	2,061,667
Restricted stock units issued (in shares)		12,039
Stock options exercised	1,445			1,445
Stock options exercised (in shares)		21,268
Return of common stock to pay withholding taxes on restricted stock	(668)		$ (668)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(3,363)	3,363
Stock issued under employee stock purchase plan	2,368			2,368
Stock issued under employee stock purchase plan (in shares)		15,659
Stock compensation expense	13,323			13,323
Stock repurchase program	$ (34,874)	$ (2)	$ (34,872)
Stock repurchase program, Shares	(180,929)	(180,929)	180,929
Other comprehensive income (loss)	$ (5,801)					(5,801)
Net income	13,071				13,071
Ending Balance at Sep. 30, 2019	991,457	$ 452	$ (214,926)	722,020	501,467	(17,556)
Ending Balance (in shares) at Sep. 30, 2019		45,238,952	2,245,959
Beginning Balance at Mar. 31, 2020	$ 1,065,466	$ 451	$ (265,411)	739,133	602,482	(11,189)
Beginning Balance (in shares) at Mar. 31, 2020	45,008,687	45,008,687	2,533,374
Restricted stock units issued		$ 1		(1)
Restricted stock units issued (in shares)		124,749
Stock options exercised	$ 1,010			1,010
Stock options exercised (in shares)		31,488
Return of common stock to pay withholding taxes on restricted stock	(9,857)		$ (9,857)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(52,515)	52,515
Stock compensation expense	9,298			9,298
Stock repurchase program	(11,310)	$ (1)	$ (11,309)
Stock repurchase program, Shares		(67,649)	67,649
Other comprehensive income (loss)	2,654					2,654
Net income	44,588				44,588
Ending Balance at Jun. 30, 2020	1,101,848	$ 450	$ (286,577)	749,440	647,070	(8,535)
Ending Balance (in shares) at Jun. 30, 2020		45,044,760	2,653,538
Beginning Balance at Mar. 31, 2020	$ 1,065,466	$ 451	$ (265,411)	739,133	602,482	(11,189)
Beginning Balance (in shares) at Mar. 31, 2020	45,008,687	45,008,687	2,533,374
Stock options exercised (in shares)	153,000
Stock repurchase program	$ (11,300)
Stock repurchase program, Shares	(67,649)
Other comprehensive income (loss)	$ 3,990
Net income	106,801
Ending Balance at Sep. 30, 2020	$ 1,182,409	$ 452	$ (287,654)	767,527	709,283	(7,199)
Ending Balance (in shares) at Sep. 30, 2020	45,189,883	45,189,883	2,657,140
Beginning Balance at Jun. 30, 2020	$ 1,101,848	$ 450	$ (286,577)	749,440	647,070	(8,535)
Beginning Balance (in shares) at Jun. 30, 2020		45,044,760	2,653,538
Restricted stock units issued (in shares)		11,554
Stock options exercised	4,545	$ 1		4,544
Stock options exercised (in shares)		121,066
Return of common stock to pay withholding taxes on restricted stock	(1,077)		$ (1,077)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(3,602)	3,602
Stock issued under employee stock purchase plan	1,979	$ 1		1,978
Stock issued under employee stock purchase plan (in shares)		16,105
Stock compensation expense	11,565			11,565
Other comprehensive income (loss)	1,336					1,336
Net income	62,213				62,213
Ending Balance at Sep. 30, 2020	$ 1,182,409	$ 452	$ (287,654)	$ 767,527	$ 709,283	$ (7,199)
Ending Balance (in shares) at Sep. 30, 2020	45,189,883	45,189,883	2,657,140

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities:
Net income	$ 106,801	$ 101,994
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,137	9,052
Bad debt (recoveries) expense	(373)	152
Stock-based compensation	20,863	26,445
Write-down of inventory and other	3,122	2,157
Accretion on marketable securities	473	(2,276)
Change in fair value of other investments	(33,872)	5,943
Deferred tax provision	14,187	10,195
Change in fair value of contingent consideration	2,117	661
Other non-cash operating activities	2,008	2,177
Changes in assets and liabilities:
Accounts receivable	4,767	(3,828)
Inventories	6,071	(12,204)
Prepaid expenses and other assets	1,744	(4,077)
Accounts payable	(10,128)	781
Accrued expenses and other liabilities	(21,988)	(1,268)
Deferred revenue	2,039	2,983
Net cash provided by operating activities	108,968	138,887
Investing activities:
Purchases of marketable securities	(294,558)	(268,485)
Proceeds from the sale and maturity of marketable securities and other	220,197	262,881
Purchases of other investments and intangible assets	(3,100)	(7,800)
Acquisition of Breethe Inc., net of cash acquired	(52,183)
Proceeds from sales of Shockwave Medical securities	67,882
Purchases of property and equipment	(19,552)	(24,607)
Net cash used for investing activities	(81,314)	(38,011)
Financing activities:
Proceeds from the exercise of stock options	5,555	2,706
Taxes paid related to net share settlement upon vesting of stock awards	(10,934)	(41,206)
Repurchase of common stock	(11,310)	(34,873)
Proceeds from the issuance of stock under employee stock purchase plan	1,978	2,368
Net cash used for financing activities	(14,711)	(71,005)
Effect of exchange rate changes on cash and cash equivalents	(3,043)	(613)
Net increase in cash and cash equivalents	9,900	29,258
Cash and cash equivalents at beginning of period	192,341	121,021
Cash and cash equivalents at end of period	202,241	150,279
Supplemental disclosure of cash flow information:
Cash paid for income taxes	25,254	6,349
Supplemental disclosure of non-cash activities:
Contingent consideration related to the acquisition of Breethe, Inc.	13,300
Property and equipment in accounts payable and accrued expenses	1,244	3,825
Right-of-use assets obtained in exchange for lease liabilities	$ 193	$ 14,513

Nature of Business

Nature of Business	6 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Nature of Business	Note 1. Nature of Business 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	6 Months Ended
	Sep. 30, 2020
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 unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial reporting and in accordance with Article 10 of Regulation S-X. Accordingly, they do not include all of the information and note disclosures required by GAAP for complete financial statements. These statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2020 that has been filed with the SEC. In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all normal and recurring adjustments that are necessary for a fair presentation of results for the interim periods presented. The results of operations for any interim period may not be indicative of results for the full fiscal year or any other subsequent period. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements. Actual results may differ from these estimates. There have been no changes in the Company’s significant accounting policies for the three and six months ended September 30, 2020 as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2020 that has been filed with the SEC. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements. Actual results may differ from these estimates. COVID-19 Pandemic The Company is subject to risks and uncertainties as a result of the COVID-19 pandemic. Considerable uncertainty still surrounds the COVID-19 virus and its potential effects, and the extent of and effectiveness of responses taken on international, national and local levels. Measures taken to limit the impact of COVID-19, including shelter-in-place orders, social distancing measures, travel bans and restrictions, and business and government shutdowns, continue to create significant negative economic impacts on a global basis. The extent of the impact of the COVID-19 pandemic on the Company's business remains uncertain and difficult to predict, as the response to the pandemic continues to evolve. Beginning in mid-March 2020 and continuing into the first quarter of fiscal 2021, the Company experienced a significant decline in patient utilization 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 April 2020, 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 globally through the second quarter of fiscal 2021 as restrictions were lifted and limitations eased. In the second quarter of fiscal 2021, patient procedure volume trends have improved gradually as both demand for procedures and availability of healthcare resources improved during the summer months. While the Company currently expects to see sequential quarterly improvement in the remainder of fiscal 2021, 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 based on some of the resurgence that is now occurring in cities across the globe . The Company is closely monitoring the impact of COVID-19 on all aspects of its business and geographies, including the impact on its customers, employees, suppliers, vendors, business partners and distribution channels. The extent to which the COVID-19 global 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; these developments include, but are not limited to, the duration and spread of the outbreak, its severity, the actions to contain the virus or address its impact, 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. Even after the COVID-19 outbreak has subsided, the Company may continue to experience materially adverse impacts on its financial condition and results of operations. As of the date of issuance of these consolidated financial statements, the extent to which the COVID-19 pandemic may materially impact the Company's financial condition, liquidity, or results of operations is uncertain. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326).” This new standard requires 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. 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 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).” This new standard modifies the disclosure requirements on fair value measurements, including the removal of disclosures of the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels, and the valuation processes for Level 3 fair value measurements. The guidance also adds certain disclosure requirements related to Level 3 fair value measurements. 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. 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 intra-period 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. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. ASU 2019-12 will become effective for the Company in fiscal 2022. 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 2022.

Acquisition

Acquisition	6 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Acquisition	Note 3. Acquisition Acquisition of Breethe, Inc. The Company acquired Breethe, Inc. (“Breethe”), a Maryland corporation on April 24, 2020. Breethe is engaged in research and development of a novel extracorporeal membrane oxygenation (“ECMO”) system that will complement and expand its 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, such as ARDS, H1N1, or COVID-19. 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. Preliminary Purchase Price Allocation The acquisition 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 purchase price allocation presented herein is preliminary. The final purchase price allocation will be determined after completion of an analysis to determine the fair value of all assets acquired and liabilities assumed, but in no event later than one year following completion of the acquisition. Accordingly, the final acquisition accounting adjustments could differ materially from the preliminary amounts presented herein. Any increase or decrease in the fair value of the assets acquired and liabilities assumed, as compared to the information shown herein, could also change the portion of purchase price allocated to goodwill and could impact the operating results of the Company following the acquisition due to differences in purchase price allocation, depreciation and amortization related to some of these assets and liabilities. 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 preliminary 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 44,048 In-process research and development 27,000 Other assets acquired 895 Total assets acquired 76,091 Liabilities assumed: Accounts payable and other liabilities 1,562 Deferred tax liabilities 3,379 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 expected to be deductible for income tax purposes. In process research and development (“IPR&D”) is 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 and is therefore considered IPR&D. The assigned values are allocated among the various IPR&D assets acquired. 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 our condensed consolidated statements of operations.

Net Income Per Share

Net Income Per Share	6 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Income Per Share	Note 4. 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 period. Diluted net income per share is computed by dividing net income by the weighted average number of dilutive common shares outstanding during the period. Diluted shares outstanding are calculated by adding to the weighted average shares outstanding any potential dilutive securities outstanding for the period. 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 for the three and six months ended September 30, 2020 and 2019 were as follows (in thousands, except per share data): For the Three Months Ended September 30, For the Six Months Ended September 30, Basic Net Income Per Share 2020 2019 2020 2019 Net income $ 62,213 $ 13,071 $ 106,801 $ 101,994 Weighted average shares – basic 45,104 45,319 45,057 45,267 Net income per share – basic $ 1.38 $ 0.29 $ 2.37 $ 2.25 For the Three Months Ended September 30, For the Six Months Ended September 30, Diluted Net Income Per Share 2020 2019 2020 2019 Net income $ 62,213 13,071 106,801 101,994 Weighted average shares – basic 45,104 45,319 45,057 45,267 Effect of dilutive securities 557 593 552 764 Weighted average shares – diluted 45,661 45,912 45,609 46,031 Net income per share – diluted $ 1.36 $ 0.28 $ 2.34 $ 2.22 Share-based compensation awards of approximately 0.1 million and 0.3 million shares for the three months ended September 30, 2020, and 2019, respectively, and approximately 0.2 million and 0.3 million for the six months ended September 30, 2020, and 2019, respectively, were outstanding but were not included in the computation of diluted net income per share because the effect of including such shares would have been anti-dilutive or are contingently issuable upon meeting performance criteria in the periods presented.

Revenue Recognition

Revenue Recognition	6 Months Ended
	Sep. 30, 2020
Revenue From Contract With Customer [Abstract]
Revenue Recognition	Note 5. Revenue Recognition The Company generates revenue primarily from the sale of Impella 2.5, Impella CP, Impella 5.0, Impella LD, Impella RP, Impella 5.5 and Impella AIC products. The Company also earns revenue from preventative maintenance service contracts and maintenance calls. 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 . 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. Disaggregation of Revenue The Company generally sells most of its products and services through a direct sales force in the U.S., Germany and Japan and through direct sales or distributors in other international markets (e.g., certain other European markets, Canada, Latin America, and Asia-Pacific). 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 following table disaggregates the Company’s revenue by products and services: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) (in $000's) Impella product revenue $ 199,676 $ 196,939 $ 355,093 $ 396,804 Service and other revenue 10,088 8,035 19,521 15,836 Total revenue $ 209,764 $ 204,974 $ 374,614 $ 412,640 The following table disaggregates the Company’s revenue by geographical location: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) (in $000's) U.S. revenue $ 172,147 $ 172,015 $ 306,872 $ 347,500 International revenue 37,617 32,959 67,742 65,140 Total revenue $ 209,764 $ 204,974 $ 374,614 $ 412,640 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 during the three and six months ended September 30, 2020 and 2019, were not material. 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 three and six months ended September 30, 2020 and 2019, were not material. Contract Balances Deferred Revenue The Company’s deferred revenue balance was $21.3 million and $19.1 million as of September 30, 2020 and March 31, 2020 respectively. The deferred revenue balance is due to the timing of product shipment and completion of recognizing revenue when the customer obtains control of the product, and additional preventative maintenance service contracts and the subsequent recognition of the contract ratably over the term of the service contract. During the three and six months ended September 30, 2020, the Company recognized $5.4 million and $14.6 million of revenue that was included in the deferred revenue balance as of March 31, 2020, respectively. During the three and six months ended September 30, 2019, the Company recognized $4.0 million and $12.5 million of revenue that was included in the deferred revenue balance as of March 31, 2019, respectively.

Cash Equivalents, Marketable Se

Cash Equivalents, Marketable Securities and Fair Value Measurements	6 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Cash Equivalents, Marketable Securities and Fair Value Measurements	Note 6. Cash Equivalents, Marketable Securities and Fair Value Measurements The Company’s cash equivalents and marketable securities at September 30, 2020 and March 31, 2020 are invested in the following: Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value September 30, 2020 (in $000's) Money market funds $ 104,305 $ — $ — $ 104,305 Repurchase agreements 20,000 — — 20,000 Total cash equivalents 124,305 — — 124,305 Short-term U.S. Treasury mutual fund securities 75,505 85 (1 ) 75,589 Short-term government-backed securities 85,360 105 (9 ) 85,456 Short-term corporate debt securities 128,738 1,043 — 129,781 Short-term commercial paper 39,991 31 (5 ) 40,017 Total short-term marketable securities 329,594 1,264 (15 ) 330,843 Long-term U.S. Treasury mutual fund securities 10,246 2 — 10,248 Long-term government-backed securities 141,378 164 (6 ) 141,536 Long-term corporate debt securities 49,627 1,202 — 50,829 Total long-term marketable securities 201,251 1,368 (6 ) 202,613 $ 655,150 $ 2,632 $ (21 ) $ 657,761 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 $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 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 following table summarizes the terms of the cross-currency swap agreement as of September 30, 2020 (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 of September 30, 2020: Derivatives designated as hedging instruments under ASC 815 Balance Sheet classification Fair Value Cross-currency swap Other assets (long-term liabilities) $ (2,860 ) 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 second quarter for fiscal year 2021 was mainly due to the appreciation of the Euro against the U.S. dollar. For both the three and six months ended September 30, 2020, the Company recorded income of $0.7 million, in other income, net, included in the consolidated statements of operations related to the interest rate differential of the cross-currency swaps. 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, Inc. 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: September 30, 2020 March 31, 2020 (in $000's) ECP $ 10,117 $ 9,000 Breethe, Inc. 14,300 — $ 24,417 $ 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 2% to 16%), the probability of achieving the various technical, regulatory and commercial milestones (estimated to be 65%) and projected revenues, which are based on the Company’s most recent internal operational budgets and long-range strategic plans. Breethe, Inc. In April 2020, the Company acquired Breethe, Inc. 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 riskiness of 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 2% to 16%), the probability of achieving the various technical, regulatory and commercial milestones (estimated to range from 25% to 99%) and projected revenues, which are based on the Company’s most recent internal operational budgets 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 tables present the Company’s fair value hierarchy for its financial instruments measured at fair value as of September 30, 2020 and March 31, 2020: Level 1 Level 2 Level 3 Total September 30, 2020 (in $000's) Assets Money market funds $ 104,305 $ — $ — $ 104,305 Repurchase agreements — 20,000 — 20,000 Short-term government-backed securities — 85,456 — 85,456 Short-term corporate debt securities — 129,781 — 129,781 Short-term commercial paper — 40,017 — 40,017 Short-term U.S. Treasury mutual fund securities — 75,589 — 75,589 Long-term U.S. Treasury mutual fund securities — 10,248 — 10,248 Long-term government-backed securities — 141,536 — 141,536 Long-term corporate debt securities — 50,829 — 50,829 Investment in Shockwave Medical 22,494 — — 22,494 Liabilities Contingent consideration — — 24,417 24,417 Cross-currency swap agreement — 2,860 — 2,860 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, Inc. (“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. 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, Inc. 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 for the three and six months ended September 30, 2020 and 2019: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) Beginning balance $ 23,701 $ 9,931 $ 9,000 $ 9,575 Additions — — 13,300 — Change in fair value 716 305 2,117 661 Ending balance $ 24,417 $ 10,236 $ 24,417 $ 10,236 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.

Property and Equipment

Property and Equipment	6 Months Ended
	Sep. 30, 2020
Property Plant And Equipment [Abstract]
Property and Equipment	Note 7. Property and Equipment The components of property and equipment are as follows: September 30, 2020 March 31, 2020 (in $000's) Land $ 7,454 $ 7,179 Building and building improvements 102,644 100,176 Leasehold improvements 15,183 14,546 Machinery and equipment 78,343 71,636 Furniture and fixtures 15,166 14,600 Construction in progress 26,277 15,075 Total cost 245,067 223,212 Accumulated depreciation (69,485 ) (58,281 ) Property and equipment, net $ 175,582 $ 164,931

Goodwill, In-Process Research a

Goodwill, In-Process Research and Development and Other Assets	6 Months Ended
	Sep. 30, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, In-Process Research and Development and Other Assets	Note 8. Goodwill, In-Process Research and Development and Other Assets Goodwill The carrying amount of goodwill at September 30, 2020 and March 31, 2020 was $78.1 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, Inc. in April 2020. The carrying value of goodwill and the change in the balance for the six months ended September 30, 2020 are as follows: (in $000's) Balance, March 31, 2020 $ 31,969 Breethe, Inc. acquisition 44,048 Foreign currency translation impact 2,105 Balance, September 30, 2020 $ 78,122 The Company evaluates goodwill at least annually at 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. In-Process Research & Development The carrying amount of IPR&D assets at September 30, 2020 and March 31, 2020 was $42.9 million and $14.9 million, respectively, and was recorded in conjunction with the Company’s acquisition of ECP and AIS, in July 2014 and Breethe, Inc, in April 2020. The components of IPR&D are as follows: September 30, 2020 March 31, 2020 (in $000's) ECP $ 15,895 $ 14,913 Breethe, Inc. 27,000 — $ 42,895 $ 14,913 The estimated fair value of IPR&D assets at the acquisition date was determined using a probability-weighted income approach, which discounts expected future cash flows to present value. The projected cash flow estimates for the future Impella ECP TM The carrying value of the Company’s IPR&D assets and the change in the balance for the six months ended September 30, 2020 are as follows: (in $000's) Balance, March 31, 2020 $ 14,913 Breethe, Inc. acquisition 27,000 Foreign currency translation impact 982 Balance, September 30, 2020 $ 42,895 The Company evaluates IPR&D assets at least annually at 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 IPR&D assets. Other Assets The components of other assets are as follows: September 30, 2020 March 31, 2020 (in $000's) Investment in Shockwave Medical $ 22,494 $ 55,704 Other investments 39,041 38,741 Operating lease right of use asset (Note 8) 11,021 11,760 Cross currency swap (Note 6) — 3,786 Other intangible assets and other assets 10,038 7,664 Total other assets $ 82,594 $ 117,655 Investment in Shockwave Medical The fair value of the Company’s investment in Shockwave Medical, a publicly-traded medical device company, was $22.5 million and $55.7 million as of September 30, 2020 and March 31, 2020, respectively. During the three and six months ended September 30, 2020, amounts recorded in other income (expense), net of tax, were gains of $8.2 million and $26.2 million, respectively. During the three and six months ended September 30, 2019, amounts recorded in other income (expense), net of tax, were losses of $34.5 million and $4.5 million, respectively. During the quarter ended September 30, 2020, the Company sold approximately 1.4 million of its shares for cash proceeds of $67.9 million and total realized gain of $47.3 million. The Company held 0.3 million shares of Shockwave Medical at September 30, 2020. Other Investments The carrying value of the Company’s portfolio of other investments and the change in the balance for the three and six months ended September 30, 2020 and 2019 are as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) Beginning balance $ 38,741 $ 26,584 38,741 24,584 Additions 1,100 5,000 3,100 7,000 Reclassification — — (2,000 ) — Impairment (800 ) — (800 ) — Ending balance $ 39,041 $ 31,584 $ 39,041 $ 31,584 During the three and six months ended September 30, 2020, the Company recorded an impairment loss of $0.8 million in other (expense) income relating to certain of the Company’s investment in other private medical device companies. Other Intangible Assets and Other Included within other intangible assets and other is $4.1 million related to license manufacturing rights to certain technology from third parties. These intangible assets are classified with other assets in the Company’s consolidated balance sheet and are amortized over their useful life of 15 years.

Leases

Leases	6 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	Note 9. Leases The following table presents supplemental balance sheet information related to our operating leases: September 30, 2020 March 31, 2020 (in $000's) Assets Operating lease right-of-use assets in other assets $ 11,021 $ 11,760 Liabilities Operating lease liabilities in other current liabilities 3,683 3,671 Operating lease liabilities in other long-term liabilities 7,807 8,549 Total operating lease liabilities $ 11,490 $ 12,220 Expense charged to operations under operating leases were $1.1 million and $2.2 Maturities of lease liabilities as of September 30, 2020 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2021 $ 2,153 2022 3,088 2023 1,925 2024 1,782 2025 1,578 Thereafter 2,033 Total minimum lease payments 12,559 Less: imputed interest (1,069 ) Present value of operating lease liabilities $ 11,490 Weighted average remaining lease term 4.99 Weighted average discount rate 3.14 %

Accrued Expenses

Accrued Expenses	6 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	Note 10. Accrued Expenses Accrued expenses consist of the following: September 30, 2020 March 31, 2020 (in $000's) Employee compensation $ 29,081 $ 32,273 Sales and income taxes 11,239 21,641 Research and development 5,481 5,749 Professional, legal, and accounting fees 3,320 6,880 Warranty 1,739 1,818 Marketing 1,092 1,705 Other 5,275 5,041 $ 57,227 $ 75,107 The accrual for employee compensation consists primarily of accrued bonuses, commissions, employee benefits and payroll taxes at September 30, 2020 and March 31, 2020.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholders' Equity	Note 11. 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. The Company did not make any repurchases during the three months ended September 30, 2020. The remaining authorization under the stock repurchase program was $103.8 million as September 30, 2020. The following table provides shares bought through stock repurchase program during the three and six months ended September 30, 2020 and 2019: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 Shares repurchased — 180,929 67,649 180,929 Average price per share — $ 192.75 $ 167.19 $ 192.75 Value of shares repurchased (in millions) — $ 34.9 $ 11.3 $ 34.9 Accumulated Other Comprehensive Income (Loss) The components of accumulated other comprehensive income (loss), are as follows (in thousands): Six Months Ended September 30, 2020 Foreign Currency Translation Gains (Losses) Unrealized Gains on Investments Gains (Losses) on Derivative Instruments Total Balance, April 1, 2020 (16,860 ) 1,672 3,999 (11,189 ) Other comprehensive income (loss) 1,360 1,755 (461 ) 2,654 Balance, June 30, 2020 (15,500 ) 3,427 3,538 (8,535 ) Other comprehensive income (loss) 2,416 (814 ) (266 ) 1,336 Balance, September 30, 2020 (13,084 ) 2,613 3,272 (7,199 ) Six Months Ended September 30, 2019 Foreign Currency Translation Gains (Losses) Unrealized Gains on Investments Gains (Losses) on Derivative Instruments Total Balance, April 1, 2019 (15,028 ) 339 — (14,689 ) Other comprehensive income 2,334 600 — 2,934 Balance, June 30, 2019 (12,694 ) 939 — (11,755 ) Other comprehensive income (5,716 ) (85 ) — (5,801 ) Balance, September 30, 2019 (18,410 ) 854 — (17,556 )

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	Note 12. Stock-Based Compensation The following table summarizes stock-based compensation expense by financial statement line item in the Company’s condensed consolidated statements of operations for the three and six months ended September 30, 2020 and 2019: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) Cost of revenue $ 923 $ 881 $ 1,627 $ 1,722 Research and development 1,705 1,823 3,147 3,706 Selling, general and administrative 8,937 10,619 16,089 21,017 $ 11,565 $ 13,323 $ 20,863 $ 26,445 Stock Options The following table summarizes the stock option activity for the six months ended September 30, 2020: 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 65 221.12 Exercised (153 ) 36.41 Cancelled and expired (8 ) 227.25 Outstanding at end of period 774 $ 134.90 5.77 $ 117,144 Exercisable at end of period 592 $ 98.68 4.84 $ 110,352 Options vested and expected to vest at end of period 773 $ 134.92 5.77 $ 117,040 Stock options generally vest and become exercisable annually over three years. The remaining unrecognized stock-based compensation expense for unvested stock option awards at September 30, 2020, was approximately $13.0 million and the estimated weighted-average period over which this cost will be recognized is 1.9 years. The aggregate intrinsic value of stock options exercised was $37.8 million for the six months ended September 30, 2020. The total cash received as a result of employee stock option exercises for the six months ended September 30, 2020, was approximately $5.6 million. 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 during the three and six months ended September 30, 2020 and 2019 was as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 Weighted average grant-date fair value $ 100.51 $ 70.40 $ 76.10 $ 95.62 Valuation assumptions: Risk-free interest rate 0.30 % 1.54 % 0.31 % 2.02 % Expected option life (years) 4.17 4.13 4.22 4.14 Expected volatility 43.5 % 44.2 % 42.82 % 42.3 % Restricted Stock Units The following table summarizes activity of restricted stock units for the six months ended September 30, 2020: Number of Shares Weighted Average Grant Date Fair Value (in thousands) (per share) Restricted stock units at beginning of period 320 $ 263.92 Granted 194 254.55 Vested (136 ) 226.71 Forfeited (101 ) 267.28 Restricted stock units at end of period 277 $ 274.31 Restricted stock units generally vest annually over three years. The remaining unrecognized compensation expense for outstanding restricted stock units, including performance and market-based awards, as of September 30, 2020 was $59.3 million and the estimated weighted-average period over which this cost will be recognized is 2.1 years. The weighted average grant-date fair value for restricted stock units granted during the six months ended September 30, 2020 was $254.55. The total fair value of restricted stock units vested during the six months ended September 30, 2020 was $26.8 million. Performance-Based Awards In May 2020, performance-based awards of restricted stock units for the potential issuance of up to 61,674 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. As of September 30, 2020, the Company is recognizing compensation expense based on the probable outcomes related to the prescribed performance targets on the outstanding awards. Market-Based Awards In May 2020, the Company awarded certain executive officers and employees a total of up to 61,562 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 twenty 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 three-year 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 fair value per share $347.05 - $349.28 Target performance (number of shares) 30,781

Income Taxes

Income Taxes	6 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 13. Income Taxes The Company’s income tax provision was $10.7 million and $4.3 million for the three months ended September 30, 2020 and 2019, respectively. The Company’s income tax provision was $27.2 million and $18.5 million for the six months ended September 30, 2020 and 2019, respectively. The Company’s effective tax rate was 14.7% and 24.7% for the three months ended September 30, 2020 and 2019, respectively. The Company’s effective tax rate was 20.3% and 15.4% for the , respectively. The significant differences between the statutory income tax rate and effective income tax rate for the three and six months ended September 30, 2020 and 2019 were as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 Statutory income tax rate 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) resulting from: — Excess tax benefits from stock-based awards (10.9 ) (2.7 ) (6.3 ) (11.0 ) Credits (1.7 ) (2.1 ) (1.7 ) (1.7 ) State taxes, net 4.1 3.3 4.1 3.4 Permanent differences 2.6 1.7 3.4 1.9 Excess foreign tax credit 0.4 — 0.4 — Other (0.8 ) 3.5 (0.6 ) 1.7 Effective tax rate 14.7 % 24.7 % 20.3 % 15.4 % T he Company recognizes excess tax benefits and shortfalls in the income tax provision as discrete items in the period in which restricted stock units vest or stock option exercises occur. The Company recognized excess tax benefits associated with stock-based awards of $7.9 million and $0.5 million as an income tax benefit for the three months ended September 30, 2020 and 2019, respectively. The Company recognized excess tax benefits associated with stock-based awards of $8.5 million and $13.3 million for the six months ended September 30, 2020 and 2019. These recognized excess tax benefits resulted from restricted stock units that vested or stock options that were exercised during each period. 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. The Company is subject to the examination of its income tax returns by the Internal Revenue Service (“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 our financial statements. On October 29, 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 federal, state and foreign tax authorities.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 14. 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 21, 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®, Impella CP®, Impella 5.0®, and Impella RP® heart pumps infringe certain claims of the three original issued U.S. patents (“2016 Action”). In July 2017, the Court granted a motion to add three of the four additional continuation patents to the 2016 Action. In April 2018, the Court conducted a Markman hearing on claim interpretation. On September 7, 2018, the judge issued a Memorandum and Order on Claim Construction, where he interpreted the disputed claim terms in the case. Maquet then filed a motion for reconsideration of the Court’s construction of one of the disputed claim terms. The motion was denied on May 22, 2019. As a result of the Court’s denial, only one of the six originally asserted patents is in dispute. The Company filed a motion for summary judgement (MSJ) for the remaining patent on September 18, 2019 (non-infringement) and April 13, 2020 (invalidity). The parties argued the MSJ for non-infringement on November 19, 2019, the MSJ for invalidity on August 20, 2020 and are waiting for Court’s resolution. The Court has not set a date for trial. The only remaining patent asserted in this case expired on September 1, 2020. In November 2017, Maquet filed a second action in D. Mass (“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 has reviewed and not yet responded to the complaints. The Company believes that the allegations are without merit and plans to defend itself vigorously. On June 28, 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 they proposed a new class period of May 3, 2018 to July 31, 2019. As prescribed by a scheduling order, the Company may file a motion to dismiss on or before November 16, 2020. The Company intends to do so but does not expect a decision on that motion until at least the second quarter of calendar year 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. 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	6 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Segment and Enterprise Wide Disclosures	Note 15. 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 (meaning sales outside the U.S., primarily in Europe and Japan) accounted for 18% and 16% of total revenue for each of the three and six months ended September 30, 2020 and 2019, respectively. T he Company’s long-lived assets are located in the U.S., except for $52.9 million and $46.7 million at September 30, 2020 and March 31, 2020, respectively, which are located primarily in Germany.

Basis of Preparation and Summ_2

Basis of Preparation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
COVID-19 Pandemic	COVID-19 Pandemic The Company is subject to risks and uncertainties as a result of the COVID-19 pandemic. Considerable uncertainty still surrounds the COVID-19 virus and its potential effects, and the extent of and effectiveness of responses taken on international, national and local levels. Measures taken to limit the impact of COVID-19, including shelter-in-place orders, social distancing measures, travel bans and restrictions, and business and government shutdowns, continue to create significant negative economic impacts on a global basis. The extent of the impact of the COVID-19 pandemic on the Company's business remains uncertain and difficult to predict, as the response to the pandemic continues to evolve. Beginning in mid-March 2020 and continuing into the first quarter of fiscal 2021, the Company experienced a significant decline in patient utilization 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 April 2020, 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 globally through the second quarter of fiscal 2021 as restrictions were lifted and limitations eased. In the second quarter of fiscal 2021, patient procedure volume trends have improved gradually as both demand for procedures and availability of healthcare resources improved during the summer months. While the Company currently expects to see sequential quarterly improvement in the remainder of fiscal 2021, 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 based on some of the resurgence that is now occurring in cities across the globe . The Company is closely monitoring the impact of COVID-19 on all aspects of its business and geographies, including the impact on its customers, employees, suppliers, vendors, business partners and distribution channels. The extent to which the COVID-19 global 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; these developments include, but are not limited to, the duration and spread of the outbreak, its severity, the actions to contain the virus or address its impact, 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. Even after the COVID-19 outbreak has subsided, the Company may continue to experience materially adverse impacts on its financial condition and results of operations. As of the date of issuance of these consolidated financial statements, the extent to which the COVID-19 pandemic may materially impact the Company's financial condition, liquidity, or results of operations is uncertain.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326).” This new standard requires 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. 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 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).” This new standard modifies the disclosure requirements on fair value measurements, including the removal of disclosures of the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels, and the valuation processes for Level 3 fair value measurements. The guidance also adds certain disclosure requirements related to Level 3 fair value measurements. 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.
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 intra-period 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. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. ASU 2019-12 will become effective for the Company in fiscal 2022. 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 2022.
Leases	The following table presents supplemental balance sheet information related to our operating leases: September 30, 2020 March 31, 2020 (in $000's) Assets Operating lease right-of-use assets in other assets $ 11,021 $ 11,760 Liabilities Operating lease liabilities in other current liabilities 3,683 3,671 Operating lease liabilities in other long-term liabilities 7,807 8,549 Total operating lease liabilities $ 11,490 $ 12,220 Expense charged to operations under operating leases were $1.1 million and $2.2 Maturities of lease liabilities as of September 30, 2020 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2021 $ 2,153 2022 3,088 2023 1,925 2024 1,782 2025 1,578 Thereafter 2,033 Total minimum lease payments 12,559 Less: imputed interest (1,069 ) Present value of operating lease liabilities $ 11,490 Weighted average remaining lease term 4.99 Weighted average discount rate 3.14 %
Adoption of Topic 606, Revenue from Contracts with Customers	The Company generates revenue primarily from the sale of Impella 2.5, Impella CP, Impella 5.0, Impella LD, Impella RP, Impella 5.5 and Impella AIC products. The Company also earns revenue from preventative maintenance service contracts and maintenance calls.

Acquisition (Tables)

Acquisition (Tables)	6 Months Ended
	Sep. 30, 2020
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 preliminary 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 44,048 In-process research and development 27,000 Other assets acquired 895 Total assets acquired 76,091 Liabilities assumed: Accounts payable and other liabilities 1,562 Deferred tax liabilities 3,379 Net assets acquired $ 71,150

Net Income Per Share (Tables)

Net Income Per Share (Tables)	6 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Income Per Share	The Company’s basic and diluted net income per share for the three and six months ended September 30, 2020 and 2019 were as follows (in thousands, except per share data): For the Three Months Ended September 30, For the Six Months Ended September 30, Basic Net Income Per Share 2020 2019 2020 2019 Net income $ 62,213 $ 13,071 $ 106,801 $ 101,994 Weighted average shares – basic 45,104 45,319 45,057 45,267 Net income per share – basic $ 1.38 $ 0.29 $ 2.37 $ 2.25 For the Three Months Ended September 30, For the Six Months Ended September 30, Diluted Net Income Per Share 2020 2019 2020 2019 Net income $ 62,213 13,071 106,801 101,994 Weighted average shares – basic 45,104 45,319 45,057 45,267 Effect of dilutive securities 557 593 552 764 Weighted average shares – diluted 45,661 45,912 45,609 46,031 Net income per share – diluted $ 1.36 $ 0.28 $ 2.34 $ 2.22

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Sep. 30, 2020
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: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) (in $000's) Impella product revenue $ 199,676 $ 196,939 $ 355,093 $ 396,804 Service and other revenue 10,088 8,035 19,521 15,836 Total revenue $ 209,764 $ 204,974 $ 374,614 $ 412,640 The following table disaggregates the Company’s revenue by geographical location: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) (in $000's) U.S. revenue $ 172,147 $ 172,015 $ 306,872 $ 347,500 International revenue 37,617 32,959 67,742 65,140 Total revenue $ 209,764 $ 204,974 $ 374,614 $ 412,640

Cash Equivalents, Marketable _2

Cash Equivalents, Marketable Securities and Fair Value Measurements (Tables)	6 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Cash Equivalents and Marketable Securities	The Company’s cash equivalents and marketable securities at September 30, 2020 and March 31, 2020 are invested in the following: Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value September 30, 2020 (in $000's) Money market funds $ 104,305 $ — $ — $ 104,305 Repurchase agreements 20,000 — — 20,000 Total cash equivalents 124,305 — — 124,305 Short-term U.S. Treasury mutual fund securities 75,505 85 (1 ) 75,589 Short-term government-backed securities 85,360 105 (9 ) 85,456 Short-term corporate debt securities 128,738 1,043 — 129,781 Short-term commercial paper 39,991 31 (5 ) 40,017 Total short-term marketable securities 329,594 1,264 (15 ) 330,843 Long-term U.S. Treasury mutual fund securities 10,246 2 — 10,248 Long-term government-backed securities 141,378 164 (6 ) 141,536 Long-term corporate debt securities 49,627 1,202 — 50,829 Total long-term marketable securities 201,251 1,368 (6 ) 202,613 $ 655,150 $ 2,632 $ (21 ) $ 657,761 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 September 30, 2020 (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 of September 30, 2020: Derivatives designated as hedging instruments under ASC 815 Balance Sheet classification Fair Value Cross-currency swap Other assets (long-term liabilities) $ (2,860 )
Components of Contingent Consideration Liabilities	The components of contingent consideration liability are as follows: September 30, 2020 March 31, 2020 (in $000's) ECP $ 10,117 $ 9,000 Breethe, Inc. 14,300 — $ 24,417 $ 9,000
Financial Instruments Measured at Fair Value	The following tables present the Company’s fair value hierarchy for its financial instruments measured at fair value as of September 30, 2020 and March 31, 2020: Level 1 Level 2 Level 3 Total September 30, 2020 (in $000's) Assets Money market funds $ 104,305 $ — $ — $ 104,305 Repurchase agreements — 20,000 — 20,000 Short-term government-backed securities — 85,456 — 85,456 Short-term corporate debt securities — 129,781 — 129,781 Short-term commercial paper — 40,017 — 40,017 Short-term U.S. Treasury mutual fund securities — 75,589 — 75,589 Long-term U.S. Treasury mutual fund securities — 10,248 — 10,248 Long-term government-backed securities — 141,536 — 141,536 Long-term corporate debt securities — 50,829 — 50,829 Investment in Shockwave Medical 22,494 — — 22,494 Liabilities Contingent consideration — — 24,417 24,417 Cross-currency swap agreement — 2,860 — 2,860 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 for the three and six months ended September 30, 2020 and 2019: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) Beginning balance $ 23,701 $ 9,931 $ 9,000 $ 9,575 Additions — — 13,300 — Change in fair value 716 305 2,117 661 Ending balance $ 24,417 $ 10,236 $ 24,417 $ 10,236

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Sep. 30, 2020
Property Plant And Equipment [Abstract]
Components of Property and Equipment	The components of property and equipment are as follows: September 30, 2020 March 31, 2020 (in $000's) Land $ 7,454 $ 7,179 Building and building improvements 102,644 100,176 Leasehold improvements 15,183 14,546 Machinery and equipment 78,343 71,636 Furniture and fixtures 15,166 14,600 Construction in progress 26,277 15,075 Total cost 245,067 223,212 Accumulated depreciation (69,485 ) (58,281 ) Property and equipment, net $ 175,582 $ 164,931

Goodwill, In-Process Research_2

Goodwill, In-Process Research and Development and Other Assets (Tables)	6 Months Ended
	Sep. 30, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Carrying Value of Goodwill and Change in Balance	The carrying value of goodwill and the change in the balance for the six months ended September 30, 2020 are as follows: (in $000's) Balance, March 31, 2020 $ 31,969 Breethe, Inc. acquisition 44,048 Foreign currency translation impact 2,105 Balance, September 30, 2020 $ 78,122
Summary of Components of In-Process Research & Development	The components of IPR&D are as follows: September 30, 2020 March 31, 2020 (in $000's) ECP $ 15,895 $ 14,913 Breethe, Inc. 27,000 — $ 42,895 $ 14,913
Carrying value of In-Process Research and Development	The carrying value of the Company’s IPR&D assets and the change in the balance for the six months ended September 30, 2020 are as follows: (in $000's) Balance, March 31, 2020 $ 14,913 Breethe, Inc. acquisition 27,000 Foreign currency translation impact 982 Balance, September 30, 2020 $ 42,895
Summary of Components of Other Assets	The components of other assets are as follows: September 30, 2020 March 31, 2020 (in $000's) Investment in Shockwave Medical $ 22,494 $ 55,704 Other investments 39,041 38,741 Operating lease right of use asset (Note 8) 11,021 11,760 Cross currency swap (Note 6) — 3,786 Other intangible assets and other assets 10,038 7,664 Total other assets $ 82,594 $ 117,655
Carrying value of Other Investments	The carrying value of the Company’s portfolio of other investments and the change in the balance for the three and six months ended September 30, 2020 and 2019 are as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) Beginning balance $ 38,741 $ 26,584 38,741 24,584 Additions 1,100 5,000 3,100 7,000 Reclassification — — (2,000 ) — Impairment (800 ) — (800 ) — Ending balance $ 39,041 $ 31,584 $ 39,041 $ 31,584

Leases (Tables)

Leases (Tables)	6 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Supplemental Balance Sheet Information Related to Operating Leases	The following table presents supplemental balance sheet information related to our operating leases: September 30, 2020 March 31, 2020 (in $000's) Assets Operating lease right-of-use assets in other assets $ 11,021 $ 11,760 Liabilities Operating lease liabilities in other current liabilities 3,683 3,671 Operating lease liabilities in other long-term liabilities 7,807 8,549 Total operating lease liabilities $ 11,490 $ 12,220
Maturities of Lease Liabilities	Maturities of lease liabilities as of September 30, 2020 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2021 $ 2,153 2022 3,088 2023 1,925 2024 1,782 2025 1,578 Thereafter 2,033 Total minimum lease payments 12,559 Less: imputed interest (1,069 ) Present value of operating lease liabilities $ 11,490 Weighted average remaining lease term 4.99 Weighted average discount rate 3.14 %

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses consist of the following: September 30, 2020 March 31, 2020 (in $000's) Employee compensation $ 29,081 $ 32,273 Sales and income taxes 11,239 21,641 Research and development 5,481 5,749 Professional, legal, and accounting fees 3,320 6,880 Warranty 1,739 1,818 Marketing 1,092 1,705 Other 5,275 5,041 $ 57,227 $ 75,107

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Stock Repurchase Activity	The following table provides shares bought through stock repurchase program during the three and six months ended September 30, 2020 and 2019: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 Shares repurchased — 180,929 67,649 180,929 Average price per share — $ 192.75 $ 167.19 $ 192.75 Value of shares repurchased (in millions) — $ 34.9 $ 11.3 $ 34.9
Schedule of Accumulated Other Comprehensive Income (Loss)	The components of accumulated other comprehensive income (loss), are as follows (in thousands): Six Months Ended September 30, 2020 Foreign Currency Translation Gains (Losses) Unrealized Gains on Investments Gains (Losses) on Derivative Instruments Total Balance, April 1, 2020 (16,860 ) 1,672 3,999 (11,189 ) Other comprehensive income (loss) 1,360 1,755 (461 ) 2,654 Balance, June 30, 2020 (15,500 ) 3,427 3,538 (8,535 ) Other comprehensive income (loss) 2,416 (814 ) (266 ) 1,336 Balance, September 30, 2020 (13,084 ) 2,613 3,272 (7,199 ) Six Months Ended September 30, 2019 Foreign Currency Translation Gains (Losses) Unrealized Gains on Investments Gains (Losses) on Derivative Instruments Total Balance, April 1, 2019 (15,028 ) 339 — (14,689 ) Other comprehensive income 2,334 600 — 2,934 Balance, June 30, 2019 (12,694 ) 939 — (11,755 ) Other comprehensive income (5,716 ) (85 ) — (5,801 ) Balance, September 30, 2019 (18,410 ) 854 — (17,556 )

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Recognized	The following table summarizes stock-based compensation expense by financial statement line item in the Company’s condensed consolidated statements of operations for the three and six months ended September 30, 2020 and 2019: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 (in $000's) Cost of revenue $ 923 $ 881 $ 1,627 $ 1,722 Research and development 1,705 1,823 3,147 3,706 Selling, general and administrative 8,937 10,619 16,089 21,017 $ 11,565 $ 13,323 $ 20,863 $ 26,445
Summary of Stock Option Activity	The following table summarizes the stock option activity for the six months ended September 30, 2020: 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 65 221.12 Exercised (153 ) 36.41 Cancelled and expired (8 ) 227.25 Outstanding at end of period 774 $ 134.90 5.77 $ 117,144 Exercisable at end of period 592 $ 98.68 4.84 $ 110,352 Options vested and expected to vest at end of period 773 $ 134.92 5.77 $ 117,040
Summary of Weighted Average Grant-Date Fair Values And Weighted Average Assumptions Used to Calculate Fair Value of Options Granted	For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 Weighted average grant-date fair value $ 100.51 $ 70.40 $ 76.10 $ 95.62 Valuation assumptions: Risk-free interest rate 0.30 % 1.54 % 0.31 % 2.02 % Expected option life (years) 4.17 4.13 4.22 4.14 Expected volatility 43.5 % 44.2 % 42.82 % 42.3 %
Restricted Stock Units
Summary of Restricted Stock Units Activity	The following table summarizes activity of restricted stock units for the six months ended September 30, 2020: Number of Shares Weighted Average Grant Date Fair Value (in thousands) (per share) Restricted stock units at beginning of period 320 $ 263.92 Granted 194 254.55 Vested (136 ) 226.71 Forfeited (101 ) 267.28 Restricted stock units at end of period 277 $ 274.31
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 fair value per share $347.05 - $349.28 Target performance (number of shares) 30,781

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Differences Between Statutory Income Tax Rate and Effective Income Tax Rate	The significant differences between the statutory income tax rate and effective income tax rate for the three and six months ended September 30, 2020 and 2019 were as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2020 2019 2020 2019 Statutory income tax rate 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) resulting from: — Excess tax benefits from stock-based awards (10.9 ) (2.7 ) (6.3 ) (11.0 ) Credits (1.7 ) (2.1 ) (1.7 ) (1.7 ) State taxes, net 4.1 3.3 4.1 3.4 Permanent differences 2.6 1.7 3.4 1.9 Excess foreign tax credit 0.4 — 0.4 — Other (0.8 ) 3.5 (0.6 ) 1.7 Effective tax rate 14.7 % 24.7 % 20.3 % 15.4 %

Acquisition - Additional Inform

Acquisition - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended
	Apr. 30, 2020	Sep. 30, 2020
Restructuring Cost And Reserve [Line Items]
Business acquisition, transaction costs		$ 0.9
Breethe, Inc
Restructuring Cost And Reserve [Line Items]
Payments to acquire businesses, cash paid	$ 55
Breethe, Inc | Maximum
Restructuring Cost And Reserve [Line Items]
Potential payouts payments	$ 55

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) $ in Thousands	Apr. 24, 2020USD ($)
Business Combinations [Abstract]
Cash and cash equivalents	$ 3,404
Property and equipment	744
Goodwill	44,048
In-process research and development	27,000
Other assets acquired	895
Total assets acquired	76,091
Accounts payable and other liabilities	1,562
Deferred tax liabilities	3,379
Net assets acquired	$ 71,150

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				6 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic Net Income Per Share
Net income	$ 62,213	$ 44,588	$ 13,071	$ 88,923	$ 106,801	$ 101,994
Weighted average shares – basic	45,104		45,319		45,057	45,267
Net income per share – basic	$ 1.38		$ 0.29		$ 2.37	$ 2.25
Diluted Net Income Per Share
Net income	$ 62,213	$ 44,588	$ 13,071	$ 88,923	$ 106,801	$ 101,994
Weighted average shares – basic	45,104		45,319		45,057	45,267
Effect of dilutive securities	557		593		552	764
Weighted average shares – diluted	45,661		45,912		45,609	46,031
Net income per share – diluted	$ 1.36		$ 0.28		$ 2.34	$ 2.22

Net Income Per Share - Addition

Net Income Per Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares excluded from the calculation of diluted weighted average shares outstanding	0.1	0.3	0.2	0.3

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Disaggregated Revenue by Major Business Line (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Table]
Total revenue	$ 209,764	$ 204,974	$ 374,614	$ 412,640
U.S.
Disaggregation Of Revenue [Table]
Total revenue	172,147	172,015	306,872	347,500
International
Disaggregation Of Revenue [Table]
Total revenue	37,617	32,959	67,742	65,140
Impella Product
Disaggregation Of Revenue [Table]
Total revenue	199,676	196,939	355,093	396,804
Service and Other
Disaggregation Of Revenue [Table]
Total revenue	$ 10,088	$ 8,035	$ 19,521	$ 15,836

Revenue Recognition - Deferred

Revenue Recognition - Deferred Revenue - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Revenue From Contract With Customer [Abstract]
Deferred revenue	$ 21,314		$ 21,314		$ 19,147
Deferred Revenue, Revenue Recognized	$ 5,400	$ 4,000	$ 14,600	$ 12,500

Investable Cash Equivalents and

Investable Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	$ 655,150	$ 591,917
Gross Unrealized Gains	2,632	1,985
Gross Unrealized Losses	(21)	(313)
Fair Market Value	657,761	593,589
Cash Equivalents
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	124,305	135,019
Fair Market Value	124,305	135,019
Repurchase Agreement
Total Cash Equivalents and Marketable Securities [Line Items]
Fair Market Value	20,000	20,000
Repurchase Agreement | Cash Equivalents
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	20,000	20,000
Fair Market Value	20,000	20,000
Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	329,594	249,877
Gross Unrealized Gains	1,264	981
Gross Unrealized Losses	(15)	(83)
Fair Market Value	330,843	250,775
Long-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	201,251	207,021
Gross Unrealized Gains	1,368	1,004
Gross Unrealized Losses	(6)	(230)
Fair Market Value	202,613	207,795
Money Market Funds
Total Cash Equivalents and Marketable Securities [Line Items]
Fair Market Value	104,305	115,019
Money Market Funds | Cash Equivalents
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	104,305	115,019
Fair Market Value	104,305	115,019
Commercial Paper | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	39,991	32,757
Gross Unrealized Gains	31	74
Gross Unrealized Losses	(5)
Fair Market Value	40,017	32,831
U.S. Treasury mutual fund securities | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	75,505	42,236
Gross Unrealized Gains	85	412
Gross Unrealized Losses	(1)
Fair Market Value	75,589	42,648
U.S. Treasury mutual fund securities | Long-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	10,246
Gross Unrealized Gains	2
Fair Market Value	10,248
Government-backed securities | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	85,360	67,594
Gross Unrealized Gains	105	401
Gross Unrealized Losses	(9)
Fair Market Value	85,456	67,995
Government-backed securities | Long-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	141,378	90,911
Gross Unrealized Gains	164	153
Gross Unrealized Losses	(6)
Fair Market Value	141,536	91,064
Corporate Debt Securities | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	128,738	107,290
Gross Unrealized Gains	1,043	94
Gross Unrealized Losses		(83)
Fair Market Value	129,781	107,301
Corporate Debt Securities | Long-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	49,627	116,110
Gross Unrealized Gains	1,202	851
Gross Unrealized Losses		(230)
Fair Market Value	$ 50,829	$ 116,731

Cash Equivalents, Marketable _3

Cash Equivalents, Marketable Securities and Fair Value Measurements - Additional Information (Detail) € in Millions, $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended
	Apr. 30, 2020USD ($)	Jul. 31, 2014USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2020EUR (€)	Oct. 31, 2019EUR (€)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other income, net			$ 0.7	$ 0.7
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				65.00%
ECP and AIS | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate			2.00%	2.00%	2.00%
ECP and AIS | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate			16.00%	16.00%	16.00%
Breethe, Inc
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire businesses, cash paid	$ 55
Breethe, Inc | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate			2.00%	2.00%	2.00%
Commercial milestones				25.00%
Breethe, Inc | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Potential payouts payments	$ 55
Discount rate			16.00%	16.00%	16.00%
Commercial milestones				99.00%
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	$ 93.5	€ 85

Schedule of Cross-Currency Rate

Schedule of Cross-Currency Rate Swap Derivatives (Detail) € in Thousands, $ in Thousands	6 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2020EUR (€)
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) $ in Thousands	Sep. 30, 2020USD ($)
Cross Currency Interest Rate Contract | Other assets (long term liabilities)
Fair Value	$ (2,860)

Schedule of Components of Conti

Schedule of Components of Contingent Consideration Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Contingent consideration liabilities	$ 24,417	$ 9,000
ECP
Contingent consideration liabilities	10,117	$ 9,000
Breethe, Inc
Contingent consideration liabilities	$ 14,300

Financial Instruments Measured

Financial Instruments Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	$ 657,761	$ 593,589
Contingent consideration	24,417	9,000
Cross Currency Interest Rate Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative fair value	2,860	3,786
Repurchase Agreement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	20,000	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	330,843	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	202,613	207,795
Shockwave Medical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	22,494	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	104,305	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	40,017	32,831
Level 1 | Shockwave Medical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	22,494	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	104,305	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	2,860	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	20,000	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	40,017	32,831
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	24,417	9,000
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	75,589	42,648
U.S. Treasury mutual fund securities | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	10,248
U.S. Treasury mutual fund securities | Level 2 | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	75,589	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	85,456	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	141,536	91,064
Government-backed securities | Level 2 | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	85,456	67,995
Government-backed securities | Level 2 | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	141,536	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	129,781	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	50,829	116,731
Corporate Debt Securities | Level 2 | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	129,781	107,301
Corporate Debt Securities | Level 2 | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	50,829	$ 116,731
Long Term U.S. Treasury Mutual Fund Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	10,248
Long Term U.S. Treasury Mutual Fund Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	$ 10,248

Change in Fair Value of Conting

Change in Fair Value of Contingent Consideration as Determined by Level 3 Inputs (Detail) - Contingent Consideration - ECP Entwicklungsgesellschaft mbH - Level 3 - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 23,701	$ 9,931	$ 9,000	$ 9,575
Additions	0	0	13,300	0
Change in fair value	716	305	2,117	661
Ending balance	$ 24,417	$ 10,236	$ 24,417	$ 10,236

Components of Property and Equi

Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Property Plant And Equipment [Abstract]
Land	$ 7,454	$ 7,179
Building and building improvements	102,644	100,176
Leasehold improvements	15,183	14,546
Machinery and equipment	78,343	71,636
Furniture and fixtures	15,166	14,600
Construction in progress	26,277	15,075
Total cost	245,067	223,212
Accumulated depreciation	(69,485)	(58,281)
Property and equipment, net	$ 175,582	$ 164,931

Goodwill, In-Process Research_3

Goodwill, In-Process Research and Development and Other Assets - Additional Information (Detail) shares in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020USD ($)shares	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)shares	Sep. 30, 2019USD ($)	Mar. 31, 2020USD ($)
Goodwill [Line Items]
Goodwill	$ 78,122,000		$ 78,122,000		$ 31,969,000
Accumulated impairment loss, goodwill	0		0
In-process research and development	42,895,000		42,895,000		14,913,000
Accumulated impairment losses on IPR&D assets	0		0
License Manufacturing Rghts to Technology
Goodwill [Line Items]
Payments to third party			$ 4,100,000
Other Intangible Assets
Goodwill [Line Items]
Intangible asset, amortized useful life			15 years
Other Income (Expense)
Goodwill [Line Items]
Impairment loss in other investment	800,000		$ 800,000
Shockwave Medical
Goodwill [Line Items]
Investment in Shockwave Medical	22,494,000		$ 22,494,000		55,704,000
Cash proceeds	$ 67,900,000
Shares sold | shares	1.4		1.4
Shares held by the company | shares	0.3		0.3
Shockwave Medical | Other Income (Expense)
Goodwill [Line Items]
Realized gain on the sale of investment recorded in other income	$ 47,300,000
Unrealized gain (loss) recorded in other income	8,200,000	$ (34,500,000)	$ 26,200,000	$ (4,500,000)
ECP Entwicklungsgesellschaft mbH
Goodwill [Line Items]
In-process research and development	$ 42,900,000		$ 42,900,000		$ 14,900,000
ECP Entwicklungsgesellschaft mbH | Measurement Input, Discount Rate | Maximum
Goodwill [Line Items]
Fair value inputs, discount rate	0.21		0.21
ECP Entwicklungsgesellschaft mbH | Measurement Input, Discount Rate | Minimum [Member]
Goodwill [Line Items]
Fair value inputs, discount rate	0.15		0.15

Carrying Value of Goodwill and

Carrying Value of Goodwill and Change in Balance (Detail) $ in Thousands	6 Months Ended
	Sep. 30, 2020USD ($)
Goodwill [Line Items]
Beginning balance	$ 31,969
Foreign currency translation impact	2,105
Ending balance	78,122
Breethe, Inc
Goodwill [Line Items]
Breethe, Inc. acquisition	$ 44,048

Summary of Components of In-Pro

Summary of Components of In-Process Research & Development (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Goodwill [Line Items]
In-process research and development	$ 42,895	$ 14,913
ECP
Goodwill [Line Items]
In-process research and development	15,895	$ 14,913
Breethe, Inc.
Goodwill [Line Items]
In-process research and development	$ 27,000

Carrying value of In-Process Re

Carrying value of In-Process Research and Development (Detail) $ in Thousands	6 Months Ended
	Sep. 30, 2020USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 14,913
Breethe, Inc. acquisition	27,000
Foreign currency translation impact	982
Ending balance	$ 42,895

Summary of Components of Other

Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Goodwill [Line Items]
Fair value of investment	$ 39,041	$ 38,741	$ 38,741	$ 31,584	$ 26,584	$ 24,584
Operating lease right of use asset (Note 8)	11,021		11,760
Cross currency swap (Note 6)			3,786
Other intangible assets and other assets	10,038		7,664
Total other assets	82,594		117,655
Shockwave Medical
Goodwill [Line Items]
Investment in Shockwave Medical	$ 22,494		$ 55,704

Carrying value of Other Investm

Carrying value of Other Investments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 38,741	$ 26,584	$ 38,741	$ 24,584
Additions	1,100	5,000	3,100	7,000
Reclassification			(2,000)
Impairment	(800)		(800)
Ending balance	$ 39,041	$ 31,584	$ 39,041	$ 31,584

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information Related to Operating Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Leases [Abstract]
Operating lease right-of-use assets in other assets	$ 11,021	$ 11,760
Operating lease liabilities in other current liabilities	3,683	3,671
Operating lease liabilities in other long-term liabilities	7,807	8,549
Total operating lease liabilities	$ 11,490	$ 12,220

Leases - Additional Information

Leases - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 1,100	$ 2,200	$ 1,100	$ 2,200

Maturities of Lease Liabilities

Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Leases [Abstract]
2021	$ 2,153
2022	3,088
2023	1,925
2024	1,782
2025	1,578
Thereafter	2,033
Total minimum lease payments	12,559
Less: imputed interest	(1,069)
Present value of operating lease liabilities	$ 11,490		$ 12,220
Weighted average remaining lease term	4 years 11 months 26 days
Weighted average discount rate		3.14%

Accrued Expenses (Detail)

Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Payables and Accruals [Abstract]
Employee compensation	$ 29,081	$ 32,273
Sales and income taxes	11,239	21,641
Research and development	5,481	5,749
Professional, legal, and accounting fees	3,320	6,880
Warranty	1,739	1,818
Marketing	1,092	1,705
Other	5,275	5,041
Accrued expenses	$ 57,227	$ 75,107

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Sep. 30, 2020	Mar. 31, 2020	Aug. 31, 2019
Stockholders Equity Note [Abstract]
Class B Preferred Stock, Authorized	1,000,000	1,000,000
Class B Preferred Stock, par value	$ 0.01	$ 0.01
Class B Preferred Stock, Issued	0	0
Class B Preferred Stock, outstanding	0	0
Stock repurchase program, authorized amount			$ 200
Stock repurchase program, remaining authorized repurchase amount	$ 103.8

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Stock Repurchase Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stockholders Equity Note [Abstract]
Shares repurchased		180,929	67,649	180,929
Average price per share		$ 192.75	$ 167.19	$ 192.75
Value of shares repurchased (in millions)	$ 11,310	$ 34,874	$ 11,300	$ 34,900

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Jun. 30, 2019
Shareholders Equity [Line Items]
Beginning Balance	$ 1,101,848	$ 1,065,466	$ 1,002,593	$ 936,890
Ending Balance	1,182,409	1,101,848	991,457	1,002,593
Foreign Currency Translation Gains (Losses)
Shareholders Equity [Line Items]
Beginning Balance	(15,500)	(16,860)	(12,694)	(15,028)
Other comprehensive income (loss)	2,416	1,360	(5,716)	2,334
Ending Balance	(13,084)	(15,500)	(18,410)	(12,694)
Unrealized Gains on Investments
Shareholders Equity [Line Items]
Beginning Balance	3,427	1,672	939	339
Other comprehensive income (loss)	(814)	1,755	(85)	600
Ending Balance	2,613	3,427	854	939
Gains (Losses) on Derivative Instruments
Shareholders Equity [Line Items]
Beginning Balance	3,538	3,999
Other comprehensive income (loss)	(266)	(461)
Ending Balance	3,272	3,538
Accumulated Other Comprehensive Loss
Shareholders Equity [Line Items]
Beginning Balance	(8,535)	(11,189)	(11,755)	(14,689)
Other comprehensive income (loss)	1,336	2,654	(5,801)	2,934
Ending Balance	$ (7,199)	$ (8,535)	$ (17,556)	$ (11,755)

Stock-Based Compensation Recogn

Stock-Based Compensation Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 11,565	$ 13,323	$ 20,863	$ 26,445
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	923	881	1,627	1,722
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	1,705	1,823	3,147	3,706
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 8,937	$ 10,619	$ 16,089	$ 21,017

Summary of Stock Option Activit

Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)$ / sharesshares	Mar. 31, 2019
Options
Outstanding at beginning of period | shares	869
Granted | shares	65
Exercised | shares	(153)
Cancelled and expired | shares	(8)
Outstanding at end of period | shares	774
Exercisable at end of period | shares	592
Options vested and expected to vest at end of period | shares	773
Weighted Average Exercise Price
Outstanding at beginning of period | $ / shares	$ 112.03
Granted | $ / shares	221.12
Exercised | $ / shares	36.41
Cancelled and expired | $ / shares	227.25
Outstanding at end of period | $ / shares	134.90
Exercisable at end of period | $ / shares	98.68
Options vested and expected to vest at end of period | $ / shares	$ 134.92
Weighted Average Remaining Contractual Term (years)
Outstanding	5 years 9 months 7 days	5 years 3 months 18 days
Exercisable at end of period	4 years 10 months 2 days
Options vested and expected to vest at end of period	5 years 9 months 7 days
Aggregate Intrinsic Value
Outstanding at end of period | $	$ 117,144
Exercisable at end of period | $	110,352
Options vested and expected to vest at end of period | $	$ 117,040

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	6 Months Ended
	May 31, 2020	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options exercised in period		$ 37,800
Proceeds from the exercise of stock options		$ 5,555	$ 2,706
Granted		30,781,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Unrecognized stock-based compensation expense		$ 13,000
Unrecognized stock-based compensation expense, weighted-average recognition period		1 year 10 months 24 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Unrecognized stock-based compensation expense		$ 59,300
Unrecognized stock-based compensation expense, weighted-average recognition period		2 years 1 month 6 days
Weighted average grant-date fair value		$ 254.55
Fair value of units vested		$ 26,800
Granted		194,000
Performance Based Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	61,674
Market-Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	61,562
Stock units minimum range percent	0.00%
Stock units maximum range percent	200.00%
Compensation expense period description	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
Market-Based Awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense, weighted-average recognition period	3 years
Market-Based Awards | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense, weighted-average recognition period	2 years

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	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Valuation assumptions:
Risk-free interest rate			0.20%
Expected volatility			35.50%
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value	$ 100.51	$ 70.40	$ 76.10	$ 95.62
Valuation assumptions:
Risk-free interest rate	0.30%	1.54%	0.31%	2.02%
Expected option life (years)	4 years 2 months 1 day	4 years 1 month 17 days	4 years 2 months 19 days	4 years 1 month 20 days
Expected volatility	43.50%	44.20%	42.82%	42.30%

Summary of Restricted Stock Uni

Summary of Restricted Stock Units Activity (Detail) shares in Thousands	6 Months Ended
	Sep. 30, 2020$ / sharesshares
Number of Shares
Granted	30,781
Restricted Stock Units
Number of Shares
Beginning Balance	320
Granted	194
Vested	(136)
Forfeited	(101)
Ending Balance	277
Weighted Average Grant Date Fair Value
Beginning Balance | $ / shares	$ 263.92
Granted | $ / shares	254.55
Vested | $ / shares	226.71
Forfeited | $ / shares	267.28
Ending Balance | $ / shares	$ 274.31

Summary of Assumptions Used To

Summary of Assumptions Used To Value Awards And Estimated Grant-Date Fair Value (Detail) shares in Thousands	6 Months Ended
	Sep. 30, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.20%
Expected volatility	35.50%
Target performance (number of shares) | shares	30,781
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining performance period (years)	1 year 10 months 24 days
Estimated 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 24 days
Estimated fair value per share	$ 349.28

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income tax provision	$ 10,702	$ 4,287	$ 27,190	$ 18,502
Effective income tax rate	14.70%	24.70%	20.30%	15.40%
U.S. federal statutory corporate tax rate	21.00%	21.00%	21.00%	21.00%
Excess tax benefits from stock-based awards	$ 7,900	$ 500	$ 8,500	$ 13,300

Differences Between Statutory I

Differences Between Statutory Income Tax Rate and Effective Income Tax Rate (Detail)	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Statutory income tax rate	21.00%	21.00%	21.00%	21.00%
Excess tax benefits from stock-based awards	(10.90%)	(2.70%)	(6.30%)	(11.00%)
Credits	(1.70%)	(2.10%)	(1.70%)	(1.70%)
State taxes, net	4.10%	3.30%	4.10%	3.40%
Permanent differences	2.60%	1.70%	3.40%	1.90%
Excess foreign tax credit	0.40%		0.40%
Other	(0.80%)	3.50%	(0.60%)	1.70%
Effective tax rate	14.70%	24.70%	20.30%	15.40%

Segment and Enterprise Wide D_2

Segment and Enterprise Wide Disclosures - Additional Information (Detail) $ in Millions	3 Months Ended
	Sep. 30, 2020USD ($)Segment	Sep. 30, 2019	Mar. 31, 2020USD ($)
Segment Reporting Information [Line Items]
Number of business segments | Segment	1
International
Segment Reporting Information [Line Items]
Long-lived assets | $	$ 52.9		$ 46.7
Customer Concentration Risk | Revenue | International
Segment Reporting Information [Line Items]
Percentage of revenue accounted	18.00%	16.00%