Abiomed (ABMD) 10-Q 31 Oct 19 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Sep. 30, 2019	Oct. 24, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2020
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		45,155,108
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, 2019	Mar. 31, 2019
Current assets:
Cash and cash equivalents	$ 150,279	$ 121,021
Short-term marketable securities	295,041	370,677
Accounts receivable, net	94,319	90,809
Inventories	90,295	80,942
Prepaid expenses and other current assets	17,498	13,748
Total current assets	647,432	677,197
Long-term marketable securities	106,025	21,718
Property and equipment, net	157,896	145,005
Goodwill	31,727	32,601
In-process research and development	14,800	15,208
Long-term deferred tax assets, net	67,277	77,502
Other assets	99,191	85,115
Total assets	1,124,348	1,054,346
Current liabilities:
Accounts payable	31,736	32,185
Accrued expenses	57,907	57,420
Deferred revenue	19,322	16,393
Other current liabilities	3,264
Total current liabilities	112,229	105,998
Contingent consideration	10,236	9,575
Long-term deferred tax liabilities	800	822
Other long-term liabilities	9,626	1,061
Total liabilities	132,891	117,456
Commitments and contingencies (Note 13)
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 - 47,484,911 shares at September 30, 2019 and 47,026,226 shares at March 31, 2019 Outstanding - 45,238,952 shares at September 30, 2019 and 45,122,985 shares at March 31, 2019	452	451
Additional paid in capital	722,020	690,507
Retained earnings	501,467	399,473
Treasury stock at cost - 2,245,959 shares at September 30, 2019 and 1,903,241 shares at March 31, 2019	(214,926)	(138,852)
Accumulated other comprehensive loss	(17,556)	(14,689)
Total stockholders' equity	991,457	936,890
Total liabilities and stockholders' equity	$ 1,124,348	$ 1,054,346

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2019	Mar. 31, 2019
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	47,484,911	47,026,226
Common stock, Outstanding	45,238,952	45,122,985
Treasury stock, shares	2,245,959	1,903,241

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 204,974	$ 181,778	$ 412,640	$ 361,788
Costs and expenses:
Cost of revenue	34,867	29,846	71,940	60,696
Research and development	23,969	22,717	47,759	43,990
Selling, general and administrative	85,956	78,895	172,034	160,034
Costs and Expenses, Total	144,792	131,458	291,733	264,720
Income from operations	60,182	50,320	120,907	97,068
Other (expenses) income:
Investment income, net	2,932	1,671	5,981	3,222
Other (expense) income, net	(45,756)	(158)	(6,392)	30
Nonoperating Income (Expense), Total	(42,824)	1,513	(411)	3,252
Income before income taxes	17,358	51,833	120,496	100,320
Income tax provision (benefit)	4,287	1,706	18,502	(39,873)
Net income	$ 13,071	$ 50,127	$ 101,994	$ 140,193
Basic net income per share	$ 0.29	$ 1.11	$ 2.25	$ 3.13
Basic weighted average shares outstanding	45,319	44,961	45,267	44,754
Diluted net income per share	$ 0.28	$ 1.09	$ 2.22	$ 3.04
Diluted weighted average shares outstanding	45,912	46,153	46,031	46,164

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 13,071	$ 50,127	$ 101,994	$ 140,193
Other comprehensive income (loss):
Foreign currency translation losses	(5,716)	(600)	(3,382)	(7,452)
Net unrealized (losses) gains on marketable securities	(85)	(22)	515	121
Other comprehensive loss	(5,801)	(622)	(2,867)	(7,331)
Comprehensive income	$ 7,270	$ 49,505	$ 99,127	$ 132,862

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, 2018	$ 689,524	$ 444	$ (67,078)	$ 619,905	$ 140,457	$ (4,204)
Beginning Balance (in shares) at Mar. 31, 2018		44,375,337	1,725,312
Restricted stock units issued		$ 4		(4)
Restricted stock units issued (in shares)		384,887
Stock options exercised	5,798	$ 3		5,795
Stock options exercised (in shares)		282,368
Stock issued to directors	33			33
Stock issued to directors (in shares)		80
Return of common stock to pay withholding taxes on restricted stock	(67,598)	$ (2)	$ (67,596)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(166,401)	166,401
Stock compensation expense	12,245			12,245
Other comprehensive income (loss)	(6,709)					(6,709)
Net income	90,066				90,066
Ending Balance at Jun. 30, 2018	723,359	$ 449	$ (134,674)	637,974	230,523	(10,913)
Ending Balance (in shares) at Jun. 30, 2018		44,876,271	1,891,713
Beginning Balance at Mar. 31, 2018	689,524	$ 444	$ (67,078)	619,905	140,457	(4,204)
Beginning Balance (in shares) at Mar. 31, 2018		44,375,337	1,725,312
Other comprehensive income (loss)	(7,331)
Net income	140,193
Ending Balance at Sep. 30, 2018	792,954	$ 450	$ (136,743)	660,132	280,650	(11,535)
Ending Balance (in shares) at Sep. 30, 2018		45,038,453	1,896,971
Beginning Balance at Jun. 30, 2018	723,359	$ 449	$ (134,674)	637,974	230,523	(10,913)
Beginning Balance (in shares) at Jun. 30, 2018		44,876,271	1,891,713
Restricted stock units issued (in shares)		18,827
Stock options exercised	4,815	$ 1		4,814
Stock options exercised (in shares)		142,978
Stock issued to directors	34			34
Stock issued to directors (in shares)		74
Return of common stock to pay withholding taxes on restricted stock	(2,069)		$ (2,069)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(5,258)	5,258
Stock issued under employee stock purchase plan	1,376			1,376
Stock issued under employee stock purchase plan (in shares)		5,561
Stock compensation expense	15,934			15,934
Other comprehensive income (loss)	(622)					(622)
Net income	50,127				50,127
Ending Balance at Sep. 30, 2018	792,954	$ 450	$ (136,743)	660,132	280,650	(11,535)
Ending Balance (in shares) at Sep. 30, 2018		45,038,453	1,896,971
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	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	45,122,985	1,903,241
Stock options exercised (in shares)	58,000
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	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 (in 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	45,238,952	2,245,959

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net income	$ 101,994	$ 140,193
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	9,052	6,347
Bad debt expense	152	467
Stock-based compensation	26,445	28,179
Write-down of inventory and other	2,157	1,733
Accretion on marketable securities	(2,276)	(848)
Change in fair value of other investments	5,943
Deferred tax provision	10,195	(45,676)
Change in fair value of contingent consideration	661	3
Other non-cash operating activities	2,177
Changes in assets and liabilities:
Accounts receivable	(3,828)	(5,131)
Inventories	(12,204)	(16,750)
Prepaid expenses and other assets	(4,077)	(1,987)
Accounts payable	781	761
Accrued expenses and other liabilities	(1,268)	826
Deferred revenue	2,983	(926)
Net cash provided by operating activities	138,887	107,191
Investing activities:
Purchases of marketable securities	(268,485)	(112,956)
Proceeds from the sale and maturity of marketable securities and other	262,881	136,844
Purchases of other investments and intangible assets	(7,800)	(11,426)
Purchases of property and equipment	(24,607)	(27,345)
Net cash used for investing activities	(38,011)	(14,883)
Financing activities:
Proceeds from the exercise of stock options	2,706	10,613
Taxes paid related to net share settlement upon vesting of stock awards	(41,206)	(69,666)
Repurchase of common stock	(34,873)
Proceeds from the issuance of stock under employee stock purchase plan	2,368	1,375
Net cash used for financing activities	(71,005)	(57,678)
Effect of exchange rate changes on cash	(613)	(1,223)
Net increase in cash and cash equivalents	29,258	33,407
Cash and cash equivalents at beginning of period	121,021	42,975
Cash and cash equivalents at end of period	150,279	76,382
Supplemental disclosure of cash flow information:
Cash paid for income taxes	6,349	3,530
Supplemental disclosure of non-cash activities:
Property and equipment in accounts payable and accrued expenses	3,825	$ 1,399
Right-of-use assets obtained in exchange for lease liabilities	$ 14,513

Nature of Business

Nature of Business	6 Months Ended
	Sep. 30, 2019
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, 2019
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, 2019 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. There have been no changes in the Company’s significant accounting policies for the three and six months ended September 30, 2019 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, 2019 that has been filed with the SEC, except as described in “Recently Adopted Accounting Pronouncements”. Recently Adopted Accounting Pronouncements Effective April 1, 2019, the Company adopted the Financial Accounting Standards Board, or FASB standard update ASU 2016-02 (“Topic 842”), “Leases,” which requires lessees with lease arrangements exceeding a one-year term, to record a right-of-use asset and lease obligation on the balance sheet, whether operating or financing, and related lease expenses for operating leases and amortization and interest expense for financing leases in the statement of operations. Additional information and disclosures required by this standard are contained in “Note 8. Leases.” Recently Issued Accounting Pronouncements Not Yet Effective In June 2016, the FASB issued ASU 2016-13 (“Topic 326”), “Financial Instruments-Credit Losses” This new guidance will require financial instruments to be measured at amortized cost, and accounts receivables to be presented at the net amount expected to be collected. The new model requires an entity to estimate credit losses based on historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments. ASU 2016-13 is effective for annual reporting periods beginning after December 31, 2019. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. ASU 2016-13 will become effective for the Company in fiscal 2021. In January 2017, the FASB issued ASU 2017-04, (“Topic 350”), “Intangibles - Goodwill and Other” This new guidance 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. ASU 2017-04 is effective for annual reporting periods beginning after December 15, 2019. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. ASU 2017-04 will become effective for the Company in fiscal 2021. In August 2018, the FASB issued ASU 2018-13 (“Topic 820”), “Fair Value Measurement” This new guidance modifies the disclosure requirements for fair value measurements. The Company has investments accounted for and disclosed under Topic 820 and will modify disclosures as applicable to conform with the new guidance. ASU 2018-13 is effective for annual reporting periods beginning after December 15, 2019 and early adoption is permitted. The Company does not expect the adoption of this standard and the required disclosure changes to have a material impact on its consolidated financial statements. ASU 2018-13 will become effective for the Company in fiscal 2021.

Net Income Per Share

Net Income Per Share	6 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Income Per Share	Note 3. 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, 2019 and 2018 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 2019 2018 2019 2018 Net income $ 13,071 $ 50,127 $ 101,994 $ 140,193 Weighted average shares - basic 45,319 44,961 45,267 44,754 Net income per share - basic $ 0.29 $ 1.11 $ 2.25 $ 3.13 For the Three Months Ended September 30, For the Six Months Ended September 30, Diluted Net Income Per Share 2019 2018 2019 2018 Net income $ 13,071 50,127 101,994 140,193 Weighted average shares - basic 45,319 44,961 45,267 44,754 Effect of dilutive securities 593 1,192 764 1,410 Weighted average shares - diluted 45,912 46,153 46,031 46,164 Net income per share - diluted $ 0.28 $ 1.09 $ 2.22 $ 3.04 Share-based compensation awards of approximately 0.3 million and 0.1 million shares for the three months ended September 30, 2019, and 2018, respectively, and approximately 0.3 million and 0.2 million for the six months ended September 30, 2019, and 2018, 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, 2019
Revenue From Contract With Customer [Abstract]
Revenue Recognition	Note 4. Revenue Recognition Adoption of Topic 606, Revenue from Contracts with Customers The Company adopted Topic 606 on April 1, 2018, using the modified retrospective method for all contracts not completed as of the date of adoption. The adoption of Topic 606 did not have a material impact on the Company’s consolidated balance sheet, statement of operations, stockholders’ equity or cash flows as of the adoption date or for the three and six months ended September 30, 2019. The Company has made the following accounting policy elections and elected to use certain practical expedients, as permitted by the FASB, in applying Topic 606: (1) the Company accounts for amounts collected from customers for sales and other taxes, net of related amounts remitted to tax authorities; (2) the Company does not adjust the promised amount of consideration for the effects of a significant financing component because, at contract inception, the Company expects the period between the time when the Company transfers a promised good or service to the customer and the time when the customer pays for that good or service will be one year or less; (3) the Company expenses costs to obtain a contract as they are incurred if the expected period of benefit, and therefore the amortization period, is one year or less; (4) the Company accounts for shipping and handling activities that occur after control transfers to the customer as a fulfillment cost rather than an additional promised service and these fulfillment costs are recorded as selling, general and administrative expenses; (5) the Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract with the customer; and (6) the Company does not disclose the transaction price allocated to unsatisfied performance obligations when the original expected contract duration is one year or less. The Company generates revenue primarily from the sale of Impella 2.5, Impella CP, Impella 5.0, Impella LD, Impella RP and Impella AIC products. The Company also earns revenue from preventative maintenance service contracts and maintenance calls . The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer • Identification of the performance obligation in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligation in the contract • Recognition of revenue when, or as, a performance obligation is satisfied Identification of contracts and performance obligations The Company accounts for a contract with a customer when there is an approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of the consideration is probable. The Company's performance obligations consist mainly of transferring control of products and services identified in the contracts, purchase orders or invoices. For each contract, the Company considers the obligation to transfer products and services to the customer, each of which are distinct, to be performance obligations. Transaction price and allocation to performance obligations Transaction prices of products or services are typically based on contracted rates with customers and there is only variable consideration in limited instances. To the extent that the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing the expected value method or the most likely amount, depending on the circumstances, to which the Company expects to be entitled. An expected value method may be an appropriate estimate of the amount of variable consideration if an entity has a large number of contracts with similar characteristics whereas the most likely amount method may be an appropriate estimate of the amount of variable consideration if the contract has only two possible outcomes. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of the Company’s anticipated performance and all information (historical, current and forecasted) that is reasonably available. Sales and other taxes collected on behalf of third parties are excluded from revenue. The Company does not provide for rights of return to customers on product sales and, therefore, does not record a provision for returns. Customers typically have a limited time frame to notify the Company of any defective or non-conforming products. The Company’s limited warranty provision is accounted for using the cost accrual method and is recognized as expense when products are sold and is not considered a separate performance obligation. If a contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price based on the estimated relative standalone selling prices of the promised products or services underlying each performance obligation. The Company determines standalone selling prices based on the price at which the performance obligation is sold separately. Revenue Recognition Revenue is recognized when, or as, obligations under the terms of a contract are satisfied, which occurs when control of the promised products or services is transferred to customers. Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products or services to a customer. Product revenue is generally recognized when the customer obtains control of the Company’s products, which occurs at a point in time, and may be upon shipment or upon delivery based on the contractual shipping terms of a contract. Service revenue is generally recognized over time as the services are rendered to the customer based on the extent of progress towards completion of the performance obligation. The Company recognizes service revenue over the term of the service contract. Services are expected to be transferred to the customer throughout the term of the contract and the Company believes recognizing revenue ratably over the term of the contract best depicts the transfer of value to the customer. Revenue generated from preventative maintenance calls is recognized at a point in time when the services are provided to the customer. Revenue from the sale of products and services are evidenced by either a contract with the customer or a valid purchase order and an invoice which includes all relevant terms of sale and shipment of product or service provided has been incurred. The Company performs a review of each specific customer's credit worthiness and ability to pay prior to acceptance as a customer. Further, the Company performs periodic reviews of its customers' creditworthiness prospectively . Disaggregation of Revenue 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 distribution agreements in other international markets (e.g., certain other European markets, Canada, Latin America, Middle East and Asia-Pacific). Revenue is categorized as Impella 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 categorizes the Company’s revenue by products and services: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) (in $000's) Impella product revenue $ 196,939 $ 175,270 $ 396,804 $ 348,945 Service and other revenue 8,035 6,508 15,836 12,843 Total revenue $ 204,974 $ 181,778 $ 412,640 $ 361,788 The following table categorizes the Company’s revenue by geographical location: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) (in $000's) U.S. revenue $ 172,015 $ 158,243 $ 347,500 $ 315,838 International revenue 32,959 23,535 65,140 45,950 Total revenue $ 204,974 $ 181,778 $ 412,640 $ 361,788 Reserves for Variable Consideration Revenues from product sales are recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established and which result from discounts or rebates that are offered within contracts between the Company and its customers relating to the Company’s sales of its products. These reserves are based on the amounts earned or are expected to be claimed on the related sales and are classified as a liability. Where appropriate, these estimates take into consideration relevant factors such as the Company’s historical experience, current contractual and statutory requirements, specific known market events and trends, industry data and forecasted customer buying and payment patterns. These reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the contract. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results in the future vary from the Company’s estimates, the Company adjusts these estimates, which would affect revenue and earnings in the period such variances become known. 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 product revenue is recognized, resulting in a reduction to revenue and the establishment of a liability, which are all included in accrued expenses in the consolidated balance sheets. Rebates normally result from administrative fees required by certain customers and 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, 2019 and 2018 were not material. Contract Balances The timing of revenue recognition, billings, shipments and cash collections results in accounts receivables and deferred revenue on the consolidated balance sheet. A receivable is recognized in the period the Company’s right to the consideration from the customer is unconditional. The change in the accounts receivable balances relate to the timing of revenue recognition, billings and cash collections. The Company generally does not have any performance obligations with a term of more than one year. Payment terms vary by contract type and type of customer and generally range from 30 to 60 days for direct sales customers. Payment terms with certain international distributors can range from 60 to 120 days. The Company’s contracts with customers do not typically include extended payment terms. Deferred Revenue When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, deferred revenue is recorded. Deferred revenue is recognized as revenue after control of the products or services is transferred to the customer and all revenue recognition criteria have been met. The Company’s deferred revenue balance was $19.3 million as of September 30, 2019 and $16.4 million as of March 31, 2019 respectively. This deferred revenue is recognized as revenue when the customer obtains control of the product for product sales, and revenue is recognized on preventative maintenance service contracts ratably over the term of the service contract. 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. Costs to Obtain or Fulfill a Customer Contract The Company has certain costs to obtain and fulfill a customer contract, such as commissions and shipping costs. The Company recognizes the incremental costs of obtaining contracts as an expense when incurred if the amortization period of the assets that the Company otherwise would have recognized is one year or less. The Company accounts for shipping and handling activities related to contracts with customers as costs to fulfill the promise to transfer the associated products. These costs are included in Selling, general, and administrative expenses.

Cash Equivalents, Marketable Se

Cash Equivalents, Marketable Securities and Fair Value Measurements	6 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Cash Equivalents, Marketable Securities and Fair Value Measurements	Note 5. Cash Equivalents, Marketable Securities and Fair Value Measurements The Company’s cash equivalents and marketable securities at September 30, 2019 and March 31, 2019 are classified on the balance sheet as follows: September 30, 2019 March 31, 2019 (in $000's) Cash equivalents $ 73,694 $ 80,089 Short-term marketable securities 295,041 370,677 Long-term marketable securities 106,025 21,718 $ 474,760 $ 472,484 The Company’s cash equivalents and marketable securities at September 30, 2019 and March 31, 2019 are invested in the following: Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value September 30, 2019: (in $000's) Money market funds $ 53,694 $ — $ — $ 53,694 Repurchase agreements 20,000 — — 20,000 Short-term U.S. Treasury mutual fund securities 28,012 39 — 28,051 Short-term government-backed securities 124,117 129 (24 ) 124,222 Short-term corporate debt securities 92,865 183 — 93,048 Short-term commercial paper 49,230 29 (4 ) 49,255 Long-term U.S. Treasury mutual fund securities 6,964 6 — 6,970 Long-term government-backed securities 43,898 28 (18 ) 43,908 Long-term corporate debt securities 55,127 486 (1 ) 55,612 $ 473,907 $ 900 $ (47 ) $ 474,760 Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value March 31, 2019: (in $000's) Money market funds $ 60,089 $ — $ — $ 60,089 Repurchase agreements 20,000 — — 20,000 Short-term U.S. Treasury mutual fund securities 58,786 13 (12 ) 58,787 Short-term government-backed securities 126,336 60 (15 ) 126,381 Short-term corporate debt securities 128,626 97 (9 ) 128,714 Short-term commercial paper 56,780 16 (1 ) 56,795 Long-term corporate debt securities 21,529 189 — 21,718 $ 472,146 $ 375 $ (37 ) $ 472,484 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 presents the Company’s fair value hierarchy for its financial instruments measured at fair value as of September 30, 2019 and March 31, 2019: Level 1 Level 2 Level 3 Total September 30, 2019: (in $000's) Assets Money market funds $ 53,694 $ — $ — $ 53,694 Repurchase agreements — 20,000 — 20,000 Short-term U.S. Treasury mutual fund securities — 28,051 — 28,051 Short-term government-backed securities — 124,222 — 124,222 Short-term corporate debt securities — 93,048 — 93,048 Short-term commercial paper — 49,255 — 49,255 Long-term U.S. Treasury mutual fund securities 6,970 — 6,970 Long-term government-backed securities — 43,908 — 43,908 Long-term corporate debt securities — 55,612 — 55,612 Investment in Shockwave Medical 50,248 — — 50,248 Liabilities Contingent consideration — — 10,236 10,236 Level 1 Level 2 Level 3 Total March 31, 2019: (in $000's) Assets Money market funds $ 60,089 $ — $ — $ 60,089 Repurchase agreements — 20,000 — 20,000 Short-term U.S. Treasury mutual fund securities — 58,787 — 58,787 Short-term government-backed securities — 126,381 — 126,381 Short-term corporate debt securities — 128,714 — 128,714 Short-term commercial paper — 56,795 — 56,795 Long-term corporate debt securities — 21,718 — 21,718 Investment in Shockwave Medical 56,195 — — 56,195 Liabilities Contingent consideration — — 9,575 9,575 The Company has determined that the estimated fair value of its money market funds and its investment in Shockwave Medical, a publicly traded medical device company, are reported as Level 1 financial assets as they are valued at quoted market prices in active markets. The investment in Shockwave Medical is classified within other assets in the consolidated balance sheet. The Company has determined that the estimated fair value of its repurchase agreements, U.S. Treasury mutual fund securities, government-backed securities, corporate debt securities and commercial paper 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. The Company’s financial liabilities consisted of contingent consideration potentially payable related to the acquisition of ECP Entwicklungsgesellschaft mbH, or ECP, and AIS GmbH Aachen Innovative Solutions, or AIS, in July 2014. The Company acquired ECP and 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 This liability is reported as Level 3 as the estimated fair value of the contingent consideration related to the acquisition of ECP requires significant management judgment or estimation and is calculated using the following valuation methods: Milestone Payment Fair Value at September 30, 2019 Valuation Methodology Significant Unobservable Input Weighted Average (range, if applicable) (in $000's) Clinical and regulatory milestone $ 7,000 $ 5,544 Probability weighted income approach Projected fiscal year of milestone payments 2021 to 2023 Discount rate 3.1% to 3.3% Probability of occurrence Probability adjusted level of 45% for the base case scenario and 15% to 40% for various downside and upside scenarios Revenue-based milestone 8,000 4,692 Monte Carlo simulation model Projected fiscal year of milestone payments 2025 to 2035 Discount rate 17% Expected volatility for forecasted revenues 50% Probability of payment (risk-neutral) 73% $ 15,000 $ 10,236 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, 2019 and 2018: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) Beginning balance $ 9,931 $ 10,331 $ 9,575 $ 10,490 Additions — — — — Payments — — — — Change in fair value 305 162 661 3 Ending balance $ 10,236 $ 10,493 $ 10,236 $ 10,493 The change in fair value of the contingent consideration was primarily due to estimates related to development timelines and the passage of time on the fair value measurement of milestones. Adjustments associated with the change in fair value of contingent consideration are included in research and development expenses in the Company’s consolidated statements of operations. Significant increases or decreases in any of the 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 liability. The fair value of the contingent consideration at each reporting date is updated by reflecting the changes in fair value reflected in the Company’s consolidated statement of operations. There is no assurance that any of the conditions for the milestone payments will be met .

Property and Equipment

Property and Equipment	6 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Property and Equipment	Note 6. Property and Equipment The components of property and equipment are as follows: September 30, 2019 March 31, 2019 (in $000's) Land $ 7,148 $ 7,262 Building and building improvements 96,147 86,705 Leasehold improvements 12,923 2,190 Machinery and equipment 62,679 59,146 Furniture and fixtures 13,984 11,456 Construction in progress 12,038 17,946 Total cost 204,919 184,705 Accumulated depreciation (47,023 ) (39,700 ) Property and equipment, net $ 157,896 $ 145,005

Goodwill, In-Process Research a

Goodwill, In-Process Research and Development and Other Assets	6 Months Ended
	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, In-Process Research and Development and Other Assets	Note 7. Goodwill, In-Process Research and Development and Other Assets Goodwill The carrying amount of goodwill at September 30, 2019 and March 31, 2019 was $31.7 million and $32.6 million, respectively, and has been recorded in connection with the Company’s acquisition of Impella Cardiosystems AG, in May 2005 and ECP and AIS in July 2014. The carrying value of goodwill and the change in the balance for the six months ended September 30, 2019 are as follows: (in $000's) Balance, March 31, 2019 $ 32,601 Foreign currency translation impact (874 ) Balance, September 30, 2019 $ 31,727 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 in-process research & development, or IPR&D, assets at September 30, 2019 and March 31, 2019 was $14.8 million and $15.2 million, respectively, and was recorded in conjunction with the Company’s acquisition of ECP and AIS, in July 2014. 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, 2019 are as follows: (in $000's) Balance, March 31, 2019 $ 15,208 Foreign currency translation impact (408 ) Balance, September 30, 2019 $ 14,800 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 Other assets are made of the following: September 30, 2019 March 31, 2019 (in $000's) Equity method and other investments $ 81,836 $ 80,779 Right of use asset - leases (Note 8) 12,257 — Other intangible assets and other 5,098 4,336 Total other assets $ 99,191 $ 85,115 Equity Method and Other Investments The Company periodically makes investments in medical device companies that focus on heart failure, heart pump and other medical device technologies. For investments in convertible debt or preferred stock securities that do not have readily determinable market values, the Company measures these investments at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment. The Company measures investments in equity securities at fair value and recognize changes in fair value in net income. For equity method investments the amount of the company’s initial investment is adjusted each period by the Company’s share of the investee’s income or loss. The Company monitors any events or changes in circumstances that may have a significant effect on the fair value of investments, either due to impairment or based on observable price changes, and makes any necessary adjustments. The following table summarizes the Company’s equity method and other investments as of September 30, 2019 and March 31, 2019, which are classified as September 30, 2019 March 31, 2019 (in $000's) Other investments $ 78,836 $ 80,779 Equity method investment 3,000 — Total equity and other investments $ 81,836 $ 80,779 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, 2019 and 2018 are as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) Beginning balance $ 122,433 $ 13,814 $ 80,779 $ 12,649 Additions 5,000 8,511 7,000 9,676 Disposals — — — — Change in fair value, net (45,597 ) — (5,943 ) — Ending balance $ 81,836 $ 22,325 $ 81,836 $ 22,325 In fiscal 2019, the Company invested $25.0 million in Shockwave Medical. The fair value of this investment included within other investments as of September 30, 2019 and March 31, 2019 was $50.2 million and $56.2 million, respectively. The Company recognized a pre-tax unrealized losses of $45.6 million and $5.9 million on its investment in Shockwave Medical for the three and six months ended September 30, 2019, respectively. In July 20 19 , the Company invested $ 3.0 million in a small private medical device company . Based on the Company’s controlling economic interest and significant influence exertion over the investee’s operating and financial policies , this investment was accounted for using the equity method . The Company recognizes its share of the results of operations related to this equity method investment one quarter in arrears when the results of the entity become available, in other income (expense), net of tax in the condensed consolidated statement of operations . During the six months ended September 30, 2019 , the Company made additional investments of $ million in other private medical device companies. Other Intangible Assets and Other Included within other intangible assets and other is $3.6 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, 2019
Leases [Abstract]
Leases	Note 8. Leases The Company has lease agreements for real estate including corporate offices, warehouse space, vehicles and certain office equipment. At the inception of a contractual arrangement, the Company determines whether it contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company calculates the associated lease liability and corresponding right-of-use, or ROU, asset upon lease commencement. Operating lease assets and liabilities are recognized based on the present value of minimum lease payments over the lease term using an appropriate discount rate. ROU assets also include any lease payments made at or before lease commencement and any initial direct costs incurred and exclude any lease incentives received. The discount rate used is the rate that the Company would have to pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments in a similar economic environment. At the lease commencement date, the discount rate implicit in the lease is used to discount the lease liability if readily determinable. If not readily determinable or lease do not contain an implicit rate, the Company’s incremental borrowing rate is used as the discount rate. Discount rates are updated when there is a new lease or a modification to an existing lease, and the methodology is reassessed annually. The Company records operating lease liabilities within current liabilities or long-term liabilities based upon the length of time associated with the lease payments. The Company records its operating lease ROU as long-term assets. Leases with an initial term of 12 months or less are not recognized on the consolidated balance sheet. Instead, the Company recognizes lease expense for such leases on a straight-line basis over the lease term. The Company have elected the practical expedient where lease agreements with lease and non-lease components are accounted for as a single lease component for all assets. The Company’s financing leases are not material to our financial statements. The Company adopted Topic 842 on April 1, 2019 using the optional transition method. As such, the disclosures required under Topic 842 are not presented for periods before the date of adoption. For the comparative period prior to adoption, the Company presents the disclosures which were previously required under Topic 840. The Company elected the package of transitional practical expedients for leases existing prior to the adoption date. The Company did not reassess whether existing contracts are or contain leases, leases retained their historical lease classification and initial direct costs were not reassessed for capitalization under the new standard. Operating lease assets and operating lease liabilities were recognized based on the present value of minimum lease payments over the remaining lease term as of the adoption date. The following table presents supplemental balance sheet information related to our operating leases: September 30, 2019 (in $000's) Assets Operating lease right-of-use assets in other assets $ 12,257 Liabilities Operating lease liabilities in other current liabilities 3,264 Operating lease liabilities in other long-term liabilities 9,439 Total operating lease liabilities $ 12,703 Expense charged to operations under operating leases was $1.1 million and $2.2 million during the three and six months ended September 30, 2019, respectively. Short-term lease expenses were not material. Under ASC Topic 840, Leases (“ASC 840”), the Company recognized rent expense on a straight-line basis over the term of the lease and recorded the difference between the amount charged to expense and the rent paid as prepaid rent or deferred rent liability. As of March 31, 2019, the amount of deferred rent was $0.3 million, which was subsequently reclassified as contra-asset against the ROU asset upon adoption of ASU No. 2016-02 on April 1, 2019. Maturities of operating lease liabilities as of September 30, 2019 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2020 $ 1,077 2021 3,373 2022 2,881 2023 1,591 2024 1,457 Thereafter 3,722 Total minimum lease payments 14,101 Less: imputed interest (1,398 ) Present value of operating lease liabilities $ 12,703 Weighted average remaining lease term 5.71 Weighted average discount rate 3.22 % Minimum future lease payments previously disclosed under ASC 840 in our Annual Report on Form 10-K for the year ended March 31, 2019 were as follows: (in thousands) Fiscal Years Ended March 31, 2020 $ 3,398 2021 2,712 2022 2,000 2023 1,462 2024 1,414 Thereafter 3,288 Total minimum lease payments $ 14,274

Accrued Expenses

Accrued Expenses	6 Months Ended
	Sep. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	Note 9. Accrued Expenses Accrued expenses consist of the following: September 30, 2019 March 31, 2019 (in $000's) Employee compensation $ 28,246 $ 32,926 Sales and income taxes 14,826 12,262 Professional, legal, and accounting fees 4,114 2,757 Research and development 3,323 3,309 Marketing 2,702 1,707 Warranty 1,545 1,272 Other 3,151 3,187 $ 57,907 $ 57,420 Employee compensation consists primarily of accrued b onuses, commissions, employee benefits , payroll taxes (on equity awards) at September 30, 2019 and March 31, 2019 .

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Stockholders' Equity	Note 10. Stockholders’ Equity Stock Repurchase Program In August 2019, the Company’s Board of Directors authorized a stock repurchase program for up to $200 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 Securities Exchange Act of 1934 (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. During the three months ended September 30, 2019, the Company repurchased 180,929 shares for $34.9 million in open market purchases at an average cost of $192.75 per share, including commission expense.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	Note 11. 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, 2019 and 2018: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) Cost of product revenue $ 881 $ 774 $ 1,722 $ 1,349 Research and development 1,823 2,618 3,706 4,584 Selling, general and administrative 10,619 12,542 21,017 22,246 $ 13,323 $ 15,934 $ 26,445 $ 28,179 Stock Options The following table summarizes the stock option activity for the six months ended September 30, 2019: Weighted Weighted Average Aggregate Average Remaining Intrinsic Options Exercise Contractual Value (in thousands) Price Term (years) (in thousands) Outstanding at beginning of period 853 $ 87.14 5.57 Granted 107 264.56 Exercised (58 ) 47.01 Cancelled and expired (12 ) 231.53 Outstanding at end of period 890 $ 109.03 5.68 $ 85,789 Exercisable at end of period 667 $ 61.69 4.64 $ 82,730 Options vested and expected to vest at end of period 886 $ 109.06 5.68 $ 85,484 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, 2019 was approximately $17.0 million and the estimated weighted-average period over which this cost will be recognized is 2.1 years. The aggregate intrinsic value of options exercised was $11.1 million for the six months ended September 30, 2019. The total cash received as a result of employee stock option exercises for the six months ended September 30, 2019 was approximately $2.7 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, 2019 and 2018 was as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 Weighted average grant-date fair value $ 70.40 $ 148.51 $ 95.62 $ 142.81 Valuation assumptions: Risk-free interest rate 1.54 % 2.87 % 2.02 % 2.93 % Expected option life (years) 4.13 3.99 4.14 4.04 Expected volatility 44.24 % 43.9 % 42.34 % 42.7 % Restricted Stock Units The following table summarizes activity of restricted stock units for the six months ended September 30, 2019: Number of Shares Weighted Average Grant Date Fair Value (in thousands) (per share) Restricted stock units at beginning of period 620 $ 193.53 Granted 155 258.07 Vested (385 ) 144.16 Forfeited (59 ) 309.74 Restricted stock units at end of period 331 $ 261.95 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, 2019 was $61.1 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, 2019 was $258.07. The total fair value of restricted stock units vested during the six months ended September 30, 2019 was $97.9 million. Performance-Based Awards In May 2019, performance-based awards of restricted stock units for the potential issuance of up to 196,580 shares of common stock were issued to certain executive officers and employees, which vest upon achievement of prescribed service milestones by the award recipients and the achievement of prescribed performance milestones by the Company. As of September 30, 2019, the Company is recognizing compensation expense based on the probable outcome related to the prescribed performance targets on the outstanding awards.

Income Taxes

Income Taxes	6 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Note 12. Income Taxes The Company’s income tax provision was $4.3 million and $1.7 million for the three months ended September 30, 2019 and 2018, respectively. The Company’s income tax provision was $18.5 million for the six months ended September 30, 2019 and the Company had an income tax benefit of $39.9 million for the six months ended September 30, 2018. , respectively The significant differences between the statutory income tax rate and effective income tax rate for the three and six months ended September 30, 2019 and 2018 were as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 Statutory income tax rate 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) resulting from: — Excess tax benefits from stock-based awards (2.7 ) (24.9 ) (11.0 ) (66.6 ) Credits (2.1 ) (1.8 ) (1.7 ) (1.8 ) State taxes, net 3.3 4.3 3.4 4.3 Permanent differences 1.7 1.8 1.9 1.8 Other 3.5 2.9 1.7 1.6 Effective tax rate 24.7 % 3.3 % 15.4 % (39.7 ) % 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 $0.5 million and $12.9 million as an income tax benefit for the three months ended September 30, 2019 and 2018, respectively. The Company recognized excess tax benefits associated with stock-based awards of $13.3 million and $66.8 million as an income tax benefit for the six months ended September 30, 2019 and 2018, respectively. 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 and its subsidiaries are subject to U.S. federal income tax, as well as income tax of multiple state and foreign jurisdictions. During fiscal 2019, the Company closed an income tax audit in Germany, which covered fiscal years 2012 through 2015 and an Internal Revenue Service (“IRS”) audit in the U.S. relating to its fiscal year 2016 tax return. These audits did not materially impact our financial statements. 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, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 13. 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, has challenged a number of Company-owned patents in Europe in connection with the launch of Thoratec’s HeartMate PHP TM ® In September 2019, the highest court in Germany, the Federal Court of Justice, recently ruled in favor of the Company in a patent challenge filed by Thoratec in 2015, validating the strengths of the Company’s Impella-related patents. The Federal Court of Justice’s ruling follows its November 2018 ruling, another favorable ruling for the Company in the European Patent Office Technical Boards of Appeal on the Company’s pigtail patents and design for insertion. These rulings are now final and unappealable. 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 and will expire in September 2020. In September 2016, Maquet filed a response to the Company’s suit in D. Mass., including various counterclaims alleging that the Company’s Impella 2.5 ® ® ® ® In November 2017, Maquet filed a second action in D. Mass (the “2017 Action”) alleging that the Company’s Impella 2.5 ® ® ® 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 ® 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, 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. However, and since October 7, 2019, two of the shareholders have withdrawn their applications to be lead plaintiff. The court is expected to select one of the two remaining shareholders as lead plaintiff in November or December. The complaints allege that the defendants 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. The Company is unable to estimate the potential liability with respect to the legal 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 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.

Segment and Enterprise Wide Dis

Segment and Enterprise Wide Disclosures	6 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment and Enterprise Wide Disclosures	Note 14. 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 16% and 13% of total revenue for the three months ended September 30, 2019 and 2018, respectively, and 16% and 13% of total revenue for the six months ended September 30, 2019 and 2018, respectively he Company’s long-lived assets are located in the U.S., except for $43.6 million and $43.4 million at September 30, 2019 and March 31, 2019, 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, 2019
Accounting Policies [Abstract]
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Effective April 1, 2019, the Company adopted the Financial Accounting Standards Board, or FASB standard update ASU 2016-02 (“Topic 842”), “Leases,” which requires lessees with lease arrangements exceeding a one-year term, to record a right-of-use asset and lease obligation on the balance sheet, whether operating or financing, and related lease expenses for operating leases and amortization and interest expense for financing leases in the statement of operations. Additional information and disclosures required by this standard are contained in “Note 8. Leases.”
Recently Issued Accounting Pronouncements Not Yet Effective	Recently Issued Accounting Pronouncements Not Yet Effective In June 2016, the FASB issued ASU 2016-13 (“Topic 326”), “Financial Instruments-Credit Losses” This new guidance will require financial instruments to be measured at amortized cost, and accounts receivables to be presented at the net amount expected to be collected. The new model requires an entity to estimate credit losses based on historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments. ASU 2016-13 is effective for annual reporting periods beginning after December 31, 2019. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. ASU 2016-13 will become effective for the Company in fiscal 2021. In January 2017, the FASB issued ASU 2017-04, (“Topic 350”), “Intangibles - Goodwill and Other” This new guidance 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. ASU 2017-04 is effective for annual reporting periods beginning after December 15, 2019. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements. ASU 2017-04 will become effective for the Company in fiscal 2021. In August 2018, the FASB issued ASU 2018-13 (“Topic 820”), “Fair Value Measurement” This new guidance modifies the disclosure requirements for fair value measurements. The Company has investments accounted for and disclosed under Topic 820 and will modify disclosures as applicable to conform with the new guidance. ASU 2018-13 is effective for annual reporting periods beginning after December 15, 2019 and early adoption is permitted. The Company does not expect the adoption of this standard and the required disclosure changes to have a material impact on its consolidated financial statements. ASU 2018-13 will become effective for the Company in fiscal 2021.
Leases	The Company adopted Topic 842 on April 1, 2019 using the optional transition method. As such, the disclosures required under Topic 842 are not presented for periods before the date of adoption. For the comparative period prior to adoption, the Company presents the disclosures which were previously required under Topic 840. The Company elected the package of transitional practical expedients for leases existing prior to the adoption date. The Company did not reassess whether existing contracts are or contain leases, leases retained their historical lease classification and initial direct costs were not reassessed for capitalization under the new standard. Operating lease assets and operating lease liabilities were recognized based on the present value of minimum lease payments over the remaining lease term as of the adoption date. The following table presents supplemental balance sheet information related to our operating leases: September 30, 2019 (in $000's) Assets Operating lease right-of-use assets in other assets $ 12,257 Liabilities Operating lease liabilities in other current liabilities 3,264 Operating lease liabilities in other long-term liabilities 9,439 Total operating lease liabilities $ 12,703 Expense charged to operations under operating leases was $1.1 million and $2.2 million during the three and six months ended September 30, 2019, respectively. Short-term lease expenses were not material. Under ASC Topic 840, Leases (“ASC 840”), the Company recognized rent expense on a straight-line basis over the term of the lease and recorded the difference between the amount charged to expense and the rent paid as prepaid rent or deferred rent liability. As of March 31, 2019, the amount of deferred rent was $0.3 million, which was subsequently reclassified as contra-asset against the ROU asset upon adoption of ASU No. 2016-02 on April 1, 2019. Maturities of operating lease liabilities as of September 30, 2019 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2020 $ 1,077 2021 3,373 2022 2,881 2023 1,591 2024 1,457 Thereafter 3,722 Total minimum lease payments 14,101 Less: imputed interest (1,398 ) Present value of operating lease liabilities $ 12,703 Weighted average remaining lease term 5.71 Weighted average discount rate 3.22 % Minimum future lease payments previously disclosed under ASC 840 in our Annual Report on Form 10-K for the year ended March 31, 2019 were as follows: (in thousands) Fiscal Years Ended March 31, 2020 $ 3,398 2021 2,712 2022 2,000 2023 1,462 2024 1,414 Thereafter 3,288 Total minimum lease payments $ 14,274
Adoption of Topic 606, Revenue from Contracts with Customers	Adoption of Topic 606, Revenue from Contracts with Customers The Company adopted Topic 606 on April 1, 2018, using the modified retrospective method for all contracts not completed as of the date of adoption. The adoption of Topic 606 did not have a material impact on the Company’s consolidated balance sheet, statement of operations, stockholders’ equity or cash flows as of the adoption date or for the three and six months ended September 30, 2019. The Company has made the following accounting policy elections and elected to use certain practical expedients, as permitted by the FASB, in applying Topic 606: (1) the Company accounts for amounts collected from customers for sales and other taxes, net of related amounts remitted to tax authorities; (2) the Company does not adjust the promised amount of consideration for the effects of a significant financing component because, at contract inception, the Company expects the period between the time when the Company transfers a promised good or service to the customer and the time when the customer pays for that good or service will be one year or less; (3) the Company expenses costs to obtain a contract as they are incurred if the expected period of benefit, and therefore the amortization period, is one year or less; (4) the Company accounts for shipping and handling activities that occur after control transfers to the customer as a fulfillment cost rather than an additional promised service and these fulfillment costs are recorded as selling, general and administrative expenses; (5) the Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract with the customer; and (6) the Company does not disclose the transaction price allocated to unsatisfied performance obligations when the original expected contract duration is one year or less. The Company generates revenue primarily from the sale of Impella 2.5, Impella CP, Impella 5.0, Impella LD, Impella RP and Impella AIC products. The Company also earns revenue from preventative maintenance service contracts and maintenance calls . The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer • Identification of the performance obligation in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligation in the contract • Recognition of revenue when, or as, a performance obligation is satisfied

Net Income Per Share (Tables)

Net Income Per Share (Tables)	6 Months Ended
	Sep. 30, 2019
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, 2019 and 2018 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 2019 2018 2019 2018 Net income $ 13,071 $ 50,127 $ 101,994 $ 140,193 Weighted average shares - basic 45,319 44,961 45,267 44,754 Net income per share - basic $ 0.29 $ 1.11 $ 2.25 $ 3.13 For the Three Months Ended September 30, For the Six Months Ended September 30, Diluted Net Income Per Share 2019 2018 2019 2018 Net income $ 13,071 50,127 101,994 140,193 Weighted average shares - basic 45,319 44,961 45,267 44,754 Effect of dilutive securities 593 1,192 764 1,410 Weighted average shares - diluted 45,912 46,153 46,031 46,164 Net income per share - diluted $ 0.28 $ 1.09 $ 2.22 $ 3.04

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Sep. 30, 2019
Revenue From Contract With Customer [Abstract]
Schedule of Categorizes Revenue by Major Business Line and Geographical Location	The following table categorizes the Company’s revenue by products and services: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) (in $000's) Impella product revenue $ 196,939 $ 175,270 $ 396,804 $ 348,945 Service and other revenue 8,035 6,508 15,836 12,843 Total revenue $ 204,974 $ 181,778 $ 412,640 $ 361,788 The following table categorizes the Company’s revenue by geographical location: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) (in $000's) U.S. revenue $ 172,015 $ 158,243 $ 347,500 $ 315,838 International revenue 32,959 23,535 65,140 45,950 Total revenue $ 204,974 $ 181,778 $ 412,640 $ 361,788

Cash Equivalents, Marketable _2

Cash Equivalents, Marketable Securities and Fair Value Measurements (Tables)	6 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Cash Equivalents and Marketable Securities by Balance Sheet Classification	The Company’s cash equivalents and marketable securities at September 30, 2019 and March 31, 2019 are classified on the balance sheet as follows: September 30, 2019 March 31, 2019 (in $000's) Cash equivalents $ 73,694 $ 80,089 Short-term marketable securities 295,041 370,677 Long-term marketable securities 106,025 21,718 $ 474,760 $ 472,484
Cash Equivalents and Marketable Securities	The Company’s cash equivalents and marketable securities at September 30, 2019 and March 31, 2019 are invested in the following: Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value September 30, 2019: (in $000's) Money market funds $ 53,694 $ — $ — $ 53,694 Repurchase agreements 20,000 — — 20,000 Short-term U.S. Treasury mutual fund securities 28,012 39 — 28,051 Short-term government-backed securities 124,117 129 (24 ) 124,222 Short-term corporate debt securities 92,865 183 — 93,048 Short-term commercial paper 49,230 29 (4 ) 49,255 Long-term U.S. Treasury mutual fund securities 6,964 6 — 6,970 Long-term government-backed securities 43,898 28 (18 ) 43,908 Long-term corporate debt securities 55,127 486 (1 ) 55,612 $ 473,907 $ 900 $ (47 ) $ 474,760 Amortized Gross Unrealized Gross Unrealized Fair Market Cost Gains Losses Value March 31, 2019: (in $000's) Money market funds $ 60,089 $ — $ — $ 60,089 Repurchase agreements 20,000 — — 20,000 Short-term U.S. Treasury mutual fund securities 58,786 13 (12 ) 58,787 Short-term government-backed securities 126,336 60 (15 ) 126,381 Short-term corporate debt securities 128,626 97 (9 ) 128,714 Short-term commercial paper 56,780 16 (1 ) 56,795 Long-term corporate debt securities 21,529 189 — 21,718 $ 472,146 $ 375 $ (37 ) $ 472,484
Financial Instruments Measured at Fair Value	The following tables presents the Company’s fair value hierarchy for its financial instruments measured at fair value as of September 30, 2019 and March 31, 2019: Level 1 Level 2 Level 3 Total September 30, 2019: (in $000's) Assets Money market funds $ 53,694 $ — $ — $ 53,694 Repurchase agreements — 20,000 — 20,000 Short-term U.S. Treasury mutual fund securities — 28,051 — 28,051 Short-term government-backed securities — 124,222 — 124,222 Short-term corporate debt securities — 93,048 — 93,048 Short-term commercial paper — 49,255 — 49,255 Long-term U.S. Treasury mutual fund securities 6,970 — 6,970 Long-term government-backed securities — 43,908 — 43,908 Long-term corporate debt securities — 55,612 — 55,612 Investment in Shockwave Medical 50,248 — — 50,248 Liabilities Contingent consideration — — 10,236 10,236 Level 1 Level 2 Level 3 Total March 31, 2019: (in $000's) Assets Money market funds $ 60,089 $ — $ — $ 60,089 Repurchase agreements — 20,000 — 20,000 Short-term U.S. Treasury mutual fund securities — 58,787 — 58,787 Short-term government-backed securities — 126,381 — 126,381 Short-term corporate debt securities — 128,714 — 128,714 Short-term commercial paper — 56,795 — 56,795 Long-term corporate debt securities — 21,718 — 21,718 Investment in Shockwave Medical 56,195 — — 56,195 Liabilities Contingent consideration — — 9,575 9,575
Valuation Method Used to Calculate Level 3 Liabilities Measured at Estimated Fair Value of Contingent Consideration Related to Acquisition	This liability is reported as Level 3 as the estimated fair value of the contingent consideration related to the acquisition of ECP requires significant management judgment or estimation and is calculated using the following valuation methods: Milestone Payment Fair Value at September 30, 2019 Valuation Methodology Significant Unobservable Input Weighted Average (range, if applicable) (in $000's) Clinical and regulatory milestone $ 7,000 $ 5,544 Probability weighted income approach Projected fiscal year of milestone payments 2021 to 2023 Discount rate 3.1% to 3.3% Probability of occurrence Probability adjusted level of 45% for the base case scenario and 15% to 40% for various downside and upside scenarios Revenue-based milestone 8,000 4,692 Monte Carlo simulation model Projected fiscal year of milestone payments 2025 to 2035 Discount rate 17% Expected volatility for forecasted revenues 50% Probability of payment (risk-neutral) 73% $ 15,000 $ 10,236
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, 2019 and 2018: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) Beginning balance $ 9,931 $ 10,331 $ 9,575 $ 10,490 Additions — — — — Payments — — — — Change in fair value 305 162 661 3 Ending balance $ 10,236 $ 10,493 $ 10,236 $ 10,493

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Components of Property and Equipment	The components of property and equipment are as follows: September 30, 2019 March 31, 2019 (in $000's) Land $ 7,148 $ 7,262 Building and building improvements 96,147 86,705 Leasehold improvements 12,923 2,190 Machinery and equipment 62,679 59,146 Furniture and fixtures 13,984 11,456 Construction in progress 12,038 17,946 Total cost 204,919 184,705 Accumulated depreciation (47,023 ) (39,700 ) Property and equipment, net $ 157,896 $ 145,005

Goodwill, In-Process Research_2

Goodwill, In-Process Research and Development and Other Assets (Tables)	6 Months Ended
	Sep. 30, 2019
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, 2019 are as follows: (in $000's) Balance, March 31, 2019 $ 32,601 Foreign currency translation impact (874 ) Balance, September 30, 2019 $ 31,727
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, 2019 are as follows: (in $000's) Balance, March 31, 2019 $ 15,208 Foreign currency translation impact (408 ) Balance, September 30, 2019 $ 14,800
Summary of Other Assets	Other assets are made of the following: September 30, 2019 March 31, 2019 (in $000's) Equity method and other investments $ 81,836 $ 80,779 Right of use asset - leases (Note 8) 12,257 — Other intangible assets and other 5,098 4,336 Total other assets $ 99,191 $ 85,115
Equity Method and Other Investments Classified as Other Assets	The following table summarizes the Company’s equity method and other investments as of September 30, 2019 and March 31, 2019, which are classified as September 30, 2019 March 31, 2019 (in $000's) Other investments $ 78,836 $ 80,779 Equity method investment 3,000 — Total equity and other investments $ 81,836 $ 80,779
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, 2019 and 2018 are as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) Beginning balance $ 122,433 $ 13,814 $ 80,779 $ 12,649 Additions 5,000 8,511 7,000 9,676 Disposals — — — — Change in fair value, net (45,597 ) — (5,943 ) — Ending balance $ 81,836 $ 22,325 $ 81,836 $ 22,325

Leases (Tables)

Leases (Tables)	6 Months Ended
	Sep. 30, 2019
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, 2019 (in $000's) Assets Operating lease right-of-use assets in other assets $ 12,257 Liabilities Operating lease liabilities in other current liabilities 3,264 Operating lease liabilities in other long-term liabilities 9,439 Total operating lease liabilities $ 12,703
Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities as of September 30, 2019 are as follows: (in thousands, except lease term and discount rate) Fiscal Years Ended March 31, 2020 $ 1,077 2021 3,373 2022 2,881 2023 1,591 2024 1,457 Thereafter 3,722 Total minimum lease payments 14,101 Less: imputed interest (1,398 ) Present value of operating lease liabilities $ 12,703 Weighted average remaining lease term 5.71 Weighted average discount rate 3.22 %
Minimum Future Lease Payments	Minimum future lease payments previously disclosed under ASC 840 in our Annual Report on Form 10-K for the year ended March 31, 2019 were as follows: (in thousands) Fiscal Years Ended March 31, 2020 $ 3,398 2021 2,712 2022 2,000 2023 1,462 2024 1,414 Thereafter 3,288 Total minimum lease payments $ 14,274

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Sep. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses consist of the following: September 30, 2019 March 31, 2019 (in $000's) Employee compensation $ 28,246 $ 32,926 Sales and income taxes 14,826 12,262 Professional, legal, and accounting fees 4,114 2,757 Research and development 3,323 3,309 Marketing 2,702 1,707 Warranty 1,545 1,272 Other 3,151 3,187 $ 57,907 $ 57,420

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Sep. 30, 2019
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, 2019 and 2018: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 (in $000's) Cost of product revenue $ 881 $ 774 $ 1,722 $ 1,349 Research and development 1,823 2,618 3,706 4,584 Selling, general and administrative 10,619 12,542 21,017 22,246 $ 13,323 $ 15,934 $ 26,445 $ 28,179
Summary of Stock Option Activity	The following table summarizes the stock option activity for the six months ended September 30, 2019: Weighted Weighted Average Aggregate Average Remaining Intrinsic Options Exercise Contractual Value (in thousands) Price Term (years) (in thousands) Outstanding at beginning of period 853 $ 87.14 5.57 Granted 107 264.56 Exercised (58 ) 47.01 Cancelled and expired (12 ) 231.53 Outstanding at end of period 890 $ 109.03 5.68 $ 85,789 Exercisable at end of period 667 $ 61.69 4.64 $ 82,730 Options vested and expected to vest at end of period 886 $ 109.06 5.68 $ 85,484
Summary of Weighted Average Grant-Date Fair Values And Weighted Average Assumptions Used to Calculate Fair Value of Options Granted	The weighted average grant-date fair values and weighted average assumptions used in the calculation of fair value of options granted during the three and six months ended September 30, 2019 and 2018 was as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 Weighted average grant-date fair value $ 70.40 $ 148.51 $ 95.62 $ 142.81 Valuation assumptions: Risk-free interest rate 1.54 % 2.87 % 2.02 % 2.93 % Expected option life (years) 4.13 3.99 4.14 4.04 Expected volatility 44.24 % 43.9 % 42.34 % 42.7 %
Summary of Restricted Stock Units Activity	The following table summarizes activity of restricted stock units for the six months ended September 30, 2019: Number of Shares Weighted Average Grant Date Fair Value (in thousands) (per share) Restricted stock units at beginning of period 620 $ 193.53 Granted 155 258.07 Vested (385 ) 144.16 Forfeited (59 ) 309.74 Restricted stock units at end of period 331 $ 261.95

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Sep. 30, 2019
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, 2019 and 2018 were as follows: For the Three Months Ended September 30, For the Six Months Ended September 30, 2019 2018 2019 2018 Statutory income tax rate 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) resulting from: — Excess tax benefits from stock-based awards (2.7 ) (24.9 ) (11.0 ) (66.6 ) Credits (2.1 ) (1.8 ) (1.7 ) (1.8 ) State taxes, net 3.3 4.3 3.4 4.3 Permanent differences 1.7 1.8 1.9 1.8 Other 3.5 2.9 1.7 1.6 Effective tax rate 24.7 % 3.3 % 15.4 % (39.7 ) %

Net Income Per Share - Addition

Net Income Per Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares excluded from the calculation of diluted weighted average shares outstanding	0.3	0.1	0.3	0.2

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, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Basic Net Income Per Share
Net income	$ 13,071	$ 88,923	$ 50,127	$ 90,066	$ 101,994	$ 140,193
Weighted average shares - basic	45,319		44,961		45,267	44,754
Net income per share - basic	$ 0.29		$ 1.11		$ 2.25	$ 3.13
Diluted Net Income Per Share
Net income	$ 13,071	$ 88,923	$ 50,127	$ 90,066	$ 101,994	$ 140,193
Weighted average shares - basic	45,319		44,961		45,267	44,754
Effect of dilutive securities	593		1,192		764	1,410
Weighted average shares - diluted	45,912		46,153		46,031	46,164
Net income per share - diluted	$ 0.28		$ 1.09		$ 2.22	$ 3.04

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Categorizes Revenue by Major Business Line (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 204,974	$ 181,778	$ 412,640	$ 361,788
Impella Product
Disaggregation Of Revenue [Line Items]
Total revenue	196,939	175,270	396,804	348,945
Service and Other
Disaggregation Of Revenue [Line Items]
Total revenue	$ 8,035	$ 6,508	$ 15,836	$ 12,843

Revenue Recognition - Schedul_2

Revenue Recognition - Schedule of Categorizes Revenue by Major Geographical Location (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total Revenue [Line Items]
Total revenue	$ 204,974	$ 181,778	$ 412,640	$ 361,788
U.S.
Total Revenue [Line Items]
Total revenue	172,015	158,243	347,500	315,838
International
Total Revenue [Line Items]
Total revenue	$ 32,959	$ 23,535	$ 65,140	$ 45,950

Revenue Recognition - Terms - A

Revenue Recognition - Terms - Additional Information (Detail)	6 Months Ended
	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers, performance obligation term	1 year
Contract with customer payment terms, description	Payment terms vary by contract type and type of customer and generally range from 30 to 60 days for direct sales customers. Payment terms with certain international distributors can range from 60 to 120 days. The Company’s contracts with customers do not typically include extended payment terms.
Minimum | Direct Sales Customers
Disaggregation Of Revenue [Line Items]
Contract with customer payment terms, period	30 days
Minimum | International Distributors
Disaggregation Of Revenue [Line Items]
Contract with customer payment terms, period	60 days
Maximum | Direct Sales Customers
Disaggregation Of Revenue [Line Items]
Contract with customer payment terms, period	60 days
Maximum | International Distributors
Disaggregation Of Revenue [Line Items]
Contract with customer payment terms, period	120 days

Revenue Recognition - Deferred

Revenue Recognition - Deferred Revenue - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Mar. 31, 2019
Revenue From Contract With Customer [Abstract]
Deferred revenue	$ 19,322	$ 19,322	$ 16,393
Deferred Revenue, Revenue Recognized	$ 4,000	$ 12,500

Cash Equivalents and Marketable

Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Cash equivalents	$ 73,694	$ 80,089
Short-term marketable securities	295,041	370,677
Long-term marketable securities	106,025	21,718
Total cash and marketable securities	$ 474,760	$ 472,484

Investable Cash Equivalents and

Investable Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	$ 473,907	$ 472,146
Gross Unrealized Gains	900	375
Gross Unrealized Losses	(47)	(37)
Fair Market Value	474,760	472,484
Repurchase Agreement
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	20,000	20,000
Fair Market Value	20,000	20,000
Money Market Funds
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	53,694	60,089
Fair Market Value	53,694	60,089
Commercial Paper | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	49,230	56,780
Gross Unrealized Gains	29	16
Gross Unrealized Losses	(4)	(1)
Fair Market Value	49,255	56,795
U.S. Treasury mutual fund securities | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	28,012	58,786
Gross Unrealized Gains	39	13
Gross Unrealized Losses		(12)
Fair Market Value	28,051	58,787
U.S. Treasury mutual fund securities | Long-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	6,964
Gross Unrealized Gains	6
Fair Market Value	6,970
Government-backed securities | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	124,117	126,336
Gross Unrealized Gains	129	60
Gross Unrealized Losses	(24)	(15)
Fair Market Value	124,222	126,381
Government-backed securities | Long-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	43,898
Gross Unrealized Gains	28
Gross Unrealized Losses	(18)
Fair Market Value	43,908
Corporate Debt Securities | Short-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	92,865	128,626
Gross Unrealized Gains	183	97
Gross Unrealized Losses		(9)
Fair Market Value	93,048	128,714
Corporate Debt Securities | Long-term Investments
Total Cash Equivalents and Marketable Securities [Line Items]
Amortized Cost	55,127	21,529
Gross Unrealized Gains	486	189
Gross Unrealized Losses	(1)
Fair Market Value	$ 55,612	$ 21,718

Financial Instruments Measured

Financial Instruments Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	$ 474,760	$ 472,484
Contingent consideration	10,236	9,575
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
Shockwave Medical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	50,248	56,195
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	53,694	60,089
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	49,255	56,795
Level 1 | Shockwave Medical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	50,248	56,195
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	53,694	60,089
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	49,255	56,795
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	10,236	9,575
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	28,051	58,787
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	6,970
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	28,051	58,787
U.S. Treasury mutual fund 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	6,970
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	124,222	126,381
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	43,908
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	124,222	126,381
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	43,908
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	93,048	128,714
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	55,612	21,718
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	93,048	128,714
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	$ 55,612	$ 21,718

Cash Equivalents, Marketable _3

Cash Equivalents, Marketable Securities and Fair Value Measurements - Additional Information (Detail) - ECP Entwicklungsgesellschaft mbH and AIS GmbH Aachen Innovative Solutions $ in Millions	1 Months Ended
	Jul. 31, 2014USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire businesses, cash paid	$ 13
Potential payouts payments	$ 15

Valuation Method Used to Calcul

Valuation Method Used to Calculate Level 3 Liabilities Measured at Estimated Fair Value of Contingent Consideration Related to Acquisition (Detail) $ in Thousands	6 Months Ended
	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 10,236	$ 9,575
ECP Entwicklungsgesellschaft mbH | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Alternative investment, measurement input	0.21
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 10,236	$ 9,575
Level 3 | ECP Entwicklungsgesellschaft mbH
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Milestone Payment	15,000
Contingent consideration	10,236
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Milestone Payment	7,000
Contingent consideration	$ 5,544
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone | Contingent Consideration | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Projected fiscal year of milestone payments	2021
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone | Contingent Consideration | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Projected fiscal year of milestone payments	2023
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone | Various Downside and Upside Scenarios | Contingent Consideration | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Probability of occurrence	15.00%
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone | Various Downside and Upside Scenarios | Contingent Consideration | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Probability of occurrence	40.00%
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone | Base Case Scenario | Contingent Consideration
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Probability of occurrence	45.00%
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone | Discount Rate | Contingent Consideration | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Alternative investment, measurement input	0.031
Level 3 | ECP Entwicklungsgesellschaft mbH | Probability weighted income approach | Clinical and regulatory milestone | Discount Rate | Contingent Consideration | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Alternative investment, measurement input	0.033
Level 3 | ECP Entwicklungsgesellschaft mbH | Monte Carlo simulation model | Revenue-based milestone
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Milestone Payment	$ 8,000
Contingent consideration	$ 4,692
Level 3 | ECP Entwicklungsgesellschaft mbH | Monte Carlo simulation model | Revenue-based milestone | Contingent Consideration
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Probability of payment (risk neutral)	73.00%
Level 3 | ECP Entwicklungsgesellschaft mbH | Monte Carlo simulation model | Revenue-based milestone | Contingent Consideration | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Projected fiscal year of milestone payments	2025
Level 3 | ECP Entwicklungsgesellschaft mbH | Monte Carlo simulation model | Revenue-based milestone | Contingent Consideration | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Projected fiscal year of milestone payments	2035
Level 3 | ECP Entwicklungsgesellschaft mbH | Monte Carlo simulation model | Revenue-based milestone | Discount Rate | Contingent Consideration
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Alternative investment, measurement input	0.17
Level 3 | ECP Entwicklungsgesellschaft mbH | Monte Carlo simulation model | Revenue-based milestone | Measurement Input, Price Volatility | Contingent Consideration
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Alternative investment, measurement input	0.50

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 9,931	$ 10,331	$ 9,575	$ 10,490
Additions	0	0	0	0
Payments	0	0	0	0
Change in fair value	305	162	661	3
Ending balance	$ 10,236	$ 10,493	$ 10,236	$ 10,493

Components of Property and Equi

Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Property Plant And Equipment [Abstract]
Land	$ 7,148	$ 7,262
Building and building improvements	96,147	86,705
Leasehold improvements	12,923	2,190
Machinery and equipment	62,679	59,146
Furniture and fixtures	13,984	11,456
Construction in progress	12,038	17,946
Total cost	204,919	184,705
Accumulated depreciation	(47,023)	(39,700)
Property and equipment, net	$ 157,896	$ 145,005

Goodwill, In-Process Research_3

Goodwill, In-Process Research and Development and Other Assets - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)
Goodwill [Line Items]
Goodwill	$ 31,727,000	$ 31,727,000	$ 32,601,000
Accumulated impairment loss, goodwill	0	0
In-process research and development	14,800,000	14,800,000	15,208,000
Accumulated impairment losses on IPR&D assets	0	0
Aggregate carrying amount of other investments	78,836,000	78,836,000	80,779,000
Equity method investment	3,000,000	3,000,000
Other intangible assets and other	5,098,000	5,098,000	4,336,000
License Manufacturing Rghts to Technology
Goodwill [Line Items]
Other intangible assets and other	3,600,000	$ 3,600,000
Other Intangible Assets
Goodwill [Line Items]
Intangible asset, amortized useful life		15 years
Shockwave Medical
Goodwill [Line Items]
Investment in affiliate			25,000,000
Fair value of investment	50,200,000	$ 50,200,000	56,200,000
Pre-tax unrealized losses on investment	(45,600,000)	(5,900,000)
Medical Device Companies
Goodwill [Line Items]
Aggregate carrying amount of other investments	4,000,000	4,000,000
Equity method investment	3,000,000	3,000,000
ECP Entwicklungsgesellschaft mbH
Goodwill [Line Items]
In-process research and development	$ 14,800,000	$ 14,800,000	$ 15,200,000
ECP Entwicklungsgesellschaft mbH | Measurement Input, Discount Rate
Goodwill [Line Items]
Fair value inputs, discount rate	0.21	0.21

Carrying Value of Goodwill and

Carrying Value of Goodwill and Change in Balance (Detail) $ in Thousands	6 Months Ended
	Sep. 30, 2019USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 32,601
Foreign currency translation impact	(874)
Ending balance	$ 31,727

Carrying value of In-Process Re

Carrying value of In-Process Research and Development (Detail) $ in Thousands	6 Months Ended
	Sep. 30, 2019USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 15,208
Foreign currency translation impact	(408)
Ending balance	$ 14,800

Summary of Other Assets (Detail

Summary of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Other Assets [Abstract]
Equity method and other investments	$ 81,836	$ 122,433	$ 80,779	$ 22,325	$ 13,814	$ 12,649
Right of use asset - leases	12,257
Other intangible assets and other	5,098		4,336
Total other assets	$ 99,191		$ 85,115

Equity Method and Other Investm

Equity Method and Other Investments Classified as Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Long Term Investments [Abstract]
Other investments	$ 78,836		$ 80,779
Equity method investment	3,000
Total equity and other investments	$ 81,836	$ 122,433	$ 80,779	$ 22,325	$ 13,814	$ 12,649

Carrying value of Other Investm

Carrying value of Other Investments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 122,433	$ 13,814	$ 80,779	$ 12,649
Additions	5,000	8,511	7,000	9,676
Change in fair value, net	(45,597)		(5,943)
Ending balance	$ 81,836	$ 22,325	$ 81,836	$ 22,325

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information Related to Operating Leases (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating lease right-of-use assets in other assets	$ 12,257
Operating lease liabilities in other current liabilities	3,264
Operating lease liabilities in other long-term liabilities	9,439
Total operating lease liabilities	$ 12,703

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Mar. 31, 2019
Leases [Abstract]
Operating lease expense	$ 1.1	$ 2.2
Deferred rent			$ 0.3

Maturities of Operating Lease L

Maturities of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
2020	$ 1,077
2021	3,373
2022	2,881
2023	1,591
2024	1,457
Thereafter	3,722
Total minimum lease payments	14,101
Less: imputed interest	(1,398)
Present value of operating lease liabilities	$ 12,703
Weighted average remaining lease term	5 years 8 months 15 days
Weighted average discount rate	3.22%

Minimum Future Lease Payments (

Minimum Future Lease Payments (Detail) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
2020	$ 3,398
2021	2,712
2022	2,000
2023	1,462
2024	1,414
Thereafter	3,288
Total minimum lease payments	$ 14,274

Accrued Expenses (Detail)

Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Payables and Accruals [Abstract]
Employee compensation	$ 28,246	$ 32,926
Sales and income taxes	14,826	12,262
Professional, legal, and accounting fees	4,114	2,757
Research and development	3,323	3,309
Marketing	2,702	1,707
Warranty	1,545	1,272
Other	3,151	3,187
Accrued expenses	$ 57,907	$ 57,420

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2019	Aug. 31, 2019
Stockholders Equity Note [Abstract]
Stock repurchase program, authorized amount		$ 200,000
Shares repurchased (in shares)	180,929
Shares repurchased, value	$ 34,874
Average cost price per share including commission expense	$ 192.75

Stock-Based Compensation Recogn

Stock-Based Compensation Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 13,323	$ 15,934	$ 26,445	$ 28,179
Cost of product revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	881	774	1,722	1,349
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	1,823	2,618	3,706	4,584
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 10,619	$ 12,542	$ 21,017	$ 22,246

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, 2019USD ($)$ / sharesshares	Mar. 31, 2019$ / sharesshares
Options
Outstanding at beginning of period | shares	853
Granted | shares	107
Exercised | shares	(58)
Cancelled and expired | shares	(12)
Outstanding at end of period | shares	890	853
Exercisable at end of period | shares	667
Options vested and expected to vest at end of period | shares	886
Weighted Average Exercise Price
Outstanding at beginning of period | $ / shares	$ 87.14
Granted | $ / shares	264.56
Exercised | $ / shares	47.01
Cancelled and expired | $ / shares	231.53
Outstanding at end of period | $ / shares	109.03	$ 87.14
Exercisable at end of period | $ / shares	61.69
Options vested and expected to vest at end of period | $ / shares	$ 109.06
Weighted Average Remaining Contractual Term (years)
Outstanding	5 years 8 months 4 days	5 years 6 months 25 days
Exercisable at end of period	4 years 7 months 20 days
Options vested and expected to vest at end of period	5 years 8 months 4 days
Aggregate Intrinsic Value
Outstanding at end of period | $	$ 85,789
Exercisable at end of period | $	82,730
Options vested and expected to vest at end of period | $	$ 85,484

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	6 Months Ended
	May 31, 2019	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Aggregate intrinsic value of options exercised in period		$ 11,100
Proceeds from the exercise of stock options		2,706	$ 10,613
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense		$ 17,000
Unrecognized stock-based compensation expense, estimated weighted-average recognition period		2 years 1 month 6 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Unrecognized stock-based compensation expense		$ 61,100
Unrecognized stock-based compensation expense, estimated weighted-average recognition period		2 years 1 month 6 days
Weighted average grant-date fair value		$ 258.07
Fair value of units vested		$ 97,900
Restricted share unit issued		155,000
Performance Based Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share unit issued	196,580

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) - Stock Options - $ / shares	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value	$ 70.40	$ 148.51	$ 95.62	$ 142.81
Valuation assumptions:
Risk-free interest rate	1.54%	2.87%	2.02%	2.93%
Expected option life (years)	4 years 1 month 17 days	3 years 11 months 26 days	4 years 1 month 20 days	4 years 14 days
Expected volatility	44.24%	43.90%	42.34%	42.70%

Summary of Restricted Stock Uni

Summary of Restricted Stock Units Activity (Detail) - Restricted Stock Units shares in Thousands	6 Months Ended
	Sep. 30, 2019$ / sharesshares
Number of Shares
Beginning Balance | shares	620
Granted | shares	155
Vested | shares	(385)
Forfeited | shares	(59)
Ending Balance | shares	331
Weighted Average Grant Date Fair Value
Beginning Balance | $ / shares	$ 193.53
Granted | $ / shares	258.07
Vested | $ / shares	144.16
Forfeited | $ / shares	309.74
Ending Balance | $ / shares	$ 261.95

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income tax provision (benefit)	$ 4,287	$ 1,706	$ 18,502	$ (39,873)
Effective income tax rate	24.70%	3.30%	15.40%	(39.70%)
Excess tax benefits from stock-based awards	$ 500	$ 12,900	$ 13,300	$ 66,800

Differences Between Statutory I

Differences Between Statutory Income Tax Rate and Effective Income Tax Rate (Detail)	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Statutory income tax rate	21.00%	21.00%	21.00%	21.00%
Excess tax benefits from stock-based awards	(2.70%)	(24.90%)	(11.00%)	(66.60%)
Credits	(2.10%)	(1.80%)	(1.70%)	(1.80%)
State taxes, net	3.30%	4.30%	3.40%	4.30%
Permanent differences	1.70%	1.80%	1.90%	1.80%
Other	3.50%	2.90%	1.70%	1.60%
Effective tax rate	24.70%	3.30%	15.40%	(39.70%)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended
	May 31, 2016
Patent One
Commitments and Contingencies [Line Items]
Patent expiration period	2020-09
Patent Two
Commitments and Contingencies [Line Items]
Patent expiration period	2020-12
Patent Three
Commitments and Contingencies [Line Items]
Patent expiration period	2021-10

Segment and Enterprise Wide D_2

Segment and Enterprise Wide Disclosures - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018	Sep. 30, 2019USD ($)Segment	Sep. 30, 2018	Mar. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Number of business segments | Segment			1
International
Segment Reporting Information [Line Items]
Long-lived assets | $	$ 43.6		$ 43.6		$ 43.4
Customer Concentration Risk | Revenue | International
Segment Reporting Information [Line Items]
Percentage of revenue accounted	16.00%	13.00%	16.00%	13.00%