Financial Instruments Measured at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	$ 888,996	$ 907,791
Contingent consideration	18,151	21,510
Cross Currency Interest Rate Contract
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative fair value	4,508	(489)
Short-term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	663,829	625,789
Long Term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	159,876	220,089
Shockwave Medical
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	56,730	61,535
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	59,296	32,955
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	5,995	28,958
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	116,281	147,731
Level 1 | Shockwave Medical
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	56,730	61,535
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	59,296	32,955
Level 2 | Cross Currency Interest Rate Contract
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative fair value	4,508	(489)
Level 2 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, fair value disclosure	5,995	28,958
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	116,281	147,731
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration	18,151	21,510
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	356,203	285,626
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	47,203	87,372
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	356,203	285,626
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	47,203	87,372
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	158,414	131,401
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	102,812	122,772
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	158,414	131,401
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	102,812	122,772
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	32,931	61,031
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	9,861	9,945
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	32,931	61,031
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	$ 9,861	$ 9,945