Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2021		Mar. 31, 2020		Mar. 31, 2019
Income Statement [Abstract]
Revenue	$ 847,522		$ 840,883		$ 769,432
Costs and expenses:
Cost of revenue	161,907		151,305		129,567
Research and development	121,875		98,759		93,503
Selling, general and administrative	334,183		341,600		321,550
Costs and Expenses, Total	617,965		591,664		544,620
Income from operations	229,557		249,219		224,812
Other income:
Investment income, net	6,717		12,167		8,166
Other income (expense), net	51,946		(4,561)		30,382
Nonoperating Income (Expense), Total	58,663	[1]	7,606	[1]	38,548
Income before income taxes	288,220		256,825		263,360
Income tax provision	62,695	[2]	53,816	[2]	4,344
Net income	$ 225,525		$ 203,009		$ 259,016
Basic net income per share	$ 5.00		$ 4.49		$ 5.77
Basic weighted average shares outstanding	45,140		45,179		44,911
Diluted net income per share	$ 4.94		$ 4.43		$ 5.61
Diluted weighted average shares outstanding	45,674		45,816		46,151

[1] In fiscal year 2019, the Company invested $25.0 million in medical device company Shockwave Medical. The fair value of this investment as of March 31, 2021 was $38.7 million. The Company recognized a pre-tax gain of $50.8 million for the year ended March 31, 2021 and a pre-tax loss of $0.5 million for the year ended March 31, 2020 in other income (expense), net.

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