Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 1,031,753	$ 847,522	$ 840,883
Costs and expenses:
Cost of revenue	188,158	161,907	151,305
Research and development	163,403	121,875	98,759
Selling, general and administrative	423,486	334,183	341,600
Acquired in process research and development	115,986	0	0
Costs and Expenses, Total	891,033	617,965	591,664
Other income:
Income from operations	140,720	229,557	249,219
Interest and other income, net	(49,840)	(58,663)	(7,606)
Income before income taxes	190,560	288,220	256,825
Income tax provision	54,055	62,695	53,816
Net income	$ 136,505	$ 225,525	$ 203,009
Net income per share - basic	$ 3.00	$ 5.00	$ 4.49
Weighted average shares outstanding - basic	45,445	45,140	45,179
Net income per share - diluted	$ 2.98	$ 4.94	$ 4.43
Weighted average shares outstanding - diluted	45,881,000	45,674,000	45,816,000