Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 248,142	$ 209,764	$ 500,727	$ 374,614
Costs and expenses:
Cost of revenue	43,886	38,736	89,074	74,719
Research and development	41,041	30,525	78,749	56,882
Selling, general and administrative	102,779	79,167	206,263	147,611
Acquired in-process research and development			115,490
Costs and Expenses, Total	187,706	148,428	489,576	279,212
Operating income	60,436	61,336	11,151	95,402
Other income:
Investment income, net	977	1,822	2,027	4,219
Other income, net	5,858	9,757	44,743	34,370
Nonoperating Income (Expense), Total	6,835	11,579	46,770	38,589
Income before income taxes	67,271	72,915	57,921	133,991
Income tax provision	10,318	10,702	27,493	27,190
Net income	$ 56,953	$ 62,213	$ 30,428	$ 106,801
Net income per share - basic	$ 1.25	$ 1.38	$ 0.67	$ 2.37
Weighted average shares outstanding - basic	45,437	45,104	45,374	45,057
Net income per share - diluted	$ 1.24	$ 1.36	$ 0.66	$ 2.34
Weighted average shares outstanding - diluted	45,893	45,661	45,857	45,609