CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Product revenue	$ 153,989	$ 114,624	$ 419,202	$ 320,541
Funded research and development	33	50	111	83
Total Revenue	154,022	114,674	419,313	320,624
Costs and expenses:
Cost of product revenue	24,994	18,987	68,483	51,366
Research and development	17,706	16,349	54,027	50,061
Selling, general and administrative	66,556	53,935	187,233	158,053
Costs and Expenses, Total	109,256	89,271	309,743	259,480
Income from operations	44,766	25,403	109,570	61,144
Other income (expense):
Investment income, net	969	457	2,385	1,068
Other expense, net	(81)	(34)	(25)	(225)
Nonoperating Income (Expense), Total	888	423	2,360	843
Income before income taxes	45,654	25,826	111,930	61,987
Income tax provision	32,208	10,394	36,607	24,770
Net income	$ 13,446	$ 15,432	$ 75,323	$ 37,217
Basic net income per share	$ 0.30	$ 0.36	$ 1.71	$ 0.86
Basic weighted average shares outstanding	44,247	43,431	44,095	43,125
Diluted net income per share	$ 0.29	$ 0.34	$ 1.65	$ 0.83
Diluted weighted average shares outstanding	45,869	44,770	45,731	44,597