Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Revenue:
Product revenue	$ 183,280	$ 157,614	$ 125,286
Funded research and development	363	510	1,089
Total Revenue	183,643	158,124	126,375
Costs and expenses:
Cost of product revenue	37,322	31,596	24,507
Research and development	30,707	25,647	27,159
Selling, general and administrative	107,251	84,227	71,711
Amortization of intangible assets		111	1,478
Costs and Expenses, Total	175,280	141,581	124,855
Income from operations	8,363	16,543	1,520
Other income:
Investment income (expense), net	118	(7)	(3)
Gain on settlement of investment			1,017
Other income	49	326	9
Other income (expense), net	167	319	1,023
Income (loss) before income tax provision	8,530	16,862	2,543
Income tax provision	1,179	1,848	1,048
Net income	$ 7,351	$ 15,014	$ 1,495
Basic net income per share	$ 0.19	$ 0.38	$ 0.04
Basic weighted average shares outstanding	39,334	39,113	38,374
Diluted net income per share	$ 0.18	$ 0.37	$ 0.04
Diluted weighted average shares outstanding	41,606	41,052	40,172