Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue:
Product revenue	$ 44,288	$ 37,319	$ 86,897	$ 75,966
Funded research and development	57	98	118	234
Total Revenue	44,345	37,417	87,015	76,200
Costs and expenses:
Cost of product revenue	9,027	7,194	17,750	14,640
Research and development	7,721	5,854	15,008	12,566
Selling, general and administrative	26,199	18,437	54,166	39,390
Amortization of intangible assets				111
Costs and Expenses, Total	42,947	31,485	86,924	66,707
Income from operations	1,398	5,932	91	9,493
Other income (expense):
Investment income (expense), net	25	1	41	(1)
Other income (expense), net	6	(9)	(15)	(13)
Nonoperating Income (Expense), Total	31	(8)	26	(14)
Income before income tax provision	1,429	5,924	117	9,479
Income tax provision	370	455	781	891
Net income (loss)	$ 1,059	$ 5,469	$ (664)	$ 8,588
Basic net income (loss) per share	$ 0.03	$ 0.14	$ (0.02)	$ 0.22
Basic weighted average shares outstanding	39,260	39,431	38,971	39,288
Diluted net income (loss) per share	$ 0.03	$ 0.13	$ (0.02)	$ 0.21
Diluted weighted average shares outstanding	41,337	41,722	38,971	41,645