Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Revenue:
Product revenue	$ 125,286	$ 99,837	$ 84,765
Funded research and development	1,089	1,314	948
Revenues, Total	126,375	101,151	85,713
Costs and expenses:
Cost of product revenue	24,507	21,977	22,529
Research and development	27,159	26,677	25,954
Selling, general and administrative	71,711	62,287	60,837
Amortization of intangible assets	1,478	1,395	1,469
Costs and Expenses, Total	124,855	112,336	110,789
Income (loss) from operations	1,520	(11,185)	(25,076)
Other income (expense):
Investment (expense) income, net	(3)	9	373
Gain on sale of WorldHeart stock		456	6,389
Gain on settlement of investment	1,017
Other income (expense), net	9	(143)	(39)
Nonoperating Income (Expense), Total	1,023	322	6,723
Income (loss) before income tax provision	2,543	(10,863)	(18,353)
Income tax provision	1,048	892	671
Net income (loss)	$ 1,495	$ (11,755)	$ (19,024)
Basic net income (loss) per share	$ 0.04	$ (0.32)	$ (0.52)
Basic weighted average shares outstanding	38,374	37,167	36,875
Diluted net income (loss) per share	$ 0.04	$ (0.32)	$ (0.52)
Diluted weighted average shares outstanding	40,172	37,167	36,875