Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Net revenues	$ 40,945	$ 55,387	$ 91,217	$ 109,535
Cost of revenues	17,716	21,397	37,973	43,739
Gross profit	23,229	33,990	53,244	65,796
Operating expenses:
Research and development	24,711	56,550	57,916	91,056
Selling, general and administrative	7,919	9,146	16,977	18,672
Gain on sale of TPack	0	0	0	(19,699)
Amortization of purchased intangible assets	42	62	104	192
Restructuring	(110)	999	1,101	1,092
Total operating expenses	32,562	66,757	76,098	91,313
Operating loss	(9,333)	(32,767)	(22,854)	(25,517)
Interest income, net	393	488	729	4,154
Other (expense) income, net	(2,505)	88	(2,526)	217
Loss before income taxes	(11,445)	(32,191)	(24,651)	(21,146)
Income tax expense	272	192	131	380
Net loss	$ (11,717)	$ (32,383)	$ (24,782)	$ (21,526)
Basic and diluted net loss per share (in Dollars per share)	$ (0.15)	$ (0.45)	$ (0.32)	$ (0.30)
Shares used in calculating basic and diluted net loss per share (in Shares)	78,487	72,610	78,202	70,985