Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Net revenues	$ 51,698	$ 56,347	$ 139,316	$ 182,120
Cost of revenues	22,958	23,795	61,874	77,830
Gross profit	28,740	32,552	77,442	104,290
Operating expenses:
Research and development	82,711	28,279	151,865	86,256
Selling, general and administrative	12,675	11,406	38,676	32,903
Amortization of purchased intangible assets	338	650	1,589	2,552
Restructuring charges, net	6,218	2	6,218	875
Total operating expenses	101,942	40,337	198,348	122,586
Operating loss	(73,202)	(7,785)	(120,906)	(18,296)
Interest income (expense), net	892	828	3,316	3,578
Other income (expense), net	1,366	86	1,539	209
Loss before income taxes	(70,944)	(6,871)	(116,051)	(14,509)
Income tax expense	618	206	458	597
Net loss	$ (71,562)	$ (7,077)	$ (116,509)	$ (15,106)
Basic and diluted net loss per share (USD per share)	$ (1.08)	$ (0.12)	$ (1.81)	$ (0.24)
Shares used in calculating basic and diluted net loss per share	66,113	60,990	64,489	62,465