Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Net revenues	$ 195,642	$ 230,887	$ 247,710
Cost of revenues	83,048	98,804	95,282
Gross profit	112,594	132,083	152,428
Operating expenses:
Research and development	187,419	175,656	108,732
Selling, general and administrative	51,684	45,794	49,173
Amortization of purchased intangible assets	1,926	3,202	5,285
Restructuring charges, net	6,435	875	532
Total operating expenses	247,464	225,527	163,722
Operating loss	(134,870)	(93,444)	(11,294)
Interest income (expense), net and other-than-temporary impairment	2,595	4,247	9,890
Other income (expense), net	(2,394)	7,437	797
Loss before income taxes	(134,669)	(81,760)	(607)
Income tax expense	(554)	928	399
Net loss	$ (134,115)	$ (82,688)	$ (1,006)
Basic and diluted net loss per share (in dollars per share)	$ (2.06)	$ (1.33)	$ (0.02)
Shares used in calculating basic and diluted net loss per share	65,258	62,245	65,160