Stock-Based Employee Compensation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011
Compensation Expense
Compensation Expense	$ 3,250	$ 4,029	$ 6,532	$ 8,149
Cost of revenue [Member]
Compensation Expense
Compensation Expense	252	453	555	879
Research and development [Member]
Compensation Expense
Compensation Expense	1,295	2,320	2,838	4,319
Selling, general and administrative [Member]
Compensation Expense
Compensation Expense	1,336	1,509	2,613	2,856
Discontinued operations [Member]
Compensation Expense
Compensation Expense	$ 367	$ (253)	$ 526	$ 95