Share-Based Compensation Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Dec. 29, 2012	Dec. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	$ 1,482	$ 2,393	$ 6,359	$ 9,570
Cost of Sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	202	302	635	859
Selling, General and Administrative Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	867	1,557	4,145	7,094
Research and Development Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	$ 413	$ 534	$ 1,579	$ 1,617