Share-Based Compensation Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jul. 02, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	$ 2,977	$ 4,780
Cost of Sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	216	296
Selling, General and Administrative Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	2,261	3,938
Research and Development Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	$ 500	$ 546