Share-Based Compensation - Expense (Details) (USD $)	3 Months Ended		9 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 28, 2013	Dec. 29, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			621,000	552,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross				5,000
Total share-based compensation expense	$ 1,262,000	$ 1,482,000	$ 5,130,000	$ 6,359,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition			1 year 10 months 24 days
Cost of Sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	184,000	202,000	558,000	635,000
Selling, General and Administrative Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	728,000	867,000	3,488,000	4,145,000
Research and Development Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	350,000	413,000	1,084,000	1,579,000
Stock Options
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 9,200,000		$ 9,200,000