Fair Value Measurement (Levels 1-3) (Details) - Measured on a Recurring Basis - USD ($) $ in Thousands	Jun. 28, 2015	Mar. 29, 2015
Quoted Prices in Active Markets for Identical Assets (Level 1)
Cash Equivalents and Short-Term Investments:
US government treasuries and agencies securities	$ 144,307	$ 135,945
Money market funds	48,839	55,578
Asset-backed securities	0	0
Corporate bonds	0	0
International government bonds	0	0
Corporate commercial paper	0	0
Bank deposits	0	0
Repurchase agreement	0	0
Municipal bonds	0	0
Total assets measured at fair value	193,146	191,523
Significant Other Observable Inputs (Level 2)
Cash Equivalents and Short-Term Investments:
US government treasuries and agencies securities	0	0
Money market funds	0	0
Asset-backed securities	36,748	31,830
Corporate bonds	237,526	245,675
International government bonds	1,004	1,006
Corporate commercial paper	1,200	4,999
Bank deposits	14,250	16,915
Repurchase agreement	434	191
Municipal bonds	6,024	6,044
Total assets measured at fair value	297,186	306,660
Significant Unobservable Inputs (Level 3)
Cash Equivalents and Short-Term Investments:
US government treasuries and agencies securities	0	0
Money market funds	0	0
Asset-backed securities	0	0
Corporate bonds	0	0
International government bonds	0	0
Corporate commercial paper	0	0
Bank deposits	0	0
Repurchase agreement	0	0
Municipal bonds	0	0
Total assets measured at fair value	0	0
Total
Cash Equivalents and Short-Term Investments:
US government treasuries and agencies securities	144,307	135,945
Money market funds	48,839	55,578
Asset-backed securities	36,748	31,830
Corporate bonds	237,526	245,675
International government bonds	1,004	1,006
Corporate commercial paper	1,200	4,999
Bank deposits	14,250	16,915
Repurchase agreement	434	191
Municipal bonds	6,024	6,044
Total assets measured at fair value	$ 490,332	$ 498,183