Fair Value Measurement (Levels 1-3) (Details) - Measured on a Recurring Basis - USD ($) $ in Thousands	Jan. 03, 2016	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	$ 62,434	$ 135,945
Money market funds	70,960	55,578
Asset-backed securities	0	0
Corporate bonds	0	0
International government bonds		0
Corporate commercial paper	0	0
Bank deposits	0	0
Repurchase agreement	0	0
Municipal bonds	0	0
Total assets measured at fair value	133,394	191,523
Convertible Notes	0
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	14,501	31,830
Corporate bonds	108,314	245,675
International government bonds		1,006
Corporate commercial paper	3,483	4,999
Bank deposits	13,595	16,915
Repurchase agreement	129	191
Municipal bonds	900	6,044
Total assets measured at fair value	140,922	306,660
Convertible Notes	(284,280)
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
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
Convertible Notes	0
Total
Cash Equivalents and Short-Term Investments:
US government treasuries and agencies securities	62,434	135,945
Money market funds	70,960	55,578
Asset-backed securities	14,501	31,830
Corporate bonds	108,314	245,675
International government bonds		1,006
Corporate commercial paper	3,483	4,999
Bank deposits	13,595	16,915
Repurchase agreement	129	191
Municipal bonds	900	6,044
Total assets measured at fair value	274,316	$ 498,183
Convertible Notes	$ (284,280)