Investments - Unrealized Loss (Details) - USD ($) $ in Thousands	Jul. 02, 2017	Apr. 02, 2017
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	$ 137,440	$ 140,733
Unrealized Loss Less than 12 months	(684)	(872)
Fair Value 12 months or Greater	66,450	0
Unrealized Loss 12 months or Greater	(868)	0
Fair Value Total	203,890	140,733
Unrealized Loss Total	(1,552)	(872)
Corporate bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	98,494	71,308
Unrealized Loss Less than 12 months	(529)	(326)
Fair Value 12 months or Greater	25,038	0
Unrealized Loss 12 months or Greater	(240)	0
Fair Value Total	123,532	71,308
Unrealized Loss Total	(769)	(326)
Asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	14,503	11,294
Unrealized Loss Less than 12 months	(42)	(23)
Fair Value 12 months or Greater	892	0
Unrealized Loss 12 months or Greater	(8)	0
Fair Value Total	15,395	11,294
Unrealized Loss Total	(50)	(23)
U.S. government treasuries and agencies securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	24,443	55,497
Unrealized Loss Less than 12 months	(113)	(508)
Fair Value 12 months or Greater	37,884	0
Unrealized Loss 12 months or Greater	(607)	0
Fair Value Total	62,327	55,497
Unrealized Loss Total	(720)	(508)
International government bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	0	2,634
Unrealized Loss Less than 12 months	0	(15)
Fair Value 12 months or Greater	2,636	0
Unrealized Loss 12 months or Greater	(13)	0
Fair Value Total	2,636	2,634
Unrealized Loss Total	$ (13)	$ (15)