Investments - Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Apr. 01, 2018	Apr. 02, 2017
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair value less than 12 months	$ 118,225	$ 140,733
Unrealized loss less than 12 months	(1,635)	(872)
Fair value 12 months or greater	63,384	0
Unrealized loss 12 months or greater	(1,085)	0
Fair value total	181,609	140,733
Unrealized loss total	(2,720)	(872)
Corporate bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair value less than 12 months	78,726	71,308
Unrealized loss less than 12 months	(1,324)	(326)
Fair value 12 months or greater	23,286	0
Unrealized loss 12 months or greater	(380)	0
Fair value total	102,012	71,308
Unrealized loss total	(1,704)	(326)
U.S. government treasuries and agencies securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair value less than 12 months	25,352	55,497
Unrealized loss less than 12 months	(221)	(508)
Fair value 12 months or greater	34,920	0
Unrealized loss 12 months or greater	(673)	0
Fair value total	60,272	55,497
Unrealized loss total	(894)	(508)
Asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair value less than 12 months	14,147	11,294
Unrealized loss less than 12 months	(90)	(23)
Fair value 12 months or greater	2,540	0
Unrealized loss 12 months or greater	(20)	0
Fair value total	16,687	11,294
Unrealized loss total	(110)	(23)
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	2,638	0
Unrealized loss 12 months or greater	(12)	0
Fair value total	2,638	2,634
Unrealized loss total	$ (12)	$ (15)