Investments (Unrealized Loss) (Details) - USD ($) $ in Thousands	Jan. 03, 2016	Mar. 29, 2015
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	$ 162,512	$ 105,588
Unrealized Loss Less than 12 months	(567)	(159)
Fair Value 12 months or Greater	0	0
Unrealized Loss 12 months or Greater	0	0
Fair Value Total	162,512	105,588
Unrealized Loss Total	(567)	(159)
Corporate bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	90,142	67,367
Unrealized Loss Less than 12 months	(386)	(121)
Fair Value 12 months or Greater	0	0
Unrealized Loss 12 months or Greater	0	0
Fair Value Total	90,142	67,367
Unrealized Loss Total	(386)	(121)
Asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	14,501	17,736
Unrealized Loss Less than 12 months	(32)	(9)
Fair Value 12 months or Greater	0	0
Unrealized Loss 12 months or Greater	0	0
Fair Value Total	14,501	17,736
Unrealized Loss Total	(32)	(9)
U.S. government treasuries and agencies securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	56,969	18,478
Unrealized Loss Less than 12 months	(149)	(23)
Fair Value 12 months or Greater	0	0
Unrealized Loss 12 months or Greater	0	0
Fair Value Total	56,969	18,478
Unrealized Loss Total	(149)	(23)
Municipal bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	900	1,001
Unrealized Loss Less than 12 months	0	(2)
Fair Value 12 months or Greater	0	0
Unrealized Loss 12 months or Greater	0	0
Fair Value Total	900	1,001
Unrealized Loss Total	0	(2)
International government bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Fair Value Less than 12 months	0	1,006
Unrealized Loss Less than 12 months	0	(4)
Fair Value 12 months or Greater	0	0
Unrealized Loss 12 months or Greater	0	0
Fair Value Total	0	1,006
Unrealized Loss Total	$ 0	$ (4)