Fair Value Measurements - Investments (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Sep. 27, 2014	Mar. 29, 2014
Available for sale Securities Current
Schedule of Available-for-sale Securities
Cost	$ 31,519	$ 40,793
Unrealized Gain	10	13
Unrealized Loss	0	0
Fair Value	(31,529)	(40,806)
Available for sale Securities Current | Commercial Paper
Schedule of Available-for-sale Securities
Cost	20,397	6,700
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	(20,397)	(6,700)
Available for sale Securities Current | Government agencies
Schedule of Available-for-sale Securities
Cost	2,000	8,035
Unrealized Gain	2	2
Unrealized Loss	0	0
Fair Value	(2,002)	(8,037)
Available for sale Securities Current | Corporate Bonds
Schedule of Available-for-sale Securities
Cost	5,164	17,321
Unrealized Gain	0	7
Unrealized Loss	0	0
Fair Value	(5,164)	17,328
Available for sale Securities Current | Municipal Bonds
Schedule of Available-for-sale Securities
Cost	3,958	8,737
Unrealized Gain	8	4
Unrealized Loss	0	0
Fair Value	(3,966)	(8,741)
Available for sale Securities Non Current
Schedule of Available-for-sale Securities
Cost	0	3,976
Unrealized Gain	0	9
Unrealized Loss	0	0
Fair Value	0	(3,985)
Available for sale Securities Non Current | Municipal Bonds
Schedule of Available-for-sale Securities
Cost	0	3,976
Unrealized Gain	0	9
Unrealized Loss	0	0
Fair Value	$ 0	$ (3,985)