Marketable Securities (Narrative) (Details) $ in Thousands	12 Months Ended
	Mar. 31, 2018 USD ($) security	Mar. 25, 2017 USD ($) security
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	$ 2,433	$ 55
Amortized cost on available for sale securities held at gross unrealized loss	$ 198,200	$ 99,900
Number of securities | security	0	4
Minimum
Schedule of Available-for-sale Securities [Line Items]
Maturity period for highly-rated securities	1 year
Maximum
Schedule of Available-for-sale Securities [Line Items]
Maturity period for highly-rated securities	3 years