Postretirement Benefit Plans (Narrative) (Details) $ in Thousands		12 Months Ended
	Mar. 16, 2018 USD ($)	Mar. 31, 2018 USD ($) participant	Mar. 25, 2017 USD ($) Participant	Mar. 26, 2016 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Number of pension plan participants offered ETV | Participant			49
Number of pension plan participants accepting ETV | Participant			9
Contribution paid	$ 11,000	$ 12,900	$ 500
ETV pension expense			400
Number of pension plan participants authorized to terminate from Scheme | participant		60
Funded status of Scheme at end of year		$ 0	$ 1,020
Weighted-average discount rate assumption used to determine benefit obligations			2.70%	3.60%
Accumulated other comprehensive loss		11,361	$ 573	$ (332)
Employee matching contribution		6,700	5,500	4,300
Actuarial Gains (Losses) on Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		$ 11,189	$ (760)	$ (870)