Pension (detail) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014
General Discussion Of Pension And Other Postretirement Benefits [Abstract]
Defined Benefit Plan, Service Cost	$ 2,519,000	$ 1,868,000	$ 5,039,000	$ 3,736,000
Defined Benefit Plan, Interest Cost	2,177,000	2,032,000	4,355,000	4,064,000
Defined Benefit Plan, Expected Return on Plan Assets	(2,625,000)	(2,740,000)	(5,252,000)	(5,479,000)
Defined Benefit Plan, Actuarial Net (Gains) Losses	844,000	31,000	1,687,000	61,000
Defined Benefit Plan, Amortization of Transition Obligations (Assets)	27,000	0	55,000	0
Defined Benefit Plan, Net Periodic Benefit Cost	$ 2,942,000	$ 1,191,000	5,884,000	$ 2,382,000
Defined Benefit Plan, Contributions by Employer			$ 600,000