Retirement Benefits - Components of Net Periodic Benefit Cost for Corporation's Defined Benefit Pension and Postretirement Benefits Plans (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Nov. 25, 2016	Nov. 27, 2015	Nov. 25, 2016	Nov. 27, 2015
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 203	$ 231	$ 608	$ 549
Interest cost	1,586	1,542	4,767	4,650
Expected return on plan assets	(1,510)	(1,622)	(4,538)	(4,949)
Amortization of prior service cost (credit)	1	1	3	3
Amortization of actuarial loss (gain)	886	861	2,663	2,555
Defined benefit plan, net periodic benefit cost, total	1,166	1,013	3,503	2,808
Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	40	1	212	251
Interest cost	527	471	1,582	1,521
Expected return on plan assets	(593)	(665)	(1,757)	(2,015)
Amortization of prior service cost (credit)	(175)	(174)	(524)	(524)
Amortization of actuarial loss (gain)	(381)	(676)	(1,115)	(1,276)
Defined benefit plan, net periodic benefit cost, total	$ (582)	$ (1,043)	$ (1,602)	$ (2,043)