Retirement Benefits - Components of Periodic Benefit Cost for Corporation's Defined Benefit Pension and Postretirement Benefit Plans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 30, 2013	Aug. 24, 2012	Aug. 30, 2013	Aug. 24, 2012
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 320	$ 333	$ 640	$ 667
Interest cost	1,736	1,839	3,478	3,683
Expected return on plan assets	(1,567)	(1,609)	(3,141)	(3,222)
Amortization of prior service cost (credit)	51	62	102	123
Amortization of actuarial loss (gain)	913	815	1,830	1,631
Defined benefit plan, net periodic benefit cost, total	1,453	1,440	2,909	2,882
Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	137	212	275	425
Interest cost	612	800	1,225	1,600
Expected return on plan assets	(762)	(840)	(1,525)	(1,680)
Amortization of prior service cost (credit)	(325)	(519)	(650)	(1,038)
Amortization of actuarial loss (gain)	(212)		(425)
Defined benefit plan, net periodic benefit cost, total	$ (550)	$ (347)	$ (1,100)	$ (693)