Retirement Benefits - Components of Periodic Benefit Cost for Corporation's Defined Benefit Pension and Postretirement Benefits Plans (Detail) - USD ($) $ in Thousands	3 Months Ended
	May. 29, 2015	May. 30, 2014
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 159	$ 144
Interest cost	1,558	1,837
Expected return on plan assets	(1,668)	(1,623)
Amortization of prior service cost (credit)	1	1
Amortization of actuarial loss (gain)	848	706
Defined benefit plan, net periodic benefit cost, total	898	1,065
Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	125	100
Interest cost	525	675
Expected return on plan assets	(675)	(700)
Amortization of prior service cost (credit)	(175)	(325)
Amortization of actuarial loss (gain)	(300)	(225)
Defined benefit plan, net periodic benefit cost, total	$ (500)	$ (475)