Pension and Savings Plans - Net Periodic Benefit Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 25, 2018	Aug. 26, 2017
Retirement Benefits [Abstract]
Interest cost	$ 10,356	$ 10,335
Expected return on plan assets	(18,997)	(20,056)
Recognized net actuarial losses	10,736	13,873
Settlement loss	130,263
Net periodic benefit expense	$ 132,358	$ 4,152