Employee and Retiree Benefits (Postretirement Benefit Income) (Details) - USD ($) $ in Thousands	12 Months Ended
Aug. 26, 2017	Aug. 27, 2016
Retirement Benefits [Abstract]
Interest cost	$ 29	$ 327
Service cost	16	108
Amortization of prior service benfit	(40,444)	(7,736)
Amortization of net actuarial loss	15,648	1,612
Net periodic postretirement benefit income	$ (24,751)	$ (5,689)

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Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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