Business Segments - Reconciliation of Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 26, 2016	Nov. 28, 2015
Segment Reporting [Abstract]
Net income	$ 11,738	$ 8,558
Interest expense	1,128	0
Provision for taxes	5,620	4,336
Depreciation	1,580	1,370
Amortization of intangible assets	2,051	0
EBITDA	22,117	14,264
Postretirement health care benefit income	(12,813)	(1,345)
Transaction costs	5,462	0
Non-operating income	(87)	(135)
Adjusted EBITDA	$ 14,679	$ 12,784