Business Segments - Reconciliation of Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 27, 2017	May 28, 2016	May 27, 2017	May 28, 2016
Segment Reporting [Abstract]
Net income	$ 19,391	$ 14,438	$ 46,407	$ 32,350
Interest expense	5,265	0	11,571	0
Provision for income taxes	10,258	6,232	23,794	14,699
Depreciation	1,859	1,480	5,287	4,243
Amortization of intangible assets	10,159	0	22,578	0
EBITDA	46,932	22,150	109,637	51,292
Postretirement health care benefit income	0	(1,593)	(24,796)	(4,531)
Legal settlement	0	(2,750)	0	(2,750)
Transaction costs	450	0	6,374	0
Non-operating income	(54)	(77)	(137)	(194)
Adjusted EBITDA	$ 47,328	$ 17,730	$ 91,078	$ 43,817