Business Segments - Reconciliation of Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 26, 2018	May 27, 2017	May 26, 2018	May 27, 2017
Segment Reporting [Abstract]
Net income	$ 32,521	$ 19,391	$ 72,567	$ 46,407
Interest expense	4,172	5,265	13,871	11,571
Provision for income taxes	11,684	10,258	28,478	23,794
Depreciation	2,351	1,859	6,679	5,287
Amortization of intangible assets	1,933	10,159	5,921	22,578
EBITDA	52,661	46,932	127,516	109,637
Postretirement health care benefit income	0	0	0	(24,796)
Transaction costs	800	450	850	6,374
Non-operating income	(100)	(54)	(212)	(137)
Adjusted EBITDA	$ 53,361	$ 47,328	$ 128,154	$ 91,078