Consolidated Statements of Income and Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Aug. 26, 2017	Aug. 27, 2016	Aug. 29, 2015
Income Statement [Abstract]
Amortization of prior service credit (net of tax of $15,409, $2,947, and $2,110)	$ 15,409	$ 2,947	$ 2,110
Amortization of net actuarial loss (net of tax of $5,975, $621, and $565)	5,976	621	565
Increase in actuarial loss (net of tax of $35, $415, and $250)	35	415	250
Plan amendment (net of tax of $2,402, $10,895, and $1,509)	2,402	10,895	1,509
Change in fair value of interest rate swap (net of tax of $316, $0, and $0)	$ 314	$ 0	$ 0