Condensed Consolidated Stockholders' Statement of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance at Aug. 26, 2017	$ 441,674	$ 25,888	$ 80,401	$ 679,138	$ (1,023)	$ (342,730)
Beginning balance (in shares) at Aug. 26, 2017		51,776				(20,183)
Stock-based compensation	5,465		5,403			$ 62
Stock-based compensation (in shares)						4
Issuance of restricted stock	87		(1,625)			$ 1,712
Issuance of restricted stock (in shares)						101
Repurchase of common stock	(6,481)					$ (6,481)
Repurchase of common stock (in shares)						(169)
Common stock dividends	(9,557)			(9,557)
Amortization of net actuarial loss (net of tax of $3, $3, $8, and $9)	20				20
Change in fair value of interest rate swap (net of tax of $114, $42, $327, and $877)	2,046				2,046
Net income	72,567			72,567
Ending balance at May. 26, 2018	505,821	$ 25,888	84,179	742,148	1,043	$ (347,437)
Ending balance (in shares) at May. 26, 2018		51,776				(20,247)
Beginning balance at Feb. 24, 2018	477,809	$ 25,888	80,721	712,809	907	$ (342,516)
Beginning balance (in shares) at Feb. 24, 2018		51,776				(20,117)
Stock-based compensation	3,540		3,515			$ 25
Stock-based compensation (in shares)						2
Issuance of restricted stock	0		(57)			$ 57
Issuance of restricted stock (in shares)						3
Repurchase of common stock	(5,003)					$ (5,003)
Repurchase of common stock (in shares)						(135)
Common stock dividends	(3,182)			(3,182)
Amortization of net actuarial loss (net of tax of $3, $3, $8, and $9)	7				7
Change in fair value of interest rate swap (net of tax of $114, $42, $327, and $877)	129				129
Net income	32,521			32,521
Ending balance at May. 26, 2018	505,821	$ 25,888	84,179	742,148	1,043	$ (347,437)
Ending balance (in shares) at May. 26, 2018		51,776				(20,247)
Beginning balance at Aug. 25, 2018	534,445	$ 25,888	86,223	768,816	892	$ (347,374)
Beginning balance (in shares) at Aug. 25, 2018		51,776				(20,243)
Stock-based compensation	5,752		5,683			$ 69
Stock-based compensation (in shares)						4
Issuance of restricted stock	1,528		(2,056)			$ 3,584
Issuance of restricted stock (in shares)						208
Issuance of stock under ESPP	296		46			$ 250
Issuance of stock under ESPP (in shares)						15
Repurchase of common stock	(7,724)					$ (7,724)
Repurchase of common stock (in shares)						(255)
Common stock dividends	(10,240)			(10,240)
Amortization of net actuarial loss (net of tax of $3, $3, $8, and $9)	24				24
Change in fair value of interest rate swap (net of tax of $114, $42, $327, and $877)	(1,018)				(1,018)
Net income	79,930			79,930
Ending balance at May. 25, 2019	602,993	$ 25,888	89,896	838,506	(102)	$ (351,195)
Ending balance (in shares) at May. 25, 2019		51,776				(20,271)
Beginning balance at Feb. 23, 2019	570,666	$ 25,888	89,682	805,851	252	$ (351,007)
Beginning balance (in shares) at Feb. 23, 2019		51,776				(20,292)
Stock-based compensation	1,130		1,118			$ 12
Stock-based compensation (in shares)						1
Issuance of restricted stock	0		(904)			$ 904
Issuance of restricted stock (in shares)						52
Repurchase of common stock	(1,104)					$ (1,104)
Repurchase of common stock (in shares)						(32)
Common stock dividends	(3,516)			(3,516)
Amortization of net actuarial loss (net of tax of $3, $3, $8, and $9)	8				8
Change in fair value of interest rate swap (net of tax of $114, $42, $327, and $877)	(362)				(362)
Net income	36,171			36,171
Ending balance at May. 25, 2019	$ 602,993	$ 25,888	$ 89,896	$ 838,506	$ (102)	$ (351,195)
Ending balance (in shares) at May. 25, 2019		51,776				(20,271)