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	1,926		1,888			$ 38
Stock-based compensation (in shares)						2
Issuance of restricted stock	86		(1,568)			$ 1,654
Issuance of restricted stock (in shares)						97
Repurchase of common stock	(1,478)					$ (1,478)
Repurchase of common stock (in shares)						(33)
Common stock dividends	(6,375)			(6,375)
Amortization of net actuarial loss (net of tax of $2, $2, $5, and $6)	13				13
Change in fair value of interest rate swap (net of tax of $206, $448, $213, and $835)	1,917				1,917
Net income	40,046			40,046
Ending balance at Feb. 24, 2018	477,809	$ 25,888	80,721	712,809	907	$ (342,516)
Ending balance (in shares) at Feb. 24, 2018		51,776				(20,117)
Beginning balance at Nov. 25, 2017	456,631	$ 25,888	80,040	693,909	(383)	$ (342,823)
Beginning balance (in shares) at Nov. 25, 2017		51,776				(20,140)
Stock-based compensation	1,103		1,084			$ 19
Stock-based compensation (in shares)						1
Issuance of restricted stock	0		(403)			$ 403
Issuance of restricted stock (in shares)						24
Repurchase of common stock	(115)					$ (115)
Repurchase of common stock (in shares)						(2)
Common stock dividends	(3,188)			(3,188)
Amortization of net actuarial loss (net of tax of $2, $2, $5, and $6)	7				7
Change in fair value of interest rate swap (net of tax of $206, $448, $213, and $835)	1,283				1,283
Net income	22,088			22,088
Ending balance at Feb. 24, 2018	477,809	$ 25,888	80,721	712,809	907	$ (342,516)
Ending balance (in shares) at Feb. 24, 2018		51,776				(20,117)
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	4,622		4,565			$ 57
Stock-based compensation (in shares)						3
Issuance of restricted stock	1,528		(1,152)			$ 2,680
Issuance of restricted stock (in shares)						156
Issuance of stock under ESPP	296		46			$ 250
Issuance of stock under ESPP (in shares)						15
Repurchase of common stock	(6,620)					$ (6,620)
Repurchase of common stock (in shares)						(223)
Common stock dividends	(6,724)			(6,724)
Amortization of net actuarial loss (net of tax of $2, $2, $5, and $6)	16				16
Change in fair value of interest rate swap (net of tax of $206, $448, $213, and $835)	(656)				(656)
Net income	43,759			43,759
Ending balance at Feb. 23, 2019	570,666	$ 25,888	89,682	805,851	252	$ (351,007)
Ending balance (in shares) at Feb. 23, 2019		51,776				(20,292)
Beginning balance at Nov. 24, 2018	556,478	$ 25,888	88,288	787,794	878	$ (346,370)
Beginning balance (in shares) at Nov. 24, 2018		51,776				(20,178)
Stock-based compensation	2,133		2,117			$ 16
Stock-based compensation (in shares)						1
Issuance of restricted stock	0		(769)			$ 769
Issuance of restricted stock (in shares)						45
Issuance of stock under ESPP	296		46			$ 250
Issuance of stock under ESPP (in shares)						15
Repurchase of common stock	(5,672)					$ (5,672)
Repurchase of common stock (in shares)						(175)
Common stock dividends	(3,541)			(3,541)
Amortization of net actuarial loss (net of tax of $2, $2, $5, and $6)	8				8
Change in fair value of interest rate swap (net of tax of $206, $448, $213, and $835)	(634)				(634)
Net income	21,598			21,598
Ending balance at Feb. 23, 2019	$ 570,666	$ 25,888	$ 89,682	$ 805,851	$ 252	$ (351,007)
Ending balance (in shares) at Feb. 23, 2019		51,776				(20,292)