Consolidated Statement of Shareholders' Equity (unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock	Paid-In Capital	Retained Earnings
Balance (in shares) at Aug. 30, 2017		29,624	(500)
Balance at Aug. 30, 2017	$ 144,052	$ 9,480	$ (4,775)	$ 31,850	$ 107,497
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(5,537)				(5,537)
Share-based compensation expense (in shares)		30
Share-based compensation expense	867	$ 10		857
Common stock issued under employee benefit plans (in shares)		163
Common stock issued under employee benefit plans	0	$ 52		(52)
Balance (in shares) at Dec. 20, 2017		29,817	(500)
Balance at Dec. 20, 2017	139,382	$ 9,542	$ (4,775)	32,655	101,960
Balance (in shares) at Aug. 30, 2017		29,624	(500)
Balance at Aug. 30, 2017	144,052	$ 9,480	$ (4,775)	31,850	107,497
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(17,108)
Balance (in shares) at Mar. 14, 2018		29,951	(500)
Balance at Mar. 14, 2018	128,196	$ 9,585	$ (4,775)	32,997	90,389
Balance (in shares) at Dec. 20, 2017		29,817	(500)
Balance at Dec. 20, 2017	139,382	$ 9,542	$ (4,775)	32,655	101,960
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(11,571)				(11,571)
Share-based compensation expense (in shares)		27
Share-based compensation expense	385	$ 8		377
Common stock issued under employee benefit plans (in shares)		20
Common stock issued under employee benefit plans	0	$ 7		(7)
Common stock issued under nonemployee benefit plans (in shares)		87
Common stock issued under nonemployee benefit plans	0	$ 28		(28)
Balance (in shares) at Mar. 14, 2018		29,951	(500)
Balance at Mar. 14, 2018	128,196	$ 9,585	$ (4,775)	32,997	90,389
Balance (in shares) at Aug. 29, 2018		30,003	(500)
Balance at Aug. 29, 2018	112,628	$ 9,602	$ (4,775)	33,872	73,929
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(7,489)				(7,489)
Share-based compensation expense (in shares)		42
Share-based compensation expense	439	$ 13		426
Common stock issued under employee benefit plans (in shares)		81
Common stock issued under employee benefit plans	0	$ 26		(26)
Common stock issued under nonemployee benefit plans (in shares)		38
Common stock issued under nonemployee benefit plans	0	$ 12		(12)
Balance (in shares) at Dec. 19, 2018		30,164	(500)
Balance at Dec. 19, 2018	108,057	$ 9,653	$ (4,775)	34,260	68,919
Balance (in shares) at Aug. 29, 2018		30,003	(500)
Balance at Aug. 29, 2018	112,628	$ 9,602	$ (4,775)	33,872	73,929
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(856)
Balance (in shares) at Mar. 13, 2019		30,289	(500)
Balance at Mar. 13, 2019	115,083	$ 9,693	$ (4,775)	34,614	75,551
Balance (in shares) at Dec. 19, 2018		30,164	(500)
Balance at Dec. 19, 2018	108,057	$ 9,653	$ (4,775)	34,260	68,919
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	6,632				6,632
Share-based compensation expense (in shares)		98
Share-based compensation expense	394	$ 31		363
Common stock issued under employee benefit plans (in shares)		12
Common stock issued under employee benefit plans	0	$ 4		(4)
Common stock issued under nonemployee benefit plans (in shares)		15
Common stock issued under nonemployee benefit plans	0	$ 5		(5)
Balance (in shares) at Mar. 13, 2019		30,289	(500)
Balance at Mar. 13, 2019	$ 115,083	$ 9,693	$ (4,775)	$ 34,614	$ 75,551