Earnings Per Share - Components of Basic and Diluted Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		4 Months Ended		6 Months Ended
	Mar. 13, 2019	Mar. 14, 2018	Dec. 19, 2018	Dec. 20, 2017	Mar. 13, 2019	Mar. 14, 2018
Numerator:
Income (loss) from continuing operations	$ 6,640	$ (11,461)			$ (843)	$ (16,963)
Loss from discontinued operations, net of income taxes	(8)	(110)			(13)	(145)
NET INCOME (LOSS)	$ 6,632	$ (11,571)	$ (7,489)	$ (5,537)	$ (856)	$ (17,108)
Denominator:
Denominator for basic earnings per share—weighted-average shares (in shares)	29,769	29,950			29,671	29,802
Effect of potentially dilutive securities:
Employee and non-employee stock options (in shares)	30	0			0	0
Denominator for earnings per share assuming dilution (in shares)	29,799	29,950			29,671	29,802
Income (loss) per share from continuing operations:
Basic (in dollars per share)	$ 0.22	$ (0.38)			$ (0.03)	$ (0.57)
Assuming dilution (in dollars per share)	0.22	(0.38)			(0.03)	(0.57)
Loss per share from discontinued operations:
Basic (in dollars per share)	0.00	(0.01)			0.00	0.00
Assuming dilution (in dollars per share)	0.00	(0.01)			0.00	0.00
Net income (loss) per share:
Basic (in dollars per share)	0.22	(0.39)			(0.03)	(0.57)
Assuming dilution (in dollars per share)	$ 0.22	$ (0.39)			$ (0.03)	$ (0.57)