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Earnings Per Share - Computation of Basic and Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Jan. 01, 2017	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Earnings Per Share Basic [Line Items]
Net income	$ (12,950)	$ 5,950	$ 2,778	$ 5,326	$ 7,694	$ 8,187	$ 2,124	$ (1,119)	$ 1,104	$ 16,886	$ 15,297
Weighted-average shares of common stock outstanding:
Basic									21,439,000	21,607,000	21,741,000
Dilutive effect of common stock equivalents arising from share option, nonvested share and nonvested share unit awards									146,000	209,000	186,000
Diluted									21,585,000	21,816,000	21,927,000
Basic earnings per share	$ (0.62)	$ 0.28	$ 0.13	$ 0.25	$ 0.36	$ 0.38	$ 0.10	$ (0.05)	$ 0.05	$ 0.78	$ 0.70
Diluted earnings per share	$ (0.62)	$ 0.28	$ 0.13	$ 0.24	$ 0.35	$ 0.38	$ 0.10	$ (0.05)	$ 0.05	$ 0.77	$ 0.70
Share Option Awards [Member]
Weighted-average shares of common stock outstanding:
Antidilutive shares/unit awards excluded from diluted calculation									83,000	200,000	481,000
Nonvested Share Awards and Nonvested Share Unit Awards [Member]
Weighted-average shares of common stock outstanding:
Antidilutive shares/unit awards excluded from diluted calculation									145,000	0	2,000