Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017	Dec. 31, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 7,788	$ 6,039	$ 4,686	$ 443	$ 7,159
Net income (loss) available to common stockholders	$ 6,053	$ 4,689	$ 3,642	$ 344
Basic weighted average common shares outstanding	35,720,243	35,415,416	35,693,027	35,399,820
Basic net income (loss) per share	$ 0.17	$ 0.13	$ 0.10	$ 0.01
Dilutive effect of preferred stock and non-vested shares	9,481,023	9,526,403	9,541,577	9,580,756
Shares used in computing diluted net income (loss) per share	45,201,266	44,941,819	45,234,604	44,980,576
Diluted net income (loss) per share	$ 0.17	$ 0.13	$ 0.10	$ 0.01
Restricted Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less: Income attributable to participating securities	$ (139)	$ (104)	$ (83)	$ (8)
Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less: Income attributable to participating securities	$ (1,596)	$ (1,246)	$ (961)	$ (91)