Consolidated Statements of Equity - USD ($) $ in Thousands		Total	Common Stock [Member]		Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings (Accumulated Deficit) [Member]	Class B Common Stock [Member]
Beginning balance, shares at Dec. 31, 2013			29,544,557		65,478
Beginning balance at Dec. 31, 2013		$ 124,473	$ 295		$ (2,777)	$ 116,647	$ 0	$ 10,308
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, warrants and employee stock purchase plan (in shares)	[1]		275,783
Proceeds from exercise of stock options, warrants and employee stock purchase plan		2,676	$ 3	[1]		2,673
Treasury shares acquired (in shares)					2,108
Treasury shares acquired, net		(71)			$ (71)
Tax benefit on exercise of stock options		253				253
Stock-based compensation expense		1,418				1,418
Other		(62)				(62)
Net (loss) income		11,428						11,428
Other comprehensive income (loss)		0
Ending balance at Dec. 30, 2014		140,115	$ 298	[1],[2]	$ (2,848)	120,929	0	21,736
Ending balance, shares at Dec. 30, 2014			29,820,340	[1]	67,586
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, warrants and employee stock purchase plan (in shares)	[1]		318,332
Proceeds from exercise of stock options, warrants and employee stock purchase plan		952	$ 3	[1]		949
Treasury shares acquired (in shares)					2,356,285
Treasury shares acquired, net		(35,000)			$ (32,152)	(2,848)
Stock-based compensation expense		1,698				1,698
Other		(94)				(94)
Net (loss) income		(13,765)						(13,765)
Other comprehensive income (loss)		(134)					(134)
Ending balance at Dec. 29, 2015		93,772	$ 301	[1],[2]	$ (35,000)	120,634	(134)	7,971
Ending balance, shares at Dec. 29, 2015			30,138,672	[1]	2,423,871
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, warrants and employee stock purchase plan (in shares)	[1]		162,253
Proceeds from exercise of stock options, warrants and employee stock purchase plan		1,100	$ 2	[1]		1,098
Stock-based compensation expense		2,540				2,540
Net (loss) income		(71,677)						(71,677)
Other comprehensive income (loss)		83					83
Ending balance at Jan. 03, 2017		$ 25,818	$ 303		$ (35,000)	$ 124,272	$ (51)	$ (63,706)
Ending balance, shares at Jan. 03, 2017			30,300,925		2,423,871				1,522,098

[1] Unless otherwise noted, activity relates to Class A common stock

[2] Includes 1,522,098 shares of Class B common stock