Note 9 - Earnings (Loss) Per Share ("EPS") - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016
Basic net loss per share:
Net loss	$ (11,238)	$ (8,761)	$ (24,360)	$ (15,903)
Weighted average common shares outstanding (in shares)	10,458	10,266	10,396	10,262
Basic net loss per share (in dollars per share)	$ (1.07)	$ (0.85)	$ (2.34)	$ (1.55)
Diluted net loss per share:
Net loss	$ (11,238)	$ (8,761)	$ (24,360)	$ (15,903)
Weighted average common shares outstanding (in shares)	10,458	10,266	10,396	10,262
Dilutive stock options, restricted stock and restricted stock units (in shares)
Weighted average common shares outstanding – assuming dilution (in shares)	10,458	10,266	10,396	10,262
Diluted net loss per share (in dollars per share)	$ (1.07)	$ (0.85)	$ (2.34)	$ (1.55)
Warrant [Member]
Diluted net loss per share:
Outstanding securities and warrants that were not included in the diluted calculation because their effect would be anti-dilutive (in shares)	1,812	1,652	1,812	1,652