Earnings (Loss) Per Share (EPS) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Sep. 29, 2017	Sep. 30, 2016
Net Income (Loss) Available to Common Stockholders, Diluted [Abstract]
Net income (loss)	$ 13,690	$ 11,458	$ 12,341	$ (1,972)
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Basic (in shares)	31,594,000	30,782,000	31,304,000	30,756,000
Stock options, restricted stock and restricted stock units (in shares)	579,000	371,000	420,000	0
Denominator for diluted EPS (in shares)	32,173,000	31,153,000	31,724,000	30,756,000
Basic EPS (in dollars per share)	$ 0.43	$ 0.37	$ 0.39	$ (0.06)
Diluted EPS (in dollars per share)	$ 0.43	$ 0.37	$ 0.39	$ (0.06)
Anitdilutive Securities Excluded From Earnings Per Share [Abstract]
Time-vested stock options, restricted stock and restricted stock units (in shares)	295,000	629,000	850,000	1,862,000
Performance-vested stock options and restricted stock units (in shares)	188,000	373,000	320,000	417,000