Net Income Per Share (Schedule of Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Numerator:
Net income from continuing operations	$ 839	$ 533	$ 13,682	$ 1,551
Net (income) from discontinued operations	0	(5,763)	0	(1,191)
Net income (loss)	$ 839	$ (5,230)	$ 13,682	$ 360
Denominator:
Weighted average common shares - basic (in shares)	31,246	31,674	31,365	31,550
Potentially dilutive common share equivalent (in shares)	866	1,068	1,153	1,172
Weighted average common shares - dilutive (in shares)	32,112	32,742	32,518	32,722
Earnings Per Share, Basic [Abstract]
Income per share - basic, continuing operations (in dollars per share)	$ 0.03	$ 0.02	$ 0.44	$ 0.05
Income per share - basic, discontinued operations (in dollars per share)	0	(0.19)	0	(0.04)
Net income per share - basic (in dollars per share)	0.03	(0.17)	0.44	0.01
Earnings Per Share, Diluted [Abstract]
Income per share - diluted, continuing operations (in dollars per share)	0.03	0.02	0.42	0.05
Income per share - diluted, discontinued operations (in dollars per share)	0	(0.18)	0	(0.04)
Net income per share - diluted (in dollars per share)	$ 0.03	$ (0.16)	$ 0.42	$ 0.01
Anti-dilutive employee stock-based awards, excluded (in shares)	1,208	1,014	692	892