Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net loss
Loss from continuing operations	$ (2,480)	$ (4,285)	$ (12,519)	$ (16,886)
Income from discontinued operations	0	1,244	0	3,980
Net loss	$ (2,480)	$ (3,041)	$ (12,519)	$ (12,906)
Basic earnings (loss) per common share
Weighted-average common shares outstanding (in shares)	62,012	61,543	61,866	61,445
Continuing operations (in dollars per share)	$ (0.04)	$ (0.07)	$ (0.20)	$ (0.27)
Discontinued operations (in dollars per share)	0.00	0.02	0.00	0.06
Basic earnings per common share (in dollars per share)	$ (0.04)	$ (0.05)	$ (0.20)	$ (0.21)
Diluted earnings (loss) per common share
Weighted-average common and common equivalent shares outstanding (in shares)	62,012	61,543	61,866	61,445
Continuing operations (in dollars per share)	$ (0.04)	$ (0.07)	$ (0.20)	$ (0.27)
Discontinued operations (in dollars per share)	0.00	0.02	0.00	0.06
Diluted earnings per common share (in dollars per share)	$ (0.04)	$ (0.05)	$ (0.20)	$ (0.21)
Computation of shares used in earnings (loss) per common share
Weighted-average common shares outstanding (in shares)	62,012	61,543	61,866	61,445
Weighted-average common equivalent shares - dilutive effect of stock options and awards (in shares)	0	0	0	0
Weighted-average common and common equivalent shares outstanding (in shares)	62,012	61,543	61,866	61,445
Stock Options
Stock-based compensation
Weighted-average anti-dilutive shares have been excluded from the EPS calculations (in shares)	2,800	4,100	3,100	4,200
Unvested Shares
Stock-based compensation
Weighted-average anti-dilutive shares have been excluded from the EPS calculations (in shares)	1,700	1,300	1,100	1,100