Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net Loss
Loss from continuing operations	$ (7,386)	$ (6,700)
Income from discontinued operations	0	1,097
Net loss	$ (7,386)	$ (5,603)
Basic Earnings (Loss) per Common Share
Weighted-average common shares outstanding (in shares)	61,686	61,331
Continuing operations (in dollars per share)	$ (0.12)	$ (0.11)
Discontinued operations (in dollars per share)	0.00	0.02
Basic earnings per common share (in dollars per share)	$ (0.12)	$ (0.09)
Diluted Earnings (Loss) per Common Share
Weighted-average common and common equivalent shares outstanding (in shares)	61,686	61,331
Continuing operations (in dollars per share)	$ (0.12)	$ (0.11)
Discontinued operations (in dollars per share)	0.00	0.02
Diluted earnings per common share (in dollars per share)	$ (0.12)	$ (0.09)
Computation of Shares Used in Earnings (Loss) Per Common Share
Weighted-average common shares outstanding (in shares)	61,686	61,331
Weighted-average common equivalent shares - dilutive effect of stock options and awards (in shares)	0	0
Weighted-average common and common equivalent shares outstanding (in shares)	61,686	61,331
Stock Options
Stock-based compensation arrangement by stock-based payment award
Weighted-average anti-dilutive shares have been excluded from the EPS calculations (in shares)	3,600	4,400
Unvested Shares
Stock-based compensation arrangement by stock-based payment award
Weighted-average anti-dilutive shares have been excluded from the EPS calculations (in shares)	900	900