Stockholders' Equity - Computation of basic and diluted earnings (loss) per common share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Weighted average Common Shares outstanding
Weighted average Common Shares outstanding	102,634,273	99,467,804
Nonvested shares	(1,202,185)	(1,107,846)
Weighted average Common Shares—Basic	101,432,088	98,359,958
Dilutive effect of restricted stock	601,509	615,511
Dilutive effect of employee stock purchase plan	131,221	161,428
Weighted average Common Shares outstanding—Diluted	102,164,818	99,136,897
Net Income (Loss)
Income from continuing operations	$ 9,163	$ 5,049
Discontinued operations	(7)	333
NET INCOME	$ 9,156	$ 5,382
Basic Earnings (Loss) Per Common Share
Income from continuing operations (in dollars per share)	$ 0.09	$ 0.05
Discontinued operations (in dollars per share)	0.00	0.00
Net income (in dollars per share)	0.09	0.05
Diluted Earnings (Loss) Per Common Share
Income from continuing operations (in dollars per share)	0.09	0.05
Discontinued operations (in dollars per share)	0.00	0.00
Net income (in dollars per share)	$ 0.09	$ 0.05