Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Per Common Share - Basic:
Net income	$ 3,782	$ 6,882	$ 10,954	$ 15,403
Weighted-average common shares outstanding	44,182	44,112	44,182	44,102
Basic income per share (in dollars per share)	$ 0.09	$ 0.16	$ 0.25	$ 0.35
Income Per Common Share - Diluted:
Net income	$ 3,782	$ 6,882	$ 10,954	$ 15,403
Weighted-average common shares outstanding	44,182	44,112	44,182	44,102
Weighted-average incremental shares related to vesting of nonvested shares	33	141	46	154
Weighted-average common shares outstanding and common share equivalents	44,215	44,253	44,228	44,256
Diluted income per share (in dollars per share)	$ 0.09	$ 0.16	$ 0.25	$ 0.35