Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
A reconciliation between basic and diluted earnings per share computations
Net income (loss) available to common stockholders	$ 1,745	$ 4,671	$ 9,592	$ 10,043	$ 2,291	$ 383	$ 3,662	$ 2,607	$ 26,051	$ 8,943	$ (137,218)
Net loss available to common stockholders (in shares)									64,204	63,054	62,459
Attributable to participating securities									(855)	(257)
Net income or loss available to common stockholders, Loss (excluding income attributable to participating securities)									25,196	8,686
Net loss available to common stockholders (in dollars per share)	$ 0.03	$ 0.07	$ 0.15	$ 0.15	$ 0.04	$ 0.01	$ 0.06	$ 0.04	$ 0.39	$ 0.14	$ (2.20)
Stock options, effect of dilutive securities, (in shares)									21	154
Attributable to participating securities									(854)	(256)
Restricted stock, effect of dilutive securities (in shares)									0	0	0
DILUTED EPS, Loss									$ 25,197	$ 8,687	$ (137,218)
DILUTED EPS (in shares)									64,225	63,208	62,459
DILUTED EPS, Per Share Amount (in dollars per share)	$ 0.03	$ 0.07	$ 0.15	$ 0.15	$ 0.04	$ 0.01	$ 0.06	$ 0.04	$ 0.39	$ 0.14	$ (2.20)