Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
A reconciliation between basic and diluted earnings per share computations
Income (loss) available to common stockholders	$ (51,910)	$ 4,671	$ (235,233)	$ 24,306
Attributable to participating securities		(123)		(649)
Net income (loss) available to common stockholders, Loss (excluding income attributable to participating securities)	$ (51,910)	$ 4,548	$ (235,233)	$ 23,657
Net income (loss) available to common stockholders (in shares)	65,035	64,265	64,901	64,073
Stock options, Effect of dilutive securities		$ 0		$ 0
Net income (loss) available to common stockholders, Per Share Amount	$ (0.80)	$ 0.07	$ (3.62)	$ 0.37
Stock options, effect of dilutive securities, (in shares)		87		55
Attributable to participating securities		$ (123)		$ (649)
Restricted stock, effect of dilutive securities (in shares)	0	0	0	0
DILUTED EPS, Income (Loss)	$ (51,910)	$ 4,548	$ (235,233)	$ 23,657
DILUTED EPS, Shares	65,035	64,352	64,901	64,128
DILUTED EPS, Per Share Amount	$ (0.80)	$ 0.07	$ (3.62)	$ 0.37