Earnings Per 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
A reconciliation between basic and diluted earnings per share computations
Income (loss) available to common stockholders	$ (61,083)	$ 9,592	$ (183,323)	$ 19,635
Attributable to participating securities		(273)		(571)
Net income or loss available to common stockholders, Loss (excluding income attributable to participating securities)	$ (61,083)	$ 9,319	$ (183,323)	$ 19,064
Net loss available to common stockholders (in shares)	64,891	64,103	64,833	63,940
Stock options, Effect of dilutive securities		$ 0		$ 0
Net loss available to common stockholders, Per Share Amount	$ (0.94)	$ 0.15	$ (2.83)	$ 0.30
Stock options, effect of dilutive securities, (in shares)		64		56
Attributable to participating securities		$ (273)		$ (571)
Restricted stock, effect of dilutive securities (in shares)	0	0	0	0
DILUTED EPS, Loss	$ (61,083)	$ 9,319	$ (183,323)	$ 19,064
DILUTED EPS, Shares	64,891	64,167	64,833	63,996
DILUTED EPS, Per Share Amount	$ (0.94)	$ 0.15	$ (2.83)	$ 0.30