Earnings Per Common Share (Reconciliation of Earnings (loss) Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator (both basic and diluted)
Net loss	$ (34,620)	$ (17,540)	$ (92,310)	$ (106,840)
Denominator
Weighted-average shares (denominator for basic earnings per share)	64,905	64,449	64,755	64,262
Diluted effect of outstanding stock options, restricted stock and restricted stock unit awards	0	0	0	0
Denominator for diluted earnings per share	64,905	64,449	64,755	64,262
Loss per common share - Basic	$ (0.53)	$ (0.27)	$ (1.43)	$ (1.66)
Loss per common share - Diluted	$ (0.53)	$ (0.27)	$ (1.43)	$ (1.66)
Stock Compensation Plan [Member]
Denominator
Potentially dilutive securities excluded as anti-dilutive	4,550	5,273	4,985	4,862