Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Basic EPS Two Class Method:
Net income (loss)	$ (354,588)	$ 2,474	$ (1,124,532)	$ 14,743	$ (283,427)
Income, share amounts	44,546	43,850	44,431	43,768
Earnings Per Share, Basic	$ (7.96)	$ 0.06	$ (25.31)	$ 0.34
Dilutive Securities:
Dilutive RSA's, Shares	0	564	0	469
Dilutive RSU's, Shares	0	59	0	62
Diluted EPS:
Net Income (Loss) Available to Common Stockholders, Diluted	$ (354,588)	$ 2,474	$ (1,124,532)	$ 14,743
Weighted Average Number of Shares Outstanding, Diluted	44,546	44,473	44,431	44,299
Earnings Per Share, Diluted	$ (7.96)	$ 0.06	$ (25.31)	$ 0.33
Stock Options [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	1,300	1,400	1,300	1,400
Restricted Stock [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	1,000	200	800	300
Restricted Stock Units (RSUs) [Member]
Earnings Per Share (Textual)
Contingently Issuable Shares Not Included in Diluted EPS	1,200	700	1,200	700