Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Basic EPS Two Class Method:
Net Income	$ (292,867)	$ 6,827	$ (769,944)	$ 12,269	$ (283,427)
Income, share amounts	44,516	43,826	44,374	43,727
Earnings Per Share, Basic	$ (6.58)	$ 0.16	$ (17.35)	$ 0.28
Dilutive Securities:
Dilutive RSA's, Shares	0	429	0	424
Dilutive RSU's, Shares	0	57	0	64
Diluted EPS:
Net Income (Loss) Available to Common Stockholders, Diluted	$ (292,867)	$ 6,827	$ (769,944)	$ 12,269
Weighted Average Number of Shares Outstanding, Diluted	44,516	44,312	44,374	44,215
Earnings Per Share, Diluted	$ (6.58)	$ 0.15	$ (17.35)	$ 0.28
Stock Options [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	1,300	1,400	1,300	1,500
Restricted Stock [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	700	300	700	300
Restricted Stock Units (RSUs) [Member]
Earnings Per Share (Textual)
Contingently Issuable Shares Not Included in Diluted EPS	1,200	700	1,200	700