Earnings Per Share Calculation of Basic and Diluted EPS (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
Earnings Per Share [Abstract]
Net income (loss), as reported	$ 145,765	$ 27,858	$ (4,705)	$ 61,010
Less: Dividends distributed to Warrants	40	77	127	249
Less: Undistributed earnings allocated to Warrants	218	91	0	679
Net income (loss) attributable to common shareholders for basic EPS	145,507	27,690	(4,832)	60,082
Add: Undistributed earnings allocated to dilutive securities	1	0	0	2
Net income (loss) attributable to common shareholders for diluted EPS	$ 145,508	$ 27,690	$ (4,832)	$ 60,084
Weighted average shares outstanding - basic (shares)	89,950	94,437	91,367	95,060
Impact of dilutive securities (shares)	503	75	0	214
Weighted average shares outstanding - diluted (shares)	90,453	94,512	91,367	95,274
Basic (usd per share)	$ 1.62	$ 0.29	$ (0.05)	$ 0.63
Diluted (usd per share)	$ 1.61	$ 0.29	$ (0.05)	$ 0.63