Earnings Per Share , Calculation of Numerator and Denominator (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator
Basic earnings: net income attributable to common stockholders									$ 17,369	$ 137,325	$ 22,376
Income (loss) Attributable to Common Stockholders Allocable To Non Vested Restricted Shares									115	(1,757)	(127)
Net income attributable to common shareholders after restricted stock allocation									17,484	135,568	22,249
Allocation of income to restricted stock awards									(115)	0	127
Amounts attributable to Seris A-4 Preferred Stock									0	0	76
Diluted earnings: net income attributable to common stockholders after allocation									$ 17,369	$ 135,568	$ 22,452
Denominator
Weighted average common shares outstanding									65,856	53,686	41,337
Add: dilutive stock options									8	16	16
Add: dilutive restricted stock									457	0	237
Add: dilutive Series A-4 Preferred Stock									0	0	215
Diluted weighted average common shares and securities									66,321	53,702	41,805
Basic	$ (0.02)	$ 0.27	$ (0.12)	$ 0.14	$ 1.57	$ 0.53	$ 0.23	$ 0.13	$ 0.27	$ 2.53	$ 0.54
Diluted	$ (0.02)	$ 0.27	$ (0.12)	$ 0.14	$ 1.56	$ 0.53	$ 0.23	$ 0.13	$ 0.26	$ 2.52	$ 0.54