Earnings Per Common Share (Basic and Diluted EPS) (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
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Income (loss) attributable to common stockholders									$ 30,880	$ (4,831)	$ 94,032
Weighted average common shares outstanding, basic (in shares)									66,055	41,260	38,828
Weighted average common shares outstanding, diluted (in shares)									66,609	41,260	39,291
Basic EPS
Net income (loss) per share (in dollars per share)	$ 0.16	$ 0.14	$ 0.27	$ (0.10)	$ (0.16)	$ 0.10	$ 0.05	$ (0.09)	$ 0.47	$ (0.12)	$ 2.42
Diluted EPS
Net income (loss) per share (in dollars per share)	$ 0.16	$ 0.14	$ 0.27	$ (0.10)	$ (0.16)	$ 0.10	$ 0.05	$ (0.09)	$ 0.46	$ (0.12)	$ 2.39
Restricted Stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities									207	0	463
Restricted stock units [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities									129	0	0
Stock options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities									218	0	0