Earnings Per Share - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator:
Net income attributable to common stockholders – Basic	$ 982	$ 22,407	$ 21,544	$ 22,090	$ 40,523	$ 38,272	$ 30,326	$ 21,258	$ 67,023	$ 130,379	$ 65,387
Net income from continuing operations									67,023	130,379	65,387
Net income from discontinued operations (net of tax)									0	0	0
Net income attributable to common stockholders– Dilutive									$ 67,023	$ 130,379	$ 65,387
Denominator:
Weighted average basic and dilutive shares outstanding (in shares)									108,399	87,867	59,102
EPS:
Basic income per common share (in dollars per share)	$ 0.01	$ 0.20	$ 0.20	$ 0.21	$ 0.42	$ 0.42	$ 0.34	$ 0.29	$ 0.62	$ 1.48	$ 1.11
Basic EPS from continuing operations (in dollars per share)									0.62	1.48	1.11
Basic EPS from discontinued operations (net of tax) (in dollars per share)									0.00	0.00	0.00
Diluted income per common share (in dollars per share)	$ 0.01	$ 0.20	$ 0.20	$ 0.21	$ 0.42	$ 0.42	$ 0.34	$ 0.29	0.62	1.48	1.11
Dilutive EPS from continuing operations (in dollars per share)									0.62	1.48	1.11
Dilutive EPS from discontinued operations (net of tax) (in dollars per share)									$ 0.00	$ 0.00	$ 0.00