Net Income (Loss) Per Share and Equity - Narratives (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Distributions Declared
Interest expense	$ 11,791	$ 10,320	$ 23,244	$ 20,680
Dividends payment			Jul. 14, 2017
Distributions payable	21,396		$ 21,396		$ 20,995
Class A
Distributions Declared
Interest expense	$ 100	$ 100	$ 200	$ 200
Distributions declared per share (in dollars per share)	$ 0.1563	$ 0.1563	$ 0.3126	$ 0.3126
Aggregate distributions declared			$ 34,100
Class C
Distributions Declared
Distributions declared per share (in dollars per share)	$ 0.1382	$ 0.1376	$ 0.2762	$ 0.2713
Aggregate distributions declared			$ 8,500