Accrued and Other Liabilities - Schedule of Changes in Accrued and Other Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accrued Liabilities and Other Liabilities [Roll Forward]
Beginning balance	$ 4,154	$ 5,473	$ 6,014
Income attributable to noncontrolling interests	15,375	5,218	9,054
Distributions to noncontrolling interests	(8,865)	(7,772)	(9,503)
Other	366	1,235	(92)
Ending balance	$ 11,030	$ 4,154	$ 5,473