Summary of Significant Accounting Policies - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassifications [Line Items]
Property operating expense	$ 41,818	$ 37,852
Gain on sales of properties		23,408
INCOME FROM CONTINUING OPERATIONS	$ 9,180	31,845
Loss from discontinued operations		0
Gain on sales of properties		0
LOSS FROM DISCONTINUED OPERATIONS		0
As Previously Reported
Reclassifications [Line Items]
Property operating expense		37,834
Gain on sales of properties		23,403
INCOME FROM CONTINUING OPERATIONS		31,858
Loss from discontinued operations		(18)
Gain on sales of properties		5
LOSS FROM DISCONTINUED OPERATIONS		$ (13)