Summary of Significant Accounting Policies - Impact of Adoption of New Accounting Standard (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Rental income	$ 110,229	$ 102,709
Other operating	1,895	1,935
Revenues	112,124	104,644
Interest and other income, net	493	38
NET INCOME	$ 9,180	31,845
Adjustments for New Accounting Pronouncement
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Rental income		102,709
Other operating		1,935
Revenues		104,644
Interest and other income, net		38
NET INCOME		31,845
Adjustments for New Accounting Pronouncement | As Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Rental income		104,088
Other operating		481
Revenues		104,569
Interest and other income, net		113
NET INCOME		$ 31,845