Revenues - Summary of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Rental revenue	$ 182,616	$ 177,679
Fee income:
Total fee income	5,999	3,465
Other income	3,177	3,127
Total fee and other income	9,176	6,592
Total revenues	191,792	184,271
Property Management Fees [Member]
Fee income:
Total fee income	1,642	1,502
Asset Management Fees [Member]
Fee income:
Total fee income	2,318	1,610
Acquisition, Disposition and Leasing Fee [Member]
Fee income:
Total fee income	1,331
Other Fee Income [Member]
Fee income:
Total fee income	$ 708	$ 353