Real Estate and Lease Intangibles - Real Estate Acquisitions and Dispositions (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) Property ApartmentUnit
Properties acquired | Property	5
Property Units acquired | ApartmentUnit	1,478
Purchase Price	$ 707,005
Properties disposed | Property	5
Property Units disposed | ApartmentUnit	1,292
Sales Price	$ 708,820
Rental Properties - Consolidated [Member]
Properties acquired | Property	5
Property Units acquired | ApartmentUnit	1,478
Purchase Price	$ 707,005
Properties disposed | Property	5
Property Units disposed | ApartmentUnit	1,292
Sales Price	$ 706,120
Land [Member]
Purchase Price	113,700
Sales Price	$ 2,700