Real Estate - Disposed Properties to Unaffiliated Parties (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($) Property ApartmentUnit
Properties disposed | Property	4
Property Units disposed | ApartmentUnit	1,506
Sales Price | $	$ 797,250
Rental Properties - Consolidated [Member]
Properties disposed | Property	2
Property Units disposed | ApartmentUnit	561
Sales Price | $	$ 402,750
Rental Properties - Unconsolidated [Member]
Properties disposed | Property	2
Property Units disposed | ApartmentUnit	945
Sales Price | $	$ 394,500