Commitments to Acquire/Dispose of Real Estate - Separate Agreement to Acquire (Details) - Subsequent Event [Member] $ in Thousands	Aug. 02, 2018 USD ($) Property ApartmentUnit
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	372
Purchase Price | $	$ 135,500
Rental Properties Disposed [Member]
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	372
Purchase Price | $	$ 135,500