Business - Ownership Breakdown (Details)	Jun. 30, 2017 Property ApartmentUnit
Property/Unit schedule
Properties | Property	301
Apartment Units | ApartmentUnit	77,034
Wholly Owned Properties
Property/Unit schedule
Properties | Property	279
Apartment Units | ApartmentUnit	72,021
Master-Leased Properties – Consolidated
Property/Unit schedule
Properties | Property	3
Apartment Units | ApartmentUnit	853
Partially Owned Properties – Consolidated
Property/Unit schedule
Properties | Property	17
Apartment Units | ApartmentUnit	3,215
Partially Owned Properties – Unconsolidated
Property/Unit schedule
Properties | Property	2
Apartment Units | ApartmentUnit	945