Business - Ownership Breakdown (Details)	Sep. 30, 2019 Property ApartmentUnit
Property/Unit schedule
Properties | Property	308
Apartment Units | ApartmentUnit	80,299
Wholly Owned Properties
Property/Unit schedule
Properties | Property	290
Apartment Units | ApartmentUnit	76,602
Master-Leased Properties - Consolidated
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	162
Partially Owned Properties - Consolidated
Property/Unit schedule
Properties | Property	17
Apartment Units | ApartmentUnit	3,535