Commitments and Contingencies (Details) $ in Millions		12 Months Ended
	Jan. 04, 2019 USD ($)	Dec. 31, 2018 USD ($) shares	Dec. 31, 2016 USD ($)	Sep. 30, 2025 USD ($)	Oct. 16, 2023 USD ($)	Sep. 30, 2023 USD ($)	Oct. 16, 2021 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2017
Loss Contingencies [Line Items]
Settlement amount		$ 0.4
Reserves for warranties and general liability		3.1						$ 3.3
Payments from reserves		1.4
Letters of credit outstanding, amount		$ 1.3
DownREIT operating partnership units, outstanding | shares		738,423
Operating partnership units outstanding, fair value		$ 87.2
Congressional Plaza | Put Option
Loss Contingencies [Line Items]
Maximum partnership percentage required to purchase		100.00%
Indexed ownership interest percentage		26.63%
Congressional Plaza | Put Option | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 78.0
Congressional Plaza | Put Option | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		83.0
Montrose Crossing | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		13.0
Montrose Crossing | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 14.0
Montrose Crossing | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		10.10%
Plaza El Segundo | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 23.0
Plaza El Segundo | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 26.0
Plaza El Segundo | Put Option
Loss Contingencies [Line Items]
Number of members with purchase options		2
The Grove at Shrewsbury | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage									4.80%
Brook 35 | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage									8.80%
Grove at Shrewsbury and Brook 35 | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 9.0
Grove at Shrewsbury and Brook 35 | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		10.0
Scenario, Forecast | Mercer Mall
Loss Contingencies [Line Items]
Purchase price under option						$ 55.0
Scenario, Forecast | Mercer Mall | Put Option
Loss Contingencies [Line Items]
Purchase price under option				$ 60.0
Scenario, Forecast | Melville Mall
Loss Contingencies [Line Items]
Purchase price under option					$ 5.0		$ 5.0
Capital improvement, development, and redevelopment projects
Loss Contingencies [Line Items]
Contractual obligations		$ 568.2
Member One In Plaza El Segundo | Plaza El Segundo | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		10.00%
Member Two In Plaza El Segundo | Plaza El Segundo | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		11.80%
Santana Row | gain on sale of real estate
Loss Contingencies [Line Items]
Reversal of warranty reserve			$ 4.9
Pending Litigation
Loss Contingencies [Line Items]
Potential remaining liability (less than)		$ 0.1
Subsequent Event | Brook 35
Loss Contingencies [Line Items]
Indexed ownership interest percentage	6.50%
Payments acquire noncontrolling interests	$ 0.8