Debt - Fair Value (Details) $ in Millions	Sep. 30, 2022 USD ($) item	Dec. 31, 2021 USD ($) item
Fixed rate mortgages and unsecured indebtedness | Book value
Fair Value of Debt
Fair value of consolidated fixed rate mortgages and unsecured indebtedness | $	$ 23,200	$ 23,300
Fixed rate mortgages and unsecured indebtedness | Fair value
Fair Value of Debt
Fair value of consolidated fixed rate mortgages and unsecured indebtedness | $	$ 20,170	$ 24,597
Discount Rate | Weighted average | Fixed rate mortgages
Fair Value of Debt
Debt percentage- measurement input | item	0.0606	0.0317
Discount Rate | Weighted average | Unsecured Debt
Fair Value of Debt
Debt percentage- measurement input | item	0.0577	0.0333