Debt - Fair Value (Details) $ in Millions	Jun. 30, 2023 USD ($) item	Dec. 31, 2022 USD ($) item
Fixed rate mortgages and unsecured indebtedness | Book value
Fair Value of Debt
Fair value of consolidated fixed rate mortgages and unsecured indebtedness | $	$ 24,300	$ 22,600
Fixed rate mortgages and unsecured indebtedness | Fair value
Fair Value of Debt
Fair value of consolidated fixed rate mortgages and unsecured indebtedness | $	$ 21,915	$ 20,020
Discount Rate | Weighted average | Fixed rate mortgages
Fair Value of Debt
Debt percentage- measurement input | item	0.0637	0.0610
Discount Rate | Weighted average | Unsecured Debt
Fair Value of Debt
Debt percentage- measurement input | item	0.0616	0.0587