Debt - Fair Value (Details) $ in Millions	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Fixed rate mortgages and unsecured indebtedness | Book value
Fair Value of Debt
Fair value of consolidated fixed rate mortgages and unsecured indebtedness	$ 25,200	$ 25,600
Fixed rate mortgages and unsecured indebtedness | Fair value
Fair Value of Debt
Fair value of consolidated fixed rate mortgages and unsecured indebtedness	$ 24,279	$ 24,248
Discount Rate | Weighted average | Fixed rate mortgages
Fair Value of Debt
Debt percentage- measurement input	0.0570	0.0610
Discount Rate | Weighted average | Unsecured Debt
Fair Value of Debt
Debt percentage- measurement input	0.0587	0.0610