Debt - Fair Value (Details) $ in Millions	Jun. 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	$ 25,000	$ 25,600
Fixed rate mortgages and unsecured indebtedness | Fair value
Fair Value of Debt
Fair value of consolidated fixed rate mortgages and unsecured indebtedness	$ 23,131	$ 24,248
Discount Rate | Weighted average | Fixed rate mortgages
Fair Value of Debt
Debt percentage- measurement input	0.0656	0.0610
Discount Rate | Weighted average | Unsecured Debt
Fair Value of Debt
Debt percentage- measurement input	0.0658	0.0610