Derivative Instruments and Hedging Activities - Incremental Collateral and Termination Payments upon Potential Future Ratings Downgrade (Details) $ in Millions	Sep. 30, 2024 USD ($)
Bilateral Downgrade Agreement
Derivatives
Incremental collateral or termination payments upon potential future ratings downgrade	$ 543
One-notch downgrade
Derivatives
Incremental collateral or termination payments upon potential future ratings downgrade	213
Two-notch downgrade
Derivatives
Incremental collateral or termination payments upon potential future ratings downgrade	$ 458