Derivative Financial Instruments - Dealer Counterparties and Central Clearing Parties (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Credit Derivatives [Line Items]
Unsecured positions in a net gain with counterparties after collateral postings	$ 1,341	$ 951
Asset Pledged as Collateral
Credit Derivatives [Line Items]
Pledged securities	38,085	41,270
Dealer and other counterparties:
Credit Derivatives [Line Items]
Cash and other collateral received from counterparties	489	609
Derivatives in a net gain position	468	735
Unsecured positions in a net gain with counterparties after collateral postings	92	126
Cash collateral posted	1,247	960
Derivatives in a net loss position	1,332	1,052
Central counterparties clearing:
Credit Derivatives [Line Items]
Derivatives in a net gain position	12	2
Cash collateral posted	14	14
Derivatives in a net loss position	0	8
Central counterparties clearing: | Asset Pledged as Collateral
Credit Derivatives [Line Items]
Pledged securities	$ 492	$ 1,249