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Derivative Financial Instruments - Narrative (Details)	3 Months Ended
Derivative Financial Instruments - Narrative (Details)	Mar. 31, 2025 USD ($) counterparty contract	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($) contract
Derivative [Line Items]
Change in fair value of derivatives	$ (223,000,000)	$ 164,000,000
Fair value hedging adjustments for hedged assets	0		$ 0
Fair value hedging adjustments for hedged liabilities	$ 0
Number of counterparties, net exposure threshold set to zero \| counterparty	1
Counterparties, collateral required threshold	0.00%
Derivatives not designated as hedging instruments
Derivative [Line Items]
Change in fair value of derivatives	$ (222,000,000)	164,000,000
Other embedded derivatives
Derivative [Line Items]
Term of contract, term one	1 year
Term of contract, term two	2 years
Term of contract, term three	3 years
Term of contract, term five	5 years
Term of contract, term six	6 years
Other embedded derivatives \| Derivatives not designated as hedging instruments
Derivative [Line Items]
Change in fair value of derivatives	$ 0	3,000,000
Call options and interest rate swaps \| Derivatives for Trading and Investment \| Derivatives not designated as hedging instruments
Derivative [Line Items]
Collateral posted	621,000,000		771,000,000
Net Credit Risk	79,000,000		34,000,000
Call options and interest rate swaps \| Cash and Cash Equivalents \| Derivatives not designated as hedging instruments
Derivative [Line Items]
Collateral posted	$ 544,000,000		$ 679,000,000
Futures contracts
Derivative [Line Items]
Number of instruments held \| contract	472		527
Collateral held	$ 7,000,000		$ 7,000,000
Futures contracts \| Derivatives not designated as hedging instruments
Derivative [Line Items]
Change in fair value of derivatives	$ 5,000,000	$ 6,000,000