Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Loss Contingencies [Line Items]
Undiscounted liability of future guaranty fund assessments	$ 3	$ 1
Future credits to premium taxes	21	10
Possible losses in excess of amounts accrued	25
Amount of previously accrued interest subject to full or partial reversal if cumulative fund performance is not maintained	93
Federal Home Loan Bank Borrowings | Line of Credit
Loss Contingencies [Line Items]
Non-putable funding agreements	1,249	$ 1,175
Purchase of mortgage loans
Loss Contingencies [Line Items]
Amount of purchase commitments	221
Investment purchase commitment
Loss Contingencies [Line Items]
Amount of purchase commitments	1,617
Investment purchase commitment | VOEs
Loss Contingencies [Line Items]
Amount of purchase commitments	$ 415