Other Contract Holder Funds - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2026	Dec. 31, 2025
Policyholder Account Balance [Line Items]
Debt carrying value	$ 2,027	$ 2,030
FHLBI capital stock	119	119
Funding agreements	1,900	1,900
Other borrowings on mortgage-related securities and commercial mortgage loans	$ 2,800	$ 2,800
All Annuity Accounts \| At Guaranteed Minimum
Policyholder Account Balance [Line Items]
Account values, percentage	92.00%	93.00%
Closed Block Life \| At Guaranteed Minimum
Policyholder Account Balance [Line Items]
Account values, percentage	82.00%	82.00%
Fair Value
Policyholder Account Balance [Line Items]
FHLBI capital stock	$ 119	$ 119
FABN funding agreements \| Medium term notes
Policyholder Account Balance [Line Items]
Debt maximum issuable amount	4,100
Debt carrying value	7,500	$ 8,000
Agreement-Backed Commercial Paper Program
Policyholder Account Balance [Line Items]
Commercial paper	1,300
Agreement-Backed Commercial Paper Program \| Commercial Paper
Policyholder Account Balance [Line Items]
Debt face amount	$ 3,000

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