Condensed Consolidated Balance Sheets Parenthetical - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest	$ 39	$ 30
Available-for-sale Securities, Pledged as Collateral, Debt Securities, Amortized Cost	1,106	1,223
Reinsurance Recoverable, Allowance for Credit Loss	0	0
Allowance for Credit Loss, Receivable, Other, Current	$ 0
Common Stock, Par or Stated Value Per Share	$ 50
Common Stock, Shares Authorized	100,000
Common Stock, Shares, Issued	55,000
Financing Receivable, Allowance for Credit Loss, Current	$ 17	19
Total assets	145,830	131,291
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	$ 21,623	$ 19,743