Fair Value - Financial Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Carrying Amount
Assets:
Other invested assets, primarily mortgage loans	$ 1,079	$ 1,019
Liabilities:
Short-term debt	1,051	4
Long-term debt	8,435	8,936
Estimated Fair Value
Assets:
Other invested assets, primarily mortgage loans	1,072	987
Liabilities:
Short-term debt	1,053	5
Long-term debt	8,426	8,668
Estimated Fair Value | Level 1
Assets:
Other invested assets, primarily mortgage loans
Liabilities:
Short-term debt
Long-term debt
Estimated Fair Value | Level 2
Assets:
Other invested assets, primarily mortgage loans
Liabilities:
Short-term debt	1,051
Long-term debt	7,431	7,702
Estimated Fair Value | Level 3
Assets:
Other invested assets, primarily mortgage loans	1,072	987
Liabilities:
Short-term debt	2	5
Long-term debt	$ 995	$ 966