Future Policy Benefits Reserves - Narratives (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Insurance [Abstract]
Pretax change in LFPB	$ 7	$ 15
Liability for future policy benefit, expected future gross premium, discounted, before reinsurance	$ 3,600	$ 3,800	$ 3,600	$ 3,800
Liability for future policy benefit, weighted-average duration (in years)	11 years	11 years	11 years	11 years
Liability for future policy benefit, adverse development, expense	$ 65	$ 84	$ 93	$ 128
Liability future policy benefit, losses recognized in prior period	$ 43	$ 20	$ 54	$ 28