Future Contract Benefits - Summary of Changes in Present Values of LFPB (Group Protection) (Details) - Group Protection - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025	Dec. 31, 2024
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	$ 5,836	$ 5,628
Less: Effect of cumulative changes in discount rate assumptions			$ (363)	$ (550)
Beginning balance of original discount rate	6,199	6,178
Effect of actual variances from expected experience			$ (111)	$ (178)
Adjusted balance as of beginning-of-year	6,088	6,000
New incidence	753	808
Interest	108	100
Benefit payments	(748)	(724)
Ending balance at original discount rate	6,201	6,184
Effect of cumulative changes in discount rate assumptions	(420)	(425)
Balance as of end-of-period	5,781	5,759
Less: Reinsurance recoverables	3,526	3,439
Net balance as of end-of-period, net of reinsurance	$ 2,255	$ 2,320
Weighted-average duration of future policyholder benefit liability (years)	5 years	5 years