Future Contract Benefits - Summary of Reconciliation of Future Contract Benefits (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	$ 42,128	$ 40,002
Other
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	3,334	3,241
Payout Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	2,052	2,008	$ 2,118
Traditional Life
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	3,503	3,504	$ 3,660
Group Protection
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	5,794	5,628
UL and Other
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	18,285	16,663
Other Operations [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	9,160	8,958
Other Operations [Member] | Protective
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	5,400	5,400
Other Operations [Member] | Swiss Re
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	$ 1,900	$ 1,700