Future Contract Benefits - Summary of Reconciliation of Future Contract Benefits (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	$ 39,212	$ 40,174
Other
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	3,290	3,343
Payout Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	2,034	2,084	$ 2,067
Traditional Life
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	3,518	3,553	$ 3,366
Group Protection
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	5,640	5,689
UL and Other
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	15,234	15,752
Other Operations
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	9,496	9,753
Other Operations | Protective
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	5,500	5,600
Other Operations | Swiss Re
Liability for Future Policy Benefit, Activity [Line Items]
Future contract benefits	$ 2,000	$ 2,100