Future Contract Benefits (Summary of Discounted and Undiscounted Expected Future Gross Premiums and Expected Future Benefit Payments) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Traditional Life [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Expected future benefit payments, undiscounted	$ 13,257	$ 13,166
Expected future gross premiums, undiscounted	13,171	13,026
Expected future gross premiums, discounted	9,172	8,887
Expected future benefit payments, discounted	9,417	9,086
Group Protection [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Expected future benefit payments, undiscounted	7,086	7,063
Expected future benefit payments, discounted	6,061	6,059
Payout Annuities [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Expected future gross premiums, undiscounted	3,460	3,471
Expected future benefit payments, discounted	$ 2,067	$ 2,003