Employee Benefits - Derivative Instruments (Details) - Combined Pension Plan - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Exchange-traded U.S. equity futures
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	$ 70	$ 108
Exchange-traded Treasury and other interest rate futures
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	1,256	1,688
Exchange-traded Foreign currency futures
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	2	11
Exchange-traded EURO futures
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	0	5
Interest rate swaps
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	82	127
Credit default swaps
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	139	132
Index swaps
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	90	1,036
Foreign exchange forwards
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	50	93
Options
Defined Benefit Plan Disclosure [Line Items]
Derivative, notional amount	$ 251	$ 654