Benefit Plans (Fair Value of Plan Assets Measured on a Recurring Basis) (Details) - Pension Benefits - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 2,025	$ 2,577	$ 2,420
Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,025	2,577
Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,470	1,719
Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	363	777
Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,091	934
Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	8
Fair Value Measured at Net Asset Value Per Share | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	534	838
Fair Value Measured at Net Asset Value Per Share | Fair Value, Recurring | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21	20
Total fixed maturity securities | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,081	793
Total fixed maturity securities | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Total fixed maturity securities | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,065	785
Total fixed maturity securities | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	8
Corporate and other bonds | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	866	653
Corporate and other bonds | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate and other bonds | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	859	645
Corporate and other bonds | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	8
States, municipalities and political subdivisions | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49	30
States, municipalities and political subdivisions | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
States, municipalities and political subdivisions | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49	30
States, municipalities and political subdivisions | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Asset-backed | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	166	110
Asset-backed | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Asset-backed | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	157	110
Asset-backed | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9	0
Equity securities | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	231	873
Equity securities | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	218	732
Equity securities | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13	141
Equity securities | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short term investments | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	146	45
Short term investments | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	145	45
Short term investments | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	0
Short term investments | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other assets | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	8
Other assets | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other assets | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	8
Other assets | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash | Total | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash | Level 1 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash | Level 2 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash | Level 3 | Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0