Employee Benefit Plans - Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other Postretirement
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 614	$ 769	$ 744
Other Postretirement | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	482	607
Other Postretirement | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	337	437
Other Postretirement | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	145	170
Other Postretirement | Cash equivalents | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	24	16
Other Postretirement | Cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	15	12
Other Postretirement | Cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	9	4
Other Postretirement | U.S. government obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	8	27
Other Postretirement | U.S. government obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	8	27
Other Postretirement | U.S. government obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
Other Postretirement | Corporate obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	52	85
Other Postretirement | Corporate obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
Other Postretirement | Corporate obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	52	85
Other Postretirement | Municipal obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	35	43
Other Postretirement | Municipal obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
Other Postretirement | Municipal obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	35	43
Other Postretirement | Agency, asset and mortgage-backed obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	49	38
Other Postretirement | Agency, asset and mortgage-backed obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
Other Postretirement | Agency, asset and mortgage-backed obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	49	38
Other Postretirement | Equity securities, U.S. companies | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	7	4
Other Postretirement | Equity securities, U.S. companies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	7	4
Other Postretirement | Equity securities, U.S. companies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 0	$ 0
Other Postretirement | Investment funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of funds comprised of equity securities	55.00%	55.00%
Percentage of funds comprised of debt securities	45.00%	45.00%
Percentage of funds invested in United States securities	88.00%	88.00%
Percentage of funds invested in international securities	12.00%	12.00%
Other Postretirement | Investment funds | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 307	$ 394
Other Postretirement | Investment funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	307	394
Other Postretirement | Investment funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
Other Postretirement | Investment funds | NAV
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	132	161
Other Postretirement | Limited partnership interests | NAV
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	1
U.S. | Pension
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	2,013	2,795	2,824
U.S. | Pension | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	1,096	1,412
U.S. | Pension | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	308	277
U.S. | Pension | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	788	1,135
U.S. | Pension | Cash equivalents | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	51	64
U.S. | Pension | Cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
U.S. | Pension | Cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	51	64
U.S. | Pension | U.S. government obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	109	142
U.S. | Pension | U.S. government obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	109	142
U.S. | Pension | U.S. government obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
U.S. | Pension | Corporate obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	613	912
U.S. | Pension | Corporate obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
U.S. | Pension | Corporate obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	613	912
U.S. | Pension | Municipal obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	43	66
U.S. | Pension | Municipal obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
U.S. | Pension | Municipal obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	43	66
U.S. | Pension | Agency, asset and mortgage-backed obligations | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	81	93
U.S. | Pension | Agency, asset and mortgage-backed obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
U.S. | Pension | Agency, asset and mortgage-backed obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	81	93
U.S. | Pension | Equity securities, U.S. companies | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	198	135
U.S. | Pension | Equity securities, U.S. companies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	198	135
U.S. | Pension | Equity securities, U.S. companies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	$ 0
U.S. | Pension | Equity securities, international companies | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	1
U.S. | Pension | Equity securities, international companies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	1
U.S. | Pension | Equity securities, international companies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 0
U.S. | Pension | Investment funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of funds comprised of equity securities	53.00%	54.00%
Percentage of funds comprised of debt securities	47.00%	46.00%
Percentage of funds invested in United States securities	95.00%	89.00%
Percentage of funds invested in international securities	5.00%	11.00%
U.S. | Pension | Investment funds | NAV
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 885	$ 1,349
U.S. | Pension | Limited partnership interests | NAV
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	32	34
United Kingdom | Pension
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	1,363	2,363	$ 2,334
United Kingdom | Pension | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	1,267	2,255
United Kingdom | Pension | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	712	1,313
United Kingdom | Pension | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	341	673
United Kingdom | Pension | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	214	269
United Kingdom | Pension | Cash equivalents | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	30	32
United Kingdom | Pension | Cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	1	5
United Kingdom | Pension | Cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	29	27
United Kingdom | Pension | Cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
United Kingdom | Pension | United Kingdom government | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	711	1,308
United Kingdom | Pension | United Kingdom government | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	711	1,308
United Kingdom | Pension | United Kingdom government | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
United Kingdom | Pension | United Kingdom government | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 0	$ 0
United Kingdom | Pension | Investment funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of funds comprised of equity securities	25.00%	23.00%
Percentage of funds comprised of debt securities	75.00%	77.00%
United Kingdom | Pension | Investment funds | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 312	$ 646
United Kingdom | Pension | Investment funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
United Kingdom | Pension | Investment funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	312	646
United Kingdom | Pension | Investment funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
United Kingdom | Pension | Investment funds | NAV
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	96	108
United Kingdom | Pension | Real estate funds | Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	214	269
United Kingdom | Pension | Real estate funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
United Kingdom | Pension | Real estate funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	0	0
United Kingdom | Pension | Real estate funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value, end of year	$ 214	$ 269