Income Taxes - Income from continuing operations before income tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income (loss) before income taxes:
Income before income taxes	$ 3,169	$ 3,156	$ 1,931
Current:
Total current tax expense	914	762	612
Deferred tax expense (benefit):
Total deferred tax expense (benefit)	(373)	(252)	11
Total income tax expense	541	510	623
Domestic Tax Authority
Income (loss) before income taxes:
Income before income taxes	31	85	15
Current:
Total current tax expense	4	2	2
Deferred tax expense (benefit):
Total deferred tax expense (benefit)	0	0	(1)
Foreign Tax Authority | U.K.
Income (loss) before income taxes:
Income before income taxes	338	502	549
Current:
Total current tax expense	185	206	50
Deferred tax expense (benefit):
Total deferred tax expense (benefit)	(116)	(152)	131
Foreign Tax Authority | U.S.
Income (loss) before income taxes:
Income before income taxes	219	161	(818)
Current:
Total current tax expense	240	195	197
Deferred tax expense (benefit):
Total deferred tax expense (benefit)	(126)	(69)	(83)
State and Local Jurisdiction | U.S.
Current:
Total current tax expense	74	43	72
Deferred tax expense (benefit):
Total deferred tax expense (benefit)	(39)	(21)	(30)
Other
Income (loss) before income taxes:
Income before income taxes	2,581	2,408	2,185
Current:
Total current tax expense	411	316	291
Deferred tax expense (benefit):
Total deferred tax expense (benefit)	$ (92)	$ (10)	$ (6)