Income Taxes - Schedule of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal - current	$ 1,450	$ 1,646	$ 1,716
Federal - deferred	(164)	(843)	324
Federal income tax expense (benefit), continuing operations	1,286	803	2,040
State - current	198	135	162
State - deferred	(97)	(42)	(17)
State and local income tax expense (benefit), continuing operations	101	93	145
Foreign - current	155	124	175
Foreign - deferred	38	(1,224)	(21)
Foreign income tax expense (benefit), continuing operations	193	(1,100)	154
Income tax expense (benefit)	$ 1,580	$ (204)	$ 2,339

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