Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 22,177	$ 22,984
Net change	(28)	(3)
Ending Balance	22,383	24,449
Tax impact for the changes in each component of accumulated other comprehensive (loss) income
Total tax impact	(32)	16
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(2,945)	(2,895)
Ending Balance	(2,973)	(2,898)
Net Unrealized Gains (Losses) on Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	23	65
Net change	(28)	(12)
Ending Balance	(5)	53
Tax impact for the changes in each component of accumulated other comprehensive (loss) income
Total tax impact	(9)	(3)
Foreign Currency Foreign Currency Translation Adjustment Gains (Losses), net of hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(2,392)	(2,229)
Net change	(20)	(17)
Ending Balance	(2,412)	(2,246)
Net Unrealized Pension and Other Postretirement Benefit Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(576)	(731)
Net change	20	26
Ending Balance	(556)	(705)
Tax impact for the changes in each component of accumulated other comprehensive (loss) income
Total tax impact	7	11
Foreign currency translation adjustment, net of hedges
Tax impact for the changes in each component of accumulated other comprehensive (loss) income
Total tax impact	$ (30)	$ 8