Accumulated Other Comprehensive Loss (Components of Accumulated Other Comprehensive Loss in the Equity Section of the Balance Sheet) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 29,849		$ 32,064
Ending Balance	45,406	$ 29,849
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		35,050
Ending Balance			35,050
Accounting Standards Update 201802 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		0
Ending Balance			0
Accum Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(5,218)		(6,063)
Other comprehensive income (loss)	268	139	746
Ending Balance	(4,950)	(5,218)
Accum Other Comprehensive Income (Loss) [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(5,357)
Ending Balance			(5,357)
Accum Other Comprehensive Income (Loss) [Member] | Accounting Standards Update 201802 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(40)
Ending Balance			(40)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(425)		(361)
Other comprehensive income (loss)	394	(75)	51
Ending Balance	(31)	(425)
Defined Benefit Plans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(350)
Ending Balance			(350)
Defined Benefit Plans [Member] | Accounting Standards Update 201802 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		0
Ending Balance			0
Net Unrealized Gain/(Loss) on Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	2		0
Other comprehensive income (loss)	(2)	2	0
Ending Balance	0	2
Net Unrealized Gain/(Loss) on Securities [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		0
Ending Balance			0
Net Unrealized Gain/(Loss) on Securities [Member] | Accounting Standards Update 201802 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		0
Ending Balance			0
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(4,795)		(5,702)
Other comprehensive income (loss)	(124)	212	695
Ending Balance	$ (4,919)	(4,795)
Foreign Currency Translation [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(5,007)
Ending Balance			(5,007)
Foreign Currency Translation [Member] | Accounting Standards Update 201802 [Member] | Cumulative Effect Period Of Adoption Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		$ (40)
Ending Balance			$ (40)