Stockholders' Equity Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		$ 25,063	$ 24,555
Amounts Reclassified from Accumulated Other Comprehensive Loss		(146)	7
Other comprehensive (loss) income		(477)	(663)
Ending Balance		24,778	24,079
Accumulated Other Comprehensive Income (Loss), Net of Tax		(3,367)	(3,933)	$ (2,890)
Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Loss) Income, before Reclassifications, Net of Tax		(4)	(2)
Amounts Reclassified from Accumulated Other Comprehensive Loss		12	2
Other comprehensive (loss) income		8	0
Accumulated Other Comprehensive Income (Loss), Net of Tax		(1,425)	(1,247)	(1,433)	$ (1,247)
Other Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Loss) Income, before Reclassifications, Net of Tax		1	3
Amounts Reclassified from Accumulated Other Comprehensive Loss		(158)	0
Other comprehensive (loss) income		(157)	3
Accumulated Other Comprehensive Income (Loss), Net of Tax		433	(78)	590	(81)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Loss) Income, before Reclassifications, Net of Tax	[1]	(403)	(672)
Amounts Reclassified from Accumulated Other Comprehensive Loss		0	0
Other comprehensive (loss) income		(403)	(672)
Accumulated Other Comprehensive Income (Loss), Net of Tax		(2,373)	(2,616)	(1,970)	(1,944)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Loss) Income, before Reclassifications, Net of Tax		71	1
Amounts Reclassified from Accumulated Other Comprehensive Loss		(6)	5
Other comprehensive (loss) income		65	6
Accumulated Other Comprehensive Income (Loss), Net of Tax		(2)	8	(67)	2
Unrealized Gain (loss) on Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(10)	0
Other Comprehensive (Loss) Income, before Reclassifications, Net of Tax		4	0
Amounts Reclassified from Accumulated Other Comprehensive Loss	[2]	6	0
Other comprehensive (loss) income		10	0
Ending Balance		0	0
Total
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(2,890)	(3,270)
Other Comprehensive (Loss) Income, before Reclassifications, Net of Tax		(331)	(670)
Amounts Reclassified from Accumulated Other Comprehensive Loss		(146)	7
Other comprehensive (loss) income		(477)	(663)
Ending Balance		(3,367)	(3,933)
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (3,367)	$ (3,933)	$ (2,890)	$ (3,270)

[1] The cumulative translation adjustment loss for the three months ended March 31, 2020 was primarily driven by the strengthening of the USD against the Brazilian Real (“BRL”) and the South African Rand ("ZAR"). The cumulative translation adjustment loss for the three months ended March 31, 2021 was primarily driven by strengthening of the USD against the Swiss Franc ("CHF"), Brazilian Real ("BRL") and European Euro.

[2] Reflected in other income - net.