Stockholders' Equity Reclassifications out of AOCI (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive Loss		$ (146)	$ 7
Other Benefit Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of Prior Service Benefit	[1],[2]	(230)	0
Pension Plan
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive Loss		12	2
Other Benefit Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive Loss		(158)	0
Derivative Instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, before Tax	[3]	(5)	7
Reclassification from Accumulated Other Comprehensive Loss, Current Period, Tax	[4]	(1)	(2)
Amounts Reclassified from Accumulated Other Comprehensive Loss		(6)	5
Actuarial (Gains) Losses | Pension Plan
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, before Tax	[1],[2]	14	1
Actuarial (Gains) Losses | Other Benefit Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, before Tax	[1],[2]	23	0
Settlement Loss | Pension Plan
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, before Tax	[1],[2]	1	2
Accumulated Defined Benefit Plans Adjustment Attributable to Parent | Pension Plan
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, before Tax		15	3
Reclassification from Accumulated Other Comprehensive Loss, Current Period, Tax	[4]	(3)	(1)
Amounts Reclassified from Accumulated Other Comprehensive Loss		12	2
Accumulated Defined Benefit Plans Adjustment Attributable to Parent | Other Benefit Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, before Tax		(207)	0
Reclassification from Accumulated Other Comprehensive Loss, Current Period, Tax	[4]	49	0
Amounts Reclassified from Accumulated Other Comprehensive Loss		(158)	0
Unrealized loss on investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Loss, Current Period, Tax	[4]	0	0
Amounts Reclassified from Accumulated Other Comprehensive Loss	[1]	$ 6	$ 0

[1] Reflected in other income - net.

[2] These accumulated other comprehensive (loss) income components are included in the computation of net periodic benefit credit of the company's pension and other benefit plans. See Note 15 - Pension Plans and Other Post Employment Benefits, for additional information.

[3] Reflected in cost of goods sold.

[4] Reflected in provision for (benefit from) income taxes from continuing operations.