Income and Other Taxes - Deferred Tax Asset and Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 1986
Deferred Tax Assets And Liabilities [Line Items]
Research and development	$ 150	$ 143
Post-retirement medical benefits	94	98
Net operating losses	377	389
Operating reserves, accruals and deferrals	124	115
Tax credit carryforwards	249	231
Deferred and share-based compensation	13	26
Pension	211	298
Depreciation	35	16
Operating lease liabilities	82	84
Other	44	63
Subtotal	1,379	1,463
Valuation allowance	(396)	(399)
Total	983	1,064
Finance lease and installment sales	247	240
Intangibles and goodwill	140	128
Unremitted earnings of foreign subsidiaries	31	39
Operating lease ROU assets	76	78
Other	16	18
Total	510	503
Total Deferred Taxes, Net	473	561
Deferred tax assets	508	598
Valuation allowance, increase (decrease) in amount	(3)	2	$ (38)
Tax credit carryforwards	249
Carryforwards with no expiration
Deferred Tax Assets And Liabilities [Line Items]
Tax credit carryforwards	2
Deferred tax assets, operating loss carryforwards, not subject to expiration	1,700
Carryforwards that expire
Deferred Tax Assets And Liabilities [Line Items]
Tax credit carryforwards	247
Operating loss carryforwards	600
Other long-term liabilities
Deferred Tax Assets And Liabilities [Line Items]
Deferred tax liabilities	$ (35)	(37)
Accounting Standards Update 2018-05
Deferred Tax Assets And Liabilities [Line Items]
Undistributed Earnings of Foreign Subsidiaries		$ 350		$ 360