Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total Other comprehensive income (loss), net of tax		$ (321)	$ 33
Cumulative translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), pretax		(320)	27
Total Other comprehensive income (loss), net of tax		(339)	21
Retirement plans and other retiree benefits adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, pretax		2	(1)
Reclassification from AOCI, pretax		17	17
Other comprehensive income (loss), pretax		19	16
Other comprehensive income (loss), before reclassifications, net of tax		1	(1)
Reclassification from AOCI, net of tax		15	13
Total Other comprehensive income (loss), net of tax		16	12
Gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, pretax		25	(2)
Reclassification from AOCI, pretax		(3)	(4)
Other comprehensive income (loss), pretax		22	(6)
Other comprehensive income (loss), before reclassifications, net of tax		20	(2)
Reclassification from AOCI, net of tax		(2)	(3)
Total Other comprehensive income (loss), net of tax		18	(5)
Total Other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), pretax		(279)	37
Total Other comprehensive income (loss), net of tax	[1]	$ (305)	$ 28

[1] Accumulated other comprehensive income (loss) includes cumulative translation losses of $3,467 at March 31, 2020 ($3,134 at March 31, 2019) and $3,128 at December 31, 2019 ($3,155 at December 31, 2018), respectively, and unrecognized retirement plan and other retiree benefits costs of $1,122 at March 31, 2020 ($1,026 at March 31, 2019) and $1,138 at December 31, 2019 ($1,038 at December 31, 2018), respectively.