Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ (3,672)	$ 2,324	$ 2,231	$ 2,106
Other comprehensive income (loss) before reclassifications, net	21	(81)	(69)	(112)
Amounts reclassified, pre-tax	4	2	11	7
Tax (benefit) expense reclassified	(1)		(3)
Ending balance	(3,481)	2,316	(3,481)	2,316
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(676)	(578)	(588)	(573)
Other comprehensive income (loss) before reclassifications, net	15	(78)	(73)	(83)
Amounts reclassified, pre-tax	0	0	0	0
Tax (benefit) expense reclassified	0		0
Ending balance	(661)	(656)	(661)	(656)
Defined Benefit Pension and Post-retirement Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(163)	(154)	(167)	(135)
Other comprehensive income (loss) before reclassifications, net	0	0	(1)	(24)
Amounts reclassified, pre-tax	4	2	11	7
Tax (benefit) expense reclassified	(1)		(3)
Ending balance	(160)	(152)	(160)	(152)
Unrealized hedging (losses) gains
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(4)	(2)	(3)	0
Other comprehensive income (loss) before reclassifications, net	6	(3)	5	(5)
Amounts reclassified, pre-tax	0	0	0	0
Tax (benefit) expense reclassified	0		0
Ending balance	2	(5)	2	(5)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(843)	(734)	(758)	(708)
Ending balance	$ (819)	$ (813)	$ (819)	$ (813)