Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	$ (2,925)	$ (2,230)	$ (2,350)	$ (2,300)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(600)	44
Other Comprehensive Income (Loss), Before Reclassifications, Tax	14	18
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	11	8
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(575)	70
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	8	9
Tax cost related to unrealized currency translation adjustments other than translation of foreign denominated balance sheets	5	7
Pension and other postretirement benefit adjustments, tax cost	3	2
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(2,208)	(1,669)	(1,627)	(1,734)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(600)	44
Other Comprehensive Income (Loss), Before Reclassifications, Tax	19	21
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(581)	65
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(718)	(562)	(724)	(568)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Before Reclassifications, Tax	(5)	(1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	11	7
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	6	6
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	1	1	$ 1	$ 2
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Before Reclassifications, Tax	0	(2)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	1
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 0	$ (1)