Cost Reduction Programs and Other Charges - Summary of Activity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
2020 Cost Reduction Programs and Other Charges	$ 131	$ 89
Less: Cash payments	(64)
Less: Non-cash charges	(54)
Foreign currency translation and other	(3)
Balance, March 31, 2020	210		$ 200
Severance costs
Restructuring Cost and Reserve [Line Items]
2020 Cost Reduction Programs and Other Charges		$ 33
Merger-related and other charges
Restructuring Cost and Reserve [Line Items]
2020 Cost Reduction Programs and Other Charges	53
Less: Cash payments	(36)
Less: Non-cash charges	(39)
Foreign currency translation and other	(2)
Balance, March 31, 2020	43		67
Cost Reduction Program
Restructuring Cost and Reserve [Line Items]
2020 Cost Reduction Programs and Other Charges	78
Less: Cash payments	(28)
Less: Non-cash charges	(15)
Foreign currency translation and other	(1)
Balance, March 31, 2020	167		133
Cost Reduction Program | Severance costs
Restructuring Cost and Reserve [Line Items]
2020 Cost Reduction Programs and Other Charges	58
Less: Cash payments	(24)
Less: Non-cash charges	0
Foreign currency translation and other	(1)
Balance, March 31, 2020	150		117
Cost Reduction Program | Other cost reduction charges
Restructuring Cost and Reserve [Line Items]
2020 Cost Reduction Programs and Other Charges	20
Less: Cash payments	(4)
Less: Non-cash charges	(15)
Foreign currency translation and other	0
Balance, March 31, 2020	$ 17		$ 16