Cost Reduction Programs and Other Charges - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) employee	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Cost reduction programs and other charges		$ 567	$ 309	$ 52
Cost reduction programs and other charges, after-tax and noncontrolling interest		444	306	$ 48
Cost reduction program charges		304
Cost reduction program charges, net of tax		$ 233	70
Number of positions expected to be eliminated | employee		2,400
Number of positions eliminated | employee		1,500
Other charges, merger related		$ 263	236
Other charges, merger related, net of tax		211
Asset impairment charges	$ 73
Asset impairment charges, net of tax	$ 42
Cash requirement for the cost reduction program and other charges		460
Cash payments		260
Other charges, non-merger related			73
Severance costs
Restructuring Cost and Reserve [Line Items]
Cost reduction programs and other charges		204
Other cost reduction charges
Restructuring Cost and Reserve [Line Items]
Cost reduction programs and other charges		$ 100
Other Charges, China Unfavorable Arbitration Ruling Charge
Restructuring Cost and Reserve [Line Items]
Cost reduction program charges, net of tax			40
Other charges, non-merger related			40
Other Charges, Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Cost reduction program charges, net of tax			18
Other charges, non-merger related			21
Other Charges, Argentina Hyper-Inflation Charge
Restructuring Cost and Reserve [Line Items]
Cost reduction program charges, net of tax			12
Other charges, non-merger related			$ 12