Restructuring and Related Implementation Charges - Summary of Restructuring Charges, Cumulative to Date (Details) - Global Growth and Efficiency Program $ in Millions	Sep. 30, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Pretax charges related to the Restructuring Program to date	$ 1,820
Aftertax charges related to the Restructuring Program to date	1,353
Employee-Related Costs
Restructuring Cost and Reserve [Line Items]
Pretax charges related to the Restructuring Program to date	696
Incremental Depreciation
Restructuring Cost and Reserve [Line Items]
Pretax charges related to the Restructuring Program to date	115
Asset Impairments
Restructuring Cost and Reserve [Line Items]
Pretax charges related to the Restructuring Program to date	58
Other
Restructuring Cost and Reserve [Line Items]
Pretax charges related to the Restructuring Program to date	$ 951