2018 Global Restructuring Program Narrative (Details) $ in Millions	12 Months Ended			36 Months Ended	48 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) Employee
Restructuring Cost and Reserve
Restructuring liabilities recorded in accrued expenses	$ 73	$ 93		$ 73
2018 Global Restructuring Program
Restructuring Cost and Reserve
Restructuring liabilities recorded in accrued expenses	73	93		73
Restructuring liabilities recorded in other liabilities	20	39		20
2018 Global Restructuring Program | After Tax
Restructuring Cost and Reserve
Restructuring Charges	325	248	$ 793	1,400
2018 Global Restructuring Program | Before Tax
Restructuring Cost and Reserve
Restructuring Charges	$ 419	$ 366	$ 1,036	$ 1,800
2018 Global Restructuring Program | Minimum | Scenario, Forecast
Restructuring Cost and Reserve
Expected Number of Positions Eliminated | Employee					6,300
2018 Global Restructuring Program | Minimum | After Tax | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					$ 1,500
Restructuring and Related Cost, Expected Cost Remaining					135
2018 Global Restructuring Program | Minimum | Before Tax | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					2,000
Restructuring and Related Cost, Expected Cost Remaining					180
2018 Global Restructuring Program | Minimum | Cash charges | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					1,100
2018 Global Restructuring Program | Minimum | Non-cash charges | Before Tax | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					$ 900
2018 Global Restructuring Program | Maximum | Scenario, Forecast
Restructuring Cost and Reserve
Expected Number of Positions Eliminated | Employee					6,400
2018 Global Restructuring Program | Maximum | After Tax | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					$ 1,600
Restructuring and Related Cost, Expected Cost Remaining					215
2018 Global Restructuring Program | Maximum | Before Tax | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					2,100
Restructuring and Related Cost, Expected Cost Remaining					280
2018 Global Restructuring Program | Maximum | Cash charges | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					1,150
2018 Global Restructuring Program | Maximum | Non-cash charges | Before Tax | Scenario, Forecast
Restructuring Cost and Reserve
Restructuring and Related Cost, Expected Cost					$ 950