Restructuring Program - Additional Information (Details) - USD ($) $ in Millions				3 Months Ended		71 Months Ended
	Sep. 06, 2018	Aug. 31, 2016	May 06, 2014	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020		Dec. 31, 2019
2014-2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost		$ 5,700	$ 3,500
Reallocation of previously approved capital expenditures to be spent on restructuring program cash costs		600
2014-2018 Restructuring Program | Maximum
Restructuring Cost and Reserve [Line Items]
Approved capital expenditures		1,600	$ 2,200
2014-2018 Restructuring Program | Restructuring Program Charges
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost		4,100
2014-2018 Restructuring Program | Cash Costs
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost		3,100
2014-2018 Restructuring Program | Non-cash Costs
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost		$ 1,000
Simplify to Grow Program
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost	$ 7,700
Restructuring and implementation charges				$ 58	$ 70	$ 4,398	[1]
Restructuring charges				15	20	2,741	[1]
Cash spent in restructuring				37
Non-cash asset write-downs				3	29
Restructuring reserve				265		265		$ 301
Implementation costs				43	50	1,657	[1]
Simplify to Grow Program | Maximum
Restructuring Cost and Reserve [Line Items]
Approved capital expenditures	2,300
Increase in approved restructuring program costs	1,300
Increase in approved capital expenditures	700
Simplify to Grow Program | Other current liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve				243		243
Simplify to Grow Program | Other liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve				22		22
Simplify to Grow Program | Restructuring Program Charges
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost	5,400
Simplify to Grow Program | Cash Costs
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost	4,100
Simplify to Grow Program | Non-cash Costs
Restructuring Cost and Reserve [Line Items]
Approved restructuring program cost	$ 1,300
Simplify to Grow Program | Severance and Related Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges				14
Cash spent in restructuring				37	$ 53
Non-cash asset write-downs				2
Restructuring reserve				$ 265		$ 265		$ 301

[1] Includes all charges recorded since program inception on May 6, 2014 through March 31, 2020.