Restructuring Program - Additional Information (Details) - USD ($) $ in Millions				3 Months Ended		6 Months Ended		74 Months Ended
	Sep. 06, 2018	Aug. 31, 2016	May 06, 2014	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 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				$ 80	$ 88	$ 138	$ 158	$ 4,478
Restructuring charges				28	20	43	40	2,769
Cash spent in restructuring						69
Non-cash asset write-downs				11	6	14	35
Restructuring reserve				252		252		252	$ 301
Implementation costs				52	68	95	118	1,709
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				220		220		220
Simplify to Grow Program | Other liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve				32		32		32
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						35
Cash spent in restructuring				32	$ 36	69	$ 89
Non-cash asset write-downs						6
Restructuring reserve				$ 252		$ 252		$ 252	$ 301