Restructuring Program - Additional Information (Details) - USD ($) $ in Millions				3 Months Ended		9 Months Ended		77 Months Ended
	Sep. 06, 2018	Aug. 31, 2016	May 06, 2014	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 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				$ 114	$ 152	$ 252	$ 310	$ 4,592
Restructuring charges				68	77	111	117	2,837
Cash spent in restructuring						113
Non-cash asset write-downs				13	41	1	76
Restructuring reserve				296		296		296	$ 301
Implementation costs				46	75	141	193	1,755
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				258		258		258
Simplify to Grow Program | Other liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve				38		38		38
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						116
Cash spent in restructuring				44	$ 35	113	$ 124
Non-cash asset write-downs						6
Restructuring reserve				$ 296		$ 296		$ 296	$ 301