Equity Activity - Reclassifications and Taxes (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021		Jun. 30, 2022	Jun. 30, 2021
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	$ 7,246	$ 6,366	[1]	$ 14,107	$ 12,526	[1]
SG&A expense	4,855	4,849	[1]	9,452	9,536	[1]
Other (income) and expense	(81)	302	[1]	166	647	[1]
Interest expense	297	281	[1]	607	561	[1]
Provision for/(benefit from) income taxes	257	101	[1]	218	(58)	[1]
Net (income) loss	(1,392)	(1,325)	[1],[2]	(2,125)	(2,280)	[1],[2]
Other comprehensive income/(loss)	363	605		1,066	1,685
Services.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	5,399	4,720	[1]	10,747	9,364	[1]
Sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	1,750	1,499	[1],[3]	3,165	2,878	[1],[3]
Financing.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	96	146	[1],[3]	194	283	[1],[3]
Cost of services
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	5,399	4,720		10,747	9,364
Cost of sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	1,750	1,499		3,165	2,878
Cost of financing
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	96	146		194	283
SG&A expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
SG&A expense	4,855	4,849		9,452	9,536
Other (income) and expenses
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Other (income) and expense	(81)	302		166	647
Interest expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Interest expense	297	281		607	561
Accumulated Other Comprehensive Income/(Loss)
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Net of Tax Amount				366	532
Reclassification/amortization, Net of Tax Amount				699	1,153
Other comprehensive income/(loss), Before Tax Amount	897	745		1,885	2,330
Other comprehensive income/(loss), Tax (Expense)/Benefit	(534)	(140)		(819)	(645)
Other comprehensive income/(loss)	363	605		1,066	1,685
Foreign Currency Translation Adjustments
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Net of Tax Amount				172	393
Other comprehensive income/(loss), Before Tax Amount	213	28		655	577
Other comprehensive income/(loss), Tax (Expense)/Benefit	(347)	44		(483)	(184)
Other comprehensive income/(loss)	(134)	72		172	393
Net Unrealized Gains/(Losses) on Available-For-Sale Securities
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Before Tax Amount	0	0		(1)	0
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit	0	0		0	0
Unrealized gains/(losses) arising during the period, Net of Tax Amount	0	0		0	0
Other comprehensive income/(loss), Before Tax Amount	0	0		(1)	0
Other comprehensive income/(loss), Tax (Expense)/Benefit	0	0		0	0
Other comprehensive income/(loss)	0	0		0	0
Net Unrealized Gains/(Losses) on Cash Flow Hedges
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Before Tax Amount	200	(34)		260	153
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit	(53)	9		(69)	(39)
Unrealized gains/(losses) arising during the period, Net of Tax Amount	147	(26)		191	114
Reclassification/amortization, Net of Tax Amount				14	187
Other comprehensive income/(loss), Before Tax Amount	217	56		276	404
Other comprehensive income/(loss), Tax (Expense)/Benefit	(56)	(14)		(71)	(102)
Other comprehensive income/(loss)	161	42		205	301
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications
Reclassifications and Taxes Related to Items of Other Comprehensive Income
SG&A expense	(14)	16		(20)	31
Other (income) and expense	38	49		45	165
Interest expense	22	16		43	31
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Services.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	(13)	(7)		(28)	(21)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	(23)	10		(35)	32
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Financing.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	6	6		12	12
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Cost of services
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Provision for/(benefit from) income taxes	3	2		7	5
Net (income) loss	(10)	(5)		(21)	(16)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Cost of sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Provision for/(benefit from) income taxes	7	(3)		10	(8)
Net (income) loss	(17)	8		(25)	24
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Cost of financing
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Provision for/(benefit from) income taxes	(2)	(1)		(3)	(3)
Net (income) loss	5	4		9	9
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | SG&A expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Provision for/(benefit from) income taxes	4	(4)		5	(8)
Net (income) loss	(10)	12		(14)	23
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Other (income) and expenses
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Provision for/(benefit from) income taxes	(10)	(12)		(11)	(41)
Net (income) loss	29	37		34	123
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Interest expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Provision for/(benefit from) income taxes	(6)	(4)		(11)	(8)
Net (income) loss	16	12		32	24
Net Change Retirement-Related Benefit Plans
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Net of Tax Amount				3	25
Reclassification/amortization, Net of Tax Amount				686	966
Other comprehensive income/(loss), Before Tax Amount	468	661		954	1,350
Other comprehensive income/(loss), Tax (Expense)/Benefit	(132)	(170)		(266)	(359)
Other comprehensive income/(loss)	336	491		689	991
Retirement-Related Benefit Plans, Prior Service Costs/(Credits)
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Before Tax Amount		0		(5)	0
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit	0	0		5	0
Unrealized gains/(losses) arising during the period, Net of Tax Amount	0	0		0	0
Reclassification/amortization, Before Tax Amount	6	1		13	4
Reclassification/amortization, Tax (Expense)/Benefit	(2)	1		(3)	0
Reclassification/amortization, Net of Tax Amount	5	1		10	4
Retirement-Related Benefit Plans, Net Gains/(Losses)
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Before Tax Amount	1	2		10	22
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit	(3)	10		(7)	4
Unrealized gains/(losses) arising during the period, Net of Tax Amount	(2)	11		3	25
Reclassification/amortization, Before Tax Amount	450	643		917	1,291
Reclassification/amortization, Tax (Expense)/Benefit	(125)	(175)		(256)	(352)
Reclassification/amortization, Net of Tax Amount	325	467		662	938
Retirement-Related Benefit Plans, Curtailments and Settlements
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Before Tax Amount	11	16		19	34
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit	(3)	(5)		(5)	(10)
Unrealized gains/(losses) arising during the period, Net of Tax Amount	$ 8	$ 11		$ 14	$ 23

[1] Reclassified to reflect discontinued operations presentation.

[2] Amounts presented have not been recast to exclude discontinued operations.

[3] Reclassified to conform to current year presentation.