Equity Activity - Reclassifications and Taxes (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		$ 6,862	$ 6,160	[1]
SG&A expense		4,597	4,688	[1]
Other (income) and expense		246	346	[1]
Interest expense		311	280	[1]
Provision for/(benefit from) income taxes		(39)	(160)	[1]
Net (income) loss		(733)	(955)	[1],[2]
Other comprehensive income/(loss)		703	1,080
Services.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		5,349	4,644	[1]
Sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	[3]	1,415	1,379	[1]
Financing.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	[3]	98	137	[1]
Cost of services
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		5,349	4,644
Cost of sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		1,415	1,379
Cost of financing
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		98	137
SG&A expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
SG&A expense		4,597	4,688
Other (income) and expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Other (income) and expense		246	346
Interest expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Interest expense		311	280
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		355	475
Reclassification/amortization, Net of Tax Amount		348	606
Other comprehensive income/(loss), Before Tax Amount		987	1,586
Other comprehensive income/(loss), Tax (Expense)/Benefit		(285)	(505)
Other comprehensive income/(loss)		703	1,080
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		306	321
Other comprehensive income/(loss), Before Tax Amount		442	549
Other comprehensive income/(loss), Tax (Expense)/Benefit		(136)	(228)
Other comprehensive income/(loss)		306	321
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
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit		0	0
Unrealized gains/(losses) arising during the period, Net of Tax Amount		0	0
Other comprehensive income/(loss), Before Tax Amount		0	0
Other comprehensive income/(loss), Tax (Expense)/Benefit		0	0
Other comprehensive income/(loss)		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		60	187
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit		(16)	(47)
Unrealized gains/(losses) arising during the period, Net of Tax Amount		44	140
Reclassification/amortization, Net of Tax Amount		0	119
Other comprehensive income/(loss), Before Tax Amount		59	347
Other comprehensive income/(loss), Tax (Expense)/Benefit		(15)	(88)
Other comprehensive income/(loss)		44	259
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications
Reclassifications and Taxes Related to Items of Other Comprehensive Income
SG&A expense		(6)	15
Other (income) and expense		7	116
Interest expense		21	16
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Services.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		(15)	(14)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		(12)	22
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Financing.
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost		5	6
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		4	3
Net (income) loss		(11)	(10)
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		4	(6)
Net (income) loss		(9)	16
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		(1)	(2)
Net (income) loss		4	4
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		2	(4)
Net (income) loss		(4)	11
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassifications | Other (income) and expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Provision for/(benefit from) income taxes		(2)	(29)
Net (income) loss		5	87
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		(5)	(4)
Net (income) loss		15	12
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		5	14
Reclassification/amortization, Net of Tax Amount		348	486
Other comprehensive income/(loss), Before Tax Amount		486	689
Other comprehensive income/(loss), Tax (Expense)/Benefit		(134)	(189)
Other comprehensive income/(loss)		352	500
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		(5)	0
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit		5	0
Unrealized gains/(losses) arising during the period, Net of Tax Amount		0	0
Reclassification/amortization, Before Tax Amount		7	3
Reclassification/amortization, Tax (Expense)/Benefit		(2)	0
Reclassification/amortization, Net of Tax Amount		5	3
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		9	20
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit		(4)	(6)
Unrealized gains/(losses) arising during the period, Net of Tax Amount		5	14
Reclassification/amortization, Before Tax Amount		468	648
Reclassification/amortization, Tax (Expense)/Benefit		(131)	(177)
Reclassification/amortization, Net of Tax Amount		337	471
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		8	17
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit		(2)	(5)
Unrealized gains/(losses) arising during the period, Net of Tax Amount		$ 6	$ 12

[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.