Equity Activity - Reclassifications and Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	$ 6,968	$ 6,510
SG&A expense	5,089	4,886
Other (income) and expense	(1)	(165)
Interest expense	473	455
Services
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	5,244	5,002
Sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	1,599	1,404
Financing
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	124	104
Accumulated Other Comprehensive Income/(Loss)
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Other comprehensive income (loss), Before Tax Amount	512	(566)
Other comprehensive income/(loss), Tax (Expense)/Benefit	(213)	259
Other comprehensive income/(loss)	299	(306)
Unrealized gains/(losses) arising during the period, Net of Tax Amount	(113)	(176)
Reclassification/amortization, Net of Tax Amount	412	(130)
Foreign currency translation adjustments
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Other comprehensive income (loss), Before Tax Amount	136	(343)
Other comprehensive income/(loss), Tax (Expense)/Benefit	(116)	203
Other comprehensive income/(loss)	20	(139)
Unrealized gains/(losses) arising during the period, Net of Tax Amount	20	(139)
Reclassification/amortization, Net of Tax Amount	0	0
Net unrealized gains/(losses) on available-for-sale securities
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Other comprehensive income (loss), Before Tax Amount	0	8
Other comprehensive income/(loss), Tax (Expense)/Benefit	0	(2)
Other comprehensive income/(loss)	0	6
Unrealized gains/(losses) arising during the period, Net of Tax Amount	0	6
Reclassification/amortization, Net of Tax Amount	0	0
Net Unrealized Gains/(Losses) on Cash Flow Hedges
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Other comprehensive income (loss), Before Tax Amount	167	(382)
Other comprehensive income/(loss), Tax (Expense)/Benefit	(43)	98
Other comprehensive income/(loss)	124	(283)
Unrealized gains/(losses) arising during the period, Before Tax Amount	(175)	(58)
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit	42	16
Unrealized gains/(losses) arising during the period, Net of Tax Amount	(133)	(42)
Reclassification/amortization, Net of Tax Amount	258	(241)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Cost of services
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Reclassification/amortization, Tax (Expense)/Benefit	(4)	0
Reclassification/amortization, Net of Tax Amount	11	2
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Cost of sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Reclassification/amortization, Tax (Expense)/Benefit	1	2
Reclassification/amortization, Net of Tax Amount	0	(5)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Cost of financing
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Reclassification/amortization, Tax (Expense)/Benefit	0	0
Reclassification/amortization, Net of Tax Amount	1	1
Net Unrealized Gains/(Losses) on Cash Flow Hedges | SG&A expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Reclassification/amortization, Tax (Expense)/Benefit	0	1
Reclassification/amortization, Net of Tax Amount	1	(2)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Other (income) and expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Reclassification/amortization, Tax (Expense)/Benefit	(80)	81
Reclassification/amortization, Net of Tax Amount	240	(241)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Interest expense
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Reclassification/amortization, Tax (Expense)/Benefit	(1)	(2)
Reclassification/amortization, Net of Tax Amount	4	5
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassifications and Taxes Related to Items of Other Comprehensive Income
SG&A expense	1	(3)
Other (income) and expense	320	(322)
Interest expense	6	6
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income | Services
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	15	2
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income | Sales
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	(1)	(8)
Net Unrealized Gains/(Losses) on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income | Financing
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Cost	1	1
Total retirement-related benefit plans
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Other comprehensive income (loss), Before Tax Amount	209	151
Other comprehensive income/(loss), Tax (Expense)/Benefit	(54)	(40)
Other comprehensive income/(loss)	155	111
Unrealized gains/(losses) arising during the period, Net of Tax Amount	1	0
Reclassification/amortization, Net of Tax Amount	154	111
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	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
Reclassification/amortization, Before Tax Amount	9	(2)
Reclassification/amortization, Tax (Expense)/Benefit	(2)	1
Reclassification/amortization, Net of Tax Amount	7	(1)
Net gains/(losses) arising during the period
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Unrealized gains/(losses) arising during the period, Before Tax Amount	1	0
Unrealized gains/(losses) arising during the period, Tax (Expense)/Benefit	0	0
Unrealized gains/(losses) arising during the period, Net of Tax Amount	1	0
Reclassification/amortization, Before Tax Amount	198	151
Reclassification/amortization, Tax (Expense)/Benefit	(52)	(41)
Reclassification/amortization, Net of Tax Amount	146	111
Curtailments and settlements
Reclassifications and Taxes Related to Items of Other Comprehensive Income
Reclassification/amortization, Before Tax Amount	2	2
Reclassification/amortization, Tax (Expense)/Benefit	0	0
Reclassification/amortization, Net of Tax Amount	$ 1	$ 2