Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2024 USD ($) segment reporting_unit	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Number of reportable segments | segment	5
Non-transactions revenue, intersegment revenue elimination	$ (14,208,000,000)	$ (12,497,000,000)	$ (11,181,000,000)
Contract assets	69,000,000	75,000,000
Revenues recognized	3,200,000,000
Capitalized contract costs	$ 291,000,000	234,000,000
Capitalized contract cost amortization period (in years)	5 years
Market value of cash and cash equivalents	$ 1,666,000,000	1,290,000,000
Restricted cash	0	1,000,000
Gross deferred technology costs	338,000,000	303,000,000
Accumulated amortization of deferred technology costs	204,000,000	194,000,000
Fair value of our long-term debt borrowings	$ 10,000,000,000	10,300,000,000
Option to extend lease period (in years)	12 years
Number of reporting units | reporting_unit	5
Goodwill impairment loss	$ 0	0	0
Impairment of intangible assets	0	0	0
Cost of advertisement	229,000,000	209,000,000	177,000,000
Undistributed accumulated earnings of foreign subsidiary	8,500,000,000
Undistributed earnings of foreign subsidiaries reinvested indefinitely	$ 4,700,000,000
Minimum
Property, Plant and Equipment [Line Items]
Remaining lease terms (in years)	1 year
Minimum | Software and Software Development Costs
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	3 years
Minimum | Building and Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	15 years
Minimum | Equipment and Furniture
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	2 years
Maximum
Property, Plant and Equipment [Line Items]
Remaining lease terms (in years)	11 years
Maximum | Software and Software Development Costs
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	7 years
Maximum | Building and Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	40 years
Maximum | Equipment and Furniture
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	10 years
OSTTRA | Corporate Joint Venture
Property, Plant and Equipment [Line Items]
Ownership interest of subsidiary (as a percent)	50.00%
Noncontrolling interest ownership by noncontrolling owners (as a percent)	50.00%
Non-transaction
Property, Plant and Equipment [Line Items]
Non-transactions revenue, intersegment revenue elimination	$ (1,858,000,000)	(1,730,000,000)	(1,640,000,000)
Elimination
Property, Plant and Equipment [Line Items]
Non-transactions revenue, intersegment revenue elimination	186,000,000	177,000,000	169,000,000
Elimination | Non-transaction
Property, Plant and Equipment [Line Items]
Non-transactions revenue, intersegment revenue elimination	$ 186,000,000	$ 177,000,000	$ 169,000,000