Nature of Operations and Basis of Presentation - Narrative (Details) $ in Millions			9 Months Ended
	Oct. 10, 2025 USD ($)	Apr. 29, 2025	Sep. 30, 2025 USD ($)	Sep. 30, 2025 USD ($) segment	Sep. 30, 2025 USD ($) Segment	Dec. 31, 2024 USD ($)
Business Combination [Line Items]
Number of reportable segments				5	5
Restricted cash			$ 0	$ 0	$ 0	$ 0
Contract asset			81	81	81	69
Unearned revenue			3,200
Capitalized contract costs			$ 314	$ 314	$ 314	$ 291
Subsequent Event
Business Combination [Line Items]
Total enterprise value	$ 3,100
Minimum
Business Combination [Line Items]
Amortization period of capitalized contract cost			2 years	2 years	2 years
Maximum
Business Combination [Line Items]
Amortization period of capitalized contract cost			5 years	5 years	5 years
Scenario, Plan | Minimum | Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff
Business Combination [Line Items]
Expected term of completion for spinoff transaction		12 months
Scenario, Plan | Maximum | Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff
Business Combination [Line Items]
Expected term of completion for spinoff transaction		18 months
OSTTRA | Subsequent Event
Business Combination [Line Items]
Cash proceeds from sale of equity method investments	1,500
After tax proceeds from sale of equity method investments	1,400
Pre-tax gain on sale	270
Gain on sale after tax	$ 180
OSTTRA | Corporate Joint Venture
Business Combination [Line Items]
Investment in joint venture percentage			50.00%	50.00%	50.00%
Noncontrolling interest ownership by noncontrolling owners percentage			50.00%	50.00%	50.00%
OSTTRA | Corporate Joint Venture | Subsequent Event
Business Combination [Line Items]
Investment in joint venture percentage	50.00%
Noncontrolling interest ownership by noncontrolling owners percentage	50.00%