Transactions with Related Parties - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Related Party Transaction
Minimum tangible net worth	$ 20
Minimum ratio of profit before income taxes and interest expense	1.15
Minimum percentage of voters required to modify or terminate agreement	0.6667
Payments of Dividends	$ 500	$ 625	$ 425
Maximum borrowing capacity from Caterpillar, Variable lending agreements	3,520
Maximum lending capacity to Caterpillar, Variable lending agreements	2,290
General, operating and administrative	666	644	588
Caterpillar
Related Party Transaction
Payments of Dividends	500	625	425
Maximum borrowing capacity from Caterpillar, Variable lending agreements	3,520
Maximum lending capacity to Caterpillar, Variable lending agreements	2,290
Marketing program payments received	667	540	332
General, operating and administrative	58	50	50
Administrative support services to certain Caterpillar subsidiaries reimbursed by Caterpillar	18	16	$ 15
Amount of our portfolio that is subject to guarantees by Caterpillar	$ 568	$ 473