Fair value disclosures - Fair values of financial instruments (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Carrying Amount
Assets
Finance receivables-net (excluding finance leases)	$ 16,180	$ 15,386
Wholesale inventory receivables-net (excluding finance leases)	1,568	1,415
Carrying Amount | Machinery, Energy & Transportation
Liabilities
Long-term debt (including amounts due within one year)	8,610	9,623
Carrying Amount | Financial Products
Liabilities
Long-term debt (including amounts due within one year)	25,406	23,612
Carrying amount of assets excluded from measurement at fair value
Liabilities
Excluded items: Finance leases and failed sale leasebacks, Carrying Value	6,769	6,953
Level 3 | Fair Value
Assets
Finance receivables-net (excluding finance leases)	15,788	15,017
Wholesale inventory receivables-net (excluding finance leases)	1,527	1,368
Level 2 | Fair Value | Machinery, Energy & Transportation
Liabilities
Long-term debt (including amounts due within one year)	7,980	9,550
Level 2 | Fair Value | Financial Products
Liabilities
Long-term debt (including amounts due within one year)	$ 25,304	$ 23,299