Cat Financial Financing Activities (Details 4) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due
Period after which Collection of Future Income is Considered as Not Probable	120 days
Dealer
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest		$ 0
Dealer | Latin America
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	$ 77
Finance Receivables | Customer
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	629	683
Finance Receivables | Customer | North America
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	42	38
Finance Receivables | Customer | Europe
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	69	37
Finance Receivables | Customer | Asia Pacific
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	6	10
Finance Receivables | Customer | Mining
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	13	63
Finance Receivables | Customer | Latin America
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	142	192
Finance Receivables | Customer | Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	$ 357	$ 343