Cat Financial Financing Activities (Details 7) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($) Contracts	Dec. 31, 2017 USD ($) Customer	Dec. 31, 2016 USD ($) Contracts	Dec. 31, 2015 USD ($) Contracts
Finance Receivables | Customer
Loan and finance lease receivables
Loans and leases receivable, impaired, commitment to lend	$ 0	$ 0	$ 0	$ 0	$ 11
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			144		574	94
Pre-TDR Outstanding Recorded Investment		579			$ 454	$ 354
Post-TDR Outstanding Recorded Investment		557			$ 387	$ 338
TDRs with a payment default which had been modified within twelve months prior to the default date
Number of Contracts (in contracts) | Contracts			252		15	19
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		21			$ 5	$ 2
Finance Receivables | Customer | North America
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			43		25	14
Pre-TDR Outstanding Recorded Investment		34			$ 25	$ 1
Post-TDR Outstanding Recorded Investment		35			$ 25	$ 1
TDRs with a payment default which had been modified within twelve months prior to the default date
Number of Contracts (in contracts) | Contracts			4		5	7
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3			$ 2	$ 1
Finance Receivables | Customer | Europe
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			4		43	23
Pre-TDR Outstanding Recorded Investment		1			$ 12	$ 2
Post-TDR Outstanding Recorded Investment		1			$ 9	$ 2
TDRs with a payment default which had been modified within twelve months prior to the default date
Number of Contracts (in contracts) | Contracts			1		5	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0			$ 2	$ 0
Finance Receivables | Customer | Asia Pacific
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			10		31	21
Pre-TDR Outstanding Recorded Investment		39			$ 29	$ 26
Post-TDR Outstanding Recorded Investment		31			$ 28	$ 26
TDRs with a payment default which had been modified within twelve months prior to the default date
Number of Contracts (in contracts) | Contracts			4		1	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		1			$ 0	$ 0
Finance Receivables | Customer | Mining
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			2		4	4
Pre-TDR Outstanding Recorded Investment		57			$ 74	$ 65
Post-TDR Outstanding Recorded Investment		56			$ 66	$ 65
Finance Receivables | Customer | Latin America
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			17		437	11
Pre-TDR Outstanding Recorded Investment		26			$ 118	$ 1
Post-TDR Outstanding Recorded Investment		27			$ 82	$ 2
TDRs with a payment default which had been modified within twelve months prior to the default date
Number of Contracts (in contracts) | Contracts			243		4	12
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		17			$ 1	$ 1
Finance Receivables | Customer | Caterpillar Power Finance
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			68		34	21
Pre-TDR Outstanding Recorded Investment		422			$ 196	$ 259
Post-TDR Outstanding Recorded Investment		$ 407			$ 177	$ 242
Finance Receivables | Dealer
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts)		0			0	0
Significant Amount of Amount Disclosed Represented by a Certain Number of Customers [Member] | Customer | Latin America
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			321
Pre-TDR Outstanding Recorded Investment		$ 94
Post-TDR Outstanding Recorded Investment		64
TDRs with a payment default which had been modified within twelve months prior to the default date
Number of Contracts (in contracts) | Contracts			238
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		16
Number of Significant Customers Disclosed	2			4
Significant Amount of Amount Disclosed Represented by a Certain Number of Customers [Member] | Customer | Caterpillar Power Finance
Loan and finance lease receivables modified as TDRs
Number of Contracts (in contracts) | Contracts			48
Pre-TDR Outstanding Recorded Investment		265
Post-TDR Outstanding Recorded Investment		$ 258
TDRs with a payment default which had been modified within twelve months prior to the default date
Number of Significant Customers Disclosed | Customer				6