Accumulated Other Comprehensive Income/(Loss) (Details 2) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense)		$ (7)	$ (4)
Interest		(174)	(162)
Reclassifications before tax		124	167
Tax (provision) benefit		(29)	(50)
Total reclassifications from Accumulated other comprehensive income/(loss)	[1]	91	115
Reclassifications out of Accumulated other comprehensive income/(loss) | Derivative financial instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications before tax		(25)	(21)
Tax (provision) benefit		5	7
Total reclassifications from Accumulated other comprehensive income/(loss)		(20)	(14)
Reclassifications out of Accumulated other comprehensive income/(loss) | Derivative financial instruments | Cross currency contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense)		(29)	(22)
Interest		3	0
Reclassifications out of Accumulated other comprehensive income/(loss) | Derivative financial instruments | Interest rate contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest		$ 1	$ 1

[1] Profit attributable to Caterpillar Financial Services Corporation.