Selected Quarterly Financial Data (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 703	$ 743	$ 728	$ 711	$ 711	$ 699	$ 695	$ 680	$ 2,885		$ 2,785		$ 2,693
Profit before income taxes	166	197	208	182	204	164	141	185	753		694		584
Profit	$ 108	$ 148	$ 148	$ 131	$ 158	$ 117	$ 98	$ 140	$ 535	[1]	$ 513	[1]	$ 428	[1]

[1] Profit attributable to Caterpillar Financial Services Corporation.