Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 725	$ 748	$ 757	$ 736	$ 699	$ 735	$ 723	$ 690	$ 2,966		$ 2,847		$ 2,689
Profit before income taxes	161	184	141	142	46	163	100	124	628		433		590
Profit	$ 104	$ 129	$ 79	$ 98	$ 18	$ 125	$ 71	$ 91	$ 410	[1]	$ 305	[1]	$ 586	[1]

[1] Profit attributable to Caterpillar Financial Services Corporation.