Guarantees and Product Warranty (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Jul. 31, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]
Percentage of equity interest sold in subsidiary (as a percent)		65.00%
Related liability	$ 17		$ 7
Guarantor Obligations
Guarantees, maximum potential amount of future payments	570		365
Financial Special-Purpose Company's assets in Consolidated Statement of Financial Position	940		586
Financial Special-Purpose Company's liabilities in Consolidated Statement of Financial Position	940		586
Caterpillar dealer guarantees
Guarantor Obligations
Guarantees, maximum potential amount of future payments	167		140
Customer guarantees
Guarantor Obligations
Guarantees, maximum potential amount of future payments	176		186
Limited idemnity
Guarantor Obligations
Guarantees, maximum potential amount of future payments	1		11
Third party logistics business
Guarantor Obligations
Guarantees, maximum potential amount of future payments	182		0
Other guarantees
Guarantor Obligations
Guarantees, maximum potential amount of future payments	$ 44		$ 28