Redeemable Noncontrolling Interest - Caterpillar Japan Ltd. (Details) In Millions, unless otherwise specified	Apr. 02, 2012 USD ($)	Apr. 02, 2012 JPY (¥)	Mar. 31, 2012	Aug. 01, 2008
Redeemable Noncontrolling Interest Disclosure Abstract
Cat Japan, consolidated subsidiary, Caterpillar majority percentage ownership (as a percent)	33.00%	33.00%	67.00%	67.00%
Cat Japan, consolidated subsidiary, MHI minority percentage ownership (as a percent)				33.00%
Cost of Acquired Remaining Interest Cash Paid	$ 444	¥ 36,500

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

No definition available.

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