| **Investments in and advances to non-consolidated affiliates** | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
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| **Equity Method Investments and Joint Ventures [Abstract]**    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Investments in and advances to non-consolidated affiliates     | Investments in and Advances to Non-consolidated AffiliatesInvestments in Non-consolidated Affiliates is comprised of our interests in partially-owned affiliates of which our ownership percentages range from 10% to 50%. We do not control these affiliates, but have the ability to exercise significant influence over their operating and financial policies. Our investment in these affiliates is an integral part of our operations, and we account for them using the equity method of accounting.Prior to the termination of our NC2 Global, LLC ("NC2") joint venture agreement with Caterpillar, our 50% interest in NC2 was included in Investments in and Advances to Non-consolidated Affiliates. In September 2011, the Company acquired all of Caterpillar's ownership interest in NC2, thereby increasing our equity interest in NC2 from 50% to 100%. We have consolidated the operating results of NC2 within our Truck segment since September 30, 2011.Presented below is summarized financial information representing 100% of NC2, which was considered a significant non-consolidated affiliate during the three and six months ended April 30, 2011, prior to the increase of our equity interest in September 2011. Balance sheet information for NC2 was insignificant to our Consolidated Balance Sheet as of April 30, 2011. (in millions)Three Months Ended April 30, 2011 Six Months Ended April 30, 2011Net revenue$30 $79Net expenses46 113Loss before tax expense(16) (34)Net loss(16) (34) |

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| - Definition
The entire disclosure for equity investment, or group of investments, for which combined disclosure is appropriate, including: (a) the name of each investee and percentage of ownership of common stock, (b) accounting policies for investments in common stock, (c) difference between the amount at which the investment is carried and the amount of underlying equity in net assets and the accounting treatment of the difference, (d) the total fair value of each identified investment for which a market value is available, (e) summarized information as to assets, liabilities, and results of operations of the investees (for investments in unconsolidated subsidiaries, common stock of joint ventures, or other investments using the equity method), and (f) material effects of possible conversions, exercises, or contingent issuances of the investee. Other disclosures include (a) the names of any investee in which the investor owns 20 percent or more of the voting stock and investment is not accounted for using the equity method, and the reasons why not, and (b) the names of any investee in which the investor owns less than 20 percent of the voting stock and the investment is accounted for using the equity method, and the reasons why it is.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 35 -Paragraph 32 -URI http://asc.fasb.org/extlink&oid=6903645&loc=d3e32787-111569Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 20 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 35 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=6903645&loc=d3e32847-111569
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