Finance Receivables (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended					12 Months Ended
	Jun. 30, 2009	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2010 Retail [Member]	Dec. 31, 2010 Wholesale [Member] days	Dec. 31, 2011 Retail And Wholesale [Member]	Dec. 31, 2010 Retail And Wholesale [Member]	Dec. 31, 2009 Retail And Wholesale [Member]	Dec. 31, 2008 Retail And Wholesale [Member]	Dec. 31, 2007 Retail And Wholesale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unused lines of credit, wholesale		$ 909,900,000	$ 1,040,000,000
Approved but unfunded retail loans		139,300,000	96,500,000
Percent of gross receivables originated in Texas		11.00%	11.00%
Finance receivables reclassified from held for sale investment	3,140,000,000
Allowance for finance credit losses	72,700,000
Lower of cost or market adjustment					31,700,000
Restricted finance receivables held as collateral		2,860,000,000	3,380,000,000
Cross-border outstandings in Canada		88,400,000	88,700,000	77,100,000
Receivables past due and accruing interest						34,100,000	1,600,000	28,378,000	35,742,000	26,790,000	24,953,000	8,350,000
Finance receivables contractually past due, days							90
Level at which FICO score is considered prime			640
Non-accrual status wholesale finance receivables			$ 5,400,000