Asset-Backed Financing (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Asset-Backed Financing [Line Items]
Debt Instrument, Face Amount	$ 675,300,000	$ 1,090,000,000
Assets transferred to special purpose entities	715,700,000	1,210,000,000
Financial services interest expense	195,990,000	229,492,000	272,484,000
Weighted average interest rate of asset-backed securitization transactions	1.09%	1.96%
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	27,200,000
SPEs [Member]
Asset-Backed Financing [Line Items]
Financial services interest expense	1,400,000	1,500,000
SPEs Facility [Member]
Asset-Backed Financing [Line Items]
Total aggregate commitment	600,000,000
Financial services interest expense	25,800,000	60,200,000
NotesPreviouslyRetainedAsPartofAsset-BackedSecuritizationTransacitons [Member]
Asset-Backed Financing [Line Items]
Debt Instrument, Face Amount	89,500,000
Asset-backed Canadian Commercial Paper Conduit Facility [Member]
Asset-Backed Financing [Line Items]
Expiration date of conduit facility	Aug. 30, 2013
Maturity Date Of Debt Instrument	5 years
Financial services interest expense	1,100,000
Weighted average interest rate of conduit facility	1.95%
Maximum Borrowing Capacity Under Conduit Facility	200,000,000
Face Amount of Finance Receivables Transferred	230,000,000
Proceeds from Sale of Finance Receivables	$ 201,300,000