Asset-Backed Financing (Narrative) (Detail)			3 Months Ended	6 Months Ended
	Jun. 30, 2013 Term Asset-Backed Securitization VIEs [Member] Secured Debt [Member] SPEs [Member] USD ($)	Jul. 01, 2012 Term Asset-Backed Securitization VIEs [Member] Secured Debt [Member] SPEs [Member] USD ($)	Jun. 30, 2013 Line of Credit [Member] Asset-Backed Canadian Commercial Paper Conduit Facility [Member] Variable Interest Entity, Not Primary Beneficiary [Member] USD ($)	Jun. 30, 2013 Line of Credit [Member] Asset-Backed Canadian Commercial Paper Conduit Facility [Member] Foreign Line of Credit [Member] CAD	Jun. 30, 2013 Third-party Bank [Member] Line of Credit [Member] Asset-Backed U.S. Commercial Paper Conduit Facility VIE [Member] SPEs [Member] USD ($)	Dec. 31, 2012 Third-party Bank [Member] Line of Credit [Member] Asset-Backed U.S. Commercial Paper Conduit Facility VIE [Member] SPEs [Member] USD ($)	Jul. 01, 2012 Third-party Bank [Member] Line of Credit [Member] Asset-Backed U.S. Commercial Paper Conduit Facility VIE [Member] SPEs [Member] USD ($)
Variable Interest Entity [Line Items]
Company issued secured notes	$ 650,000,000	$ 89,500,000
Unaccreted premium	700,000	1,800,000
Total aggregate commitment				200,000,000	600,000,000
Debt Instrument, Term				5 years
Borrowings outstanding under conduit facility					0	0	0
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount			37,300,000
Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement, Transfers During Period			53,800,000
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers			$ 47,100,000