Finance and Other Receivables - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended			9 Months Ended		12 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Financing Receivable	Sep. 30, 2014 Financial Services	Dec. 31, 2013 Financial Services	Sep. 30, 2014 Financial Services Minimum Loans Receivable	Sep. 30, 2014 Financial Services Maximum Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Modifications extended contractual terms					4 months	6 months
Receivable, collection period							36 months	60 months
Impaired Loans	$ 28.3		$ 10.7
Percentage of portfolio				5.00%
Loans accounted for as troubled debt restructurings					41.4	27.6
Repossessed inventory	18.4		13.7
Proceeds from the sales of repossessed assets	$ 44.3	$ 44.5