Finance and Other Receivables (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012		Sep. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 3,838.1	$ 3,738.2
Direct financing leases	2,621.4	2,489.3
Sales-type finance leases	875.6	916.8
Dealer wholesale financing	1,736.2	1,541.0
Operating lease and other trade receivables	118.9	112.0
Unearned interest on finance leases	(363.6)	(369.0)
Loans and Leases Receivable, Net of Deferred Income, Total	8,826.6	8,428.3
Less allowance for losses	(131.7)	(130.0)		(139.1)	(139.0)
Finance and other receivables, net	8,694.9	8,298.3	[1]
Loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses	(112.1)	(112.6)
Dealer wholesale financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses	(10.9)	(11.8)		(12.4)	(11.7)
Operating lease and other trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses	$ (8.7)	$ (5.6)

[1] The December 31, 2012 consolidated balance sheet has been derived from audited financial statements.