Finance and Other Receivables (Detail) - Financial Services - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016		Sep. 30, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		$ 4,024.3	$ 3,948.6
Direct financing leases		3,142.1	2,798.0
Sales-type finance leases		761.3	867.3
Dealer wholesale financing		1,910.6	1,528.5
Operating lease receivables and other		192.1	150.9
Unearned interest: Finance leases		(362.0)	(344.7)
Finance and other receivables, net of deferred income		9,668.4	8,948.6
Less allowance for losses		(119.7)	(111.2)		$ (114.4)	$ (114.8)
Finance and other receivables, net		9,548.7	8,837.4	[1]
Loans And Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses		(104.0)	(97.1)
Dealer | Wholesale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses		(6.5)	(5.5)		(6.5)	(7.3)
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses	[2]	$ (9.2)	$ (8.6)		$ (8.4)	$ (8.3)

[1] The December 31, 2016 consolidated balance sheet has been derived from audited financial statements.

[2] Operating leases and other trade receivables.