Summary of Impaired Loans (Cash Basis Method) (Detail) - Financial Services - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income recognized:
Interest income recognized on a cash basis	$ 0.5	$ 0.6	$ 1.5	$ 1.3
Customer Retail | Fleet
Interest income recognized:
Interest income recognized on a cash basis	0.4	0.4	1.2	1.0
Customer Retail | Owner/Operator
Interest income recognized:
Interest income recognized on a cash basis	$ 0.1	0.1	0.2	0.2
Dealer | Retail
Interest income recognized:
Interest income recognized on a cash basis		$ 0.1	$ 0.1	$ 0.1