Summary of Impaired Loans (Cash Basis Method) (Detail) - Financial Services - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income recognized:
Interest income recognized on a cash basis	$ 1.7	$ 2.2	$ 1.7
Dealer | Retail
Interest income recognized:
Interest income recognized on a cash basis	0.2
Customer Retail | Fleet
Interest income recognized:
Interest income recognized on a cash basis	1.3	2.0	1.6
Customer Retail | Owner/Operator
Interest income recognized:
Interest income recognized on a cash basis	$ 0.2	$ 0.2	$ 0.1