Summary of Financial Services Lease Revenues by Lease Type (Detail) - Financial Services - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Entity Wide Information Revenue From External Customer [Line Items]
Finance lease revenues	$ 46.7	$ 45.9	$ 142.8	$ 138.3
Operating lease revenues	206.4	198.8	627.9	593.3
Total lease revenues	$ 253.1	$ 244.7	$ 770.7	$ 731.6