Goodwill and Other Intangible Assets - Components of Other Intangible Assets (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Intangible Assets by Major Class [Line Items]
Weighted-average useful life (years)	16 years
Total amortizable	$ 472.7	$ 472.8
Less: Accumulated amortization	(146.3)	(120.7)
Net amortized other intangible assets	326.4	352.1
Total other intangible assets, net	$ 660.0	686.4
Non-compete agreements
Intangible Assets by Major Class [Line Items]
Weighted-average useful life (years)	4 years
Total amortizable	$ 2.6	2.6
Dealer/customer related
Intangible Assets by Major Class [Line Items]
Weighted-average useful life (years)	17 years
Total amortizable	$ 460.3	460.3
Developed technology
Intangible Assets by Major Class [Line Items]
Weighted-average useful life (years)	5 years
Total amortizable	$ 9.8	9.9
Brand/trade names
Intangible Assets by Major Class [Line Items]
Non-amortizable—brand/trade names	$ 333.6	$ 334.3