Changes in and Reclassifications out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 2,042.1	$ 1,916.4
Interest and other borrowing costs	275.7	138.8	$ 124.5
Income taxes	(42.2)	(63.1)	(48.2)
Ending balance	1,931.2	2,042.1	1,916.4
Accumulated Gain (Loss) Net Cash Flow Hedge Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	18.4	(1.9)	(25.3)
Amounts recorded in AOCL related to Unrealized (loss) gain on derivative contracts, before tax	(5.2)	(0.9)	18.7
Amounts recorded in AOCL related to Unrealized (loss) gain on derivative contracts, income tax effect	1.3	0.2	(4.6)
Net other comprehensive income (loss)	(7.4)	20.3	23.4
Ending balance	11.0	18.4	(1.9)
Accumulated Gain (Loss) Net Cash Flow Hedge Parent | Amounts reclassified out of AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and other borrowing costs	(4.6)	27.9	12.4
Income taxes	$ 1.1	$ (6.9)	$ (3.1)