INCOME TAXES - Reconciliation of Total Amounts of Unrecognized Tax Benefits Excluding Interest and Penalties (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Beginning Balance	$ 55.8	$ 55.9	$ 46.5
Gross increases - tax positions in prior periods	2.2	0.0	7.7
Gross decreases - tax positions in prior periods	(5.1)	(0.2)	(1.6)
Gross increases - current period tax positions	0.2	0.1	3.4
Statute of limitations expiration	(0.2)	0.0	(0.1)
Ending Balance	52.9	55.8	55.9
CUSA
Income Taxes [Line Items]
Beginning Balance	53.9	54.0	46.5
Gross increases - tax positions in prior periods	2.2	0.0	5.8
Gross decreases - tax positions in prior periods	(5.1)	(0.2)	(1.6)
Gross increases - current period tax positions	0.2	0.1	3.4
Statute of limitations expiration	(0.2)	0.0	(0.1)
Ending Balance	$ 51.0	$ 53.9	$ 54.0