INCOME TAXES - Summary of Reconciliation Between Income Tax Expenses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Computed statutory tax expense	$ 46.5	$ (55.7)	$ (92.2)
State and local income taxes, net of federal income tax impact	5.4	(2.2)	(1.4)
Changes in valuation allowance	(63.9)	60.6	76.3
Foreign tax rate differential	1.4	1.3	(4.5)
Foreign tax credits	(13.0)	(4.0)	0.0
Changes in uncertain tax positions	(0.9)	1.6	7.5
U.S. tax impact of foreign operations	10.3	(1.6)	0.8
Return to provision	3.3	1.4	5.1
Expiration of attribute carryforwards	37.1	0.0	0.6
Permanent Differences	8.6	4.6	5.4
Other, net	1.7	(3.0)	(4.2)
Income taxes	29.9	3.0	(16.8)
CUSA
Income Taxes [Line Items]
Computed statutory tax expense	49.8	(50.8)	(86.6)
State and local income taxes, net of federal income tax impact	5.9	(4.2)	(0.7)
Changes in valuation allowance	(68.6)	41.8	54.3
Foreign tax rate differential	1.4	1.3	(4.5)
Foreign tax credits	(12.9)	(4.0)	0.0
Changes in uncertain tax positions	(0.9)	1.6	5.7
U.S. tax impact of foreign operations	10.4	(1.6)	0.8
Return to provision	(3.3)	1.2	(3.2)
Expiration of attribute carryforwards	36.4	0.0	0.6
Permanent Differences	8.6	4.5	5.5
Other, net	1.6	(2.9)	(4.2)
Income taxes	$ 28.4	$ (13.1)	$ (32.3)