INCOME TAX - Reconciliation Between Income Tax Expense and Computed Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax at Federal statutory rate	$ 20.0	$ 21.8	$ 18.4
State and local income taxes, net of federal tax benefit	3.5	3.7	2.9
Reversal of valuation allowances	0.0	0.0	(3.4)
Stock based compensation	(0.1)	0.0	(0.8)
Non-deductible items	0.5	0.7	0.5
Other items, net	0.6	(0.5)	(0.1)
Income tax	$ 24.5	$ 25.7	$ 17.5
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax at Federal statutory rate	21.00%	21.00%	21.00%
State and local income taxes, net of federal tax benefit	3.70%	3.70%	3.30%
Reversal of valuation allowances	0.00%	0.00%	(3.80%)
Stock based compensation	(0.10%)	0.00%	(0.90%)
Non-deductible items	0.50%	0.60%	0.50%
Other items, net	0.60%	(0.50%)	(0.10%)
Income tax	25.70%	24.80%	20.00%