INCOME TAXES - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
DEFERRED TAX ASSETS:
Federal and state NOL carryforwards, net of liability for uncertain tax positions	$ 125.8	$ 90.2	$ 123.7
Nondeductible accrual amounts	9.6	8.1	5.9
Accrued compensation	19.3	19.9	18.5
Deferred revenue and contract liabilities	34.2	15.1	7.4
Operating lease liabilities	34.7	32.4	34.4
Interest expense carryforward	17.1	0.0	0.0
Other	3.5	1.8	0.0
Total deferred tax assets	244.2	167.5	189.9
Valuation allowance	(82.7)	(36.4)	(38.5)	$ (41.9)
Total deferred tax assets, net of valuation allowance	161.5	131.1	151.4
DEFERRED TAX LIABILITIES:
Accelerated depreciation and fixed asset basis differences for tax purposes	(349.7)	(306.7)	(307.5)
Right-of-use assets	(32.7)	(30.4)	(32.7)
Total deferred tax liabilities	(382.4)	(337.1)	(340.2)
Total net deferred tax liabilities	$ (220.9)	$ (206.0)	$ (188.8)