LEASES - Lease costs (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases:
Interest expense on lease liabilities	$ 3.7	$ 4.1	$ 5.2
Total lease cost	967.4	972.2	898.4
Depreciation and amortization
Leases:
Amortization of finance lease assets	2.0	2.6	4.6
Finance lease obligations
Leases:
Interest expense on lease liabilities	3.7	4.1	5.2
Theatres \| Rent
Leases:
Operating lease cost	788.1	812.0	775.4
Variable lease cost	85.4	74.2	52.6
Theatres \| Operating expense (income)
Leases:
Operating lease cost	2.0	5.4	1.1
Equipment \| Operating expense (income)
Leases:
Operating lease cost	17.5	8.6	10.7
Variable lease cost	63.3	60.0	43.4
Office And Other \| General and administrative: other
Leases:
Operating lease cost	$ 5.4	$ 5.3	$ 5.4

Amount of interest expense on finance lease liability.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479589/842-20-55-53

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
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-Name Accounting Standards Codification
-Section 45
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
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Amount of lease cost recognized by lessee for lease contract.

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