INVESTMENTS - Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Digital Cinema Media Ltd. ("DCM")
Related Party Transactions
Loan receivable from related party	$ 0.6	$ 0.6
Digital Cinema Media Ltd. ("DCM") \| Other revenues
Related Party Transactions
Screen advertising revenues	17.8	18.8	$ 17.0
Digital Cinema Media Ltd. ("DCM") \| On-screen advertising revenue
Related Party Transactions
Amounts due from related parties	3.9	3.3
Digital Cinema Distribution Coalition, LLC ("DCDC") \| Operating expense
Related Party Transactions
Content delivery services	1.3	1.4	1.0
AC JV \| Film exhibition costs
Related Party Transactions
Gross exhibition cost	29.6	17.5	11.6
AC JV \| Fathom Events programming
Related Party Transactions
Amount due to related parties	(1.5)	(2.3)
CAPA Kinoreklame AS ("CAPA") \| Other revenues
Related Party Transactions
Screen advertising revenues	1.6	1.1	2.4
CAPA Kinoreklame AS ("CAPA") \| On-screen advertising revenue
Related Party Transactions
Amounts due from related parties	1.4	1.4
Vasteras Biografer
Related Party Transactions
Loan receivable from related party	0.8	1.0
Amount due to related parties	(0.6)	(0.9)
Screenvision \| Other revenues
Related Party Transactions
Screen advertising revenues	7.3	8.7	$ 6.9
U.S. theatres and IMAX screen \| Theatre partnerships
Related Party Transactions
Amount due to related parties	$ (0.7)	$ (0.6)