GOODWILL (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) segment
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 2,547.3
Currency translation adjustment	(52.6)
Baltics disposition-Latvia	(3.7)
Balance at the end of the period	$ 2,491.0
Number of reporting units | segment	2
Domestic theatres
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 1,796.5
Balance at the end of the period	1,796.5
International theatres
Goodwill [Roll Forward]
Balance at the beginning of the period	750.8
Currency translation adjustment	(52.6)
Baltics disposition-Latvia	(3.7)
Balance at the end of the period	$ 694.5