v3.20.4
THE COMPANY AND SIGNIFICANT ACCOUNTING POLICIES - Investments, Goodwill, Payables, Leases (Details)
$ in Millions
3 Months Ended 12 Months Ended
Sep. 30, 2019
USD ($)
Jun. 18, 2018
USD ($)
item
Dec. 31, 2020
USD ($)
Sep. 30, 2020
USD ($)
Mar. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2020
USD ($)
item
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Jan. 01, 2019
USD ($)
Dec. 26, 2013
Investments                      
Impairment of definite-lived intangible assets             $ 14.4        
Impairment of indefinite-lived intangible assets             $ 15.2 $ 0.0 $ 0.0    
Ownership percentage     49.00%       49.00%        
Number of theatres | item             3        
Number of Reporting Units | item             2        
Goodwill     $ 2,547.3     $ 4,789.1 $ 2,547.3 4,789.1 4,788.7    
Goodwill impairment $ 0.0   405.3 $ 156.8 $ 1,744.3   2,306.4        
Percentage of company's market enterprise value           80.00%          
Accounts payable related to checks issued but not yet presented to bank     $ 1.8     $ 40.9 $ 1.8 40.9      
Optional renewal term, operating lease     20 years       20 years        
Number of theatres sold | item   1                  
Net proceeds   $ 50.1             50.1    
Deferred gain on sale   $ 27.3               $ 102.4  
U.S.                      
Investments                      
Goodwill     $ 1,796.5     3,072.6 $ 1,796.5 3,072.6 3,072.6    
Percentage the reporting unit's carrying value exceeds its fair value 9.90%                    
Goodwill impairment       151.2 1,124.9   405.3        
International markets                      
Investments                      
Goodwill     750.8     $ 1,716.5 $ 750.8 $ 1,716.5 $ 1,716.1    
Percentage the reporting unit's carrying value exceeds its fair value 11.80%                    
Goodwill impairment     $ 405.3 $ 5.6 $ 619.4            
Nordic                      
Investments                      
Ownership percentage     50.00%       50.00%        
Number of theatres | item             54        
Minimum                      
Investments                      
Initial base terms of operating leases     12 years       12 years        
Operating lease, remaining lease term     1 year       1 year        
Maximum                      
Investments                      
Ownership percentage     50.00%       50.00%        
Initial base terms of operating leases     15 years       15 years        
Operating lease, remaining lease term     25 years       25 years        
NCM                      
Investments                      
Ownership percentage   4.50%                 4.00%
SV Holdco                      
Investments                      
Ownership percentage     18.30%       18.30%        
SV Holdco | Class C Units                      
Investments                      
Ownership percentage     18.30%       18.30%        
DCM                      
Investments                      
Ownership percentage     50.00%       50.00%        
AC JV, LLC                      
Investments                      
Ownership percentage     32.00%       32.00%        
DCIP                      
Investments                      
Ownership percentage     29.00%       29.00%        
DCDC                      
Investments                      
Ownership percentage     14.60%       14.60%        
SCC                      
Investments                      
Ownership percentage     10.00%       10.00%        
U.S. theatres and IMAX screen                      
Investments                      
Ownership percentage     50.00%       50.00%        
Number of theatres | item             3