v3.20.4
INVESTMENTS (Details)
$ / shares in Units, $ in Millions
1 Months Ended 3 Months Ended 12 Months Ended
Mar. 12, 2020
$ / shares
shares
Mar. 14, 2019
$ / shares
shares
Jul. 02, 2018
USD ($)
Jun. 18, 2018
USD ($)
agreement
$ / shares
shares
Dec. 26, 2013
USD ($)
item
Mar. 31, 2020
shares
Mar. 31, 2019
shares
Mar. 31, 2018
shares
Dec. 31, 2020
USD ($)
Dec. 31, 2020
USD ($)
item
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Mar. 15, 2018
$ / shares
Dec. 31, 2017
USD ($)
Investments                            
Ownership percentage                 49.00% 49.00%        
Number of Theatres | item                   3        
Equity Method Investments Ownership Transactions [Abstract]                            
Distribution and merger consideration received     $ 45.8                      
Recorded equity in earnings                   $ (30.9) $ 30.6 $ 86.7    
Amortizable intangible asset                 $ 52.7 52.7 52.5      
Fair value, reduction in investment                   8.6        
Investments in equity method investees                 $ 80.9 $ 80.9 239.1      
Europe                            
Investments                            
Ownership percentage                 50.00% 50.00%        
Number of Theatres | item                   54        
NCM                            
Investments                            
Ownership percentage       4.50% 4.00%                  
Common units returned under Common Unit Adjustment Agreement | shares 4,800,000         1,390,566 197,118 915,150            
Value of common units returned under Unit Adjustment agreement | shares   1,400,000                        
Surrender of common units for transferred theatres                   $ (6.3)   (6.3)    
Equity Method Investments Ownership Transactions [Abstract]                            
Gain on divestment of equity method investment                       30.6    
Gain (loss) on sale                       28.9    
Price per share (in dollars per share) | $ / shares $ 3.46 $ 7.24   $ 7.30                 $ 5.64  
Number of unit purchase agreements | agreement       2                    
Number of investment units sold | shares       10,738,740                    
Aggregate consideration       $ 156.8                    
Recorded equity in earnings                   28.9        
Loss NCM charged to merger, acquisition and transaction costs                       28.9    
Fair value, reduction in investment                   $ 16.0        
Investments in equity method investees                           $ 161.1
DCM                            
Investments                            
Ownership percentage                 50.00% 50.00%        
SV Holdco                            
Investments                            
Ownership percentage                 18.30% 18.30%        
SV Holdco | Class C Units                            
Investments                            
Ownership percentage                 18.30% 18.30%        
AC JV, LLC                            
Investments                            
Ownership percentage                 32.00% 32.00%        
AC JV, LLC | Founding Members                            
Investments                            
Ownership percentage         32.00%                  
Consideration received for spin-off         $ 25.0                  
AC JV, LLC | Founding Members | 5.0% Promissory Note payable to NCM due 2019                            
Investments                            
Consideration received for spin-off from each founder member         $ 8.3                  
Number of equal installments of interest and principal payments due | item         6                  
Equity Method Investments Ownership Transactions [Abstract]                            
Stated interest rate (as a percent)         5.00%                  
DCIP                            
Investments                            
Ownership percentage                 29.00% 29.00%        
Equity Method Investments Ownership Transactions [Abstract]                            
Recorded equity in earnings                   $ 14.5 $ 25.4 29.1    
Fair value, reduction in investment                 $ 125.2 8.6        
Recorded investment reduction                 0.0          
Equity recorded in net earnings                 5.1 5.1        
Investments in equity method investees                 $ 0.0 $ 0.0        
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        
DCDC                            
Investments                            
Ownership percentage                 14.60% 14.60%        
Screenvision                            
Investments                            
Ownership percentage                 18.20% 18.20%        
Percentage of attendance levels, Pre-Covid 19                   0.00%        
Equity Method Investments Ownership Transactions [Abstract]                            
Gain (loss) on sale                   $ 30.1        
Recorded equity in earnings                       $ 30.1    
Loss NCM charged to merger, acquisition and transaction costs                   $ 30.1        
Minimum | NCM                            
Equity Method Investments Ownership Transactions [Abstract]                            
Percentage change in the total annual attendance of all the founding members required to cause an earlier common unit adjustment                 2.00% 2.00%        
Maximum                            
Investments                            
Ownership percentage                 50.00% 50.00%