v3.20.4
FAIR VALUE MEASUREMENTS - Fair value on a recurring basis (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Other long-term assets:    
Derivative asset   $ 38.0
Investment in NCM $ 80.9 239.1
Recurring basis    
Other long-term assets:    
Money market mutual funds 1.1 0.6
Derivative asset   38.0
Investments measured at net asset value 10.6 11.9
Investment in NCM 5.2 0.7
Total assets at fair value 16.9 51.2
Other long-term liabilities:    
Derivative liability   0.5
Total liabilities at fair value   0.5
Recurring basis | Quoted prices in active market (Level 1)    
Other long-term assets:    
Money market mutual funds 1.1 0.6
Investment in NCM 5.2 0.7
Total assets at fair value 6.3 1.3
Recurring basis | Significant unobservable inputs (Level 3)    
Other long-term assets:    
Derivative asset   38.0
Total assets at fair value   38.0
Other long-term liabilities:    
Derivative liability   0.5
Total liabilities at fair value   0.5
Nonrecurring basis | Significant unobservable inputs (Level 3)    
Other long-term assets:    
Total assets at fair value $ 8,862.9 $ 157.7