v3.21.1
FAIR VALUE MEASUREMENTS - Fair value on a recurring basis (Details) - Recurring basis
$ in Millions
Mar. 31, 2021
USD ($)
Other long-term assets:  
Money market mutual funds $ 1.1
Investments measured at net asset value 10.7
Investment in NCM 5.8
Total assets at fair value 17.6
Quoted prices in active market (Level 1)  
Other long-term assets:  
Money market mutual funds 1.1
Investment in NCM 5.8
Total assets at fair value $ 6.9