v3.24.0.1
FAIR VALUE MEASUREMENTS - Fair value on a recurring basis (Details)
$ in Millions
Dec. 31, 2023
USD ($)
Y
$ / shares
Dec. 31, 2022
USD ($)
Other long-term assets:    
The company's recorded investment $ 56.4 $ 69.6
Price Volatility Rate | Investment in Hycroft Mining Holding Corporation Warrants    
Other long-term assets:    
Estimates to value warrants 1.30  
Discount yield | Investment in Hycroft Mining Holding Corporation Warrants    
Other long-term assets:    
Estimates to value warrants 0.40  
Expected Term | Investment in Hycroft Mining Holding Corporation Warrants    
Other long-term assets:    
Estimates to value warrants | Y 3.2  
Exercise Price | Investment in Hycroft Mining Holding Corporation Warrants    
Other long-term assets:    
Estimates to value warrants | $ / shares 10.68  
Recurring basis    
Other long-term assets:    
Total assets at fair value $ 9.1 21.7
Recurring basis | Investment in Hycroft Mining Holding Corporation Warrants    
Other long-term assets:    
Investments measured at net asset value 3.3 9.2
Recurring basis | Hycroft    
Other long-term assets:    
The company's recorded investment 5.8 12.5
Recurring basis | Quoted prices in active market (Level 1)    
Other long-term assets:    
Total assets at fair value 5.8 12.5
Recurring basis | Quoted prices in active market (Level 1) | Hycroft    
Other long-term assets:    
The company's recorded investment 5.8 12.5
Recurring basis | Significant unobservable inputs (Level 3)    
Other long-term assets:    
Total assets at fair value 3.3 9.2
Recurring basis | Significant unobservable inputs (Level 3) | Investment in Hycroft Mining Holding Corporation Warrants    
Other long-term assets:    
Investments measured at net asset value 3.3 9.2
Nonrecurring basis    
Other long-term assets:    
Total assets at fair value 107.9 133.1
Nonrecurring basis | Total Carrying Value    
Other long-term assets:    
Total assets at fair value 138.2 195.7
Nonrecurring basis | Significant unobservable inputs (Level 3)    
Other long-term assets:    
Total assets at fair value $ 138.2 $ 195.7