Annual report pursuant to Section 13 and 15(d)

ORGANIZATION - Cash Equivalents and Restricted Cash (Details)

v3.22.0.1
ORGANIZATION - Cash Equivalents and Restricted Cash (Details) - USD ($)
$ in Thousands
12 Months Ended
Feb. 07, 2022
Dec. 31, 2021
Jan. 31, 2022
Feb. 12, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Basis Of Presentation [Line Items]              
Cash and cash equivalents   $ 88,721     $ 37,698    
Total cash and cash equivalents   265,293     $ 37,698 $ 29,851 $ 20,634
Revolving Credit Facility              
Basis Of Presentation [Line Items]              
Maximum borrowing capacity   15,000          
Revolving Credit Facility | Subsequent Event              
Basis Of Presentation [Line Items]              
Maximum borrowing capacity $ 40,000            
Senior Secured Notes Due 2028              
Basis Of Presentation [Line Items]              
Proceeds from Senior Secured Notes   310,000          
Senior Secured Notes | Subsequent Event              
Basis Of Presentation [Line Items]              
Proceeds from Senior Secured Notes $ 100,000            
Senior Secured Notes | Senior Secured Notes Due 2028              
Basis Of Presentation [Line Items]              
Aggregate principal amount       $ 310,000      
Cripple Creek Project              
Basis Of Presentation [Line Items]              
Restricted cash account       $ 180,000      
Restricted cash reserved   $ 176,600          
Cripple Creek Project | Subsequent Event              
Basis Of Presentation [Line Items]              
Restricted cash reserved     $ 221,000