XML 58 R36.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]      
Allowance for uncollectible accounts $ 9.2 $ 9.9  
Income tax refund claims 19.1 18.0  
Gas imbalance receivable 1.7 1.7  
Gas imbalance payable 3.6 3.6  
Impairment to adjust other well equipment inventory $ 0.7 0.2 $ 0.2
Minimum      
Summary Of Significant Accounting Policies [Line Items]      
Other property and equipment, estimated useful lives 3 years    
Number of common stock issuable upon vesting, percentage range of PSUs granted 0.00%    
Maximum      
Summary Of Significant Accounting Policies [Line Items]      
Other property and equipment, estimated useful lives 10 years    
Number of common stock issuable upon vesting, percentage range of PSUs granted 200.00%    
Measurement Input Discount Rate      
Summary Of Significant Accounting Policies [Line Items]      
Present value of future net revenues from proved reserves, discount rate 10.00%    
Other Revenue      
Summary Of Significant Accounting Policies [Line Items]      
Refund liability $ 8.9 19.3  
ILX and Castex      
Summary Of Significant Accounting Policies [Line Items]      
Escrow deposit   $ 31.8