Annual report pursuant to Section 13 and 15(d)

Accounts Receivable and Major Customers - Additional Information (Detail)

v3.20.4
Accounts Receivable and Major Customers - Additional Information (Detail)
12 Months Ended
Dec. 31, 2020
USD ($)
Customer
Dec. 31, 2019
USD ($)
Customer
Jan. 01, 2020
USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Customers $ 39,672,000 $ 63,165,000  
Retained earnings 9,354,000 319,987,000  
Accounts Receivable, Allowance for Credit Loss 197,000 52,000  
Accounts Receivable, Credit Loss Expense (Reversal) 69,000    
Accounts Receivable, Allowance for Credit Loss, Writeoff $ 0    
Name of Major Customer [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commodity Products, Number of Customers | Customer 20    
Financing Receivable, Credit Risk Percentage 0.00%    
Accounts Receivable, Allowance for Credit Loss $ 0 0  
Accounts Receivable, Credit Loss Expense (Reversal) 0    
Accounts Receivable, Allowance for Credit Loss, Writeoff $ 0    
Joint Interest Partners, Mutual Operators [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commodity Products, Number of Customers | Customer 2    
Financing Receivable, Credit Risk Percentage 5.00%   0.00%
Accounts Receivable, Allowance for Credit Loss $ 9,000 0  
Accounts Receivable, Credit Loss Expense (Reversal) 9,000    
Accounts Receivable, Allowance for Credit Loss, Writeoff $ 0    
Joint Interest Partners, Large Partners [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commodity Products, Number of Customers | Customer 3    
Financing Receivable, Credit Risk Percentage     1.00%
Accounts Receivable, Allowance for Credit Loss $ 87,000 0  
Accounts Receivable, Credit Loss Expense (Reversal) 27,000    
Accounts Receivable, Allowance for Credit Loss, Writeoff $ 0    
Joint Interest Partners, All Others [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commodity Products, Number of Customers | Customer 20    
Financing Receivable, Credit Risk Percentage 10.00%   5.00%
Financing Receivable, Past Due $ 200,000    
Accounts Receivable, Allowance for Credit Loss 101,000 $ 52,000  
Accounts Receivable, Credit Loss Expense (Reversal) 33,000    
Accounts Receivable, Allowance for Credit Loss, Writeoff 0    
Cumulative Effect, Period of Adoption, Adjustment [Member]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accounts Receivable, Allowance for Credit Loss     $ 76,000
Cumulative Effect, Period of Adoption, Adjustment [Member] | Name of Major Customer [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accounts Receivable, Allowance for Credit Loss     0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Joint Interest Partners, Mutual Operators [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accounts Receivable, Allowance for Credit Loss     0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Joint Interest Partners, Large Partners [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accounts Receivable, Allowance for Credit Loss     60,000
Cumulative Effect, Period of Adoption, Adjustment [Member] | Joint Interest Partners, All Others [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accounts Receivable, Allowance for Credit Loss     $ 16,000
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Retained earnings $ 100,000    
Accounts Receivable | Customer Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Number of major customers | Customer 3 4  
Revenues, major customers $ 150,800,000 $ 354,600,000  
Concentration risk, percentage 56.00% 76.00%  
Accounts Receivable | Customer Concentration Risk | Major Customer 1      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers $ 72,300,000 $ 172,300,000  
Concentration risk, percentage 27.00% 37.00%  
Accounts Receivable | Customer Concentration Risk | Major Customer 2      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers $ 50,200,000 $ 84,600,000  
Concentration risk, percentage 19.00% 18.00%  
Accounts Receivable | Customer Concentration Risk | Major Customer 3      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers $ 28,300,000 $ 50,700,000  
Concentration risk, percentage 10.00% 11.00%  
Accounts Receivable | Customer Concentration Risk | Major Customer Four [Domain]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers   $ 47,000,000.0  
Concentration risk, percentage   10.00%  
Accounts Receivable | Credit Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Concentration risk, percentage 47.00% 70.00%  
Accounts receivable, major customers $ 18,600,000 $ 44,500,000