Annual report pursuant to Section 13 and 15(d)

Commitments - Narrative (Details)

v3.10.0.1
Commitments - Narrative (Details)
 12 Months Ended
Jan. 01, 2017
Mar. 11, 1997
USD ($)
well
Dec. 31, 2018
USD ($)
MMBtu_per_day
well
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Commitments [Line Items]          
Plugging and abandonment escrow account on the WCBB properties (Note 15)     $ 3,100,000    
Maximum annual contributions per employee (401K Plan)     100.00%    
Cost recognized on defined contribution plan     $ 2,600,000 $ 3,000,000 $ 1,700,000
Purchase commitment daily volume | MMBtu_per_day     2,300,000    
Chief Executive Officer          
Commitments [Line Items]          
Payment of separation costs     $ 400,000    
Management          
Commitments [Line Items]          
Employment agreement term 1 year        
Employment agreement, subsequent extension 1 year        
Employment agreement, notice period allowed for termination 30 days        
Minimum          
Commitments [Line Items]          
Minimum matching employer contribution for 401K     3.00%    
Operating lease term (exceeding one year)     1 year    
Supply agreement non-utilization fees | Muskie Proppant LLC          
Commitments [Line Items]          
Non-utilization fees incurred     $ 2,200,000 $ 0  
WCBB          
Commitments [Line Items]          
Remaining percent interest in properties   50.00%      
Monthly payments to abandonment trust obligation   $ 18,000      
Plugging commitment (wells) | well   20      
Period of well plugging commitment   20 years      
Number of wells plugged to date | well     555