Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events (Narrative) (Details)

v3.7.0.1
Subsequent Events (Narrative) (Details)
 1 Months Ended 3 Months Ended
Aug. 09, 2017
MMBTU
$ / MMBTU
Jun. 30, 2017
MMBTU
$ / MMBTU
2018    
Subsequent Event [Line Items]    
Daily Volume (in MMBtu) | MMBTU   30,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU   3.36
NYMEX Henry Hub | 2017    
Subsequent Event [Line Items]    
Daily Volume (in MMBtu) | MMBTU   681,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU   3.20
NYMEX Henry Hub | 2018    
Subsequent Event [Line Items]    
Daily Volume (in MMBtu) | MMBTU   669,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU   3.08
NYMEX Henry Hub | 2019    
Subsequent Event [Line Items]    
Daily Volume (in MMBtu) | MMBTU   57,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU   3.10
Subsequent event | NYMEX Henry Hub | 2017    
Subsequent Event [Line Items]    
Daily Volume (in MMBtu) | MMBTU 66,000  
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU 3.08  
Subsequent event | NYMEX Henry Hub | 2018    
Subsequent Event [Line Items]    
Daily Volume (in MMBtu) | MMBTU 105,000  
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU 2.94  
Subsequent event | NYMEX Henry Hub | 2019    
Subsequent Event [Line Items]    
Daily Volume (in MMBtu) | MMBTU 50,000  
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU 3.04