Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments (Schedule of Derivative Instruments) (Details)

v3.8.0.1
Derivative Instruments (Schedule of Derivative Instruments) (Details)
Mar. 31, 2018
MMBTU
$ / bbl
$ / MMBTU
bbl
NYMEX Henry Hub Swap - 2018  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 927,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU 3.02
NYMEX Henry Hub Swap - 2018 | Short | Call Option  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 50,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU 3.13
NYMEX Henry Hub Swap - 2019  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 647,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU 2.84
NYMEX Henry Hub Swap - 2019 | Short | Call Option  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 30,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU 3.10
NYMEX Henry Hub Swap - 2020  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 45,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU 2.77
ARGUS LLS Swap - 2018  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 2,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl 56.22
ARGUS LLS Swap - 2019  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 1,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl 59.55
NYMEX WTI Swap - 2018  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 4,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl 53.99
NYMEX WTI Swap - 2019  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 3,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl 57.62
Mont Belvieu C3 Swap - 2018  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 4,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl 28.97
Mont Belvieu C3 Swap - 2019  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 1,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl 27.05
Mont Belvieu C5 Swap - 2018  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 500
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl 46.62