Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments (Schedule of Derivative Instruments) (Details)

v3.10.0.1
Derivative Instruments (Schedule of Derivative Instruments) (Details)
Jun. 30, 2018
MMBTU
$ / MMBTU
$ / bbl
bbl
NYMEX Henry Hub Swap - 2018  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 1,010,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU (3.01)
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 1,154,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU (2.81)
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 204,000
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 4,500
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl (53.72)
NYMEX WTI Swap - 2019  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 4,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl (58.28)
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 3,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl (27.71)
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)
Mont Belvieu C5 Swap - 2019  
Derivative [Line Items]  
Daily Volume (Bbls/day) | bbl 500
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl (54.08)
Transco Zone 4 - 2018  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 20,000
Transco Zone 4 - 2018 | Long  
Derivative [Line Items]  
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU (0.05)
Transco Zone 4 - 2019  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 60,000
Transco Zone 4 - 2019 | Long  
Derivative [Line Items]  
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU (0.05)
Transco Zone 4 - 2020  
Derivative [Line Items]  
Daily Volume (MMBtu/day) | MMBTU 60,000
Transco Zone 4 - 2020 | Long  
Derivative [Line Items]  
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU (0.05)