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Derivative Instruments (Schedule of Derivative Instruments) (Details) | Sep. 30, 2017 MMBTU $ / bbl $ / MMBTU bbl
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NYMEX Henry Hub Swap - 2017 |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 765,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU | 3.19
NYMEX Henry Hub Swap - 2017 | Short | Call Option |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 65,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU | 3.11
NYMEX Henry Hub Swap - 2018 |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 898,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU | 3.06
NYMEX Henry Hub Swap - 2018 | Short | Call Option |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 103,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU | 3.25
NYMEX Henry Hub Swap - 2019 |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 112,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU | 3.01
NYMEX Henry Hub Swap - 2019 | Short | Call Option |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 135,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU | 3.07
ARGUS LLS Swap - 2017 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 1,500
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 53.12
ARGUS LLS Swap - 2018 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 1,000
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 53.91
NYMEX WTI Swap - 2017 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 4,500
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 54.89
NYMEX WTI Swap - 2018 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 3,000
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 52.24
Mont Belvieu C3 Swap - 2017 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 3,000
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 26.63
Mont Belvieu C3 Swap - 2018 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 3,500
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 28.03
Mont Belvieu C5 Swap - 2017 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 250
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 49.14
Mont Belvieu C5 Swap - 2018 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 500
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl | 46.62
NPGL Mid-Continent Swap - 2017 | Short | Call Option |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 50,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU | 0.26
NPGL Mid-Continent Swap - 2018 | Short | Call Option |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 12,000

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