Derivative Financial Instruments (Natural Gas Derivative Contracts) (Details) (Natural Gas Derivative Contracts [Member]) | 9 Months Ended |
Sep. 30, 2014 |
MMBTU |
2014 [Member] | Price Swap Contracts [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 1,765,000 |
Weighted Average Swap Price | 4.5 |
2014 [Member] | Price Swap Contracts [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Swap Price | 5.6 |
2014 [Member] | Price Swap Contracts [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Swap Price | 4.01 |
2014 [Member] | Short Call Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 2,739,000 |
Weighted Average Option Price | 5.41 |
2014 [Member] | Short Call Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 7.92 |
2014 [Member] | Short Call Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.75 |
2014 [Member] | Long Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 760,000 |
Weighted Average Option Price | 4.74 |
2014 [Member] | Long Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5.5 |
2014 [Member] | Long Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.25 |
2014 [Member] | Long Call Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 1,569,871 |
Weighted Average Option Price | 5.63 |
2014 [Member] | Long Call Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 7.92 |
2014 [Member] | Long Call Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.5 |
2014 [Member] | Short Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 2,268,800 |
Weighted Average Option Price | 3.52 |
2014 [Member] | Short Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4 |
2014 [Member] | Short Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 3 |
2015 [Member] | Price Swap Contracts [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 3,832,500 |
Weighted Average Swap Price | 5.07 |
2015 [Member] | Price Swap Contracts [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Swap Price | 5.91 |
2015 [Member] | Price Swap Contracts [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Swap Price | 4.31 |
2015 [Member] | Short Call Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 7,750,000 |
Weighted Average Option Price | 4.59 |
2015 [Member] | Short Call Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5.75 |
2015 [Member] | Short Call Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.51 |
2015 [Member] | Long Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 8,113,500 |
Weighted Average Option Price | 4.01 |
2015 [Member] | Long Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5 |
2015 [Member] | Long Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 3.5 |
2015 [Member] | Long Call Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 495,000 |
Weighted Average Option Price | 4.31 |
2015 [Member] | Long Call Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.31 |
2015 [Member] | Long Call Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.31 |
2015 [Member] | Short Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 9,116,000 |
Weighted Average Option Price | 3.34 |
2015 [Member] | Short Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.45 |
2015 [Member] | Short Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 3.25 |
2016 [Member] | Price Swap Contracts [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 8,418,000 |
Weighted Average Swap Price | 4.22 |
2016 [Member] | Price Swap Contracts [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Swap Price | 4.23 |
2016 [Member] | Price Swap Contracts [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Swap Price | 4.22 |
2016 [Member] | Short Call Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 455,000 |
Weighted Average Option Price | 7.5 |
2016 [Member] | Short Call Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 7.5 |
2016 [Member] | Short Call Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 7.5 |
2016 [Member] | Long Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 455,000 |
Weighted Average Option Price | 5.5 |
2016 [Member] | Long Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5.5 |
2016 [Member] | Long Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5.5 |
2016 [Member] | Short Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 1,681,100 |
Weighted Average Option Price | 3.64 |
2016 [Member] | Short Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4 |
2016 [Member] | Short Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 3.5 |
2017 [Member] | Short Call Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 6,570,000 |
Weighted Average Option Price | 5 |
2017 [Member] | Short Call Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5 |
2017 [Member] | Short Call Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.98 |
2017 [Member] | Long Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 6,570,000 |
Weighted Average Option Price | 4.5 |
2017 [Member] | Long Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.5 |
2017 [Member] | Long Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.5 |
2017 [Member] | Short Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 6,570,000 |
Weighted Average Option Price | 4 |
2017 [Member] | Short Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4 |
2017 [Member] | Short Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4 |
2018 [Member] | Short Call Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 5,475,000 |
Weighted Average Option Price | 5.5 |
2018 [Member] | Short Call Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5.53 |
2018 [Member] | Short Call Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 5.48 |
2018 [Member] | Long Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 5,475,000 |
Weighted Average Option Price | 4.5 |
2018 [Member] | Long Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.5 |
2018 [Member] | Long Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4.5 |
2018 [Member] | Short Put Options [Member] | ' |
Derivative [Line Items] | ' |
Volume in MMbtu | 5,475,000 |
Weighted Average Option Price | 4 |
2018 [Member] | Short Put Options [Member] | Maximum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4 |
2018 [Member] | Short Put Options [Member] | Minimum [Member] | ' |
Derivative [Line Items] | ' |
Option Price | 4 |