|
Derivative Instruments and Hedging Activities (Derivatives Designated as Hedging Instruments/ Derivatives Not Designated as Hedging Instruments) (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
|
Jun. 30, 2013
|
Jun. 30, 2012
|
Jun. 30, 2013
|
Jun. 30, 2012
|
|
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Unrealized gain (loss), net | $ 249 | $ 3,897 | ||
|
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
|
||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Amount of gain (loss) reclassified from OCI into income (effective portion) | 0 | 512 | 0 | 512 |
| Amount of gain (loss) recognized in income (ineffective portion and amount excluded from effectiveness testing) | 0 | 92 | 0 | 322 |
|
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
|
||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Unrealized gain (loss), net | 1,981 | 3,505 | 1,563 | 3,575 |
|
Commodity Contract [Member] | Natural gas [Member] | Not Designated as Hedging Instrument [Member]
|
||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Realized gain (loss), net | (156) | 0 | (107) | 0 |
| Total gain (loss), net | 329 | (331) | (10) | (331) |
| Unrealized gain (loss), net | 485 | (331) | 97 | (331) |
|
Commodity Contract [Member] | Crude Oil [Member] | Not Designated as Hedging Instrument [Member]
|
||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Realized gain (loss), net | 849 | 0 | 1,422 | 0 |
| Total gain (loss), net | 1,652 | 3,836 | 1,573 | 3,906 |
| Unrealized gain (loss), net | $ 803 | $ 3,836 | $ 151 | $ 3,906 |