|
Fair Value Measurements (Fair Value of Liabilities Measured on Recurring Basis) (Details) (USD $)
In Thousands, unless otherwise specified |
6 Months Ended | ||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Jun. 30, 2012
|
Dec. 31, 2011
|
Jun. 30, 2012
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Dec. 31, 2011
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Jun. 30, 2012
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Dec. 31, 2011
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Jun. 30, 2012
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Dec. 31, 2011
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Jun. 30, 2012
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
Dec. 31, 2011
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
Jun. 30, 2012
Fair Value on a nonrecurring basis [Member]
Level 3 [Member]
|
Jun. 30, 2012
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Dec. 31, 2011
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Jun. 30, 2012
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Dec. 31, 2011
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Jun. 30, 2012
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Dec. 31, 2011
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Jun. 30, 2012
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
Dec. 31, 2011
Current assets - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
Jun. 30, 2012
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Dec. 31, 2011
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Jun. 30, 2012
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Dec. 31, 2011
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Jun. 30, 2012
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Dec. 31, 2011
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Jun. 30, 2012
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
Dec. 31, 2011
Other long-term assets [Member]
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
Jun. 30, 2012
Current liabilities - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Jun. 30, 2012
Current liabilities - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Jun. 30, 2012
Current liabilities - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Jun. 30, 2012
Current liabilities - Fair market value of derivatives [Member]
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
Jun. 30, 2012
Other long-term liabilities [Member]
Fair Value on a recurring basis [Member]
Level 1 [Member]
|
Jun. 30, 2012
Other long-term liabilities [Member]
Fair Value on a recurring basis [Member]
Level 2 [Member]
|
Jun. 30, 2012
Other long-term liabilities [Member]
Fair Value on a recurring basis [Member]
Level 3 [Member]
|
Jun. 30, 2012
Other long-term liabilities [Member]
Fair Value on a recurring basis [Member]
Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
| Derivative Assets | |||||||||||||||||||||||||||||||||||
| Derivative Assets, Current | $ 4,645 | $ 2,499 | $ 0 | $ 4,645 | $ 2,499 | $ 0 | $ 4,645 | $ 2,499 | |||||||||||||||||||||||||||
| Derivative Assets, Noncurrent | 0 | 1,982 | 0 | 1,982 | |||||||||||||||||||||||||||||||
| Derivative Liabilities | |||||||||||||||||||||||||||||||||||
| Derivative Liabilities, Current | 0 | 0 | 0 | 0 | |||||||||||||||||||||||||||||||
| Derivative Liabilities, Noncurrent | 0 | 350 | 0 | 350 | |||||||||||||||||||||||||||||||
| Derivative Assets (Liabilities), at Fair Value, Net | 0 | 6,277 | 2,499 | 0 | 6,277 | 2,499 | |||||||||||||||||||||||||||||
| Asset Retirement Obligation, Fair Value Disclosure | $ 0 | ||||||||||||||||||||||||||||||||||