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Business Segment Information - Major Customers (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2014
|
Sep. 30, 2014
|
Jun. 30, 2014
|
Mar. 31, 2014
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Dec. 31, 2013
|
Sep. 30, 2013
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Jun. 30, 2013
|
Mar. 31, 2013
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Dec. 31, 2014
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Dec. 31, 2013
|
Dec. 31, 2012
|
|
| Revenue, Major Customer [Line Items] | |||||||||||
| Sales | $ 346,881 | $ 394,107 | $ 374,714 | $ 443,056 | $ 465,108 | $ 493,603 | $ 512,987 | $ 511,690 | $ 1,558,758 | $ 1,983,388 | $ 1,934,642 |
| Plains Marketing, L.P. | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Sales | 597,117 | 491,258 | 426,339 | ||||||||
| Percentage of revenue | 38.30% | 24.80% | 15.60% | ||||||||
| Shell Trading (US) Company | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Sales | 347,422 | ||||||||||
| Percentage of revenue | 17.50% | ||||||||||
| Atlas Pipeline Mid-Continent West OK LLC | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Sales | 333,027 | 211,838 | |||||||||
| Percentage of revenue | 21.40% | 10.70% | |||||||||
| Enterprise Crude Oil, LLC | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Sales | $ 394,162 | ||||||||||
| Percentage of revenue | 14.40% | ||||||||||