| Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Text Block] |
The fair values of our derivative instruments included in our consolidated balance sheets were as follows: | | | | | | | | | | | | | | | | | | | | | | Asset Derivatives | | Liability Derivatives | | Balance Sheet Location | | March 31, 2012 | | December 31, 2011 | | March 31, 2012 | | December 31, 2011 | | | | (Thousands of Dollars) | Derivatives Designated as Hedging Instruments: | | | | | | | | | | Commodity contracts | Other current assets | | $ | — |
| | $ | 36,116 |
| | $ | — |
| | $ | (33,616 | ) | Commodity contracts | Other long-term assets, net | | 25,634 |
| | 86,052 |
| | (20,257 | ) | | (66,175 | ) | Interest rate swaps | Other long-term assets, net | | 581 |
| | 2,335 |
| | — |
| | — |
| Commodity contracts | Accrued liabilities | | 640 |
| | — |
| | (24,286 | ) | | — |
| Interest rate swaps | Accrued liabilities | | — |
| | — |
| | (9,796 | ) | | (22,009 | ) | Commodity contracts | Other long-term liabilities | | — |
| | — |
| | (5,665 | ) | | — |
| Interest rate swaps | Other long-term liabilities | | — |
| | — |
| | (11,221 | ) | | (27,190 | ) | Total | | | 26,855 |
| | 124,503 |
| | (71,225 | ) | | (148,990 | ) | | | | | | | | | | | Derivatives Not Designated as Hedging Instruments: | | | | | | | | | | Commodity contracts | Other current assets | | 30,863 |
| | 15,568 |
| | (8,654 | ) | | (5,956 | ) | Commodity contracts | Other long-term assets, net | | — |
| | 7,207 |
| | — |
| | — |
| Commodity contracts | Accrued liabilities | | 21,831 |
| | 519 |
| | (36,377 | ) | | (5,943 | ) | Commodity contracts | Other long-term liabilities | | — |
| | — |
| | (874 | ) | | — |
| Total | | | 52,694 |
| | 23,294 |
| | (45,905 | ) | | (11,899 | ) | | | | | | | | | | | Total Derivatives | | | $ | 79,549 |
| | $ | 147,797 |
| | $ | (117,130 | ) | | $ | (160,889 | ) |
|
| Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Text Block] |
The earnings impact of our derivative activity was as follows: | | | | | | | | | | | | | | | | Derivatives Designated as Fair Value Hedging Instruments | | Income Statement Location | | Amount of Gain (Loss) Recognized in Income on Derivative (Effective Portion) | | Amount of Gain (Loss) Recognized in Income on Hedged Item | | Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion) | | | | | (Thousands of Dollars) | Three months ended March 31, 2012: | | | | | | | | | Interest rate swaps | | Interest expense, net | | $ | 2,228 |
| | $ | (2,228 | ) | | $ | — |
| Commodity contracts | | Cost of product sales | | (2,587 | ) | | 2,390 |
| | (197 | ) | Total | | | | $ | (359 | ) | | $ | 162 |
| | $ | (197 | ) | | | | | | | | | | Three months ended March 31, 2011: | | | | | | | | | Interest rate swaps | | Interest expense, net | | $ | (5,914 | ) | | $ | 5,960 |
| | $ | 46 |
| Commodity contracts | | Cost of product sales | | (12,066 | ) | | 12,370 |
| | 304 |
| Total | | | | $ | (17,980 | ) | | $ | 18,330 |
| | $ | 350 |
|
| | | | | | | | | | | | | | | | Derivatives Designated as Cash Flow Hedging Instruments | | Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion) | | Income Statement Location (a) | | Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | | Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion) | | | (Thousands of Dollars) | | | | (Thousands of Dollars) | Three months ended March 31, 2012: | | | | | | | | | Interest rate swaps | | $ | 3,298 |
| | Interest expense, net | | $ | (423 | ) | | $ | — |
| Commodity contracts | | (57,121 | ) | | Cost of product sales | | (7,344 | ) | | 4,010 |
| Total | | $ | (53,823 | ) | | | | $ | (7,767 | ) | | $ | 4,010 |
| | | | | | | | | | Three months ended March 31, 2011: | | | | | | | | | Interest rate swaps | | $ | 2,878 |
| | Interest expense, net | | $ | — |
| | $ | — |
|
| | (a) | Amounts are included in specified location for both the gain (loss) reclassified from accumulated other comprehensive income (OCI) into income (effective portion) and the gain (loss) recognized in income on derivative (ineffective portion). |
| | | | | | | | Derivatives Not Designated as Hedging Instruments | | Income Statement Location | | Amount of Gain (Loss) Recognized in Income | | | | | (Thousands of Dollars) | Three months ended March 31, 2012: | | | | | Commodity contracts | | Revenues | | $ | 510 |
| Commodity contracts | | Cost of product sales | | (4,318 | ) | | | | | $ | (3,808 | ) | | | | | | Three months ended March 31, 2011: | | | | | Commodity contracts | | Revenues | | $ | 264 |
| Commodity contracts | | Cost of product sales | | (15,629 | ) | Commodity contracts | | Operating expenses | | 46 |
| | | | | $ | (15,319 | ) |
|