FAIR VALUE MEASUREMENTS (Measured on Recurring Basis) (Details) (USD $) | Sep. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2012 |
In Thousands, unless otherwise specified |
Commodity contract [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value | $13,046 | $2,689 | ($23,365) | $0 | $0 | $21,358 |
Fair Value, Measurements, Recurring [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Defined Benefit Plan, Fair Value of Plan Assets | 5,468 | ' | 4,905 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Defined Benefit Plan, Fair Value of Plan Assets | 5,468 | ' | 4,905 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Defined Benefit Plan, Fair Value of Plan Assets | 0 | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Defined Benefit Plan, Fair Value of Plan Assets | 0 | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Catalyst lease obligations [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Catalyst lease obligations | 39,325 | ' | 53,089 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Catalyst lease obligations [Member] | Level 1 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Catalyst lease obligations | 0 | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Catalyst lease obligations [Member] | Level 2 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Catalyst lease obligations | 39,325 | ' | 53,089 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Catalyst lease obligations [Member] | Level 3 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Catalyst lease obligations | 0 | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 234,403 | ' | ' | ' | ' | ' |
Derivative, Collateral, Right to Reclaim Cash | -232,671 | ' | ' | ' | ' | ' |
Derivative Liability | 1,732 | ' | 30,354 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | Level 1 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 228,141 | ' | ' | ' | ' | ' |
Derivative Liability | ' | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | Level 2 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 6,262 | ' | ' | ' | ' | ' |
Derivative Liability | ' | ' | 6,989 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | Level 3 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 0 | ' | ' | ' | ' | ' |
Derivative Liability | ' | ' | 23,365 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory supply arrangement obligations [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 1,482 | ' | ' | ' | ' | ' |
Derivative assets, Effect of Counter-party Netting | 0 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | 1,482 | ' | ' | ' | ' | ' |
Derivative Liability | ' | ' | 177 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory supply arrangement obligations [Member] | Level 1 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 0 | ' | ' | ' | ' | ' |
Derivative Liability | ' | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory supply arrangement obligations [Member] | Level 2 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 1,482 | ' | ' | ' | ' | ' |
Derivative Liability | ' | ' | 177 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory supply arrangement obligations [Member] | Level 3 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 0 | ' | ' | ' | ' | ' |
Derivative Liability | ' | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Money market funds [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Cash and cash equivalents | 5,557 | ' | 5,857 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Money market funds [Member] | Level 1 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Cash and cash equivalents | 5,557 | ' | 5,857 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Money market funds [Member] | Level 2 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Cash and cash equivalents | 0 | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Money market funds [Member] | Level 3 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Cash and cash equivalents | 0 | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 284,684 | ' | ' | ' | ' | ' |
Derivative assets, Effect of Counter-party Netting | -232,671 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | 52,013 | ' | 10,933 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | Level 1 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 261,041 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | ' | ' | 4,252 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | Level 2 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 10,597 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | ' | ' | 6,681 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Commodity contract [Member] | Level 3 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 13,046 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | ' | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with intermediation agreement obligations [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 35,959 | ' | ' | ' | ' | ' |
Derivative assets, Effect of Counter-party Netting | 0 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | 35,959 | ' | 6,016 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with intermediation agreement obligations [Member] | Level 1 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 0 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | ' | ' | 0 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with intermediation agreement obligations [Member] | Level 2 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 35,959 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | ' | ' | 6,016 | ' | ' | ' |
Fair Value, Measurements, Recurring [Member] | Derivatives included with intermediation agreement obligations [Member] | Level 3 [Member] | ' | ' | ' | ' | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ' | ' | ' | ' |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 0 | ' | ' | ' | ' | ' |
Derivative assets, Net Carrying Value on Balance Sheet | ' | ' | $0 | ' | ' | ' |