FAIR VALUE MEASUREMENTS (Measured on Recurring Basis) (Details) - USD ($) $ in Millions | Jun. 30, 2022 | Dec. 31, 2021 |
Other Assets | Pension Benefits | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Defined Benefit Plan, Plan Assets, Amount | $ 19.2 | $ 20.7 |
Fair Value, Measurements, Recurring [Member] | Commodity contracts | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 119.8 | 83.5 |
Derivative, Collateral, Right to Reclaim Cash | (100.6) | (71.5) |
Derivative Liability | 19.2 | 12 |
Fair Value, Measurements, Recurring [Member] | Commodity contracts | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 119.8 | 79.7 |
Fair Value, Measurements, Recurring [Member] | Commodity contracts | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 0 | 3.8 |
Fair Value, Measurements, Recurring [Member] | Commodity contracts | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Catalyst financing arrangements | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative, Collateral, Right to Reclaim Cash | 0 | 0 |
Obligations, Fair Value Disclosure | 56.2 | 58.4 |
Fair Value, Measurements, Recurring [Member] | Catalyst financing arrangements | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Catalyst financing arrangements | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 56.2 | 58.4 |
Fair Value, Measurements, Recurring [Member] | Catalyst financing arrangements | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Renewable energy credit and emissions obligations | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative, Collateral, Right to Reclaim Cash | 0 | 0 |
Obligations, Fair Value Disclosure | 1,325.6 | 953.9 |
Fair Value, Measurements, Recurring [Member] | Renewable energy credit and emissions obligations | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Renewable energy credit and emissions obligations | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 1,325.6 | 953.9 |
Fair Value, Measurements, Recurring [Member] | Renewable energy credit and emissions obligations | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Contingent Consideration | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative, Collateral, Right to Reclaim Cash | 0 | 0 |
Obligations, Fair Value Disclosure | 157.1 | 29.4 |
Fair Value, Measurements, Recurring [Member] | Contingent Consideration | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Contingent Consideration | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Contingent Consideration | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Obligations, Fair Value Disclosure | 157.1 | 29.4 |
Fair Value, Measurements, Recurring [Member] | Money market funds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash and cash equivalents | 11 | 260.9 |
Fair Value, Measurements, Recurring [Member] | Money market funds | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash and cash equivalents | 11 | 260.9 |
Fair Value, Measurements, Recurring [Member] | Money market funds | Level 2 | | |
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 | Level 3 | | |
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 contracts | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 100.6 | 71.5 |
Derivative assets, Effect of Counter-party Netting | (100.6) | (71.5) |
Derivative assets, Net Carrying Value on Balance Sheet | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Commodity contracts | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 98.4 | 71.5 |
Fair Value, Measurements, Recurring [Member] | Commodity contracts | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 2.2 | 0 |
Fair Value, Measurements, Recurring [Member] | Commodity contracts | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory intermediation agreement obligations | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 23.1 | 19.7 |
Derivative assets, Effect of Counter-party Netting | 0 | 0 |
Derivative assets, Net Carrying Value on Balance Sheet | 23.1 | 19.7 |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory intermediation agreement obligations | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory intermediation agreement obligations | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 23.1 | 19.7 |
Fair Value, Measurements, Recurring [Member] | Derivatives included with inventory intermediation agreement obligations | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | $ 0 | $ 0 |