Fair Value Measurements - Summary of Recurring Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions | Mar. 31, 2018 | Dec. 31, 2017 |
Assets: | | |
Derivative Asset | $ 0 | $ 0 |
Fair Value, Measurements, Recurring [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Pension plan investments | 0.1 | 0.2 |
Total recurring assets at fair value | 0.1 | 0.2 |
Derivative liabilities: | | |
Total derivative liabilities | (8.4) | (10.4) |
RINs Obligation | (5.2) | (59.1) |
Liability Awards | (8.6) | (5.6) |
Total recurring liabilities at fair value | (22.2) | (75.1) |
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Pension plan investments | 0.1 | 0.2 |
Total recurring assets at fair value | 0.1 | 0.2 |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
RINs Obligation | 0 | 0 |
Liability Awards | (8.6) | (5.6) |
Total recurring liabilities at fair value | (8.6) | (5.6) |
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Pension plan investments | 0 | 0 |
Total recurring assets at fair value | 0 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
RINs Obligation | (5.2) | (59.1) |
Liability Awards | 0 | 0 |
Total recurring liabilities at fair value | (5.2) | (59.1) |
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Pension plan investments | 0 | 0 |
Total recurring assets at fair value | 0 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | (8.4) | (10.4) |
RINs Obligation | 0 | 0 |
Liability Awards | 0 | 0 |
Total recurring liabilities at fair value | (8.4) | (10.4) |
Crude Oil Swaps [Member] | Fair Value, Measurements, Recurring [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0.3 |
Crude Oil Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Crude Oil Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Crude Oil Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0.3 |
Crude Oil Percent Basis Swaps [Member] | Fair Value, Measurements, Recurring [Member] | | |
Assets: | | |
Derivative Asset | 0.1 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0.2 | 0 |
Crude Oil Percent Basis Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Crude Oil Percent Basis Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Crude Oil Percent Basis Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Assets: | | |
Derivative Asset | 0.1 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | (0.2) | 0 |
Gasoline Swaps [Member] | Fair Value, Measurements, Recurring [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (0.2) |
Gasoline Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Gasoline Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Gasoline Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (0.2) |
Gasoline Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (1.8) |
Gasoline Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Gasoline Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Gasoline Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (1.8) |
Diesel Swaps [Member] | Fair Value, Measurements, Recurring [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (0.2) |
Diesel Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Diesel Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Diesel Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (0.2) |
Diesel Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (4.1) |
Diesel Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Diesel Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Diesel Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (4.1) |
Diesel Percent Basis Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | | |
Assets: | | |
Derivative Asset | (0.1) | 0 |
Derivative liabilities: | | |
Total derivative liabilities | (0.3) | 0 |
Diesel Percent Basis Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Diesel Percent Basis Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Diesel Percent Basis Crack Spread Swaps [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Assets: | | |
Derivative Asset | (0.1) | 0 |
Derivative liabilities: | | |
Total derivative liabilities | (0.3) | 0 |
Inventory Financing Obligations | Fair Value, Measurements, Recurring [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | (8.3) | (4.4) |
Inventory Financing Obligations | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Inventory Financing Obligations | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0 |
Inventory Financing Obligations | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 8.3 | (4.4) |
Not Designated as Hedging Instrument [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | (8.4) | (10.4) |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Crude Oil Swaps [Member] | | |
Assets: | | |
Derivative Asset | 0 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0 | 0.3 |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Crude Oil Percent Basis Swaps [Member] | | |
Assets: | | |
Derivative Asset | 0.1 | 0 |
Derivative liabilities: | | |
Total derivative liabilities | 0.2 | 0 |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Gasoline Swaps [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (0.2) |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Gasoline Crack Spread Swaps [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (1.8) |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Diesel Swaps [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (0.2) |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Diesel Crack Spread Swaps [Member] | | |
Derivative liabilities: | | |
Total derivative liabilities | 0 | (4.1) |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Diesel Percent Basis Crack Spread Swaps [Member] | | |
Assets: | | |
Derivative Asset | (0.1) | 0 |
Derivative liabilities: | | |
Total derivative liabilities | (0.3) | 0 |
Fuel Product [Member] | Not Designated as Hedging Instrument [Member] | Inventory Financing Obligations | | |
Derivative liabilities: | | |
Total derivative liabilities | $ (8.3) | $ (4.4) |