Crude Oil Supply and Inventory Purchase Agreement - Barrels Subject to the Supply and Offtake Agreements (Details) - J. Aron - bbl bbl in Millions	Mar. 31, 2020	Dec. 31, 2019
El Dorado Refinery
Oil and Gas, Delivery Commitment [Line Items]
Barrels of inventory consigned to J Aron	3.5	3.5
Big Spring refinery
Oil and Gas, Delivery Commitment [Line Items]
Barrels of inventory consigned to J Aron	1.8	2.0
Krotz Spring Refinery
Oil and Gas, Delivery Commitment [Line Items]
Barrels of inventory consigned to J Aron	1.5	1.7
Baseline Step-Out Liability | El Dorado Refinery
Oil and Gas, Delivery Commitment [Line Items]
Barrels of inventory consigned to J Aron	2.0
Baseline Step-Out Liability | Big Spring refinery
Oil and Gas, Delivery Commitment [Line Items]
Barrels of inventory consigned to J Aron	0.8
Baseline Step-Out Liability | Krotz Spring Refinery
Oil and Gas, Delivery Commitment [Line Items]
Barrels of inventory consigned to J Aron	1.3