Employees Workforce (Details)	Dec. 31, 2015
Tyler Refinery [Member] | Operations and Maintenance Employees [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Employees Represented by Union	180
Tyler Refinery [Member] | Truck Drivers [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Employees Represented by Union	39
El Dorado Refinery [Member] | Operations and Maintenance Employees [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Employees Represented by Union	154