Inventory Inventory (Policies)	6 Months Ended
Inventory Inventory (Policies)	Jun. 30, 2020
Inventory Disclosure [Abstract]
Inventory, Policy [Policy Text Block]	Crude oil, work in process, refined products, blendstocks and asphalt inventory for all of our operations, excluding the Tyler refinery and merchandise inventory in our retail segment, are stated at the lower of cost determined using FIFO basis or net realizable value. Cost of all inventory at the Tyler refinery is determined using the LIFO inventory valuation method and inventory is stated at the lower of cost or market. Retail merchandise inventory consists of cigarettes, beer, convenience merchandise and food service merchandise and is stated at estimated cost as determined by the retail inventory method.

Disclosure of inventory accounting policy for inventory classes, including, but not limited to, basis for determining inventory amounts, methods by which amounts are added and removed from inventory classes, loss recognition on impairment of inventories, and situations in which inventories are stated above cost.