Uncertainties and Certain Significant Accounting Estimates	12 Months Ended
	Dec. 31, 2020
Unusual or Infrequent Items, or Both [Abstract]
UNCERTAINTIES AND CERTAIN SIGNIFICANT ACCOUNTING ESTIMATES (COVID-19)	2. UNCERTAINTIES AND CERTAIN SIGNIFICANT ACCOUNTING ESTIMATES Overview The outbreak of COVID-19 and its development into a pandemic in March 2020 and certain developments in the global oil markets have impacted and continue to impact our business. We have responded in multiple ways to the impacts from these matters on our business, and we will strive to continue to respond to these impacts. During the early months of the pandemic, we reduced the amount of crude oil processed at most of our refineries in response to the decreased demand for our products, we temporarily idled various gasoline-making units at certain of our refineries to further limit gasoline production, and we took measures to reduce jet fuel production. We also temporarily idled eight of our ethanol plants and reduced production at our remaining ethanol plants, in each case in order to address the decreased demand for ethanol. We have since increased the production to align with increasing demand, and we restarted the gasoline-making units and most of the ethanol plants that had been temporarily idled. Demand for our products taken as a whole, however, has not returned to pre-pandemic levels, and as of December 31, 2020, our refineries and plants are operating to meet current product demand. Many uncertainties remain with respect to the COVID-19 pandemic, including its resulting economic effects, and we are unable to predict the ultimate economic impacts from the pandemic on our business and how quickly national economies can recover once the pandemic subsides, the timing or effectiveness of vaccine distributions, or whether any recovery will ultimately experience a reversal or other setbacks. However, the adverse impacts of the economic effects on our business have been and will likely continue to be significant. We believe we have proactively addressed many of the known impacts of the pandemic to the extent possible and we will strive to continue to do so, but there can be no assurance that any measures we have taken or may take will be fully effective. As a result, we expect these matters may affect our estimates and assumptions on amounts reported in the financial statements and accompanying notes in the near term. Impairment Analysis of Long-Lived Assets Due to the adverse economic conditions discussed above, we reviewed our significant operating assets for the existence of impairment indicators during the year ended December 31, 2020. As a result, we reduced the estimated useful life of the ethanol plant in Riga, Michigan in September 2020 and evaluated six other ethanol plants and one refinery for potential impairment as of December 31, 2020, considering current economic conditions on our future estimated cash flows. Based on our analysis, we determined that the carrying amount of these assets was recoverable, as the undiscounted future cash flows from each asset exceeded its respective carrying value. The impact from the reduction in estimated useful life of the Riga, Michigan ethanol plant did not have a material impact on our results of operations or financial position; however, this plant ceased operations in 2020. We will continue to evaluate the economic conditions and their impact on our assumptions. Impairment Analysis of Goodwill We have $260 million of goodwill as of December 31, 2020. All of our goodwill is allocated to one reporting unit, the U.S. Gulf Coast refining region. Our annual test for the impairment of goodwill is performed on October 1 of each year. However, as discussed above, there were adverse changes in the capital and commodity markets that contributed to a significant decline in our common stock price compared to the price as of December 31, 2019 and early March 2020. Despite the decline in our common stock price, we determined our goodwill was not impaired as of October 1 and December 31, 2020. Nonetheless, we will continue to evaluate the economic conditions and their impact on our assumptions. Inventory Valuation See Note 5 regarding the estimates used to determine the market value of our inventories, as well as the recognition of a liquidation of LIFO inventory layers.