Commitments and Contingencies (Details)		12 Months Ended
	Mar. 22, 2018 USD ($)	Dec. 31, 2020 USD ($) claim refinery	Dec. 31, 2019 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jun. 17, 2013 USD ($)
Long-term Purchase Commitment [Line Items]
Renewable identification numbers (RINs) benefit			$ 5,300,000
Number of owned and operated refineries | refinery		4
Bankruptcy claims number of claims to be settled | claim		2
Bankruptcy claims amount of claims to be settled		$ 22,400,000
Settlement liabilities, current		500,000
Maximum bankruptcy claims remaining		$ 22,400,000
Predecessor working ownership percentage		3.40%
Allowed claims, settlement ratio		0.0544
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | One Major Customer
Long-term Purchase Commitment [Line Items]
Concentration risk, percentage		13.00%
Tesoro Corporation | Indemnification Agreement
Long-term Purchase Commitment [Line Items]
Guarantor obligations, deductible		$ 1,000,000
Guarantor obligations, maximum exposure, undiscounted		15,000,000
Wyoming Refinery One
Long-term Purchase Commitment [Line Items]
Accrual for environmental loss contingencies		$ 16,300,000
Environmental costs recognized, period for recognition of one third costs		5 years
Environmental costs recognized, period for recognition		30 years
Wyoming Refinery Two | Waste Water Treatment System
Long-term Purchase Commitment [Line Items]
Accrual for environmental loss contingencies		$ 11,600,000
Wyoming Refinery
Long-term Purchase Commitment [Line Items]
Loss contingency, range of possible loss, portion not accrued		$ 300,000
Maximum | Tesoro Corporation
Long-term Purchase Commitment [Line Items]
Contingent consideration, liability						$ 40,000,000
Tesoro Corporation
Long-term Purchase Commitment [Line Items]
Contingent consideration, liability						$ 20,000,000
Loss contingency, damages paid	$ 10,500,000			$ 16,800,000
Loss contingency, damages sought				$ 8,300,000	$ 4,300,000