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Inventory (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2020
Equipment and materials    
Inventory [Line Items]    
Impairment losses $ 600,000 $ 1,600,000
Crude oil inventory    
Inventory [Line Items]    
Impairment losses $ 0 7,200,000
Long-term linefill inventory    
Inventory [Line Items]    
Impairment losses   $ 1,300,000