XML 80 R56.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2017
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
Amortization period of planned major maintenance activities, minimum   3 years    
Amortization period of planned major maintenance activities, maximum   5 years    
Deferred turnaround expenditures $ 32,700,000 $ 0 $ 32,661,000 $ 0
Cost of revenues   6,029,000 4,604,000 3,017,000
Operating expense   22,861,000 16,340,000 11,428,000
General and administrative expense   $ 2,929,000 $ 2,108,000 $ 855,000
Refining Equipment | Minimum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   8 years    
Refining Equipment | Maximum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   47 years    
Logistic | Minimum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   3 years    
Logistic | Maximum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   30 years    
Retail Site | Minimum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   14 years    
Retail Site | Maximum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   18 years    
Corporate | Minimum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   3 years    
Corporate | Maximum        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   7 years    
Software        
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]        
PP&E useful life   3 years