XML 36 R24.htm IDEA: XBRL DOCUMENT v3.20.2
Summary of Significant Accounting Policies (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2020
Net sales | Customer concentration risk | Murphy USA    
Concentration Risk [Line Items]    
Major customer percentage of net sales 15.00% 13.00%