Commitments and Contingencies - Schedule of Letters of Credit (Details) - Letter of Credit - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Total letters of credit	$ 9,037	$ 8,742
Environmental remediation
Line of Credit Facility [Line Items]
Total letters of credit	4,477	4,182
Insurance programs
Line of Credit Facility [Line Items]
Total letters of credit	4,105	4,105
Rail car commitments
Line of Credit Facility [Line Items]
Total letters of credit	$ 455	$ 455