Operating Leases - Components of Operating Lease Costs (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease costs	$ 858,684	$ 787,103	$ 2,401,674	$ 2,343,735
Cost of revenues - Freight and rail
Lessee, Lease, Description [Line Items]
Operating lease costs	847,671	766,022	2,371,586	2,302,012
Cost of revenues - Production
Lessee, Lease, Description [Line Items]
Operating lease costs	8,631	17,973	22,004	32,606
Administration expenses
Lessee, Lease, Description [Line Items]
Operating lease costs	$ 2,382	$ 3,108	$ 8,084	$ 9,117