REVENUES (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 43,657,292	$ 46,917,770	$ 82,978,004	$ 88,285,965
Petroleum products
Disaggregation of Revenue [Line Items]
Revenues	41,827,809	43,545,271	78,713,134	81,834,900
Metals
Disaggregation of Revenue [Line Items]
Revenues	1,829,483	3,372,499	4,264,870	6,451,065
Northern United States
Disaggregation of Revenue [Line Items]
Revenues	9,880,565	10,115,827	19,204,348	18,953,057
Southern United States
Disaggregation of Revenue [Line Items]
Revenues	33,776,727	36,801,943	63,773,656	69,332,908
Black Oil
Disaggregation of Revenue [Line Items]
Revenues	37,907,811	38,469,131	70,722,998	70,706,377
Black Oil | Petroleum products
Disaggregation of Revenue [Line Items]
Revenues	37,907,811	38,469,131	70,722,998	70,706,377
Black Oil | Metals
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Black Oil | Northern United States
Disaggregation of Revenue [Line Items]
Revenues	9,880,565	10,115,827	19,204,348	18,953,057
Black Oil | Southern United States
Disaggregation of Revenue [Line Items]
Revenues	28,027,246	28,353,304	51,518,650	51,753,320
Refining & Marketing
Disaggregation of Revenue [Line Items]
Revenues	3,277,402	4,392,870	6,136,023	10,068,111
Refining & Marketing | Petroleum products
Disaggregation of Revenue [Line Items]
Revenues	3,277,402	4,392,870	6,136,023	10,068,111
Refining & Marketing | Metals
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Refining & Marketing | Northern United States
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Refining & Marketing | Southern United States
Disaggregation of Revenue [Line Items]
Revenues	3,277,402	4,392,870	6,136,023	10,068,111
Recovery
Disaggregation of Revenue [Line Items]
Revenues	2,472,079	4,055,769	6,118,983	7,511,477
Recovery | Petroleum products
Disaggregation of Revenue [Line Items]
Revenues	642,596	683,270	1,854,113	1,060,412
Recovery | Metals
Disaggregation of Revenue [Line Items]
Revenues	1,829,483	3,372,499	4,264,870	6,451,065
Recovery | Northern United States
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Recovery | Southern United States
Disaggregation of Revenue [Line Items]
Revenues	$ 2,472,079	$ 4,055,769	$ 6,118,983	$ 7,511,477