SUBSEQUENT EVENTS (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended			12 Months Ended
	Jan. 17, 2020	Jan. 31, 2020	Jan. 31, 2019	May 31, 2016	Dec. 31, 2019	Dec. 31, 2018	Jan. 28, 2020	Jan. 27, 2020	Jan. 22, 2020	Jan. 13, 2020	Jan. 10, 2020	Jan. 09, 2020	Jan. 03, 2020	Jan. 01, 2020
Heartland SPV | Subsequent Event
Subsequent Event [Line Items]
Share purchase value	$ 7.5
Percentage acquired	50.00%
Common Stock
Subsequent Event [Line Items]
Preferred stock dividends (in shares)						166,630
Common Stock | Subsequent Event
Subsequent Event [Line Items]
Number of common shares issued for each convertible preferred share (in shares)							17,000	252,337	25,000	9,018	104,940	601,090	1,107,893
Series B Preferred Stock
Subsequent Event [Line Items]
Preferred stock dividends (in shares)			57,394
Number of common shares issued for each convertible preferred share (in shares)					57,394
Preferred stock, shares outstanding (in shares)					3,826,055	3,604,827
Preferred stock, dividend rate					6.00%
Series B Preferred Stock | Subsequent Event
Subsequent Event [Line Items]
Preferred stock dividends (in shares)		57,394
Series B1 Preferred Stock
Subsequent Event [Line Items]
Preferred stock dividends (in shares)			135,429
Number of common shares issued for each convertible preferred share (in shares)					135,429
Preferred stock, shares outstanding (in shares)					9,028,085	10,057,597
Preferred stock, dividend rate				6.00%
Series B1 Preferred Stock | Subsequent Event
Subsequent Event [Line Items]
Preferred stock dividends (in shares)		135,429
Preferred stock, shares outstanding (in shares)							17,000	252,337	25,000	9,018	104,940	601,090	1,107,893
Common Class A | Subsequent Event
Subsequent Event [Line Items]
Aggregated capital investment	50.00%
Common Class A | Heartland SPV | Subsequent Event
Subsequent Event [Line Items]
Preferred stock, redemption period	180 days
Debt instrument redemption	25.00%
Percentage of aggregate capital investment	50.00%
Aggregate unpaid annual return	$ 21.0
Common Class A | MG SPV | Subsequent Event | Vertex Operating
Subsequent Event [Line Items]
Equity issued (in shares)	1,000
Share price (in dollars per share)	$ 1,000
Equity issued, value	$ 1.0
Preferred Class A | Tensile-Heartland | Subsequent Event
Subsequent Event [Line Items]
Ownership percentage	100.00%
Preferred stock, dividend rate	22.50%
Heartland SPV | Subsequent Event
Subsequent Event [Line Items]
Number of managers	5
Effective conversion price (in dollars per share)	1
Heartland SPV | Tensile-Heartland | Subsequent Event
Subsequent Event [Line Items]
Ownership percentage	65.00%													65.00%
Number of managers	3
Heartland SPV | Vertex Operating | Subsequent Event
Subsequent Event [Line Items]
Ownership percentage	35.00%
Number of managers	2
Vertex Refining OH, LLC
Subsequent Event [Line Items]
Ownership percentage					100.00%
Heartland SPV | Common Class A | Tensile-Heartland | Subsequent Event | Vertex Operating
Subsequent Event [Line Items]
Equity issued (in shares)	13,500
Consideration transferred	$ 13.5
Heartland SPV | Common Class A | Tensile-Heartland | Subsequent Event | Heartland SPV
Subsequent Event [Line Items]
Equity issued (in shares)	7,500
Consideration transferred	$ 7.5
Heartland SPV | A-1 Preferred Units | Tensile-Heartland | Subsequent Event | Vertex Operating
Subsequent Event [Line Items]
Equity issued (in shares)	13,500
Heartland SPV | A-1 Preferred Units | Tensile-Heartland | Subsequent Event | Heartland SPV
Subsequent Event [Line Items]
Equity issued (in shares)	7,500
Heartland SPV | Class A-2 Preferred Units | Tensile-Heartland | Subsequent Event
Subsequent Event [Line Items]
Share price (in dollars per share)	$ 1,000
Additional equity (in shares)	7,000
Vertex Refining OH, LLC | Common Class A | Heartland SPV | Subsequent Event
Subsequent Event [Line Items]
Equity issued (in shares)	13,500
Vertex Refining OH, LLC | A-1 Preferred Units | Heartland SPV | Subsequent Event
Subsequent Event [Line Items]
Equity issued (in shares)	13,500
Vertex Refining OH, LLC | Common Class B | Heartland SPV | Subsequent Event
Subsequent Event [Line Items]
Equity issued (in shares)	11,300
Vertex Refining OH, LLC | Common Class B | Heartland SPV | Subsequent Event | Vertex Splitter Corporation
Subsequent Event [Line Items]
Equity issued (in shares)	248