STOCKHOLDERS' EQUITY (Common Stock, 2018 Purchase Agreement and LP Purchase Agreement) (Details) - USD ($)												1 Months Ended		3 Months Ended	12 Months Ended		25 Months Ended
	Jan. 14, 2020	Jan. 01, 2020	Aug. 09, 2019	Feb. 01, 2019	Jan. 29, 2019	Sep. 14, 2018	Sep. 07, 2018	Aug. 10, 2018	Feb. 12, 2018	Feb. 09, 2018	Feb. 08, 2018	Feb. 11, 2020	Jan. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 11, 2020	Jan. 01, 2019	Dec. 20, 2018	Dec. 19, 2018	Sep. 06, 2018
Class of Stock [Line Items]
Common stock, shares authorized (in shares)															150,000,000	150,000,000		250,000,000	150,000,000	150,000,000
Conversion of convertible notes into common stock (in shares)									120,983
Common stock, shares outstanding (in shares)															7,898,117	2,298,738					1,543,724
Issuance of common stock, net of issuance costs															$ 6,628,000	$ 2,008,000
Conversion of convertible debt plus interest into common stock									$ 1,900,000						7,553,000	2,356,000
Share price (in dollars per share)									$ 15.60
Stock Issued During Period, Value, Issued for Services																39,000
Liability recorded related to equity purchase agreement repricing															460,000	460,000
Liability related to equity purchase agreement																460,000
Number of shares converted from debt instrument (in shares)									120,983
Conversion of debt into stock									$ 1,900,000						7,553,000	2,356,000
Liability for settlement of equity instrument																1,450,000
Other current liabilities																1,910,000
Proceeds from exercise of warrants															$ 1,575,000	$ 1,271,000
Shares issued (in shares)															7,898,117	2,298,738
Common Stock
Class of Stock [Line Items]
Conversion of convertible notes into common stock (in shares)															2,511,173	384,896
Number of shares converted (in shares)																(431,022)
Issuance of common stock for consulting services in connection with the merger (in shares)																1,527
Stock Issued During Period, Shares, Issued for Services																1,527
Number of shares converted from debt instrument (in shares)															2,511,173	384,896
Leviston Resources LLC
Class of Stock [Line Items]
Issuance costs															$ 132,000
Common Stock
Class of Stock [Line Items]
Conversion of convertible notes into common stock (in shares)															310,200	252,486
Conversion of convertible debt plus interest into common stock															$ 7,600,000	$ 2,400,000
Number of shares converted from debt instrument (in shares)															310,200	252,486
Conversion of debt into stock															$ 7,600,000	$ 2,400,000
Warrant exercises in period															310,200	252,486
Proceeds from exercise of warrants															$ 1,600,000	$ 1,300,000
Series B Preferred Stock
Class of Stock [Line Items]
Common stock issued on conversion of preferred shares															208,000
Series C Preferred Stock [Member]
Class of Stock [Line Items]
Number of shares converted (in shares)															2,548
Common stock issued on conversion of preferred shares															223,022
Stock Not Issued, Shares															4,000
Preferred Class B
Class of Stock [Line Items]
Number of shares converted (in shares)															2,340
Subsequent Events
Class of Stock [Line Items]
Shares sold in offering (in shares)		900,012
Issuance of common stock, net of issuance costs		$ 1,300,000
Leviston Resources LLC
Class of Stock [Line Items]
Proceeds from sale of stock										$ 750,000
Conversion of convertible notes into common stock (in shares)															184,357
Issuance of common stock for consulting services in connection with the merger (in shares)										11,381
New shares issued (in shares)					10,000					48,076
Beneficial Ownership Cap					4.99%
Shares sold in offering (in shares)								0
Conversion of convertible debt plus interest into common stock															$ 700,000
Equity Purchase Agreement											$ 8,000,000
Equity Purchase Agreement, Commitment Fee Percentage										5.25%
Equity Purchase Agreement, Commitment Fee Installment Percentage										1.75%
Share price (in dollars per share)										$ 15.60
Stock Issued During Period, Shares, Issued for Services										11,381
Stock Issued During Period, Value, Issued for Services										$ 140,000
Accruals for potential obligations to the Investor															$ 700,000
Number of shares converted from debt instrument (in shares)															184,357
Conversion of debt into stock															$ 700,000
Leviston Resources LLC | Settled Litigation
Class of Stock [Line Items]
Issuance of convertible notes					$ 700,000
Lincoln Park [Member]
Class of Stock [Line Items]
Proceeds from sale of stock															$ 6,600,000	$ 1,400,000
New shares issued (in shares)			1,800,000	1,000,000		466,667	40,000
Value of shares issued							$ 10,000,000
Maximum percentage of shares issued							19.99%
Maximum number of shares issued							308,590
Beneficial Ownership Cap							4.99%
Shares sold in offering (in shares)															2,778,077	328,590
Issuance of common stock, net of issuance costs															$ 6,600,000	$ 1,400,000
Share price (in dollars per share)							$ 7.05
Shares issued (in shares)															1,680,000
Lincoln Park [Member] | Subsequent Events
Class of Stock [Line Items]
Proceeds from sale of stock												$ 1,300,000					$ 9,300,000
New shares issued (in shares)													780,012	120,000
Shares sold in offering (in shares)												900,012
Issuance of common stock, net of issuance costs		$ 9,300,000
Lincoln Park [Member] | Subsequent Events | Common Stock
Class of Stock [Line Items]
New shares issued (in shares)	920,654
Preferred Class B
Class of Stock [Line Items]
Common stock issued on conversion of preferred shares															208,000
Minimum | Settled Litigation
Class of Stock [Line Items]
Issuance of common stock, net of issuance costs					$ 4,000,000
Minimum | Lincoln Park [Member]
Class of Stock [Line Items]
Share price (in dollars per share)							$ 1.50
Maximum | Lincoln Park [Member]
Class of Stock [Line Items]
Value of shares issued							$ 1,000,000								$ 10,000,000
Shares sold in offering based on market price							36,666
Shares sold in offering (in shares)							30,000