STOCKHOLDERS’ EQUITY (DEFICIT) (Details) - USD ($)
3 Months Ended 6 Months Ended
Apr. 29, 2019
Mar. 18, 2019
Jul. 13, 2018
Jun. 30, 2019
Jun. 30, 2019
Jun. 30, 2018
Apr. 25, 2019
Dec. 31, 2018
Dec. 31, 2017
Class of Stock [Line Items]                  
Capital stock authorized (in shares)       360,000,000 360,000,000        
Common stock, par or stated value per share (in usd per share)       $ 0.0001 $ 0.0001 $ 0.0001   $ 0.0001 $ 0.001
Common stock, shares authorized (in shares)       350,000,000 350,000,000     350,000,000  
Preferred stock, shares authorized (in shares)       10,000,000 10,000,000     10,000,000  
Number of shares issued in transaction (in shares) 4,318,272 4,181,068     8,499,340        
Number of securities called by each warrant (in shares)       15,120,898 15,120,898   3,897,010    
Write-off of deferred offering costs       $ 100,000 $ 100,056 $ 0      
At-the-Market Offering                  
Class of Stock [Line Items]                  
Number of shares issued in transaction (in shares)       705,714 705,714        
Sale of stock, ATM maximum equity offering price     $ 40,000,000            
Sale of stock, agent commissions fee     3.00%            
Consideration received on transaction         $ 1,675,000