SHARE-BASED COMPENSATION - Stock Option Activity (Details) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Private Innovate 2015 Stock Incentive Plan          
Number of Shares          
Number of shares, beginning balance     6,843,296    
Number of shares, options granted     0    
Number of shares, options forfeited     (414,719)    
Number of shares, options exercised     0    
Number of shares, ending balance 6,428,577   6,428,577   6,843,296
Number of shares, exercisable 5,534,191   5,534,191    
Number of shares, vested and expected to vest 6,378,011   6,378,011    
Weighted-Average Exercise Price          
Weighted-average exercise price, beginning balance     $ 1.56    
Weighted-average exercise price, options granted $ 0     $ 0  
Weighted-average exercise price, options forfeited     2.08    
Weighted-average exercise price, ending balance 1.53   1.53   $ 1.56
Weighted-average exercise price, exercisable 1.44   1.44    
Weighted-average exercise price, vested and expected to vest $ 1.52   $ 1.52    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]          
Aggregate intrinsic value, beginning balance     $ 6,617,433    
Aggregate intrinsic value, ending balance $ 34,080,300   34,080,300   $ 6,617,433
Aggregate intrinsic value, exercisable 29,819,823   29,819,823    
Aggregate intrinsic value, vested and expected to vest $ 33,841,611   $ 33,841,611    
Weighted-average remaining contractual life, outstanding (in years)     7 years 11 months 27 days   9 years 15 days
Weighted-average remaining contractual life, exercisable (in years)     7 years 10 months 24 days    
Weighted-average remaining contractual life, vested and expected to vest (in years)     7 years 11 months 23 days    
Omnibus Incentive Plan 2012          
Number of Shares          
Number of shares, beginning balance     1,683    
Number of shares, options granted     1,202,843    
Number of shares, options forfeited     0    
Number of shares, options exercised     0    
Number of shares, ending balance 1,204,526   1,204,526   1,683
Number of shares, exercisable 270,676   270,676    
Number of shares, vested and expected to vest 1,126,051   1,126,051    
Weighted-Average Exercise Price          
Weighted-average exercise price, beginning balance     $ 45.00    
Weighted-average exercise price, options granted   $ 0 6.12 $ 0  
Weighted-average exercise price, ending balance $ 6.17   6.17   $ 45.00
Weighted-average exercise price, exercisable 6.43   6.43    
Weighted-average exercise price, vested and expected to vest $ 6.18   $ 6.18    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]          
Aggregate intrinsic value, beginning balance     $ 0    
Aggregate intrinsic value, ending balance $ 869,003   869,003   $ 0
Aggregate intrinsic value, exercisable 175,359   175,359    
Aggregate intrinsic value, vested and expected to vest $ 809,494   $ 809,494    
Weighted-average remaining contractual life, outstanding (in years)     9 years 9 months 26 days   9 years 15 days
Weighted-average remaining contractual life, granted (in years)     9 years 9 months 26 days    
Weighted-average remaining contractual life, exercisable (in years)     9 years 4 months 24 days    
Weighted-average remaining contractual life, vested and expected to vest (in years)     9 years 9 months 26 days