v3.19.3
STOCKHOLDERS' EQUITY - Common Stock and Warrants Narrative (Details)
$ / shares in Units, $ in Thousands
 9 Months Ended
May 25, 2018
USD ($)
$ / shares
shares
Mar. 06, 2017
USD ($)
$ / shares
shares
Sep. 30, 2019
USD ($)
vote
$ / shares
shares
Sep. 30, 2018
USD ($)
Dec. 31, 2018
$ / shares
shares
Class of Stock [Line Items]          
Proceeds from issuance of warrants | $     $ 0 $ 112,125  
Common Stock Warrant          
Class of Stock [Line Items]          
Warrants to purchase aggregate shares of capital stock (in shares) 11,100,000 19,200,000      
Warrants, weighted average exercise price (in USD per share) | $ / shares $ 109.26 $ 31.18      
Proceeds from issuance of warrants | $ $ 112,100 $ 57,200      
Number of warrants exercised (in shares)     0    
Class A          
Class of Stock [Line Items]          
Common stock, number of votes entitled for each share held (in votes) | vote     1    
Common stock, shares authorized (in shares)     1,000,000,000   1,000,000,000
Common stock, par value (in USD per share) | $ / shares     $ 0.0000001   $ 0.0000001
Common stock, shares outstanding (in shares)     346,552,092   323,546,864
Class B          
Class of Stock [Line Items]          
Common stock, number of votes entitled for each share held (in votes) | vote     10    
Common stock, shares authorized (in shares)     500,000,000   500,000,000
Common stock, par value (in USD per share) | $ / shares     $ 0.0000001   $ 0.0000001
Common stock, shares outstanding (in shares)     82,521,716   93,501,142