Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details)

v3.19.3
Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended
Mar. 31, 2017
Sep. 30, 2019
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Phantom stock options liability   $ 700  
Fair Value, Measurements, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Earn-out liability   114 $ 114
Contingently issuable shares   440 1,371
Phantom stock options   714 1,564
Total financial liabilities   1,268 3,049
Fair Value, Measurements, Recurring | Quotes prices in active markets (Level 1)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Earn-out liability   0 0
Contingently issuable shares   0 0
Phantom stock options   0 0
Total financial liabilities   0 0
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Earn-out liability   0 0
Contingently issuable shares   0 0
Phantom stock options   0 0
Total financial liabilities   0 0
Fair Value, Measurements, Recurring | Significant other unobservable inputs (Level 3)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Earn-out liability   114 114
Contingently issuable shares   440 1,371
Phantom stock options   714 1,564
Total financial liabilities   1,268 $ 3,049
Common Stock | Price Per Share Scenario One | UMG Recordings      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Shares issued in period (in shares) 500,000    
Share price (in usd per share) $ 10.00    
Common Stock | Price Per Share Scenario Two | UMG Recordings      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Shares issued in period (in shares) 400,000    
Share price (in usd per share) $ 12.00    
Cash-Settled Phantom Stock Options | Fair Value, Measurements, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Phantom stock options   $ 1,400