Annual report pursuant to Section 13 and 15(d)

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

v3.20.1
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
Aug. 31, 2016
Dec. 31, 2019
Dec. 31, 2018
Aug. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Phantom stock options     $ 500    
Cash-settled phantom stock options     800    
Fair Value, Measurements, Recurring          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Earn-out liability       $ 114  
Contingently issuable shares     305 1,371  
Phantom stock options     464 1,564  
Total financial liabilities     769 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  
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  
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  
Contingently issuable shares     305 1,371  
Phantom stock options     464 1,564  
Total financial liabilities     $ 769 $ 3,049  
UMG Recordings | Price Per Share Scenario One | Common Stock          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Shares issued in period (in shares) 20,000 20,000      
Share price (in usd per share) $ 250.00   $ 250.00   $ 250.00
UMG Recordings | Price Per Share Scenario Two | Common Stock          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Shares issued in period (in shares) 16,000 16,000      
Share price (in usd per share) $ 300.00   $ 300.00   $ 300.00