Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Narrative) (Details)

v3.20.4
Fair Value Measurements (Narrative) (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Aug. 31, 2020
May 31, 2018
May 25, 2018
Fair Value Measurements            
Fair market value adjustment to contingent consideration liability $ 3,105,000 $ 8,126,000 $ 0      
Convertible notes 756,503,000 305,513,000        
Revolving credit facility 0 260,000,000        
Convertible Notes due 2023            
Fair Value Measurements            
Face amount 345,000,000 345,000,000     $ 345,000,000 $ 345,000,000
Convertible Notes due 2025            
Fair Value Measurements            
Face amount 517,500,000 0   $ 517,500,000    
Credit Agreement            
Fair Value Measurements            
Revolving credit facility 0 260,000,000        
Carrying Value | Convertible Notes due 2023            
Fair Value Measurements            
Convertible notes 316,636,000 305,513,000        
Total liabilities 460,817,000 $ 414,852,000        
Carrying Value | Convertible Notes due 2025            
Fair Value Measurements            
Convertible notes 439,867,000          
Fair Value | Convertible Notes due 2025            
Fair Value Measurements            
Convertible notes 540,788,000          
Private Technology Company            
Fair Value Measurements            
Fair market value adjustment to contingent consideration liability $ 3,105,000