Quarterly report pursuant to Section 13 or 15(d)

Stock-based Expense - Narrative (Details)

v3.20.1
Stock-based Expense - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based expense $ 0.4 $ 0.3
Modern Message    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Quarterly vesting, percent 5.00%  
Restricted Stock    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period (in years) 3 years  
Restricted Stock | Modern Message    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period (in years) 2 years 9 months  
Aggregate grant date fair value $ 10.7  
Time-Based Restricted Stock    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Awards granted (in shares) 905,127  
Weighted average fair value (in dollars per share) $ 61.31  
Market Based Restricted Stock Awards    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period (in years) 1 year  
Aggregate grant date fair value $ 13.5