v3.21.1
Stock incentive plans - Restricted stock unit awards (Details)
$ / shares in Units, $ in Thousands
3 Months Ended
Mar. 31, 2021
USD ($)
$ / shares
shares
Stock incentive plans  
Shares of common stock issued resulting from vesting 92,000
RSUs  
Stock incentive plans  
Unvested RSU awards expense expected to be recognized | $ $ 17,639
Weighted average period over which unrecognized compensation expense is expected to be recognized 2 years 2 months 12 days
Number of Shares  
Non-vested at beginning of period (in shares) 951,000
Granted (in shares) 893,000
Vested (in shares) (134,000)
Canceled/forfeited (in shares) (37,000)
Non-vested at end of period (in shares) 1,673,000
Weighted Average Grant Date Fair Value  
Non-vested at beginning of period (in dollars per share) | $ / shares $ 14.30
Granted (in dollars per share) | $ / shares 11.55
Vested (in dollars per share) | $ / shares 15.86
Canceled/forfeited (in dollars per share) | $ / shares 12.18
Non-vested at end of period (in dollars per share) | $ / shares $ 12.75
Service-based restricted stock unit awards | Executive And Non Executive Member | Maximum  
Stock incentive plans  
Vesting period 3 years
Service-based restricted stock unit awards | Non-employee directors and existing members  
Stock incentive plans  
Vesting period 1 year
Service-based restricted stock unit awards | Non-employee directors and new members  
Stock incentive plans  
Vesting percentage when the individual completes 12 months of continuous service 33.30%
Vesting period 3 years
Performance-based restricted stock unit awards  
Stock incentive plans  
Vesting period 3 years
2019 and 2020 performance-based RSUs  
Stock incentive plans  
2019 and 2020 Revenue goals achieved (as a percent) 58.40%
2010 and 2020 EBITDA goals achieved (as a percent) 97.40%
Number of Shares  
Granted (in shares) 107,000
Weighted Average Grant Date Fair Value  
Granted (in dollars per share) | $ / shares $ 11.54
2020 performance-based RSUs  
Stock incentive plans  
Number of awards excluded from granted and non-vested as the performance targets have not yet been defined 75,000
2021 performance-based RSUs  
Stock incentive plans  
Number of awards excluded from granted and non-vested as the performance targets have not yet been defined 177,000