Stock-based Compensation (Details) - USD ($) shares in Thousands, $ in Millions |
3 Months Ended | 9 Months Ended | ||||
---|---|---|---|---|---|---|
Sep. 30, 2021 |
Jun. 30, 2021 |
Mar. 31, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
|
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Options granted (in shares) | 10 | 24 | 200 | |||
Vesting period | 4 years | |||||
RSU | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Restricted stock units granted (in shares) | 17 | 41 | 400 | |||
RSU | Employee | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Vesting period | 4 years | |||||
RSU | Director | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Vesting period | 9 months | |||||
Options and RSUs | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Vesting period | 4 years | 4 years | ||||
Estimated grant date fair value of options and RSUs granted | $ 0.3 | $ 0.7 | $ 5.6 | |||
Stock option compensation expense | $ 1.0 | $ 1.7 | $ 4.7 | $ 4.1 |