XML 115 R98.htm IDEA: XBRL DOCUMENT v3.20.4
Stock Plans and Stock Based Compensation - Activity Related to Restricted Stock Awards (Details)
 12 Months Ended
Dec. 31, 2020
$ / shares
shares
Number of Shares  
Unvested, beginning of year (in shares) | shares 247,967
Granted (in shares) | shares 86,411
Vested (in shares) | shares (73,272)
Forfeited (in shares) | shares (6,117)
Unvested, end of year (in shares) | shares 254,989
Weighted Average Grant Date Fair Value  
Beginning balance (in dollars per share) | $ / shares $ 73.66
Granted (in dollars per share) | $ / shares 63.44
Vested (in dollars per share) | $ / shares 64.06
Forfeited (in dollars per share) | $ / shares 75.98
Ending balance (in dollars per share) | $ / shares $ 70.55