Quarterly report pursuant to Section 13 or 15(d)

Note 13 - Employee Stock Plans (Details Textual)

v3.22.2
Note 13 - Employee Stock Plans (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2022
Jun. 30, 2021
Jun. 30, 2022
Jun. 30, 2021
May 31, 2010
Share-Based Payment Arrangement, Expense $ 3,153 $ 4,055 $ 5,053 $ 6,020  
Restricted Stock Units (RSUs) [Member]          
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)     $ 36.78    
The 2010 Stock Incentive Plan [Member]          
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)         2,130,000
The 2010 Stock Incentive Plan [Member] | Equity Awards [Member]          
Share-Based Payment Arrangement, Expense 2,801 3,286 $ 3,724 4,145  
The 2010 Stock Incentive Plan [Member] | Performance Shares [Member]          
Share-Based Payment Arrangement, Expense 2,052 2,463 $ 2,711 3,274  
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)     $ 37.57    
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total 2,708   $ 2,708    
The 2010 Stock Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]          
Share-Based Payment Arrangement, Expense 1,101 $ 1,592 2,342 $ 2,746  
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total $ 1,963   $ 1,963