Quarterly report pursuant to Section 13 or 15(d)

Note 13 - Employee Stock Plans (Details Textual)

v3.23.3
Note 13 - Employee Stock Plans (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended
May 31, 2010
Sep. 30, 2023
Sep. 30, 2022
Sep. 30, 2023
Sep. 30, 2022
Share-Based Payment Arrangement, Expense   $ 0 $ 510 $ 4,236 $ 5,563
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)       $ 39.37  
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       $ 3,249 3,724
The 2010 Stock Incentive Plan [Member] | Performance Shares [Member]          
Share-Based Payment Arrangement, Expense   361 234 $ 1,183 2,945
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)       $ 37.36  
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount   2,371   $ 2,371  
The 2010 Stock Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]          
Share-Based Payment Arrangement, Expense   361 $ 276 3,053 $ 2,618
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount   $ 2,154   $ 2,154  
The 2010 Stock Incentive Plan [Member] | Minimum [Member]          
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period (Year) 10 years