Note 9 - Stockholders' Equity (Details Textual) $ / shares in Units, $ in Thousands | | | | | | | | | 1 Months Ended | 12 Months Ended | 36 Months Ended | | | |
Dec. 07, 2022 shares | Nov. 09, 2022 shares | Jun. 02, 2022 shares | Feb. 14, 2022 shares | Feb. 18, 2021 | Feb. 16, 2021 | Jul. 01, 2004 shares | Jun. 30, 2004 shares | Jul. 30, 2020 shares | Feb. 28, 2019 USD ($) | Dec. 31, 2022 USD ($) $ / shares shares | Dec. 31, 2021 USD ($) $ / shares shares | Dec. 31, 2020 USD ($) shares | Dec. 31, 2019 shares | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2017 USD ($) | Dec. 31, 2015 | Dec. 31, 2011 shares | Jul. 31, 2002 shares |
Common Stock, Number of Votes Per Share | | | | | | | | | | | | 1 | | | | | | | | | | |
Preferred Stock, Shares Authorized (in shares) | | | | | | | | | | | | 5,000,000 | | 5,000,000 | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | $ 0.001 | | $ 0.001 | | | | | | | | |
Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares) | | | | | | | | | | | | 1,000,000 | | | | | | | | | | |
Share Repurchase Program Additional Number of Shares Authorized To Be Repurchased (in shares) | | | | | | | | | | | | 6,400,000 | | | | | | | | | | |
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased (in shares) | | | | | | | | | | | | 278,799 | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding Number (in shares) | [2] | | | | | | | | | | | 106,000 | [1] | 126,000 | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Grants in Period (in shares) | | | | | | | | | | | | 0 | [2] | | | 0 | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Exercises in Period, Intrinsic Value | $ | | | | | | | | | | | | $ 273 | | $ 7,177 | $ 6,876 | | | | | | | |
Share-Based Payment Arrangement, Employee [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding Number (in shares) | | | | | | | | | | | | 0 | | | | | | | | | | |
Non-employee Director [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Annual Vesting, Percentage | | | | | | | | | | | | 25% | | | | | | | | | | |
The2011 Stock Incentive Plan [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights Vesting Percentage, Year One | | | | | | | | | | | | 25% | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Remaining Vesting Period (Month) | | | | | | | | | | | | 36 months | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | | | | | | | | | | | | | | | | | | | | | 3,200,000 | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares) | | | | 273,693 | | | | | | | | | | | | | | | | | | |
The 2002 Stock Incentive Plan [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | | | | | | | | | | | | | | | 0 | | | | | | | |
The 2003 Director Stock Option Plan [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | | | | | | | | | | | | | | | 1,350,000 | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) | | | | | | | | | | | | | | | 10 years | | | | | | | |
The 2003 Director Stock Option Plan [Member] | Non-employee Director [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total (in shares) | | | | | | | | | 38,000 | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period (Month) | | | | | | | | 6 months | | | | | | | | | | | | | | |
The 2003 Director Stock Option Plan [Member] | Board of Directors [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total (in shares) | | | | | | | | 13,000 | | | | | | | | | | | | | | |
The 2003 Director Stock Option Plan [Member] | Committee Chairperson [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total (in shares) | | | | | | | | 13,000 | | | | | | | | | | | | | | |
The 2003 Director Stock Option Plan [Member] | Board of Directors Chairman [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total (in shares) | | | | | | | | 15,000 | | | | | | | | | | | | | | |
The 2002 Employee Stock Purchase Plan [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | | | | | | | | | | | | 89,238 | | | | | | | | | | 3,050,000 |
Period Employees Eligible To Participate in Employee Stock Purchase Plan (Month) | | | | | | | | | | | | 5 months | | | | | | | | | | |
Minimum Working Hours for Eligibility of Employee Stock Purchase Plan | | | | | | | | | | | | 20 | | | | | | | | | | |
Maximum [Member] | The2011 Stock Incentive Plan [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | | | | | | | | | | | 4 years | | | | | | | | | | |
Stock Appreciation Rights (SARs) [Member] | Maximum [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards Granted | | | | | | | | | | | | | | | | | | | | 400% | | |
Percentage of Stock Appreciation Rights Units Subject to Grant | | | | | | | | | | | | 75% | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | Non-employee Director [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | | | | | | | | | | | | | | | | 2 years | 1 year | | | | |
Restricted Stock Units (RSUs) [Member] | Employees [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | | | | | | | | | | | | | | | 3 years | | | | | | |
Restricted Stock Units (RSUs) [Member] | Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares) | | | 34,887 | | | | | | | | | | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | Executive Vice President [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares) | | 16,114 | | | | | | | | | | | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Non-employee Director [Member] | Vesting After the First Anniversary Grant Date [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | | | 50% | | | | | | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 9,935 | | | | | | | | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Executive Vice President, Worldwide Sales [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 5,961 | | | | | | | | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Chief Financial Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 7,451 | | | | | | | | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Chief Operating Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 5,961 | | | | | | | | | | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Board of Directors [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | | | | | | 26,984 | | 26,551 | | 21,392 | | | | | | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Board of Directors Chairman [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted, Annualized Value | $ | | | | | | | | | | | | | | | | | | | $ 268,520 | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Directors with a Chairperson Position [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted, Annualized Value | $ | | | | | | | | | | | | | | | | | | | 249,340 | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Other Board of Directors [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted, Annualized Value | $ | | | | | | | | | | | | | | | | | | | $ 124,670 | | | |
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Director [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted, Annualized Value | $ | | | | | | | | | | | $ 124,670 | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded, Percentage | | | | | | 20% | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Vesting on February 20, 2021 [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | | | | | | | | | | 33.40% | 33.40% | | | | | | | |
Short-Term Executive PSUs [Member] | Vesting on February 22, 2022 [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | | | | | | | | | | 33.30% | 33.30% | | | | | | | |
Short-Term Executive PSUs [Member] | Vesting on February 20, 2023 [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | | | | | | | | | | 33.30% | 33.30% | | | | | | | |
Short-Term Executive PSUs [Member] | Goals One [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Threshold, Percentage | | | | | 90% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Goals One [Member] | Full Vesting Based on The Achievement of 2022 License Target [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | 50% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Goals One [Member] | Increase in Eligible PSUs, Percent [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Conditional Increase in Shares, Percentage | | | | | 2% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Goals Two [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | 50% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Goals Two [Member] | Increase in Eligible PSUs, Percent [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Conditional Increase in Shares, Percentage | | | | | 2% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Goals Two [Member] | Full Vesting Based on The Achievement of Positive Shareholder Return [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | 50% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Goals Two [Member] | Vesting Based on Actual Return Being at Least 90 Percent of S&P500 Index [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Threshold, Percentage | | | | | 90% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Goals Two [Member] | Vesting Based on Actual Return In Excess of 100 Percent of S&P500 Index [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Threshold, Percentage | | | | | 100% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | | | | | | | | 7,269 | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares) | | | | | 2,981 | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Executive Vice President, Worldwide Sales [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | | | | | | | | 1,938 | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares) | | | | | 795 | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Chief Financial Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | | | | | | | | 2,423 | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares) | | | | | 994 | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Chief Operating Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | | | | | | | | 1,938 | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares) | | | | | 795 | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Maximum [Member] | Goals One [Member] | Vesting Based on Achievement In Excess of 90 Percent [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Actual Performance Results, in Excess of Performance Threshold, Percentage | | | | | 110% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Maximum [Member] | Goals Two [Member] | Vesting Based on Actual Return Being at Least 90 Percent of S&P500 Index [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | 99% | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Threshold, Percentage | | | | | 99% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Maximum [Member] | Goals Two [Member] | Vesting Based on Actual Return In Excess of 100 Percent of S&P500 Index [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Actual Performance Results, in Excess of Performance Threshold, Percentage | | | | | 110% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Minimum [Member] | Goals One [Member] | Vesting Based on Achievement In Excess of 90 Percent [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Actual Performance Results, in Excess of Performance Threshold, Percentage | | | | | 1% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Minimum [Member] | Goals Two [Member] | Vesting Based on Actual Return Being at Least 90 Percent of S&P500 Index [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | 91% | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Threshold, Percentage | | | | | 90% | | | | | | | | | | | | | | | | | |
Short-Term Executive PSUs [Member] | Minimum [Member] | Goals Two [Member] | Vesting Based on Actual Return In Excess of 100 Percent of S&P500 Index [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Actual Performance Results, in Excess of Performance Threshold, Percentage | | | | | 1% | | | | | | | | | | | | | | | | | |
Performance Share Units [Member] | Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Percentage of License Revenue Target, Proportional Percentage to Be Received upon Achievement | | | | | | | | | | | | 98% | | | | | | | | | | |
Performance Share Units [Member] | The2011 Stock Incentive Plan [Member] | Chief Executive Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 14,903 | | | | | | | | | | | | | | | | | |
Performance Share Units [Member] | The2011 Stock Incentive Plan [Member] | Executive Vice President, Worldwide Sales [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 3,974 | | | | | | | | | | | | | | | | | |
Performance Share Units [Member] | The2011 Stock Incentive Plan [Member] | Chief Financial Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 4,969 | | | | | | | | | | | | | | | | | |
Performance Share Units [Member] | The2011 Stock Incentive Plan [Member] | Chief Operating Officer [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | | | | | 3,974 | | | | | | | | | | | | | | | | | |
Stock Options, Stock Appreciation Rights, Restricted Stock Units, and Performance Share Units [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | | | | | | | | | | | | 464,946 | | | | | | | | | | |
The 2003 Director Stock Option Plan [Member] | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number, Ending Balance (in shares) | | | | | | | | | | | | 0 | | | | | | | | | | |
| |
[1]Represent options granted to non-employee directors of the Company only. As of December 31, 2022, there were no outstanding or exercisable SAR units left and no outstanding or exercisable options granted to employees left.[2]The SAR units are convertible for a maximum number of shares of the Company’s common stock equal to 75% of the SAR units subject to the grant. | |