Note 9 - Stockholders' Equity (Details Textual)												1 Months Ended			12 Months Ended						36 Months Ended
		Feb. 18, 2021 shares	Feb. 16, 2021 USD ($) shares	Feb. 15, 2021 shares	Feb. 20, 2020 USD ($) shares	Jul. 19, 2019 $ / shares shares	May 07, 2019 USD ($) shares	Feb. 19, 2019 shares	Jul. 07, 2014 $ / shares shares	Jul. 01, 2004 shares	Jun. 30, 2004 shares	Jul. 30, 2020 shares	Jul. 30, 2019 shares	Feb. 28, 2019 USD ($)	Dec. 31, 2021 USD ($) $ / shares shares		Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2017 USD ($)	Feb. 28, 2020 shares	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)															5,700,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased (in shares)															497,608
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding Number (in shares)	[2]														126,000	[1]	289,069
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Exercisable Number (in shares)	[2],[3]														126,000
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Grants in Period (in shares)															0		0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Exercises in Period, Intrinsic Value | $															$ 7,177,000		$ 6,876,000	$ 629,000
Projected Revenue Goal | $							$ 41,000,000
Non-employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Annual Vesting, Percentage															25.00%
The2011 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights Vesting Percentage, Year One															25.00%
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
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, Expiration Period (Year)																	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)																	1,350,000
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)															200,542										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]
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding Number (in shares)															124,250
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Exercisable Number (in shares)															124,250
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] | RivieraWaves [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards Granted									400.00%
Share-based Compensation Arrangement by Share-based Payment Award, Remaining Vesting Period (Month)									36 months
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)									4 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)									113,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Employees Granted Shares (in shares)									27
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) | $ / shares									$ 15.17
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)									7 years
Stock Appreciation Rights (SARs) [Member] | RivieraWaves [Member] | SARs Vesting After One Year [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage									25.00%
Stock Appreciation Rights (SARs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards Granted																							400.00%
Percentage of Stock Appreciation Rights Units Subject to Grant															75.00%
Restricted Stock Units (RSUs) [Member] | Vesting on February 18, 2022 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		33.40%
Restricted Stock Units (RSUs) [Member] | Vesting on February 18, 2023 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		33.30%
Restricted Stock Units (RSUs) [Member] | Vesting on February 18, 2024 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		33.30%
Restricted Stock Units (RSUs) [Member] | Acquisition of Hillcrest Labs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Remaining Vesting Period (Month)					24 months	24 months
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)					3 years	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)						52,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Employees Granted Shares (in shares)						22
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) | $ / shares						$ 25.41
Restricted Stock Units (RSUs) [Member] | Acquisition of Hillcrest Labs [Member] | Restricted Stock Units Vesting After One Year [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage					34.00%	34.00%
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
Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting, Number (in shares)				5,902
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, Award Vesting Period (Year)							3 years	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)							10,000	30,000
Restricted Stock Units (RSUs) [Member] | The2011 Stock Incentive Plan [Member] | Non-employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			2 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)			1,784
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Fair Value | $			$ 124,670
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			50.00%
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)		5,962
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)		4,024
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)		3,577
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)		3,577
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	35,399		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 | $																					$ 268,520,000
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 | $																					249,340,000
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 | $																					$ 124,670,000
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 | $														$ 124,670,000
Performance Share Units [Member] | Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)																		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)							24,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Number to Be Granted If 100% License Revenue Target is Met (in shares)							20,000											23,200
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																	103.00%	116.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Proportional Percentage to Be Received for Each Increase of 1 Percent Beyond the License Revenue Target							1.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Ceiling as a Percentage of Baseline Number to Be Granted if the License Revenue Target is Exceeded							120.00%
Performance Share Units [Member] | Chief Executive Officer [Member] | Vesting on February 19, 2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage																		33.33%
Performance Share Units [Member] | Chief Executive Officer [Member] | Vesting on February 19, 2021 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage																		33.33%
Performance Share Units [Member] | Key Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)					18,500
Performance Share Units [Member] | Key Employees [Member] | Key Employees PSUs Goals One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage					50.00%
Performance Share Units [Member] | Key Employees [Member] | Key Employees PSUs Goals Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage					30.00%
Performance Share Units [Member] | Key Employees [Member] | Key Employees PSUs Goals Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)																	4,515
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage					20.00%
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)		8,943
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)		2,683
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)		2,385
Performance Share Units [Member] | Maximum [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							99.00%
Performance Share Units [Member] | Minimum [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							90.00%
Short-Term Executive PSUs [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															109.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded, Percentage		20.00%			20.00%
Short-Term Executive PSUs [Member] | Goals One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%			50.00%
Short-Term Executive PSUs [Member] | Goals Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%			50.00%
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] | Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)					17,045										5,276		19,261
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares)		1,788			3,410
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)					5,113										1,583		5,778
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares)		536			1,023
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)					4,545										1,407		5,136
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares)		477			909
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)					4,545										1,407		5,136
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Addtional Shares Issuable, Performance Goals Exceeded (in shares)		477			909
Long-term PSUs [Member]
Performance Goal, Minimum Market Cap for at Lease 30 Trading Days | $					$ 1,000,000,000
Long-term 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)					56,818
Long-term 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)					35,511
Long-term 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)					28,409
Long-term 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)					28,409
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)															974,542
Rule 10b-18, Authorization Two [Member]
Share Repurchase Program Additional Number of Shares Authorized To Be Repurchased (in shares)																						700,000

[1] Due to the ceiling imposed on the SAR grants, the outstanding amount equals a maximum of 280,427 shares of the Company's common stock issuable upon exercise.

[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.

[3] Due to the ceiling imposed on the SAR grants, the exercisable amount equals a maximum of 280,427 shares of the Company's common stock issuable upon exercise.