Note 6 - Stockholders' Equity and Stock-based Compensation (Details Textual) $ / shares in Units, $ in Thousands								1 Months Ended						3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Feb. 05, 2025 shares	Jul. 03, 2024 USD ($) $ / shares shares	Mar. 28, 2024 USD ($) $ / shares shares	Jan. 01, 2024 USD ($) shares	Apr. 30, 2023 USD ($) $ / shares shares	Jan. 01, 2023 shares	Jun. 09, 2022 USD ($) $ / shares shares	Feb. 04, 2025 USD ($)	Oct. 31, 2024 USD ($) shares	Mar. 31, 2024 shares	Dec. 31, 2023 $ / shares shares	May 31, 2021 shares	Nov. 30, 2017 shares	Mar. 27, 2025 USD ($)	Jun. 15, 2023 USD ($) shares	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2017 shares	Jan. 02, 2025 shares	Sep. 30, 2023 shares
Preferred Stock, Shares Authorized (in shares)											50,000,000						50,000,000	50,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares											$ 0.001						$ 0.001	$ 0.001
Preferred Stock, Shares Outstanding, Ending Balance (in shares)											0						0	0
Common Stock, Shares Authorized (in shares)											500,000,000						500,000,000	500,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares											$ 0.001						$ 0.001	$ 0.001
Equity Classified Subscription, Value | $																	$ 47,700
Right Offering Deemed Dividend | $																	$ 47,700	$ 0
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares											$ 0						$ 11	$ 0
Class of Warrant or Right, Expired/Redeemed During Period (in shares)																	(0)
Class of Warrant or Right, Outstanding (in shares)											0						1,498,483	0
Proceeds from Warrant Exercises | $																	$ 49,424	$ 14,828
Class of Warrant or Right, Exercised During Period (in shares)																	4,501,516
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $				$ 34,800
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)				2 years 10 months 6 days
Time-based Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value | $																	$ 1,900	900
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Intrinsic Value | $																	18,700	9,000
Share-Based Payment Arrangement, Plan Modification, Incremental Cost | $																	2,900
Modified Time Based Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award, Shares Modified (in shares)									600,113
Share Based Compensation Arrangement By Share Based Payment Award, Fair Value of Shares Modified | $									$ 8,800
Share-Based Payment Arrangement, Plan Modification, Incremental Cost | $																	2,900
Performance-based Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Intrinsic Value | $																$ 300		2,000
Share-Based Payment Arrangement, Plan Modification, Incremental Cost | $									$ 3,200
Market-based Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Intrinsic Value | $																	5,300	$ 10,500
Modified Market Based Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award, Shares Modified (in shares)									206,389
Share Based Compensation Arrangement By Share Based Payment Award, Fair Value of Shares Modified | $																	2,800
Share-Based Payment Arrangement, Plan Modification, Incremental Cost | $																	$ 400
The 2017 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)																			1,500,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)				1,200,000		1,200,000					1,375,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Number of Shares (in shares)																			1,200,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Percent																			4.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)																	77,490
The 2017 Inducement Equity Incentive 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)													1,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)										2,000,000		1,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)																	2,941,626
The 2017 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)																			250,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Number of Shares (in shares)																			450,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Percent																			1.50%
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)																	445,779
Common Stock, Capital Shares Reserved for Future Issuance (in shares)																	450,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)																	117,539	347,681
Share-Based Payment Arrangement, Tranche One [Member] | Time-based Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage																	25.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)																	1 year
Share-Based Payment Arrangement, Tranche One [Member] | The 2017 Inducement Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage													25.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)													1 year
Chief Executive Officer [Member] | Time-based Options [Member]
Share-Based Payment Arrangement, Accelerated Cost | $																	$ 700	$ 600
Loan Agreement [Member]
Debt Instrument, Decrease, Forgiveness | $					$ 65,000
Maximum [Member] | Modified Time Based Awards [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)									4 years
Maximum [Member] | The 2017 Inducement Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)													10 years
Minimum [Member] | Modified Time Based Awards [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)									2 years
Warrants Issued in 2024 Rights Offering [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		0.5	0.5
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		5,999,999
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 11
Class of Warrans or Right, Exercise Price, Percentage of Subscription Price for Units		110.00%
Warrants and Rights Outstanding, Term (Year)		5 years
Proceeds from Warrant Exercises | $																	$ 49,400
Warrants Issued in 2024 Rights Offering [Member] | Vesting of First Half [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)																	253,246
Class of Warrants or Rights, Redemption Price Per Share (in dollars per share) | $ / shares		$ 0.01
Class of Warrant or Right, Percentage Required for Redemption		150.00%															150.00%
Class of Warrant or Right, Vesting, Stock Price Trigger (in dollars per share) | $ / shares		$ 16.5															$ 18.85
Class of Warrant or Right, Period of Written Notice for Exercise (Day)		30 days
Warrants Issued in 2024 Rights Offering [Member] | Vesting of First Half [Member] | Subsequent Event [Member]
Class of Warrant or Right, Percentage Required for Redemption	150.00%
Class of Warrant or Right, Expired/Redeemed During Period (in shares)	18,221
Class of Warrant or Right, Outstanding (in shares)	0
Proceeds from Warrant Exercises | $								$ 2,600
Warrants Issued in 2024 Rights Offering [Member] | Vesting of Second Half [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)																	1,245,237
Class of Warrants or Rights, Redemption Price Per Share (in dollars per share) | $ / shares		$ 0.01
Class of Warrant or Right, Percentage Required for Redemption		200.00%															200.00%
Class of Warrant or Right, Vesting, Stock Price Trigger (in dollars per share) | $ / shares		$ 22
Class of Warrant or Right, Period of Written Notice for Exercise (Day)		30 days
Warrants Issued in 2024 Rights Offering [Member] | Vesting of Second Half [Member] | Subsequent Event [Member]
Class of Warrant or Right, Percentage Required for Redemption														200.00%
Proceeds from Warrant Exercises | $														$ 11,400
Warrants Issued in 2024 Rights Offering [Member] | Maximum [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		6,000,000
Rights Offering Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)							1
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)							7,317,072				7,317,072							7,317,072
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares							$ 2.05				$ 2.05							$ 2.05
Class of Warrants or Rights, Redemption Price Per Share (in dollars per share) | $ / shares							0.01				$ 0.01							$ 0.01
Class of Warrant or Right, Percentage Required for Redemption											200.00%							200.00%
Class of Warrant or Right, Outstanding (in shares)																					0
Proceeds from Warrant Exercises | $															$ 14,900
Class of Warrant or Right, Period of Written Notice for Exercise (Day)																		30 days
Class of Warrant or Right, Exercise, Consecutive Trading Days (Day)																		20 days
Class of Warrant or Right, Exercised During Period (in shares)															7,250,897			66,175
Rights Offering Warrants [Member] | Majority Stockholder and Co-chairman [Member] | Vesting of First Half [Member] | Subsequent Event [Member]
Class of Warrant or Right, Percentage Required for Redemption																				150.00%
Class of Warrant or Right, Outstanding (in shares)																				0
Rights Offering Warrants [Member] | Majority Stockholder and Co-chairman [Member] | Vesting of Second Half [Member] | Subsequent Event [Member]
Class of Warrant or Right, Percentage Required for Redemption																				200.00%
Class of Warrant or Right, Outstanding (in shares)																				0
The 2024 Right Offering [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares		$ 0.001	$ 0.001
Equity Offering, Units, Maximum Amount Authorized (in shares)		6,000,000	6,000,000
Equity Offering Units, Offering Value | $			$ 60,000
Shares Issued, Price Per Share (in dollars per share) | $ / shares		$ 10	$ 10
Subscription Right, Number of Units			0.10864186
Number of Shares Per Unit Issued (in shares)		1	1
Number of Warrants in Each Unit (in shares)		2	2
Share Price (in dollars per share) | $ / shares			$ 11.55
Equity Classified Subscription, Value | $			$ 47,700
Right Offering Deemed Dividend | $			$ 47,700
Stock Issued During Period, Shares, New Issues (in shares)		5,999,998
Proceeds from Issuance or Sale of Equity | $		$ 60,000
The 2024 Right Offering [Member] | Majority Stockholder and Co-chairman [Member]
Percent of Offering Purchased		88.00%
Private Placement [Member] | Majority Stockholder and Co-chairman [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.001
Shares Issued, Price Per Share (in dollars per share) | $ / shares					$ 6.51
Stock Issued During Period, Shares, New Issues (in shares)					10,022,937
Rights Offering [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							0.001
Shares Issued, Price Per Share (in dollars per share) | $ / shares							$ 2.05
Number of Shares Per Unit Issued (in shares)							1
Stock Issued During Period, Shares, New Issues (in shares)							7,317,072
Proceeds from Issuance or Sale of Equity | $							$ 15,000
Equity Offering, Units, Sale of Units (in shares)							7,317,072
Number of Warrants Per Unit (in shares)							1
Rights Offering [Member] | Majority Stockholder and Co-chairman [Member]
Percent of Offering Purchased							56.00%