Note 12 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	2023		2022		2021
Current:
Federal	$	—	$	—	$	—
State		905		363		77
Foreign		178		92		247
		1,083		455		324
Deferred:
Federal		—		—		—
State		—		—		—
		—		—		—
Total	$	1,083	$	455	$	324

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	2023			2022			2021
Tax computed at the federal statutory rate	$	4,488		$	96		$	(6,045	)
State taxes		1,312			485			(1,072	)
Foreign taxes		178			92			247
Permanent items		4,837			6,864			22,689
R&D credits		(1,806	)		(1,490	)		(3,941	)
Prior year adjustment		(1,715	)		(455	)		916
Change in valuation allowance		(6,211	)		(5,137	)		(12,470	)
Total provision	$	1,083		$	455		$	324

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	2023			2022			2021
Deferred tax assets:
Net operating loss carry forwards	$	240,960		$	253,544		$	258,390
Business credit carryforwards		62,051			59,726			59,514
Organization costs
Compensation		37,946			37,876			40,647
Sec 174 R&D expenses		19,882			10,371
Accrued legal verdict		261			3,878			14,144
Carryforward of disallowed interest		1,477			4,761			4,537
Accrued expenses		1,976			50			104
Lease liabilities		3,034			4,035			4,839
Other		4,231			3,560			1,306
Subtotal		371,818			377,801			383,481
Deferred tax liabilities:
Lease right-of-use assets		(1,997	)		(2,870	)		(3,470	)
Inventory		(921	)		242			406
Other deferred tax liabilities		(149	)		(211	)		(318	)
Subtotal		(3,067	)		(2,839	)		(3,382	)
Total deferred tax assets		368,751			374,962			380,099
Valuation allowance		(368,751	)		(374,962	)		(380,099	)
Net deferred tax assets	$	—		$	—		$	—

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	2023			2022			2021
Unrecognized tax benefits - January 1	$	2,522		$	4,261		$	3,276
Gross decreases - tax positions in a prior period		(163	)		(2,113	)		—
Gross increases - tax positions in a current period		452			374			985
Unrecognized tax benefits - December 31		2,811			2,522			4,261