Note 13 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

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

	2022		2021		2020
Current:
Federal	$	—	$	—	$	—
State		363		77		124
Foreign		92		247		83
		455		324		207
Deferred:
Federal		—		—		—
State		—		—		—
		—		—		—
Total	$	455	$	324	$	207

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

	2022			2021			2020
Tax computed at the federal statutory rate	$	96		$	(6,045	)	$	(12,540	)
State taxes		485			(1,072	)		(2,304	)
Foreign taxes		92			247			83
Permanent items		6,864			22,689			13,660
R&D credits		(1,490	)		(3,941	)		(5,231	)
Prior year adjustment		(455	)		916			(2,116	)
Change in valuation allowance		(5,137	)		(12,470	)		8,655
Total provision	$	455		$	324		$	207

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

	2022			2021			2020
Deferred tax assets:
Net operating loss carry forwards	$	253,544		$	258,390		$	261,472
Business credit carryforwards		59,726			59,514			55,574
Organization costs
Compensation		37,876			40,647			58,112
Sec 174 R&D expenses		10,371
Accrued legal verdict		3,878			14,144			11,880
Carryforward of disallowed interest		4,761			4,537			3,093
Accrued expenses		50			104			561
Lease liabilities		4,035			4,839			5,657
Other		3,560			1,306			804
Subtotal		377,801			383,481			397,153
Deferred tax liabilities:
Lease right-of-use assets		(2,870	)		(3,470	)		(4,099	)
Inventory		242			406			(21	)
Other deferred tax liabilities		(211	)		(318	)		(464	)
Subtotal		(2,839	)		(3,382	)		(4,584	)
Total deferred tax assets		374,962			380,099			392,569
Valuation allowance		(374,962	)		(380,099	)		(392,569	)
Net deferred tax assets	$	—		$	—		$	—

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

	2022			2021		2020
Unrecognized tax benefits - January 1	$	4,261		$	3,276	$	1,968
Gross decreases - tax positions in a prior period		(2,113	)		—		—
Gross increases - tax positions in a current period		374			985		1,308
Unrecognized tax benefits - December 31		2,522			4,261		3,276