Note 3 - Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value Measurements as of September 30, 2023 Using:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value
Assets
Corporate bonds	$	—	$	41,633	$	—	$	41,633
Commercial paper		48,889		—		—		48,889
Certificates of deposit		—		19,547		—		19,547
U.S. government treasuries		14,782		—		—		14,782
Asset-backed securities		—		8,426		—		8,426
Total assets	$	63,671	$	69,606	$	—	$	133,277

	Fair Value Measurements as of December 31, 2022 Using:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value
Assets
Corporate bonds	$	—	$	87,760	$	—	$	87,760
Commercial paper		37,682		—		—		37,682
Certificates of deposit		—		19,667		—		19,667
Asset-backed securities		—		6,554		—		6,554
Cash equivalents		9,438		—		—		9,438
Total assets	$	47,120	$	113,981	$	—	$	161,101