Note 3 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2024

Notes Tables

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

	Fair Value Measurements as of March 31, 2024 (000's):
	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	$	—	$	61,914	$	—	$	61,914
Commercial paper		30,124		—		—		30,124
Certificates of deposit		—		17,943		—		17,943
U.S. government treasuries		12,658		—		—		12,658
Asset-backed securities		—		9,942		—		9,942
Cash equivalents		1,549		—		—		1,549
Total assets	$	44,331	$	89,799	$	—	$	134,130
	Fair Value Measurements as of December 31, 2023 (000's):
	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	$	—	$	54,281	$	—	$	54,281
Commercial paper		28,534		—		—		28,534
Certificates of deposit		—		18,866		—		18,866
U.S. government treasuries		16,080		—		—		16,080
Asset-backed securities		—		10,472		—		10,472
Money market funds (cash equivalents)		575		—		—		575
Total assets	$	45,189	$	83,619	$	—	$	128,808