Note H - Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2022

Notes Tables

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

	Balance as of March 31, 2022		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Deerfield Warrant liability	$	80	$	—	$	—	$	80
Embedded Warrant Put Option		4		—		—		4
KVK Warrant liability		5		—		5		—
Total liabilities	$	89	$	—	$	5	$	84
Trading securities:
U.S. government-sponsored agency securities	$	7,335	$	—	$	7,335	$	—
Corporate notes and commercial paper		1,338		—		1,338		—
Certificates of deposit		481		481		—		—
U.S. Treasury securities		9,748		9,748		—		—
Total assets	$	18,902	$	10,229	$	8,673	$	—

	Balance as of December 31, 2021		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Deerfield Warrant liability	$	288	$	—	$	—	$	288
Embedded Warrant Put Option		18		—		—		18
KVK Warrant liability		24		—		24		—
Total liabilities	$	330	$	—	$	24	$	306
Trading securities:
U.S. government-sponsored agency securities	$	4,997	$	—	$	4,997	$	—
Certificates of deposit		490		490		—		—
U.S. Treasury securities		9,935		9,935		—		—
Total assets	$	15,422	$	10,425	$	4,997	$	—

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Three months ended March 31,
	2022			2021
Balance as of beginning of period	$	306		$	255
Adjustment to fair value		(222	)		37
Balance as of end of period	$	84		$	292