Note H - Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

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

	Balance as of March 31, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Deerfield Warrant liability	$	1,039	$	—	$	—	$	1,039
Embedded Warrant Put Option		288		—		—		288
Fundamental change and make-whole interest provisions embedded in 2021 Notes		—		—		—		—
Deerfield Note Conversion Feature		94		—		—		94
KVK Warrant liability		244		—		244		—
Total liabilities	$	1,665	$	—	$	244	$	1,421

	Balance as of December 31, 2018		Quoted Prices in  Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Deerfield Warrant liability	$	1,557	$	—	$	—	$	1,557
Embedded Warrant Put Option		154		—		—		154
Fundamental change and make-whole interest provisions embedded in 2021 Notes		—		—		—		—
Deerfield Note Conversion Feature		134		—		—		134
KVK Warrant liability		273		—		273		—
Total liabilities	$	2,118	$	—	$	273	$	1,845
Trading securities:
Certificates of deposit	$	246	$	246	$	—	$	—
U.S. Treasury securities		3,014		3,014		—		—
Total assets	$	3,260	$	3,260	$	—	$	—

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

	Three months ended March 31,
	2019			2018
Balance as of beginning of period	$	1,845		$	7,709
Adjustment to fair value		(424	)		9,741
Balance as of end of period	$	1,421		$	17,450