Note H - Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2016

Notes Tables

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

	Balance at June 30 , 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Underwri ter Warrant liability	$	53	$	—	$	—	$	53
Deerfield Warrant liability		5,404		—		—		5,404
Embedded Put Option		557		—		—		557
Fundamental change and make-whole interest provisions embedded in 2021 Notes		29		—		—		29
Total liabilities	$	6,043	$	—	$	—	$	6,043
Trading securities:
Certificates of deposit		11,911		11,911		—		—
Government bonds		62,073		62,073		—		—
Total assets	$	73,984	$	73,984	$	—	$	—

	Balance at December 31, 2015		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Underwriter Warrant liability	$	3,877	$	—	$	—	$	3,877
Deerfield Warrant liability		33,750		—		—		33,750
Embedded Put Option		212		—		—		212
Total liabilities	$	37,839	$	—	$	—	$	37,839
Trading securities:
Certificates of deposit		8,951		8,951		—		—
Government bonds		10,051		10,051		—		—
Total assets	$	19,002	$	19,002	$	—	$	—

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

	Three Months Ended June 30,						Six Months Ended June 30,
	2016			2015			2016			2015
Balance at beginning of period	$	27,479		$	17,728		$	37,839		$	15,966
Reclassification of 2013 Convertible Notes		—			(1,110	)		—			(1,110	)
Exercise of warrants		(673	)		—			(755	)		—
Adjustment to fair value		(20,763	)		22,661			(31,041	)		24,423
Balance at end of period	$	6,043		$	39,279		$	6,043		$	39,279