Note M - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year ended December 31,
	2016			2015			2014
Federal statutory rate		34.00	%		34.00	%		34.00	%
Effect of:
Change in valuation allowance		(69.31	)		(19.25	)		(32.88	)
Return to provision and deferred true-up		(23.83	)		—			0.36
Change in rate		(14.63	)		—			—
State tax benefit (net of federal)		15.64			4.06			5.96
Warrant liability		68.44			(15.28	)		(9.39	)
State research and development credit		0.09			0.03			0.09
Federal research and development credit		5.65			0.84			3.29
Amortization		(3.15	)		—			—
Conversion feature and put option on 2013 convertible notes		—			(1.68	)		(1.26	)
Interest expense		—			—			0.21
Stock-based compensation		(12.71	)		(1.28	)		—
Other		(0.10	)		(1.42	)		(0.29	)
Federal income tax provision effective rate		0.09	%		0.02	%		0.09	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	December 31,			December 31,			December 31,
	2016			2015			2014
Deferred tax assets relating to:
Net operating loss carryforwards	$	44,984		$	26,617		$	16,390
Research and development tax carryforward		3,166			2,254			1,793
Compensation		715			232			83
Total gross deferred tax assets		48,865			29,103			18,266
Deferred tax liabilities relating to:
Property and equipment		89			80			170
Total gross deferred tax liabilities		89			80			170
Deferred tax assets less liabilities		48,776			29,023			18,096
Valuation allowance		(48,776	)		(29,023	)		(18,096	)
Net deferred tax asset (liability)	$	—		$	—		$	—

Summary of Operating Loss Carryforwards [Table Text Block]

	Net Operating		Research
Year Incurred	Loss Carryforwards		Activities Credit		Expiration
2007	$	454	$	30		2027
2008		1,178		65		2028
2009		3,060		176		2029
2010		3,423		149		2030
2011		9,929		176		2031
2012		—		170		2032
2013		4,353		133		2033
2014		15,819		894		2034
2015		24,189		461		2035
2016		40,959		912		2036
	$	103,364	$	3,166