Note 1 - Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2014

Accounting Policies [Abstract]

Available-for-sale Securities [Table Text Block]

	September 30, 2014
	Amortized Cost		Accrued Interest		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Corporate debt securities	$	1,277	$	2	$	1	$	-	$	1,280
Commercial paper		4,998		-		1		-		4,999
Total investments	$	6,275	$	2	$	2	$	-	$	6,279

	December 31, 2013
	Amortized Cost		Accrued Interest		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Obligations of U.S. Government and its agencies	$	4,899	$	1	$	1	$	-	$	4,901
Corporate debt securities		8,528		47		2		1		8,576
Commercial paper		5,994		-		2		-		5,996
Total investments	$	19,421	$	48	$	5	$	1	$	19,473

Available for Sale Securities Debt Maturities Fair Value [Table Text Block]

	2014		2013
Maturing in one year or less	$	5,977	$	16,891
Maturing after one year through two years		302		2,582
Total investments	$	6,279	$	19,473

Schedule of Receivables from Collaborations [Table Text Block]

	September 30, 2014
	Billed		Unbilled		Total
U.S. Department of Health and Human Services	$	474	$	2,764	$	3,238
Shionogi & Co. Ltd.		-		-		-
Total receivables	$	474	$	2,764	$	3,238

	December 31, 2013
	Billed		Unbilled		Total
U.S. Department of Health and Human Services	$	90	$	1,573	$	1,663
Shionogi & Co. Ltd.		452		-		452
Total receivables	$	542	$	1,573	$	2,115

Schedule of Revenues from Collaborations [Table Text Block]

	Three Months				Nine Months
	2014		2013		2014		2013
Royalty revenue	$	5	$	8	$	1,951	$	2,042
Collaborative and other research and development revenues:
U.S. Department of Health and Human Services		2,937		2,085		5,323		3,834
Shionogi (Japan)		296		296		888		888
Total revenues	$	3,238	$	2,389	$	8,162	$	6,764