Note 2 - Cash, Cash Equivalents and Marketable Investments (Tables)

3 Months Ended

Mar. 31, 2015

Disclosure Text Block Supplement [Abstract]

Unrealized Gain (Loss) on Investments [Table Text Block]

March 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents:
Cash	$	6,553	$	—	$	—		$	6,553
Money market funds		3,759		—		—			3,759
Commercial paper		3,150		—		—			3,150
Total cash and cash equivalents		13,462		—		—			13,462
Marketable investments:
U.S. government notes		14,320		35		—			14,355
U.S. government agencies		18,259		34		(3	)		18,290
Municipal securities		3,914		3		(3	)		3,914
Commercial paper		10,735		4		—			10,739
Corporate debt securities		15,280		19		(2	)		15,297
Total marketable investments		62,508		95		(8	)		62,595
Total cash, cash equivalents and marketable investments	$	75,970	$	95	$	(8	)	$	76,057

December 31, 2014	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents:
Cash	$	7,761	$	—	$	—		$	7,761
Money market funds		242		—		—			242
Commercial paper		1,800		—		—			1,800
Total cash and cash equivalents		9,803		—		—			9,803
Marketable investments:
U.S. government notes		18,345		17		(1	)		18,361
U.S. government agencies		19,768		33		(1	)		19,800
Municipal securities		3,607		3		(3	)		3,607
Commercial paper		10,693		2		—			10,695
Corporate debt securities		18,875		13		(8	)		18,880
Total marketable investments		71,288		68		(13	)		71,343
Total cash, cash equivalents and marketable investments	$	81,091	$	68	$	(13	)	$	81,146

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amount
Due in less than one year	$	34,249
Due in 1 to 3 years		28,346
	$	62,595