Note 3 - Cash, Cash Equivalent and Marketable Investments (Tables)

9 Months Ended

Sep. 30, 2018

Notes Tables

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

September 30, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents:
Cash	$	13,355	$	—	$	—		$	13,355
Money market funds		8,511		—		—			8,511
Total cash and cash equivalents		21,866		—		—			21,866
Marketable investments:
U.S. government notes	$	2,015		—		(1	)	$	2,014
Municipal securities		202		—		(1	)		201
Corporate debt securities		2,815		1		(13	)		2,803
Total marketable investments		5,032		1		(15	)		5,018
Total cash, cash equivalents and marketable investments	$	26,898	$	1	$	(15	)	$	26,884

December 31, 2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Cash and cash equivalents:
Cash	$	14,058	$	—	$	—	$	14,058
Money market funds		126		—		—		126
Total cash and cash equivalents		14,184		—		—		14,184
Marketable investments:
U.S. government notes		11,885		—		(15)		11,870
Municipal securities		201		—		(1)		200
Commercial paper		1,836		—		(3)		1,833
Corporate debt securities		7,838		2		(15)		7,825
Total marketable investments		21,760		2		(34)		21,728
Total cash, cash equivalents and marketable investments	$	35,944	$	2	$	(34)	$	35,912

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amount
Due in less than one year	$	4,619
Due in 1 to 3 years		399
Total marketable investments	$	5,018