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

6 Months Ended

Jun. 30, 2018

Notes Tables

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

June 30, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents:
Cash	$	15,545	$	—	$	—		$	15,545
Money market funds		2,887		—		—			2,887
Total cash and cash equivalents		18,432		—		—			18,432
Marketable investments:
U.S. government notes		6,012		—		(8	)		6,004
Municipal securities		200		—		(1	)		199
Corporate debt securities		4,388		—		(18	)		4,370
Total marketable investments		10,600		—		(27	)		10,573
Total cash, cash equivalents and marketable investments	$	29,032	$	—	$	(27	)	$	29,005

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	$	9,573
Due in 1 to 3 years		1,000
Total marketable investments	$	10,573