Note 3 - Marketable Securities and Time Deposits (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

	Amortized cost				Unrealized gains (losses), net						Fair value
	2015		2014		2015			2014			2015		2014
Short term deposit	$	5,568	$	2,599	$	-		$	-		$	5,568	$	2,599
U.S. GSE securities		23,645		21,085		(114	)		(34	)		23,531		21,051
Corporate obligations		79,072		80,389		(387	)		(262	)		78,685		80,127
	$	108,285	$	104,073	$	(501	)	$	(296	)	$	107,784	$	103,777

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amortized		Unrealized gains (losses)					Fair
	cost		Gains		Losses			value
Due in one year or less	$	12,500	$	8	$	(7	)	$	12,501
Due after one year to five years		90,217		25		(527	)		89,715
	$	102,717	$	33	$	(534	)	$	102,216

	Amortized		Unrealized gains (losses)					Fair
	cost		Gains		Losses			value
Due in one year or less	$	8,910	$	4	$	(5	)	$	8,909
Due after one year to six years		92,564		110		(405	)		92,269
	$	101,474	$	114	$	(410	)	$	101,178