Note 6 - Short-term Investments (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Cash, Cash Equivalents and Investments [Table Text Block]

	December 31, 2016
	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Time deposits	$	21,532	$	-	$	-	$	21,532

	December 31, 2015
	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Time deposits	$	11,233	$	-	$	-	$	11,233

Investments Classified by Contractual Maturity Date [Table Text Block]

	December 31, 2016
	Cost		Fair Value
Time deposits
Due within one year	$	21,504	$	21,504
Due after one year through two years		28		28
	$	21,532	$	21,532

	December 31, 2015
	Cost		Fair Value
Time deposits
Due within one year	$	11,205	$	11,205
Due after one year through two years		28		28
	$	11,233	$	11,233