Note 13 - Accumulated Other Comprehensive Income (Details) - Changes in Accumulated Other Comprehensive Income - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 6,186	$ 6,096	$ 5,811		$ 5,811
Other comprehensive income (loss) before reclassifications	(3,101)	93	286
Amounts reclassified from accumulated other comprehensive income	(1)	(3)	(1)
Net current period other comprehensive income (loss)	(3,102)	90	285	$ (179)	(2,727)	$ (599)
Balance	3,084	6,186	6,096		3,084
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	6,361	6,256	6,007		6,007
Other comprehensive income (loss) before reclassifications	(3,132)	105	249
Net current period other comprehensive income (loss)	(3,132)	105	249
Balance	3,229	6,361	6,256		3,229
Available-for-sale Securities [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	20	16	(15)		(15)
Other comprehensive income (loss) before reclassifications	42	7	32
Amounts reclassified from accumulated other comprehensive income	(1)	(3)	(1)
Net current period other comprehensive income (loss)	41	4	31
Balance	61	20	16		61
Auction Rate Securities [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(195)	(176)	(181)		(181)
Other comprehensive income (loss) before reclassifications	(11)	(19)	5
Net current period other comprehensive income (loss)	(11)	(19)	5
Balance	$ (206)	$ (195)	$ (176)		$ (206)