Note 12 - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Auction Rate Securities [Member]
Balance	$ (209)
Other comprehensive income (loss) before reclassifications	(8)
Net current period other comprehensive income (loss)	(8)
Balance	(217)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Available-for-sale Securities [Member]
Balance	(166)
Other comprehensive income (loss) before reclassifications	220
Amounts reclassified from accumulated other comprehensive income	(2)
Net current period other comprehensive income (loss)	218
Balance	52
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	1,841
Other comprehensive income (loss) before reclassifications	498
Net current period other comprehensive income (loss)	498
Balance	2,339
Balance	1,466
Other comprehensive income (loss) before reclassifications	710
Amounts reclassified from accumulated other comprehensive income	(2)
Net current period other comprehensive income (loss)	708	$ 285
Balance	$ 2,174