Note 13 - Accumulated Other Comprehensive Income (Details) - Accumulated Balances of Other Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2015	$ 5,811
Balance as of March 31, 2015	6,096
Other comprehensive income before reclassifications	286
Amounts reclassified from accumulated other comprehensive income	(1)
Net current period other comprehensive income	285	(608)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2015	(15)
Balance as of March 31, 2015	16
Other comprehensive income before reclassifications	32
Amounts reclassified from accumulated other comprehensive income	(1)
Net current period other comprehensive income	31
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Auction Rate Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2015	(181)
Balance as of March 31, 2015	(176)
Other comprehensive income before reclassifications	5
Net current period other comprehensive income	5
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2015	6,007
Balance as of March 31, 2015	6,256
Other comprehensive income before reclassifications	249
Net current period other comprehensive income	$ 249