Note 17 - Accumulated Other Comprehensive Income (Details) - Accumulated Balances of Other Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2013	$ 6,260	$ 4,175
Balance	5,811	6,260	4,175
Other comprehensive income (loss) before reclassifications	(447)	2,089
Amounts reclassified from accumulated other comprehensive income	(2)	(4)
Net current period other comprehensive income (loss)	(449)	2,085	582
Available-for-sale Securities [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2013	4	37
Balance	(15)	4
Other comprehensive income (loss) before reclassifications	(17)	(29)
Amounts reclassified from accumulated other comprehensive income	(2)	(4)
Net current period other comprehensive income (loss)	(19)	(33)
Auction Rate Securities [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2013	(360)	(490)
Balance	(181)	(360)
Other comprehensive income (loss) before reclassifications	179	130
Net current period other comprehensive income (loss)	179	130
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of January 1, 2013	6,616	4,628
Balance	6,007	6,616
Other comprehensive income (loss) before reclassifications	(609)	1,988
Net current period other comprehensive income (loss)	$ (609)	$ 1,988