Note 13 - Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017
Balance			$ 431,116
Balance	$ 505,523
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Balance	(680)	$ (821)	(1,023)
Other comprehensive income before reclassifications	217	144	202
Amounts reclassified from accumulated other comprehensive loss	5	(3)
Net current period other comprehensive income	222	141	202
Balance	(458)	(680)	(821)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(700)	(1,886)	(3,192)
Other comprehensive income before reclassifications	1,500	1,186	1,306
Amounts reclassified from accumulated other comprehensive loss
Net current period other comprehensive income	1,500	1,186	1,306
Balance	800	(700)	(1,886)
AOCI Attributable to Parent [Member]
Balance	(1,380)	(2,707)	(4,215)
Other comprehensive income before reclassifications	1,717	1,330	1,508
Amounts reclassified from accumulated other comprehensive loss	5	(3)
Net current period other comprehensive income	1,722	1,327	1,508
Balance	$ 342	$ (1,380)	$ (2,707)