Note 4 - Redeemable Noncontrolling Interest - Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Redemption value adjustment	$ (2,305)	$ 295	$ (9,970)	$ 909
Redeemable Noncontrolling Interest [Member]
Balance at beginning of period	54,404	33,566	43,929	33,138
Net income	848	92	822	210
Foreign currency translation	(4,522)	4,433	(1,686)	5,357
Redemption value adjustment	2,305	(295)	9,970	(909)
Balance at end of period	$ 53,035	$ 37,796	$ 53,035	$ 37,796