Note 7 - Income Taxes - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. federal statutory income tax rate	(35.00%)	(35.00%)	(35.00%)
Effect of foreign operations	14.50%	2.50%	(25.20%)
US state income taxes net of Federal benefit	(1.10%)	(1.70%)	1.40%
Foreign earnings repatriation	6.70%	34.40%
U.S. foreign tax credit	(2.70%)	(7.80%)
Valuation allowance	1.80%	5.10%	0.50%
Other	(0.50%)	(0.10%)	1.20%
Total	(16.30%)	(2.60%)	12.90%