Note 12 - Income Taxes - Components of Income Before Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
United States									$ (14,431)	$ (247)	$ 3,173
International									71,695	42,738	33,219
Income before income taxes	$ 18,439	$ 15,781	$ 12,124	$ 10,919	$ 12,343	$ 13,304	$ 10,346	$ 6,499	$ 57,264	$ 42,491	$ 36,392