Note 11 - Income Taxes (Details) - Components of Income Before Income Tax - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Income Before Income Tax [Abstract]
United States									$ (247)	$ 3,173	$ (2,309)
International									42,738	33,219	26,316
Total income before income taxes	$ 12,343	$ 13,304	$ 10,346	$ 6,499	$ 9,572	$ 10,648	$ 6,899	$ 9,275	$ 42,491	$ 36,392	$ 24,007