Note 2 - Significant Accounting Policies - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill, balance	$ 285,041	$ 265,145
Acquisitions and adjustments	5,150	19,896
Goodwill, balance	$ 290,191	$ 285,041