Note 2 - Business Acquisitions, Goodwill and Other Purchased Intangible Assets - Purchased Intangible Assets, Subject to Amortization (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Gross Carrying Amount	$ 35,275	$ 31,544
Accumulated Amortization	17,509	13,709
Developed Technology Rights [Member]
Gross Carrying Amount	20,785	19,195
Accumulated Amortization	$ 11,977	9,597
Remaining Useful Life (Year)	3 years 219 days
Customer Relationships [Member]
Gross Carrying Amount	$ 7,935	6,996
Accumulated Amortization	$ 4,582	3,644
Remaining Useful Life (Year)	3 years 109 days
Trade Names [Member]
Gross Carrying Amount	$ 6,139	5,353
Accumulated Amortization	$ 849	468
Remaining Useful Life (Year)	12 years 146 days
Noncompete Agreements [Member]
Gross Carrying Amount	$ 312
Accumulated Amortization	$ 23
Remaining Useful Life (Year)	9 years 109 days
Order or Production Backlog [Member]
Gross Carrying Amount	$ 104
Accumulated Amortization	$ 78
Remaining Useful Life (Year)	109 days