Note 6 - Recent Acquisition, Goodwill, In-process Research and Development and Other Intangible Assets - Summary of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Balance, Goodwill	$ 13,074	$ 13,074
Increase related to Somerset acquisition	4,773
Amortization expense
Balance, Goodwill	17,847	13,074
Balance, Finite-lived Intangible Assets	7,051
In Process Research and Development [Member]
Balance, Finite-lived Intangible Assets	600	28,700
Increase related to Somerset acquisition
Amortization expense, Finite-lived Intangible Assets
Balance, Finite-lived Intangible Assets	600	28,700
Other Intangible Assets [Member]
Balance, Finite-lived Intangible Assets	6,066	1,669
Increase related to Somerset acquisition	1,245
Amortization expense, Finite-lived Intangible Assets	(260)	(53)
Balance, Finite-lived Intangible Assets	$ 7,051	$ 1,616