Note 6 - Goodwill, In-process Research and Development, and Other Intangible Assets - Summary of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Goodwill	$ 13,074	$ 13,074	$ 13,074	$ 13,074	$ 13,074	$ 13,074
Impairment	(23,200)		(23,200)
Amortization expense
In Process Research and Development [Member]
Balance, Finite-lived Intangible Assets			28,700	28,700
Impairment			(23,200)
Amortization expense, Finite-lived Intangible Assets			(117)
Balance, Finite-lived Intangible Assets	5,383	28,700	5,383	28,700
Other Intangible Assets [Member]
Balance, Finite-lived Intangible Assets			1,669	1,881
Amortization expense, Finite-lived Intangible Assets			(159)	(159)
Balance, Finite-lived Intangible Assets	$ 1,510	$ 1,722	$ 1,510	$ 1,722