Note 16 - Segment Information - Net Revenue From Unaffiliated Customers (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2017	[1],[2]	Sep. 30, 2017	[3]	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Net revenues	$ 19,381		$ 17,352		$ 15,888	$ 14,180	$ 10,272	$ 10,823	$ 10,485	$ 8,647	$ 66,801	$ 40,227
UNITED STATES
Net revenues											20,205	13,061
Foreign [Member]
Net revenues											$ 46,596	$ 27,166

[1] The quarter ended December 31, 2017 includes a $7,525 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[2] The quarter ended December 31, 2017 includes adjustments related to tax legislation enacted in December 2017, as discussed in Note 2 and 11.

[3] The quarter ended September 30, 2017 includes a $549 reduction in the fair value of contingent consideration, which was not taxable.