Note 6 - Recent Acquisition, Goodwill, In-process Research and Development and Other Intangible Assets - Summary of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2019	Jun. 30, 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	6,775
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	(536)	(106)
Balance, Finite-lived Intangible Assets	$ 6,775	$ 1,563

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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