Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

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Note 7 - Inventories - Fair Value of Impaired Inventory (Details) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)
Impairment Data; Total Subdivisions Tested	17	24	35	33
Impairment Data; Inventory Impairments	$ 200	$ 550		$ 4,850	$ 750	$ 4,850
Impairment Data; Fair Value of Inventory After Impairments	$ 767	$ 5,223		$ 19,952
Impairment Data; Number of Subdivisions Impaired	1	2		2
Measurement Input, Discount Rate [Member]
Quantitative Data; Discount Rate	12	12			12
Measurement Input, Discount Rate [Member] \| Minimum [Member]
Quantitative Data; Discount Rate				12
Measurement Input, Discount Rate [Member] \| Maximum [Member]
Quantitative Data; Discount Rate				18