Note 13 - Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Operating Lease, Right-of-Use Asset	$ 16,296
Operating lease liability, current	6,039
Operating lease liability, long-term	10,713
Total operating lease liabilities	16,752
Property, plant and equipment, gross	165,896	163,804
Accumulated depreciation	(123,426)	(119,872)
Property, plant and equipment, net	42,470	$ 43,932
Other current liabilities	97
Other long-term liabilities	529
Total finance lease liabilities	626
Assets under Finance Lease [Member]
Property, plant and equipment, gross	860
Accumulated depreciation	(225)
Property, plant and equipment, net	$ 635