Note 8 - Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2020

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	Three Months Ended March 31,
	2020			2019
Balance at beginning of period	$	1,139		$	4,564
Warranty provision for product sales		541			268
Settlements made		(111	)		(2,271	)
Unused warranty provision		(425	)		(516	)
Balance at end of period	$	1,144		$	2,045