Note 9 - Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
Balance at beginning of period	$	1,748		$	3,951		$	4,564		$	2,416
Warranty provision for product sales		92			3,840			671			5,654
Settlements made		(326	)		(36	)		(2,625	)		(100	)
Unused warranty provision		(247	)		(2,821	)		(1,343	)		(3,036	)
Balance at end of period	$	1,267		$	4,934		$	1,267		$	4,934