Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2018

Commitments and Contingencies Disclosure [Abstract]

Changes in the Liability for Product Warranty Claim Costs

Changes in the liability for product warranty claim costs were as follows:

(In thousands)	Six Months Ended June 30,
	2018			2017
Balance at beginning of period	$	339		$	134
Accruals for warranties issued during the period	769			167
Settlements (in cash or in kind) during the period	(100		)	(3		)
Balance at end of period	$	1,008		$	298