Inventories

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Inventories

5. Inventories

(Table only in thousands)	March 31, 2018			December 31, 2017
Raw materials	$	17,238		$	18,444
Work in process		5,766			3,182
Finished goods		839			940
Obsolescence allowance		(1,760	)		(1,597	)
Total inventories	$	22,083		$	20,969

Amounts credited to the allowance for obsolete inventory and charged to cost of sales amounted to $0.3million and $0.2 million for the three-month periods ended March 31, 2018 and 2017, respectively.