Restructuring and Impairment Charges (Additional Information) (Detail) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Apr. 24, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Accrued capital additions				$ 2,744	$ 2,376	$ 1,081
Impairment charges				1,506	807	0
Isola asset acquisition
Restructuring Cost and Reserve [Line Items]
Impairment charges				1,500
Brightvolt, Inc.
Restructuring Cost and Reserve [Line Items]
Impairment charges			$ 300
ROLINX
Restructuring Cost and Reserve [Line Items]
Impairment charges		$ 500
Relocation
Restructuring Cost and Reserve [Line Items]
Restructuring charges				600	2,800	700
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring charges				100	$ 400	$ 600
Severance and other related costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges				186
Fair value of restructuring charges				1,100
Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2,000			546
Severance costs	$ 500
Accrued capital additions				$ 1,600