Geographic and Segment Information - Additional Information (Detail)	3 Months Ended		12 Months Ended
	Jun. 30, 2015 Segments	Mar. 31, 2015 Segments	Dec. 31, 2017 Customer Segments	Dec. 31, 2016 Customer	Dec. 31, 2015 Customer
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | Segments	2		2
As Previously Reported [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | Segments		1
Customer Concentration Risk [Member] | Net Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of customers greater than ten percent threshold | Customer			1	2	2
Customer Concentration Risk [Member] | Net Sales [Member] | Top Ten Customers [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage			57.00%	64.00%	64.00%
Number of customers | Customer			10	10	10
Customer Concentration Risk [Member] | Net Sales [Member] | Top Customer One [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage			15.60%	23.50%	15.20%
Customer Concentration Risk [Member] | Net Sales [Member] | Top Customer Two [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage				11.40%	11.00%
Geographic Concentration Risk [Member] | Property, Plant and Equipment [Member] | Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage			97.00%