Geographic and Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014 Customer	Dec. 31, 2013 Customer	Dec. 31, 2012 Customer
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments	1
Number of business lines	3
Customer Concentration Risk [Member] | Net Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of customers	2	1	1
Customer Concentration Risk [Member] | Net Sales [Member] | Top Ten Customers [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	61.00%	59.00%	61.00%
Number of customers	10	10	10
Customer Concentration Risk [Member] | Net Sales [Member] | Customer One [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	11.40%	11.30%
Customer Concentration Risk [Member] | Net Sales [Member] | Customer Two [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	10.70%		11.50%
Geographic Concentration Risk [Member] | Property, Plant and Equipment [Member] | Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	96.00%