Geographic and Segment Information - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2014 Customer	Jun. 30, 2013 Customer	Jun. 30, 2014 Customer	Jun. 30, 2013 Customer
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments			1
Number of business lines			3
Geographic Concentration Risk [Member] | Property, Plant and Equipment [Member] | Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage			99.00%
Customer Concentration Risk [Member] | Net Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage			10.00%
Number of customers	1	2	0	4
Customer Concentration Risk [Member] | Net Sales [Member] | Top Ten Customers [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	59.00%	62.00%	57.00%	65.00%
Number of customers	10	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	10.50%	11.10%		12.80%
Customer Concentration Risk [Member] | Net Sales [Member] | Customer Two [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage		10.80%		10.90%
Customer Concentration Risk [Member] | Net Sales [Member] | Customer Three [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage				10.50%
Customer Concentration Risk [Member] | Net Sales [Member] | Customer Four [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage				10.20%