Property, Plant and Equipment (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 5,371,702,000	$ 4,961,306,000
Less accumulated depreciation and amortization	(3,112,832,000)	(2,954,753,000)
Total property, plant and equipment, net	2,258,870,000	2,006,553,000
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	207,986,000	208,048,000
Land use rights [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	26,845,000	26,845,000
Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	937,962,000	911,258,000
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,947,483,000	3,577,045,000
Software and computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	206,763,000	193,641,000
Furniture, fixtures and other equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	15,430,000	17,430,000
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	29,233,000	27,039,000
KOREA, REPUBLIC OF
Property, Plant and Equipment [Line Items]
Interest Costs Capitalized	$ 6,800,000