Supplemental Consolidating Financial Information Condensed Statement of Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Net Loss	$ (64,626)	$ (24,603)
Unrealized foreign currency translation gains	2	16
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	(602)	(252)
Net other comprehensive income (loss) related to foreign currency translation	604	268
Unrealized gains (losses) on derivatives for the period	18,274	(1,046)
Derivative (gains) losses reclassified into Net sales	(16,978)	1,027
Derivative (gains) losses reclassified into Cost of sales	8,775	(175)
Net other comprehensive income (loss) related to derivatives	10,071	(194)
Actuarial gains (losses) for the period, net of tax	2,172	(342)
Amortization included in pension cost	284	300
Net other comprehensive income (loss) related to defined benefit pension and severance plans	2,456	(42)
Other comprehensive income (loss)of investments in subsidiaries	0	0
Comprehensive income (loss)	(51,495)	(24,571)
Reportable Legal Entities [Member] | Parent Company [Member]
Net Loss	(64,626)	(24,603)
Unrealized foreign currency translation gains	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0
Unrealized gains (losses) on derivatives for the period	0	0
Derivative (gains) losses reclassified into Net sales	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0
Net other comprehensive income (loss) related to derivatives	0	0
Actuarial gains (losses) for the period, net of tax	0	0
Amortization included in pension cost	0	0
Net other comprehensive income (loss) related to defined benefit pension and severance plans	0	0
Other comprehensive income (loss)of investments in subsidiaries	13,131	(220)
Comprehensive income (loss)	(51,495)	(24,823)
Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Net Loss	3,421	(438)
Unrealized foreign currency translation gains	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0
Unrealized gains (losses) on derivatives for the period	0	0
Derivative (gains) losses reclassified into Net sales	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0
Net other comprehensive income (loss) related to derivatives	0	0
Actuarial gains (losses) for the period, net of tax	0	0
Amortization included in pension cost	103	104
Net other comprehensive income (loss) related to defined benefit pension and severance plans	103	104
Other comprehensive income (loss)of investments in subsidiaries	13,028	(324)
Comprehensive income (loss)	16,552	(658)
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Net Loss	5,744	(3,112)
Unrealized foreign currency translation gains	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0
Unrealized gains (losses) on derivatives for the period	0	0
Derivative (gains) losses reclassified into Net sales	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0
Net other comprehensive income (loss) related to derivatives	0	0
Actuarial gains (losses) for the period, net of tax	0	0
Amortization included in pension cost	0	0
Net other comprehensive income (loss) related to defined benefit pension and severance plans	0	0
Other comprehensive income (loss)of investments in subsidiaries	0	0
Comprehensive income (loss)	5,744	(3,112)
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Net Loss	43,089	8,258
Unrealized foreign currency translation gains	2	16
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	(602)	(252)
Net other comprehensive income (loss) related to foreign currency translation	604	268
Unrealized gains (losses) on derivatives for the period	18,274	(1,046)
Derivative (gains) losses reclassified into Net sales	(16,978)	1,027
Derivative (gains) losses reclassified into Cost of sales	8,775	(175)
Net other comprehensive income (loss) related to derivatives	10,071	(194)
Actuarial gains (losses) for the period, net of tax	2,172	(342)
Amortization included in pension cost	181	196
Net other comprehensive income (loss) related to defined benefit pension and severance plans	2,353	(146)
Other comprehensive income (loss)of investments in subsidiaries	0	0
Comprehensive income (loss)	56,117	8,186
Consolidation, Eliminations [Member]
Net Loss	(52,254)	(4,708)
Unrealized foreign currency translation gains	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0
Unrealized gains (losses) on derivatives for the period	0	0
Derivative (gains) losses reclassified into Net sales	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0
Net other comprehensive income (loss) related to derivatives	0	0
Actuarial gains (losses) for the period, net of tax	0	0
Amortization included in pension cost	0	0
Net other comprehensive income (loss) related to defined benefit pension and severance plans	0	0
Other comprehensive income (loss)of investments in subsidiaries	(26,159)	544
Comprehensive income (loss)	$ (78,413)	$ (4,164)