Supplemental Consolidating Financial Information Condensed Statement of Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income (loss)	$ (17,956)	$ (17,814)	$ (24,723)	$ 15,663
Unrealized foreign currency translation gains	1	(753)	16	(381)
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0	(252)	0
Net other comprehensive income (loss) related to foreign currency translation	1	(753)	268	(381)
Change in fair value of available-for-sale investment	0	0	0	157
Realized gains of available-for-sale investment reclassified into Other income (expense), net	0	0	0	(561)
Net other comprehensive income (loss) related to available-for-sale investment	0	0	0	(404)
Unrealized gains (losses) on derivatives for the period	19,072	(6,183)	22,467	(8,308)
Derivative (gains) losses reclassified into Net sales	(1,543)	6,114	504	21,328
Derivative (gains) losses reclassified into Cost of sales	822	(2,277)	586	(7,267)
Net other comprehensive income (loss) related to derivatives	18,351	(2,346)	23,557	5,753
Actuarial gains (losses) for the period, net of tax	0	(42)	(905)	(1,448)
Amortization included in pension cost	297	342	893	1,018
Net other comprehensive income (loss) related to defined benefit pension and severance plans	297	300	(12)	(430)
Other comprehensive income (loss)of investments in subsidiaries	0	0	0	0
Comprehensive income (loss)	693	(20,613)	(910)	20,201
Reportable Legal Entities [Member] | Parent Company [Member]
Net income (loss)	(17,956)	(17,814)	(24,723)	15,663
Unrealized foreign currency translation gains	0	0	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0	0	0
Change in fair value of available-for-sale investment				157
Realized gains of available-for-sale investment reclassified into Other income (expense), net				(561)
Net other comprehensive income (loss) related to available-for-sale investment				(404)
Unrealized gains (losses) on derivatives for the period	0	0	0	0
Derivative (gains) losses reclassified into Net sales	0	0	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0	0	0
Net other comprehensive income (loss) related to derivatives	0	0	0	0
Actuarial gains (losses) for the period, net of tax	0	0	0	0
Amortization included in pension cost	0	0	0	0
Net other comprehensive income (loss) related to defined benefit pension and severance plans	0	0	0	0
Other comprehensive income (loss)of investments in subsidiaries	18,649	(2,799)	23,813	4,942
Comprehensive income (loss)	693	(20,613)	(910)	20,201
Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Net income (loss)	6,926	199	37,882	65,117
Unrealized foreign currency translation gains	0	0	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0	0	0
Change in fair value of available-for-sale investment				0
Realized gains of available-for-sale investment reclassified into Other income (expense), net				0
Net other comprehensive income (loss) related to available-for-sale investment				0
Unrealized gains (losses) on derivatives for the period	0	0	0	0
Derivative (gains) losses reclassified into Net sales	0	0	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0	0	0
Net other comprehensive income (loss) related to derivatives	0	0	0	0
Actuarial gains (losses) for the period, net of tax	1	0	(564)	841
Amortization included in pension cost	102	124	308	372
Net other comprehensive income (loss) related to defined benefit pension and severance plans	103	124	(256)	1,213
Other comprehensive income (loss)of investments in subsidiaries	18,546	(2,923)	24,069	3,729
Comprehensive income (loss)	25,575	(2,600)	61,695	70,059
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Net income (loss)	2,675	(1,237)	5,361	6,121
Unrealized foreign currency translation gains	0	0	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0	0	0
Change in fair value of available-for-sale investment				0
Realized gains of available-for-sale investment reclassified into Other income (expense), net				0
Net other comprehensive income (loss) related to available-for-sale investment				0
Unrealized gains (losses) on derivatives for the period	0	0	0	0
Derivative (gains) losses reclassified into Net sales	0	0	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0	0	0
Net other comprehensive income (loss) related to derivatives	0	0	0	0
Actuarial gains (losses) for the period, net of tax	0	0	0	0
Amortization included in pension cost	0	0	0	0
Net other comprehensive income (loss) related to defined benefit pension and severance plans	0	0	0	0
Other comprehensive income (loss)of investments in subsidiaries	0	0	0	0
Comprehensive income (loss)	2,675	(1,237)	5,361	6,121
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Net income (loss)	4,226	9,029	44,289	76,434
Unrealized foreign currency translation gains	1	(753)	16	(381)
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0	(252)	0
Net other comprehensive income (loss) related to foreign currency translation	1	(753)	268	(381)
Change in fair value of available-for-sale investment				0
Realized gains of available-for-sale investment reclassified into Other income (expense), net				0
Net other comprehensive income (loss) related to available-for-sale investment				0
Unrealized gains (losses) on derivatives for the period	19,072	(6,183)	22,467	(8,308)
Derivative (gains) losses reclassified into Net sales	(1,543)	6,114	504	21,328
Derivative (gains) losses reclassified into Cost of sales	822	(2,277)	586	(7,267)
Net other comprehensive income (loss) related to derivatives	18,351	(2,346)	23,557	5,753
Actuarial gains (losses) for the period, net of tax	(1)	(42)	(341)	(2,289)
Amortization included in pension cost	195	218	585	646
Net other comprehensive income (loss) related to defined benefit pension and severance plans	194	176	244	(1,643)
Other comprehensive income (loss)of investments in subsidiaries	0	0	0	0
Comprehensive income (loss)	22,772	6,106	68,358	80,163
Consolidation, Eliminations [Member]
Net income (loss)	(13,827)	(7,991)	(87,532)	(147,672)
Unrealized foreign currency translation gains	0	0	0	0
Realized gains for foreign currency translation on business disposal reclassified into Other income (expense), net	0	0	0	0
Net other comprehensive income (loss) related to foreign currency translation	0	0	0	0
Change in fair value of available-for-sale investment				0
Realized gains of available-for-sale investment reclassified into Other income (expense), net				0
Net other comprehensive income (loss) related to available-for-sale investment				0
Unrealized gains (losses) on derivatives for the period	0	0	0	0
Derivative (gains) losses reclassified into Net sales	0	0	0	0
Derivative (gains) losses reclassified into Cost of sales	0	0	0	0
Net other comprehensive income (loss) related to derivatives	0	0	0	0
Actuarial gains (losses) for the period, net of tax	0	0	0	0
Amortization included in pension cost	0	0	0	0
Net other comprehensive income (loss) related to defined benefit pension and severance plans	0	0	0	0
Other comprehensive income (loss)of investments in subsidiaries	(37,195)	5,722	(47,882)	(8,671)
Comprehensive income (loss)	$ (51,022)	$ (2,269)	$ (135,414)	$ (156,343)