Supplemental Consolidating Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net sales	$ 674,700	$ 738,551	$ 2,176,678	$ 2,326,388
Cost of sales	581,661	663,536	1,842,512	2,065,095
Selling, general and administrative	48,499	53,658	139,381	163,004
Transaction costs	7,630	8,235	67,270	16,907
Depreciation	11,309	12,323	40,195	38,911
Amortization	2,338	2,342	7,022	7,025
Equity in losses (earnings) of investees	(95)	105	88	437
Operating income (loss)	23,168	(1,438)	80,386	35,883
Interest Income, Other	607	600	1,909	1,905
Interest Expense	(7,624)	(15,564)	(26,190)	(46,331)
Gains (Losses) on Extinguishment of Debt	0	0	(36,212)	(521)
Other Nonoperating Income (Expense)	(895)	(1,036)	(2,450)	(5,172)
Interest Expense, Related Party	0		0
Income (loss) before income taxes	15,256	(17,438)	17,443	(14,236)
Income tax benefit (expense)	(5,087)	(518)	(12,312)	(10,487)
Net income (loss)	10,169	(17,956)	5,131	(24,723)
Reportable Legal Entities [Member] | Parent Company [Member]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Selling, general and administrative	(685)	9,788	3,872	25,276
Transaction costs	1,360	8,235	40,863	16,907
Depreciation	0	0	0	0
Amortization	0	0	0	0
Equity in losses (earnings) of investees	18,210	6,134	67,478	43,502
Operating income (loss)	17,535	(11,889)	22,743	1,319
Interest Income, Other	0	0	0	0
Interest Expense	(2,276)	(5,549)	(8,577)	(16,136)
Gains (Losses) on Extinguishment of Debt			(17,112)	0
Other Nonoperating Income (Expense)	0	0	0	581
Interest Expense, Related Party	(3)		20,389
Income (loss) before income taxes	15,256	(17,438)	17,443	(14,236)
Income tax benefit (expense)	(5,087)	(518)	(12,312)	(10,487)
Net income (loss)	10,169	(17,956)	5,131	(24,723)
Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Net sales	184,196	217,299	594,107	651,515
Cost of sales	206,249	205,854	642,086	625,157
Selling, general and administrative	1,399	4,193	14,025	12,704
Transaction costs	685	0	8,694	0
Depreciation	1,559	1,219	9,595	3,589
Amortization	0	0	0	0
Equity in losses (earnings) of investees	48,456	9,576	202,844	61,741
Operating income (loss)	22,760	15,609	122,551	71,806
Interest Income, Other	0	0	0	2
Interest Expense	(4,550)	(9,162)	(15,239)	(27,568)
Gains (Losses) on Extinguishment of Debt			(19,100)	(521)
Other Nonoperating Income (Expense)	0	(313)	0	(217)
Interest Expense, Related Party	0		(20,734)
Income (loss) before income taxes	18,210	6,134	67,478	43,502
Income tax benefit (expense)	(5,205)	792	(8,659)	(5,620)
Net income (loss)	13,005	6,926	58,819	37,882
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Net sales	299,928	299,667	906,178	911,465
Cost of sales	250,868	265,903	768,937	805,599
Selling, general and administrative	24,085	20,378	54,052	64,194
Transaction costs	1,947	0	12,400	0
Depreciation	5,426	6,212	16,683	19,230
Amortization	2,317	2,335	6,988	7,006
Equity in losses (earnings) of investees	(146)	(289)	(250)	(4,540)
Operating income (loss)	15,139	4,550	46,868	10,896
Interest Income, Other	0	(1)	0	33
Interest Expense	(694)	(724)	(2,043)	(2,291)
Gains (Losses) on Extinguishment of Debt			0	0
Other Nonoperating Income (Expense)	0	602	0	235
Interest Expense, Related Party	84		23
Income (loss) before income taxes	14,529	4,427	44,848	8,873
Income tax benefit (expense)	(5,629)	(1,752)	(17,698)	(3,512)
Net income (loss)	8,900	2,675	27,150	5,361
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Net sales	420,565	463,861	1,402,330	1,504,218
Cost of sales	354,503	434,059	1,157,071	1,374,743
Selling, general and administrative	23,771	19,299	67,605	60,830
Transaction costs	3,638	0	5,313	0
Depreciation	4,324	4,892	13,917	16,092
Amortization	21	7	34	19
Equity in losses (earnings) of investees	(95)	105	88	437
Operating income (loss)	34,213	5,709	158,478	52,971
Interest Income, Other	607	601	1,909	1,870
Interest Expense	(104)	(129)	(331)	(336)
Gains (Losses) on Extinguishment of Debt			0	0
Other Nonoperating Income (Expense)	(895)	(1,321)	(2,450)	(6,177)
Interest Expense, Related Party	(40)		140
Income (loss) before income taxes	33,781	4,860	157,746	48,328
Income tax benefit (expense)	(4,553)	(634)	(7,494)	(4,039)
Net income (loss)	29,228	4,226	150,252	44,289
Consolidation, Eliminations [Member]
Net sales	(229,989)	(242,276)	(725,937)	(740,810)
Cost of sales	(229,959)	(242,280)	(725,582)	(740,404)
Selling, general and administrative	(71)	0	(173)	0
Transaction costs	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Equity in losses (earnings) of investees	(66,520)	(15,421)	(270,072)	(100,703)
Operating income (loss)	(66,479)	(15,417)	(270,254)	(101,109)
Interest Income, Other	0	0	0	0
Interest Expense	0	0	0	0
Gains (Losses) on Extinguishment of Debt			0	0
Other Nonoperating Income (Expense)	0	(4)	0	406
Interest Expense, Related Party	(41)		182
Income (loss) before income taxes	(66,520)	(15,421)	(270,072)	(100,703)
Income tax benefit (expense)	15,387	1,594	33,851	13,171
Net income (loss)	$ (51,133)	$ (13,827)	$ (236,221)	$ (87,532)