Guarantor and Non-Guarantor Financial Statements (Details) (USD $)	3 Months Ended								12 Months Ended				12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 Parent	Dec. 31, 2011 Parent		Dec. 31, 2010 Parent		Dec. 31, 2012 Guarantor Subsidiaries	Dec. 31, 2011 Guarantor Subsidiaries		Dec. 31, 2010 Guarantor Subsidiaries		Dec. 31, 2012 Non-Guarantor Subsidiaries	Dec. 31, 2011 Non-Guarantor Subsidiaries		Dec. 31, 2010 Non-Guarantor Subsidiaries		Dec. 31, 2012 Consolidating Adjustments	Dec. 31, 2011 Consolidating Adjustments	Dec. 31, 2010 Consolidating Adjustments	Dec. 31, 2012 Senior Notes	May 23, 2012 Senior Notes
Condensed Financial Statements [Line Items]
Principal amount of notes	$ 225,000,000				$ 0				$ 225,000,000	$ 0																						$ 225,000,000
Ownership interest by parent	100.00%								100.00%
Current assets:
Cash and cash equivalents	273,400,000				49,800,000				273,400,000	49,800,000	135,600,000		5,000,000	5,000,000		5,000,000		266,000,000	43,000,000		129,600,000		2,400,000	1,800,000		1,000,000		0	0	0
Short-term investments	85,000,000				0				85,000,000	0			0					85,000,000					0					0
Receivables:
Trade, less allowance for doubtful receivables	123,800,000				98,900,000				123,800,000	98,900,000			0	0				121,500,000	96,000,000				2,300,000	2,900,000				0	0
Intercompany receivables	0				0				0	0			0	0				(10,300,000)	2,300,000				400,000	200,000				9,900,000	(2,500,000)
Other	3,400,000				1,200,000				3,400,000	1,200,000			0	0				1,300,000	800,000				2,100,000	400,000				0	0
Inventories	186,000,000				205,700,000				186,000,000	205,700,000			0	0				178,700,000	196,600,000				7,300,000	9,100,000				0	0
Prepaid expenses and other current assets	70,100,000				78,900,000				70,100,000	78,900,000			0	6,900,000				68,100,000	71,000,000				2,000,000	1,000,000				0	0
Total current assets	741,700,000				434,500,000				741,700,000	434,500,000			5,000,000	11,900,000				710,300,000	409,700,000				16,500,000	15,400,000				9,900,000	(2,500,000)
Investments in and advances to unconsolidated affiliates	0				0				0	0			1,284,100,000	1,036,900,000				7,400,000	5,800,000				0	0				(1,291,500,000)	(1,042,700,000)
Property, plant, and equipment — net	384,300,000				367,800,000				384,300,000	367,800,000			0	0				371,800,000	355,900,000				12,500,000	11,900,000				0	0
Long-term intercompany receivables	0				0				0	0			163,700,000	0				400,000	22,000,000				6,400,000	2,500,000				(170,500,000)	(24,500,000)
Net asset in respect of VEBA	365,900,000				144,700,000				365,900,000	144,700,000			0	0				365,900,000	144,700,000				0	0				0	0
Deferred tax assets — net	102,000,000				226,900,000				102,000,000	226,900,000			0	0				93,400,000	218,900,000				(800,000)	(600,000)				9,400,000	8,600,000
Intangible assets — net	35,400,000				37,200,000				35,400,000	37,200,000			0	0				35,400,000	37,200,000				0	0				0	0
Goodwill	37,200,000				37,200,000				37,200,000	37,200,000			0	0				37,200,000	37,200,000				0	0				0	0
Other assets	86,000,000				72,300,000				86,000,000	72,300,000			64,000,000	50,200,000				19,200,000	19,200,000				3,000,000	2,900,000				(200,000)	0
Total	1,752,500,000				1,320,600,000				1,752,500,000	1,320,600,000	1,318,900,000		1,516,800,000	1,099,000,000				1,641,000,000	1,250,600,000				37,600,000	32,100,000				(1,442,900,000)	(1,061,100,000)
Current liabilities:
Accounts payable	62,500,000				62,200,000				62,500,000	62,200,000			100,000	0				56,500,000	57,100,000				5,900,000	5,100,000				0	0
Intercompany payable	0				0				0	0			0	0				300,000	200,000				200,000	2,300,000				(500,000)	(2,500,000)
Accrued salaries, wages, and related expenses	39,300,000				30,900,000				39,300,000	30,900,000			0	0				36,700,000	28,700,000				2,600,000	2,200,000				0	0
Other accrued liabilities	51,900,000				41,000,000				51,900,000	41,000,000			3,500,000	2,200,000				47,900,000	38,000,000				500,000	800,000				0	0
Payable to affiliate	7,900,000				14,400,000				7,900,000	14,400,000			0	0				7,900,000	14,400,000				0	0				0	0
Long-term debt-current portion	0				1,300,000				0	1,300,000				0					1,300,000					0					0
Total current liabilities	161,600,000				149,800,000				161,600,000	149,800,000			3,600,000	2,200,000				149,300,000	139,700,000				9,200,000	10,400,000				(500,000)	(2,500,000)
Net liability in respect of VEBA	5,300,000				20,600,000				5,300,000	20,600,000			0	0				5,300,000	20,600,000				0	0				0	0
Long-term intercompany payable	0				0				0	0			0	22,000,000				170,000,000	2,500,000				500,000	0				(170,500,000)	(24,500,000)
Long-term liabilities	134,500,000				126,000,000				134,500,000	126,000,000			62,100,000	54,000,000				49,600,000	53,500,000				22,800,000	18,500,000				0	0
Long-term debt	380,300,000				151,400,000				380,300,000	151,400,000			380,300,000	148,000,000				0	3,400,000				0	0				0	0
Total liabilities	681,700,000				447,800,000				681,700,000	447,800,000			446,000,000	226,200,000				374,200,000	219,700,000				32,500,000	28,900,000				(171,000,000)	(27,000,000)
Total stockholders’ equity	1,070,800,000				872,800,000				1,070,800,000	872,800,000	888,700,000	870,300,000	1,070,800,000	872,800,000				1,266,800,000	1,030,900,000				5,100,000	3,200,000				(1,271,900,000)	(1,034,100,000)
Total	1,752,500,000				1,320,600,000				1,752,500,000	1,320,600,000			1,516,800,000	1,099,000,000				1,641,000,000	1,250,600,000				37,600,000	32,100,000				(1,442,900,000)	(1,061,100,000)
CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME
Net sales	314,000,000	335,500,000	345,200,000	365,400,000	317,600,000	322,300,000	338,800,000	322,600,000	1,360,100,000	1,301,300,000	1,079,100,000		0	0		0		1,326,000,000	1,264,500,000		1,046,900,000		124,000,000	133,600,000		120,100,000		(89,900,000)	(96,800,000)	(87,900,000)
Cost of products sold:
Cost of products sold, excluding depreciation and amortization and other items	264,800,000	268,900,000	284,400,000	298,100,000	272,400,000	280,900,000	290,500,000	285,200,000	1,116,200,000	1,129,000,000	946,100,000		0	0		0		1,090,000,000	1,098,700,000		919,700,000		110,200,000	125,400,000		113,000,000		(84,000,000)	(95,100,000)	(86,600,000)
Unrealized (gains) losses on derivative instruments	100,000	(12,300,000)	100,000	(3,100,000)	7,900,000	16,800,000	9,500,000	(4,300,000)	(15,200,000)	29,900,000	700,000		0	0		0		(15,200,000)	29,900,000		700,000		0	0		0		0	0	0
Restructuring benefits									0	(300,000)	(300,000)			0		0			(300,000)		(300,000)			0		0			0	0
Depreciation and amortization									26,500,000	25,200,000	19,800,000		0	0		0		25,500,000	24,300,000		19,000,000		1,000,000	900,000		800,000		0	0	0
Selling, administrative, research and development, and general									62,200,000	62,700,000	67,700,000		2,000,000	1,800,000		1,700,000		57,700,000	56,300,000		59,900,000		8,200,000	6,200,000		7,400,000		(5,700,000)	(1,600,000)	(1,300,000)
Other operating (benefits) charges, net									4,500,000	(200,000)	4,000,000		0	0		0		4,500,000	100,000		4,000,000		0	(300,000)		0		0	0	0
Total costs and expenses									1,194,200,000	1,246,300,000	1,038,000,000		2,000,000	1,800,000		1,700,000		1,162,500,000	1,209,000,000		1,003,000,000		119,400,000	132,200,000		121,200,000		(89,700,000)	(96,700,000)	(87,900,000)
Operating (loss) income	23,900,000	56,200,000	39,600,000	46,200,000	15,600,000	4,900,000	14,700,000	19,800,000	165,900,000	55,000,000	41,100,000		(2,000,000)	(1,800,000)		(1,700,000)		163,500,000	55,500,000		43,900,000		4,600,000	1,400,000		(1,100,000)		(200,000)	(100,000)	0
Other (expense) income:
Interest expense									(29,100,000)	(18,000,000)	(11,800,000)		(28,200,000)	(16,200,000)		(11,300,000)		(1,000,000)	(1,800,000)		(500,000)		0	0		0		100,000	0	0
Other income (expense), net									2,800,000	4,300,000	(4,200,000)		800,000	4,000,000		(4,800,000)		1,500,000	400,000		500,000		600,000	(100,000)		100,000		(100,000)	0	0
(Loss) income before income taxes									139,600,000	41,300,000	25,100,000		(29,400,000)	(14,000,000)		(17,800,000)		164,000,000	54,100,000		43,900,000		5,200,000	1,300,000		(1,000,000)		(200,000)	(100,000)	0
Income tax provision									(53,800,000)	(16,200,000)	(13,100,000)		0	0		0		(62,600,000)	(21,800,000)		(21,600,000)		(2,300,000)	(600,000)		700,000		11,100,000	6,200,000	7,800,000
Earnings in equity of subsidiaries									0	0	0		115,200,000	39,100,000		29,800,000		2,600,000	800,000		(300,000)		0	0		0		(117,800,000)	(39,900,000)	(29,500,000)
Net income	9,100,000	29,200,000	21,000,000	26,500,000	6,100,000	4,100,000	4,100,000	10,800,000	85,800,000	25,100,000	12,000,000		85,800,000	25,100,000		12,000,000		104,000,000	33,100,000		22,000,000		2,900,000	700,000		(300,000)		(106,900,000)	(33,800,000)	(21,700,000)
Comprehensive income (loss)									144,800,000	(40,200,000)	30,500,000		144,800,000	(40,200,000)		30,500,000		164,000,000	(32,200,000)		41,400,000		1,900,000	700,000		(1,200,000)		(165,900,000)	31,500,000	(40,200,000)
Cash flows from operating activities:
Net cash (used in) provided by operating activities									152,400,000	62,800,000	66,300,000		(17,800,000)	(10,200,000)		(3,000,000)		164,300,000	71,900,000		71,500,000		5,900,000	1,100,000		(2,200,000)		0	0	0
Cash flows from investing activities:
Capital expenditures									(44,100,000)	(32,500,000)	(38,900,000)		0	0		0		(42,600,000)	(31,200,000)		(37,400,000)		(1,500,000)	(1,300,000)		(1,500,000)		0	0	0
Purchase of available for sale securities									(85,000,000)	(300,000)	(4,400,000)		0	0		0		(85,000,000)	(300,000)		(4,400,000)		0	0		0		0	0	0
Proceeds from disposal of property, plant and equipment									300,000	700,000	4,800,000		0	0		0		300,000	0		4,800,000		0	700,000		0		0	0	0
Cash payment for acquisition of manufacturing facility and related assets (net of $4.9 of cash received in connection with the acquisition in 2011)									0	(83,200,000)	(9,000,000)			0		0			(83,200,000)		(9,000,000)			0		0			0	0
Change in restricted cash									6,900,000	(1,000,000)	1,100,000		6,900,000	0		0		400,000	(1,000,000)		1,100,000		(400,000)	0		0		0	0	0
Net cash provided by (used in) investing activities									(121,900,000)	(116,300,000)	(46,400,000)		6,900,000	0		0		(126,900,000)	(115,700,000)		(44,900,000)		(1,900,000)	(600,000)		(1,500,000)		0	0	0
Cash flows from financing activities:
Proceeds from issuance of Convertible Notes									0	0	175,000,000					175,000,000					0					0				0
Purchase of call option in connection with issuance of cash convertible senior notes									0	0	(31,400,000)					(31,400,000)					0					0				0
Proceeds from issuance of warrants									0	0	14,300,000					14,300,000					0					0				0
Proceeds from issuance of Senior Notes									225,000,000	0	0		225,000,000					0					0					0
Repayments of capital lease									(100,000)	(100,000)	0		0	0				(100,000)	(100,000)				0	0				0	0
Repayment of promissory notes									(4,700,000)	(8,300,000)	(700,000)		0	0		0		(4,700,000)	(8,300,000)		(700,000)		0	0		0		0	0	0
Cash paid for financing costs									(6,600,000)	(2,100,000)	(8,600,000)		(6,600,000)	0		(5,900,000)		0	(2,100,000)		(2,700,000)		0	0		0		0	0	0	(6,600,000)
Repurchase of common stock									0	0	(44,200,000)					(44,200,000)					0					0				0
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest									1,300,000	200,000	0		0	0				1,300,000	200,000				0	0				0	0
Repurchase of common stock to cover employees' tax withholdings upon vesting of non-vested shares									2,200,000	3,100,000	0		2,200,000	3,100,000				0	0				0	0				0	0
Cash dividend paid to stockholders									(19,600,000)	(18,900,000)	(19,000,000)		(19,600,000)	(18,900,000)		(19,000,000)		0	0		0		0	0		0		0	0	0
Intercompany loan									0	0	0		(185,700,000)	32,200,000	[1]	(80,800,000)	[1]	189,100,000	(32,500,000)	[1]	77,000,000	[1]	(3,400,000)	300,000	[1]	3,800,000	[1]	0	0	0
Net cash provided by (used in) financing activities									193,100,000	(32,300,000)	85,400,000		10,900,000	10,200,000	[1]	8,000,000	[1]	185,600,000	(42,800,000)	[1]	73,600,000	[1]	(3,400,000)	300,000	[1]	3,800,000	[1]	0	0	0
Net increase (decrease) in cash and cash equivalents during the period									223,600,000	(85,800,000)	105,300,000		0	0		5,000,000		223,000,000	(86,600,000)		100,200,000		600,000	800,000		100,000		0	0	0
Cash and cash equivalents at beginning of period				49,800,000				135,600,000	49,800,000	135,600,000	30,300,000		5,000,000	5,000,000		0		43,000,000	129,600,000		29,400,000		1,800,000	1,000,000		900,000		0	0	0
Cash and cash equivalents at end of period	$ 273,400,000				$ 49,800,000				$ 273,400,000	$ 49,800,000	$ 135,600,000		$ 5,000,000	$ 5,000,000		$ 5,000,000		$ 266,000,000	$ 43,000,000		$ 129,600,000		$ 2,400,000	$ 1,800,000		$ 1,000,000		$ 0	$ 0	$ 0

[1] The Company treats changes in long-term intercompany balances that relate to financing activities as cash flow from financing activities. In the above tables, the Company has revised the previous classification of the changes in such intercompany balances in 2011 and 2010 from cash flows from operating activities to a separate line item in cash flows from financing activities captioned "intercompany loan”.