Financial Information for Subsidiary and Guarantor Parent (B.S.) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 269.5	$ 1,026.8	$ 304.6	$ 380.6
Accounts receivable, net	603.6us-gaap_AccountsReceivableNetCurrent	528.2us-gaap_AccountsReceivableNetCurrent
Intercompany notes receivable	0	0
Inventories, net	1,472.8us-gaap_InventoryNet	1,322.1us-gaap_InventoryNet
Prepaid expenses and other current assets	136.2us-gaap_OtherAssetsCurrent	73.7us-gaap_OtherAssetsCurrent
Total Current Assets	2,482.1us-gaap_AssetsCurrent	2,950.8us-gaap_AssetsCurrent
Property, plant and equipment, net	2,961.8us-gaap_PropertyPlantAndEquipmentNet	2,874.1us-gaap_PropertyPlantAndEquipmentNet
Cost in excess of net assets acquired	780.4us-gaap_Goodwill	727.9us-gaap_Goodwill
Intercompany notes receivable	0	0
Investments in subsidiaries	0us-gaap_EquityMethodInvestments	0us-gaap_EquityMethodInvestments
Other assets	358.3us-gaap_OtherAssetsNoncurrent	345.7us-gaap_OtherAssetsNoncurrent
Total Assets	6,582.6us-gaap_Assets	6,898.5us-gaap_Assets	6,247.8us-gaap_Assets
Accounts payable	556.7us-gaap_AccountsPayableCurrent	471.8us-gaap_AccountsPayableCurrent
Accrued liabilities	323.2us-gaap_AccruedLiabilitiesCurrent	315.8us-gaap_AccruedLiabilitiesCurrent
Intercompany notes payable	0	0
Deferred income taxes	62.2us-gaap_DeferredTaxLiabilitiesCurrent	3.5us-gaap_DeferredTaxLiabilitiesCurrent
Short-term debt and current portion of long-term debt	17.8us-gaap_DebtCurrent	419.9us-gaap_DebtCurrent
Total Current Liabilities	959.9us-gaap_LiabilitiesCurrent	1,211.0us-gaap_LiabilitiesCurrent
Long-term debt	1,509.1	1,527.4
Intercompany notes payable	0	0
Accrued postretirement benefits	415.8	442.4
Pension liabilities	739.3	368.2
Deferred income taxes	80.9	206.6
Other long-term liabilities	156.2us-gaap_OtherLiabilitiesNoncurrent	148.2us-gaap_OtherLiabilitiesNoncurrent
Total Liabilities	3,861.2us-gaap_Liabilities	3,903.8us-gaap_Liabilities
Redeemable noncontrolling interest	12.1	0
Total Stockholders’ Equity	2,709.3	2,994.7	2,587.1	2,571.6
Total Liabilities and Stockholders’ Equity	6,582.6	6,898.5
Guarantor Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	2.2	3.6
Accounts receivable, net	0.1	0.3
Intercompany notes receivable	0	0
Inventories, net	0	0
Prepaid expenses and other current assets	63.7	26.2
Total Current Assets	66.0	30.1
Property, plant and equipment, net	2.2	2.9
Cost in excess of net assets acquired	0	0
Intercompany notes receivable	0	0
Investments in subsidiaries	6,149.4	6,170.8
Other assets	23.7	35.7
Total Assets	6,241.3	6,239.5
Accounts payable	4.5	3.1
Accrued liabilities	47.5	51.6
Intercompany notes payable	1,232.6	825.6
Deferred income taxes	62.2	3.5
Short-term debt and current portion of long-term debt	0.5	402.9
Total Current Liabilities	1,347.3	1,286.7
Long-term debt	1,350.6	1,350.8
Intercompany notes payable	0	0
Accrued postretirement benefits	0	0
Pension liabilities	675.5	323.0
Deferred income taxes	80.9	206.6
Other long-term liabilities	77.7	77.7
Total Liabilities	3,532.0	3,244.8
Redeemable noncontrolling interest	0
Total Stockholders’ Equity	2,709.3	2,994.7
Total Liabilities and Stockholders’ Equity	6,241.3	6,239.5
Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	13.8	13.5
Accounts receivable, net	209.1	179.4
Intercompany notes receivable	0	0
Inventories, net	387.7	295.5
Prepaid expenses and other current assets	13.2	6.5
Total Current Assets	623.8	494.9
Property, plant and equipment, net	1,545.1	1,397.5
Cost in excess of net assets acquired	126.6	112.1
Intercompany notes receivable	0	0
Investments in subsidiaries	37.7	37.7
Other assets	28.0	32.0
Total Assets	2,361.2	2,074.2
Accounts payable	302.0	310.5
Accrued liabilities	72.0	56.6
Intercompany notes payable	1,158.2	763.8
Deferred income taxes	0	0
Short-term debt and current portion of long-term debt	0.1	0.1
Total Current Liabilities	1,532.3	1,131.0
Long-term debt	150.3	150.4
Intercompany notes payable	200.0	200.0
Accrued postretirement benefits	153.0	179.7
Pension liabilities	6.0	5.6
Deferred income taxes	0	0
Other long-term liabilities	22.5	20.2
Total Liabilities	2,064.1	1,686.9
Redeemable noncontrolling interest	0
Total Stockholders’ Equity	297.1	387.3
Total Liabilities and Stockholders’ Equity	2,361.2	2,074.2
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	253.5	1,009.7
Accounts receivable, net	394.4	348.5
Intercompany notes receivable	2,390.8	1,589.4
Inventories, net	1,085.1	1,026.6
Prepaid expenses and other current assets	59.3	41.0
Total Current Assets	4,183.1	4,015.2
Property, plant and equipment, net	1,414.5	1,473.7
Cost in excess of net assets acquired	653.8	615.8
Intercompany notes receivable	200.0	200.0
Investments in subsidiaries	0	0
Other assets	306.6	278.0
Total Assets	6,758.0	6,582.7
Accounts payable	250.2	158.2
Accrued liabilities	203.7	207.6
Intercompany notes payable	0	0
Deferred income taxes	0	0
Short-term debt and current portion of long-term debt	17.2	16.9
Total Current Liabilities	471.1	382.7
Long-term debt	8.2	26.2
Intercompany notes payable	0	0
Accrued postretirement benefits	262.8	262.7
Pension liabilities	57.8	39.6
Deferred income taxes	0	0
Other long-term liabilities	56.0	50.3
Total Liabilities	855.9	761.5
Redeemable noncontrolling interest	12.1
Total Stockholders’ Equity	5,890.0	5,821.2
Total Liabilities and Stockholders’ Equity	6,758.0	6,582.7
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0
Accounts receivable, net	0	0
Intercompany notes receivable	(2,390.8)	(1,589.4)
Inventories, net	0	0
Prepaid expenses and other current assets	0	0
Total Current Assets	(2,390.8)	(1,589.4)
Property, plant and equipment, net	0	0
Cost in excess of net assets acquired	0	0
Intercompany notes receivable	(200.0)	(200.0)
Investments in subsidiaries	(6,187.1)	(6,208.5)
Other assets	0	0
Total Assets	(8,777.9)	(7,997.9)
Accounts payable	0	0
Accrued liabilities	0	0
Intercompany notes payable	(2,390.8)	(1,589.4)
Deferred income taxes	0	0
Short-term debt and current portion of long-term debt	0	0
Total Current Liabilities	(2,390.8)	(1,589.4)
Long-term debt	0	0
Intercompany notes payable	(200.0)	(200.0)
Accrued postretirement benefits	0	0
Pension liabilities	0	0
Deferred income taxes	0	0
Other long-term liabilities	0	0
Total Liabilities	(2,590.8)	(1,789.4)
Redeemable noncontrolling interest	0
Total Stockholders’ Equity	(6,187.1)	(6,208.5)
Total Liabilities and Stockholders’ Equity	$ (8,777.9)	$ (7,997.9)

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph a

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682