ATI (ATI) 10-Q 1 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 28, 2013
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Entity Registrant Name	'ALLEGHENY TECHNOLOGIES INCORPORATED	'
Entity Central Index Key	'0001018963	'
Entity Current Reporting Status	'Yes	'
Entity Voluntary Filers	'No	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Well-known Seasoned Issuer	'Yes	'
Entity Common Stock, Shares Outstanding	'	107,982,138
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$535.70	$304.60
Accounts receivable, net of allowances for doubtful accounts of $5.2 and $5.5 as of September 30, 2013 and December 31, 2012	576.9	613.3
Inventories, net	1,344.90	1,536.60
Prepaid expenses and other current assets	120.6	56.1
Current assets of discontinued operations	115.4	0
Total current assets	2,693.50	2,510.60
Property, plant and equipment, net	2,744.70	2,559.90
Cost in excess of net assets acquired	728.1	740.1
Deferred income taxes	0	71.5
Other assets	348	365.7
Non-current assets of discontinued operations	85	0
Total assets	6,599.30	6,247.80
Current Liabilities:	'	'
Accounts payable	401.9	499.9
Accrued liabilities	304.9	330.5
Deferred income taxes	8.2	24
Short-term debt and current portion of long-term debt	419.9	17.1
Current liabilities of discontinued operations	33.7	0
Total current liabilities	1,168.60	871.5
Long-term debt	1,542.20	1,463
Accrued postretirement benefits	475	495.2
Pension liabilities	702.4	721.1
Deferred income taxes	52.1	0
Other long-term liabilities	94.9	109.9
Total liabilities	4,035.20	3,660.70
ATI Stockholders' Equity:	'	'
Preferred stock, par value $0.10: authorized-50,000,000 shares; issued-none	0	0
Common stock, par value $0.10: authorized-500,000,000 shares; issued-109,695,171 shares at September 30, 2013 and December 31, 2012; outstanding- 108,007,487 shares at September 30, 2013 and 107,398,963 shares at December 31, 2012	11	11
Additional paid-in capital	1,181.20	1,181.70
Retained earnings	2,335.90	2,427.60
Treasury stock: 1,687,684 shares at September 30, 2013 and 2,296,208 shares at December 31, 2012	-78.8	-111.3
Accumulated other comprehensive loss, net of tax	-982.6	-1,029.40
Total ATI stockholders’ equity	2,466.70	2,479.60
Noncontrolling interests	'	'
Noncontrolling interests	97.4	107.5
Total Equity	2,564.10	2,587.10
Total Liabilities and Equity	$6,599.30	$6,247.80

CONSOLIDATED_BALANCE_SHEETS_PA

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Allowances for doubtful accounts	$5.20	$5.50
Preferred stock, par value	$0.10	$0.10
Preferred stock, authorized	50,000,000	50,000,000
Preferred stock, issued	0	0
Common stock, par value	$0.10	$0.10
Common stock, authorized	500,000,000	500,000,000
Common stock, issued	109,695,171	109,695,171
Common stock, oustanding	108,007,487	107,398,963
Treasury stock	1,687,684	2,296,208

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]	'	'	'	'
Sales	$972.40	$1,131.50	$3,128.20	$3,645.50
Costs and expenses:	'	'	'	'
Cost of sales	919.3	988.8	2,886.90	3,139.60
Selling and administrative expenses	70.6	77.6	210.1	243.3
Income (loss) before interest, other income and income taxes	-17.5	65.1	31.2	262.6
Interest expense, net	-18.2	-17.2	-46.5	-55.7
Other income, net	0.4	0.2	1.3	0.6
Income (loss) from continuing operations before income tax provision (benefit)	-35.3	48.1	-14	207.5
Income tax provision (benefit)	-8.5	14.8	-4.4	66.6
Income (loss) from continuing operations	-26.8	33.3	-9.6	140.9
Income (loss)from discontinued operations, net of tax	-5.4	4	-4.4	13.4
Net income (loss)	-32.2	37.3	-14	154.3
Less: Net income (loss) attributable to noncontrolling interests	1.6	2	5.4	6.4
Net income (loss) attributable to ATI	-33.8	35.3	-19.4	147.9
Basic income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	($0.27)	$0.30	($0.14)	$1.27
Basic income (loss) from discontinued operations attributable to ATI per common share (in dollars per share)	($0.05)	$0.03	($0.04)	$0.12
Basic net income (loss) attributable to ATI per common share (in dollars per share)	($0.32)	$0.33	($0.18)	$1.39
Diluted income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	($0.27)	$0.29	($0.14)	$1.21
Diluted income (loss) from discontinued operations attributable to ATI per common share (in dollars per share)	($0.05)	$0.03	($0.04)	$0.11
Diluted net income (loss) attributable to ATI per common share (in dollars per share)	($0.32)	$0.32	($0.18)	$1.32
Dividends declared per common share (in dollars per share)	$0.18	$0.18	$0.54	$0.54
Income (loss) from continuing operations, net of tax	-28.4	31.3	-15	134.5
Income (loss) from discontinued operations, net of tax	($5.40)	$4	($4.40)	$13.40

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]	'	'	'	'
Net income (loss)	($32.20)	$37.30	($14)	$154.30
Currency translation adjustment	'	'	'	'
Unrealized net change arising during the period	12.4	15.3	3.9	10.1
Unrealized holding gain on securities	'	'	'	'
Net gain arising during the period	0.1	0	0.1	0.1
Derivatives	'	'	'	'
Net derivatives gain (loss) on hedge transactions	-18.1	7.8	-21	5.5
Reclassification to net income of net realized gain	4.3	0.6	5.5	3.5
Income taxes on derivative transactions	-5.3	3.3	-6	3.5
Total	-8.5	5.1	-9.5	5.5
Postretirement benefit plans	'	'	'	'
Amortization of net actuarial loss	33.5	29.9	100.5	89.8
Amortization to net income of net prior service credits	-3.8	-2.9	-11.4	-8.8
Income taxes on postretirement benefit plans	11.4	10.3	34.3	31
Total	18.3	16.7	54.8	50
Other comprehensive income, net of tax	22.3	37.1	49.3	65.7
Comprehensive income (loss)	-9.9	74.4	35.3	220
Less: Comprehensive income attributable to noncontrolling interests	1.7	2.6	7.9	6.4
Comprehensive income (loss) attributable to ATI	($11.60)	$71.80	$27.40	$213.60

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities:	'	'
Net income (loss)	($14)	$154.30
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	143.5	145.1
Deferred taxes	76.1	-32.9
Changes in operating asset and liabilities:	'	'
Inventories	126.7	-75.9
Accounts receivable	-11.2	23.4
Accounts payable	-77.4	-81.4
Retirement benefits	50.5	40.4
Accrued income taxes	-82	27.2
Accrued liabilities and other	15.2	45.6
Cash provided by operating activities	227.4	245.8
Investing Activities:	'	'
Purchases of property, plant and equipment	-395.5	-245.6
Asset disposals and other	0.8	1.5
Cash used in investing activities	-394.7	-244.1
Financing Activities:	'	'
Borrowings on long-term debt	500	0
Payments on long-term debt and capital leases	-17	-16.7
Net payments under credit facilities	-0.1	-10.3
Debt issuance costs	-5.2	0
Dividends paid to stockholders	-57.7	-57.3
Dividends paid to noncontrolling interests	-18	0
Purchase of subsidiary shares from noncontrolling interest	0	-0.1
Taxes on share-based compensation	2.6	5.2
Exercises of stock options and other	0.4	1.3
Shares repurchased for income tax withholding on share-based compensation	-6.6	-23.4
Cash provided by (used in) financing activities	398.4	-101.3
Increase (decrease) in cash and cash equivalents	'	'
Increase (decrease) in cash and cash equivalents	231.1	-99.6
Cash and cash equivalents at beginning of period	304.6	380.6
Cash and cash equivalents at end of period	$535.70	$281

STATEMENTS_OF_CHANGES_IN_CONSO

STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY (USD $)	Total	[CommonStockMember]	[AdditionalPaidInCapitalMember]	[RetainedEarningsMember]	[TreasuryStockMember]	[AccumulatedOtherComprehensiveIncomeMember]	[NoncontrollingInterestMember]
In Millions, unless otherwise specified
Total Stockholders' Equity at Dec. 31, 2011	$2,571.60	$11	$1,207.10	$2,361.50	($162.70)	($941.60)	$96.30
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income (loss)	154.3	'	'	147.9	'	'	6.4
Other comprehensive income	65.7	'	'	'	'	65.7	0
Cash dividends on common stock ($0.54 per share)	-57.3	'	'	-57.3	'	'	'
Purchase of subsidiary shares from noncontrolling interest	-0.1	'	'	'	'	'	-0.1
Employee stock plans	10.7	'	-23.7	-8.5	42.9	'	'
Total Stockholders' Equity at Sep. 30, 2012	2,744.90	11	1,183.40	2,443.60	-119.8	-875.9	102.6
Total Stockholders' Equity at Dec. 31, 2012	2,587.10	11	1,181.70	2,427.60	-111.3	-1,029.40	107.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income (loss)	-14	'	'	-19.4	'	'	5.4
Other comprehensive income	49.3	'	'	'	'	46.8	2.5
Cash dividends on common stock ($0.54 per share)	-57.7	'	'	-57.7	'	'	'
Employee stock plans	17.4	'	-0.5	-14.6	32.5	'	'
Dividends paid to noncontrolling interest	-18	'	'	'	'	'	-18
Total Stockholders' Equity at Sep. 30, 2013	$2,564.10	$11	$1,181.20	$2,335.90	($78.80)	($982.60)	$97.40

STATEMENTS_OF_CHANGES_IN_CONSO1

STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY (PARENTHETICAL) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Statement of Stockholders' Equity [Abstract]	'	'
Cash dividends on common stock per share	$0.54	$0.54

Accounting_Policies

Accounting Policies	9 Months Ended
	Sep. 30, 2013
Significant Accounting Policies [Abstract]	'
Accounting Policies	'
	Accounting Policies
	The interim consolidated financial statements include the accounts of Allegheny Technologies Incorporated and its subsidiaries. Unless the context requires otherwise, “Allegheny Technologies”, “ATI” and “the Company” refer to Allegheny Technologies Incorporated and its subsidiaries.
	These unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions for Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and note disclosures required by U.S. generally accepted accounting principles for complete financial statements. In management’s opinion, all adjustments (which include only normal recurring adjustments) considered necessary for a fair presentation have been included. Certain prior year amounts have been reclassified in order to conform with the fiscal year 2013 presentation. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2012 Annual Report on Form 10-K. The results of operations for these interim periods are not necessarily indicative of the operating results for any future period. The December 31, 2012 financial information has been derived from the Company’s audited consolidated financial statements.
	New Accounting Pronouncements Adopted
	In January 2013, the Company adopted changes issued by the Financial Accounting Standards Board (FASB) to the disclosure of offsetting assets and liabilities. These changes require an entity to disclose both gross information and net information about both instruments and transactions eligible for offset in the statement of financial position and instruments and transactions subject to an agreement similar to a master netting arrangement. The enhanced disclosures will enable users of an entity’s financial statements to understand and evaluate the effect or potential effect of master netting arrangements on an entity’s financial position, including the effect or potential effect of rights of setoff associated with certain financial instruments and derivative instruments. Other than the additional disclosure requirements, the adoption of these changes had no impact on the consolidated financial statements.
	In January 2013, the Company adopted changes issued by the FASB to the reporting of amounts reclassified out of accumulated other comprehensive income. These changes require an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income if the amount being reclassified is required to be reclassified in its entirety to net income. For other amounts that are not required to be reclassified in their entirety to net income in the same reporting period, an entity is required to cross-reference other disclosures that provide additional detail about those amounts. These requirements are to be applied to each component of accumulated other comprehensive income. Other than the additional disclosure requirements (see Note 13), the adoption of these changes had no impact on the consolidated financial statements.
	Pending Accounting Pronouncements
	In July 2013, the FASB issued new accounting guidance that requires an entity to net its liability for unrecognized tax positions against a net operating loss carryforward, a similar tax loss or a tax credit carryforward when settlement in this manner is available under the tax law. The provisions of this new guidance become effective for the Company in fiscal year 2014. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements.
	In February 2013, the FASB issued changes to the accounting for obligations resulting from joint and several liability arrangements. This guidance requires an entity that is joint and severally liable to measure the obligation as the sum of the amount the entity has agreed with co-obligors to pay and any additional amount it expects to pay on behalf of one or more co-obligors. Required disclosures include a description of the nature of the arrangement, how the liability arose, the relationship with co-obligors and the terms and conditions of the arrangement. These changes become effective for the Company in fiscal year 2014. The Company does not anticipate a material impact to the consolidated financial statements upon adoption.
	In March 2013, the FASB issued changes to a parent entity’s accounting for the cumulative translation adjustment upon derecognition of certain subsidiaries or groups of assets within a foreign entity or of an investment in a foreign entity. The amendments specify that a cumulative translation adjustment (CTA) should be released into earnings when an entity ceases to have a controlling financial interest in a subsidiary or group of assets within a consolidated foreign entity and the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For sales of an equity method investment that is a foreign entity, a pro rata portion of CTA attributable to the investment would be recognized in earnings when the investment is sold. When an entity sells either a part or all of its investment in a consolidated foreign entity, CTA would be recognized in earnings only if the sale results in the parent no longer having a controlling financial interest in the foreign entity. In addition, CTA should be recognized in earnings in a business combination achieved in stages (i.e., a step acquisition). These changes become effective for the Company in fiscal year 2014. The Company does not anticipate a material impact to the consolidated financial statements upon adoption.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2013
Inventory Disclosure [Abstract]	'
Inventories	'
	Inventories
	Inventories at September 30, 2013 and December 31, 2012 were as follows (in millions):
		September 30,			December 31,
		2013			2012
	Raw materials and supplies	$	330.7		$	351.6
	Work-in-process	900.3			1,063.90
	Finished goods	164.7			209
	Total inventories at current cost	1,395.70			1,624.50
	Less allowances to reduce current cost values to LIFO basis	(12.4		)	(76.9		)
	Progress payments	(38.4		)	(11.0		)
	Total inventories, net	$	1,344.90		$	1,536.60
	Inventories are stated at the lower of cost (last-in, first-out (“LIFO”), first-in, first-out (“FIFO”), and average cost methods) or market, less progress payments. Most of the Company’s inventory is valued utilizing the LIFO costing methodology. Inventory of the Company’s non-U.S. operations is valued using average cost or FIFO methods. The effect of using the LIFO methodology to value inventory, rather than FIFO, decreased cost of sales by $39.1 million for the first nine months of 2013 compared to a decrease of $28.4 million for the first nine months of 2012.

Property_Plant_And_Equipment

Property Plant And Equipment	9 Months Ended
	Sep. 30, 2013
Property, Plant and Equipment Disclosures (Abstract)	'
Property Plant and Equipment	'
	Property, Plant and Equipment
	Property, plant and equipment at September 30, 2013 and December 31, 2012 was as follows (in millions):
		September 30,			December 31,
		2013			2012
	Land	$	29.9		$	34.4
	Buildings	947.3			921
	Equipment and leasehold improvements	3,431.90			3,344.40
		4,409.10			4,299.80
	Accumulated depreciation and amortization	(1,664.4		)	(1,739.9		)
	Total property, plant and equipment, net	$	2,744.70		$	2,559.90
	The construction in progress portion of property, plant and equipment at September 30, 2013 was $900.1 million.

Discontinued_Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Discontinued Operations
	On September 16, 2013, the Company announced it had entered into an agreement to sell its tungsten materials business, which produces tungsten powder, tungsten heavy alloys, tungsten carbide materials, and carbide cutting tools, for $605 million.  The transaction, which is subject to customary closing conditions and regulatory approvals, is expected to be completed during the fourth quarter 2013.
	Also, during the third quarter of 2013, the Company completed a strategic review of its iron castings and fabricated components businesses. Based on current and forecasted results, these businesses were not projected to meet the Company's long-term profitable growth and return on capital employed expectations. As a result of this review, the Company closed its fabricated components business and recorded $6.4 million of pre-tax exit costs, including $5.6 million of non-cash impairment charges for long-lived assets, and $0.8 million primarily related to lease exit costs. The Company expects the cash requirements associated with lease-related exit costs to be approximately $3.8 - $4.3 million, to be incurred over the next four years. The planned divestiture of the iron castings business, which is held for sale at September 30, 2013, resulted in a $3.1 million pre-tax, non-cash long-lived asset impairment charge based on an analysis of the estimated fair value of the business, which represents Level 3 unobservable information in the fair value hierarchy.
	The tungsten materials, iron castings and fabricated components businesses were all previously reported as part of the Company's Engineered Products segment. The net assets of these businesses were classified as held for sale as of the end of the third quarter of 2013 and the operating results of these businesses have been included in discontinued operations in the Company's consolidated statements of operations for all periods presented. Results of discontinued operations include $9.5 million pre-tax ($8.1 million after-tax) of charges associated with the iron castings and fabricated components divestitures.
	The following table presents summarized operating results for these discontinued operations (in millions):
		Three months ended September 30,					Nine months ended September 30,
		2013			2012		2013			2012
	Sales	$	77.6		$	89	$	236.7		$	284.9
	Income (loss) before income tax provision	$	(7.1	)	$	6	$	(5.4	)	$	20.4
	Net assets of discontinued operations were $163.4 million at September 30, 2013 and consisted of the following items (in millions):
		30-Sep-13
	Accounts receivable, net of allowances for doubtful accounts	$	47.5
	Inventories, net	65
	Prepaid expenses and other current assets	2.9
	Property, plant and equipment, net	72.9
	Cost in excess of net assets acquired	11.2
	Other long-term assets	0.9
	Total Assets	200.4
	Accounts payable	20.6
	Accrued liabilities	13.1
	Long-term liabilities	3.3
	Total Liabilities	37
	Net Assets	$	163.4

Debt

Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Debt	'
	Debt
	Debt at September 30, 2013 and December 31, 2012 was as follows (in millions):
		September 30,		December 31,
		2013		2012
	Allegheny Technologies 5.875% Notes due 2023	$	500	$	—
	Allegheny Technologies 5.95% Notes due 2021	500		500
	Allegheny Technologies 4.25% Convertible Notes due 2014	402.5		402.5
	Allegheny Technologies 9.375% Notes due 2019	350		350
	Allegheny Ludlum 6.95% debentures due 2025	150		150
	ATI Ladish Series B 6.14% Notes due 2016 (a)	18.4		24.8
	ATI Ladish Series C 6.41% Notes due 2015 (b)	21.4		32.5
	Domestic Bank Group $400 million unsecured credit facility	—		—
	Foreign credit facilities	14.3		14.2
	Industrial revenue bonds, due through 2020, and other	5.5		6.1
	Total short-term and long-term debt	1,962.10		1,480.10
	Short-term debt and current portion of long-term debt	419.9		17.1
	Total long-term debt	$	1,542.20	$	1,463.00
	(a)	Includes fair value adjustments of $1.2 million at September 30, 2013 and $1.9 million at December 31, 2012.
	(b)	Includes fair value adjustments of $1.4 million at September 30, 2013 and $2.5 million at December 31, 2012.
	On July 12, 2013, ATI issued $500 million aggregate principal amount of 5.875% Senior Notes due 2023 (the “2023 Notes”). Interest on the 2023 Notes is payable semi-annually in arrears at a rate of 5.875% per year and will mature on August 15, 2023, unless redeemed or repurchased earlier. The interest rate payable on the 2023 Notes is subject to adjustment in the event of a change in the credit ratings on the 2023 Notes. A downgrade of the Company's credit ratings could result in an increase to the interest cost with respect to the 2023 Notes. The Company will use net proceeds from the offering of the 2023 Notes for general corporate purposes which may include repurchases, repayment or refinancing of debt, capital expenditures, additions to working capital, the financing of future acquisitions or strategic combinations.
	In May and September 2013, the Company amended its $400 million senior unsecured domestic revolving credit facility to, among other things, extend the expiration date of the commitments of the lenders thereunder to May 31, 2018 and to modify the maximum leverage ratio and minimum interest coverage ratio permitted under the facility. Under the terms of the facility, the Company may increase the size of the credit facility by up to $100 million without seeking the further approval of the lending group. As amended, the facility requires the Company to maintain a leverage ratio (consolidated total indebtedness divided by consolidated earnings before interest, taxes and depreciation and amortization for the four prior fiscal quarters) of 4.50 for the quarter ended September 30, 2013. The maximum leverage ratio is reduced to 4.0 beginning with the quarter ended December 31, 2013, then to 3.75 for the quarter ended March 31, 2015 and is further reduced to 3.50 beginning with the quarter ended June 30, 2015 and for each fiscal quarter thereafter. As amended, the credit facility requires that the Company maintain an interest coverage ratio (consolidated earnings before interest and taxes divided by interest expense) of not less than 2.0 for the quarter ended September 30, 2013, 1.75 for the quarter ended December 31, 2013, and 2.0 for the quarter ended March 31, 2014 and for each fiscal quarter thereafter. At September 30, 2013, the leverage ratio was 4.18 and the interest coverage ratio was 2.71. The definition of consolidated earnings before interest and taxes, and consolidated earnings before interest, taxes, depreciation and amortization as used in the interest coverage and leverage ratios excludes any non-cash pension expense or income, and consolidated indebtedness in the leverage ratio is net of cash on hand in excess of $50 million. The Company was in compliance with these required ratios during all applicable periods. As of September 30, 2013, there were no outstanding borrowings made against the facility, although a portion of the facility was used to support approximately $4 million in letters of credit. The facility includes a $200 million sublimit for the issuance of letters of credit.
	The Company has an additional separate credit facility for the issuance of letters of credit. As of September 30, 2013, $32 million in letters of credit were outstanding under this facility.
	In addition, Shanghai STAL Precision Stainless Steel Company Limited (STAL), the Company’s Chinese joint venture company in which ATI has a 60% interest, has a 205 million renminbi (approximately $33 million at September 30, 2013 exchange rates) revolving credit facility with a group of banks, which expires in August 2014. This credit facility is supported solely by STAL’s financial capability without any guarantees from the joint venture partners. As of September 30, 2013, there were no borrowings under this credit facility.
	The ATI Ladish Series B and Series C Notes are guaranteed by ATI and are equally ranked with all of ATI’s existing and future senior unsecured debt.

Derivative_Financial_Instrumen

Derivative Financial Instruments and Hedging	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments and Hedging	'
	Derivative Financial Instruments and Hedging
	As part of its risk management strategy, the Company, from time-to-time, utilizes derivative financial instruments to manage its exposure to changes in raw material prices, energy costs, foreign currencies, and interest rates. In accordance with applicable accounting standards, the Company accounts for most of these contracts as hedges. In general, hedge effectiveness is determined by examining the relationship between offsetting changes in fair value or cash flows attributable to the item being hedged, and the financial instrument being used for the hedge. Effectiveness is measured utilizing regression analysis and other techniques to determine whether the change in the fair market value or cash flows of the derivative exceeds the change in fair value or cash flow of the hedged item. Calculated ineffectiveness, if any, is immediately recognized in the consolidated statements of income.
	The Company sometimes uses futures and swap contracts to manage exposure to changes in prices for forecasted purchases of raw materials, such as nickel and natural gas. Under these contracts, which are generally accounted for as cash flow hedges, the price of the item being hedged is fixed at the time that the contract is entered into and the Company is obligated to make or receive a payment equal to the net change between this fixed price and the market price at the date the contract matures.
	The majority of ATI’s products are sold utilizing raw material surcharges and index mechanisms. However, as of September 30, 2013, the Company had entered into financial hedging arrangements primarily at the request of its customers, related to firm orders, for an aggregate notional amount of approximately 7% of its estimated annual nickel requirements. These nickel hedges extend to 2020.
	At September 30, 2013, the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas cost hedges for approximately 80% of its annual forecasted domestic requirements for 2013, approximately 75% for 2014, and approximately 30% for 2015, and electricity hedges for Western Pennsylvania operations of approximately 10% of its forecasted on-peak and off-peak requirements for 2014.
	While the majority of the Company’s direct export sales are transacted in U.S. dollars, foreign currency exchange contracts are used, from time-to-time, to limit transactional exposure to changes in currency exchange rates for those transactions denominated in a non-U.S. currency. The Company sometimes purchases foreign currency forward contracts that permit it to sell specified amounts of foreign currencies expected to be received from its export sales for pre-established U.S. dollar amounts at specified dates. The forward contracts are denominated in the same foreign currencies in which export sales are denominated. These contracts are designated as hedges of the variability in cash flows of a portion of the forecasted future export sales transactions which otherwise would expose the Company to foreign currency risk. The Company may also enter into foreign currency forward contracts that are not designated as hedges, which are denominated in the same foreign currency in which export sales are denominated. At September 30, 2013, the outstanding financial derivatives, including both hedges and undesignated derivatives, that are used to manage the Company’s exposure to foreign currency, primarily euros, represented approximately 10% of its forecasted total international sales through 2016. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions.
	The Company may enter into derivative interest rate contracts to maintain a reasonable balance between fixed- and floating-rate debt. There were no unsettled derivative financial instruments related to debt balances for the periods presented.
	There are no credit risk-related contingent features in the Company’s derivative contracts, and the contracts contained no provisions under which the Company has posted, or would be required to post, collateral. The counterparties to the Company’s derivative contracts are substantial and creditworthy commercial banks that are recognized market makers. The Company controls its credit exposure by diversifying across multiple counterparties and by monitoring credit ratings and credit default swap spreads of its counterparties. The Company also enters into master netting agreements with counterparties when possible.
	The fair values of the Company’s derivative financial instruments are presented below, representing the gross amounts recognized which are not offset by counterparty or by type of item hedged. All fair values for these derivatives were measured using Level 2 information as defined by the accounting standard hierarchy, which includes quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs derived principally from or corroborated by observable market data.
	(in millions):		Balance sheet location		September 30,				December 31,
	Asset derivatives				2013				2012
	Derivatives designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		$	0.3			$	2.9
	Nickel and other raw material contracts		Prepaid expenses and other current assets		—				0.6
	Natural gas contracts		Prepaid expenses and other current assets		0.4				0.4
	Foreign exchange contracts		Other assets		—				0.9
	Nickel and other raw material contracts		Other assets		0.1				0.3
	Natural gas contracts		Other assets		0.2				0.7
	Total derivatives designated as hedging instruments:				1				5.8
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		—				0.4
	Total derivatives not designated as hedging instruments:				—				0.4
	Total asset derivatives				$	1			$	6.2
	Liability derivatives		Balance sheet location
	Derivatives designated as hedging instruments:
	Natural gas contracts		Accrued liabilities		$	2.2			$	4.4
	Nickel and other raw material contracts		Accrued liabilities		9.3				1.1
	Foreign exchange contracts		Accrued liabilities		4				1.7
	Electricity contracts		Accrued liabilities		0.4				0.3
	Natural gas contracts		Other long-term liabilities		0.3				0.6
	Electricity contracts		Other long-term liabilities		0.1				0.4
	Foreign exchange contracts		Other long-term liabilities		3				1.4
	Nickel and other raw material contracts		Other long-term liabilities		1.5				0.3
	Total derivatives designated as hedging instruments:				20.8				10.2
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Accrued liabilities		1.6				1.6
	Total derivatives not designated as hedging instruments:				1.6				1.6
	Total liability derivatives				$	22.4			$	11.8
	For derivative financial instruments that are designated as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (OCI) and reclassified into earnings in the same period or periods during which the hedged item affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current period results. The Company did not use fair value or net investment hedges for the periods presented. The effects of derivative instruments in the tables below are presented net of related income taxes.
	Activity with regard to derivatives designated as cash flow hedges for the three and nine month periods ended September 30, 2013 and 2012 was as follows (in millions):
		Amount of Gain (Loss)								Amount of Gain (Loss)						Amount of Gain (Loss)
		Recognized in OCI on								Reclassified from						Recognized in Income
		Derivatives								Accumulated OCI						on Derivatives (Ineffective
		(Effective Portion)								into Income						Portion and Amount
										(Effective Portion) (a)						Excluded from
																Effectiveness Testing) (b)
	Derivatives in Cash Flow	Three months ended September 30,								Three months ended September 30,						Three months ended September 30,
	Hedging Relationships	2013				2012				2013			2012			2013		2012
	Nickel and other raw material contracts	$	0.2			$	4.8			$	(1.3	)	$	(1.5	)	$	—	$	—
	Natural gas contracts	0.1				1.2				(0.6		)	(1.8		)	—		—
	Electricity contracts	(0.1		)		0.2				—			(0.5		)	—		—
	Foreign exchange contracts	(11.3		)		(1.4		)		(0.7		)	3.5			—		—
	Total	$	(11.1	)		$	4.8			$	(2.6	)	$	(0.3	)	$	—	$	—
		Amount of Gain (Loss)								Amount of Gain (Loss)						Amount of Gain (Loss)
		Recognized in OCI on								Reclassified from						Recognized in Income
		Derivatives								Accumulated OCI						on Derivatives (Ineffective
		(Effective Portion)								into Income						Portion and Amount
										(Effective Portion) (a)						Excluded from
																Effectiveness Testing) (b)
	Derivatives in Cash Flow	Nine months ended September 30,								Nine months ended September 30,						Nine months ended September 30,
	Hedging Relationships	2013				2012				2013			2012			2013		2012
	Nickel and other raw material contracts	$	(8.6	)		$	0.1			$	(2.3	)	$	(2.3	)	$	—	$	—
	Natural gas contracts	(0.2		)		(2.1		)		(1.5		)	(6.8		)	—		—
Electricity contracts	(0.1		)		(0.9		)		(0.2		)	(1.6		)	—		—
Foreign exchange contracts	(4.0		)		6.3				0.6			8.6			—		—
Total	$	(12.9	)		$	3.4			$	(3.4	)	$	(2.1	)	$	—	$	—
(a)	The gains (losses) reclassified from accumulated OCI into income related to the effective portion of the derivatives are presented in cost of sales in the same period or periods in which the hedged item affects earnings.
(b)	The gains (losses) recognized in income on derivatives related to the ineffective portion and the amount excluded from effectiveness testing are presented in selling and administrative expenses.
Assuming market prices remain constant with those at September 30, 2013, a loss of $9.4 million is expected to be recognized over the next 12 months.
The disclosures of gains or losses presented above for nickel and other raw material contracts and foreign currency contracts do not take into account the anticipated underlying transactions. Since these derivative contracts represent hedges, the net effect of any gain or loss on results of operations may be fully or partially offset.
Derivatives that are not designated as hedging instruments were as follows:
In millions	Amount of Gain (Loss) Recognized
	in Income on Derivatives
Derivatives Not Designated	Three months ended September 30,								Nine months ended September 30,
as Hedging Instruments	2013				2012				2013			2012
Foreign exchange contracts	$	(0.7	)		$	(1.9	)		$	(0.3	)	$	(2.0	)
Changes in the fair value of foreign exchange contract derivatives not designated as hedging instruments are recorded in cost of sales.

Fair_Value_Of_Financial_Instru

Fair Value Of Financial Instruments	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Of Financial Instruments	'
	Fair Value of Financial Instruments
	The estimated fair value of financial instruments at September 30, 2013 was as follows:
				Fair Value Measurements at Reporting Date Using
	(In millions)	Total		Total		Quoted Prices in		Significant
		Carrying		Estimated		Active Markets for		Observable
		Amount		Fair Value		Identical Assets(Level 1)		Inputs
								(Level 2)
	Cash and cash equivalents	$	535.7	$	535.7	$	535.7	$	—
	Derivative financial instruments:
	Assets	1		1		—		1
	Liabilities	22.4		22.4		—		22.4
	Debt	1,962.10		2,102.10		2,042.40		59.7
	The estimated fair value of financial instruments at December 31, 2012 was as follows:
				Fair Value Measurements at Reporting Date Using
	(In millions)	Total		Total		Quoted Prices in		Significant
		Carrying		Estimated		Active Markets for		Observable
		Amount		Fair Value		Identical Assets		Inputs
						(Level 1)		(Level 2)
	Cash and cash equivalents	$	304.6	$	304.6	$	304.6	$	—
	Derivative financial instruments:
	Assets	6.2		6.2		—		6.2
	Liabilities	11.8		11.8		—		11.8
	Debt	1,480.10		1,703.20		1,625.60		77.6
	In accordance with accounting standards, fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Accounting standards established three levels of a fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows:
	Level 1 – Quoted prices in active markets for identical assets or liabilities.
	Level 2 – Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.
	Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs.
	The following methods and assumptions were used by the Company in estimating the fair value of its financial instruments:
	Cash and cash equivalents: Fair value was determined using Level 1 information.
	Derivative financial instruments: Fair values for derivatives were measured using exchange-traded prices for the hedged items. The fair value was determined using Level 2 information, including consideration of counterparty risk and the Company’s credit risk.
	Short-term and long-term debt: The fair values of the Company’s publicly traded debt were based on Level 1 information. The fair values of the other short-term and long-term debt were determined using Level 2 information.

Pension_Plans_and_Other_Postre

Pension Plans and Other Postretirement Benefits	9 Months Ended
	Sep. 30, 2013
Pension And Other Postretirement Benefits Disclosure [Abstract]	'
Pension Plans and Other Postretirement Benefits	'
	Pension Plans and Other Postretirement Benefits
	The Company has defined benefit pension plans and defined contribution plans covering substantially all employees. Benefits under the defined benefit pension plans are generally based on years of service and/or final average pay. The Company funds the U.S. pension plans in accordance with the Employee Retirement Income Security Act of 1974, as amended, and the Internal Revenue Code.
	The Company also sponsors several postretirement plans covering certain salaried and hourly employees. The plans provide health care and life insurance benefits for eligible retirees. In most plans, Company contributions towards premiums are capped based on the cost as of a certain date, thereby creating a defined contribution. For the non-collectively bargained plans, the Company maintains the right to amend or terminate the plans at its discretion.
	For the three month periods ended September 30, 2013 and 2012, the components of pension expense and components of other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions):
		Pension Benefits						Other Postretirement Benefits
		Three months ended September 30,						Three months ended September 30,
		2013			2012			2013			2012
	Service cost - benefits earned during the year	$	10		$	8.8		$	0.8		$	0.8
	Interest cost on benefits earned in prior years	30.3			33.1			5.6			6.5
	Expected return on plan assets	(43.8		)	(45.4		)	(0.1		)	(0.2		)
	Amortization of prior service cost (credit)	0.8			1.6			(4.6		)	(4.5		)
	Amortization of net actuarial loss	29.2			26.3			4.3			3.6
	Total retirement benefit expense	$	26.5		$	24.4		$	6		$	6.2
	For the nine month periods ended September 30, 2013 and 2012, the components of pension expense and components of other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions):
		Pension Benefits						Other Postretirement Benefits
		Nine months ended September 30,						Nine months ended September 30,
		2013			2012			2013			2012
	Service cost - benefits earned during the year	$	30		$	26.3		$	2.4		$	2.4
	Interest cost on benefits earned in prior years	90.9			99.3			16.8			19.5
	Expected return on plan assets	(131.4		)	(136.1		)	(0.3		)	(0.6		)
	Amortization of prior service cost (credit)	2.3			4.8			(13.7		)	(13.6		)
	Amortization of net actuarial loss	87.6			78.9			12.9			10.9
	Total retirement benefit expense	$	79.4		$	73.2		$	18.1		$	18.6
	Other postretirement benefit costs for a defined contribution plan were $2.0 million for both the three and nine months ended September 30, 2013.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Third quarter 2013 results included a benefit for income taxes of $8.5 million, or 24.1% of loss before tax, compared to a provision of $14.8 million, or 30.8% of income before tax, for the comparable period. The third quarter of 2013 included a lower than normal tax benefit due to the impacts of income taxes reported in both domestic and foreign jurisdictions.
	For the first nine months of 2013, the benefit for income taxes was $4.4 million, or 31.4% of loss before tax, compared to a provision of $66.6 million, or 32.1% of income before tax, for the nine months of 2012. The first nine months of 2013 included a discrete tax benefit of $6.7 million, primarily associated with adjustments to prior years’ taxes and 2013 Federal tax law changes. The first nine months of 2012 included a discrete tax benefit of $4.2 million primarily related to state income taxes.

Business_Segments

Business Segments	9 Months Ended
	Sep. 30, 2013
Segment Reporting Disclosure [Abstract]	'
Business Segments	'
	Business Segments
	In the third quarter of 2013, the Company restructured its Engineered Products segment due to the planned divestitures of its tungsten materials and casting services businesses and the closure of the fabricated components business (see Note 4). Such restructuring included the integration of the previously standalone specialty steel forgings business into ATI Ladish’s forgings operations in the High Performance Metals segment, and the integration of its precision titanium and specialty alloy flat-rolled finishing business into ATI Allegheny Ludlum’s specialty plate business in the Flat-Rolled Products segment. The segment results for High Performance Metals and Flat-Rolled Products below reflect these changes for all periods presented. The other businesses that comprised the Engineered Products segment are classified as discontinued operations, and are not reported within business segment results.
	Following is certain financial information with respect to the Company’s business segments for the periods indicated (in millions):
		Three months ended September 30,						Nine months ended September 30,
		2013			2012			2013			2012
	Total sales:
	High Performance Metals	$	481.2		$	591.8		$	1,561.70		$	1,858.00
	Flat-Rolled Products	515.6			573.1			1,644.00			1,892.50
		996.8			1,164.90			3,205.70			3,750.50
	Intersegment sales:
	High Performance Metals	17.3			21.2			53.6			69.1
	Flat-Rolled Products	7.1			12.2			23.9			35.9
		24.4			33.4			77.5			105
	Sales to external customers:
	High Performance Metals	463.9			570.6			1,508.10			1,788.90
	Flat-Rolled Products	508.5			560.9			1,620.10			1,856.60
		$	972.4		$	1,131.50		$	3,128.20		$	3,645.50
	Operating profit (loss):
	High Performance Metals	$	48		$	87.4		$	192		$	303.8
	Flat-Rolled Products	(20.4		)	26.1			(16.7		)	118.4
	Total operating profit	27.6			113.5			175.3			422.2
	Corporate expenses	(8.1		)	(14.9		)	(32.3		)	(52.4		)
	Interest expense, net	(18.2		)	(17.2		)	(46.5		)	(55.7		)
	Closed company and other expenses	(2.1		)	(2.7		)	(11.0		)	(14.8		)
	Retirement benefit expense	(34.5		)	(30.6		)	(99.5		)	(91.8		)
	Income (loss) before income taxes	$	(35.3	)	$	48.1		$	(14.0	)	$	207.5
	Retirement benefit expense represents defined benefit plan pension expense, and other postretirement benefit expense for both defined benefit and defined contribution plans. Operating profit with respect to the Company’s business segments excludes any retirement benefit expense. Costs associated with multiemployer pension plans are included in segment operating profit, and costs associated with defined contribution pension plans are included in segment operating profit or corporate expenses, as applicable.
	Corporate expenses for the three months ended September 30, 2013 were $8.1 million compared to $14.9 million for the three months ended September 30, 2012. The decrease in corporate expenses was primarily related to lower incentive compensation expenses associated with annual and long-term performance plans, and a favorable litigation settlement.
	Interest expense, net of interest income, in the third quarter was $18.2 million, compared to net interest expense of $17.2 million in the third quarter 2012. The increase in interest expense was primarily due the 2023 Notes issued on July 12, 2013, partially offset by increased capitalized interest on major strategic projects. Interest expense benefited from the capitalization of interest costs of $12.7 million in the third quarter 2013 compared to $6.6 million in the third quarter 2012. The increased capitalized interest amounts are primarily related to the Hot-Rolling and Processing Facility.
	Closed company and other expenses primarily includes charges incurred in connection with closed operations and other non-operating income or expense. These items are presented primarily in selling and administrative expenses and in other income in the statements of operations. These items resulted in net charges of $2.1 million for the three months ended September 30, 2013 and $2.7 million for the three months ended September 30, 2012.
	Retirement benefit expense, which includes pension expense and other postretirement expense, increased to $34.5 million in the third quarter 2013, compared to $30.6 million in the third quarter 2012. This increase was primarily due to the utilization of a lower discount rate to value retirement benefit obligations and increased expense for defined contribution plan other postretirement benefits.

Per_Share_Information

Per Share Information	9 Months Ended
	Sep. 30, 2013
Earnings Per Share Disclosures [Abstract]	'
Per Share Information	'
	Per Share Information
	The following table sets forth the computation of basic and diluted income from continuing operations per common share:
		Three Months Ended					Nine months ended
	(in millions, except per share amounts):	September 30,					September 30,
		2013			2012		2013			2012
	Numerator for basic income (loss) from continuing operations per common share -
	Income (loss) from continuing operations attributable to ATI	$	(28.4	)	$	31.3	$	(15.0	)	$	134.5
	Effect of dilutive securities:
	4.25% Convertible Notes due 2014	—			2.1		—			6.5
	Numerator for diluted income (loss) from continuing operations per common share -
	Income (loss) from continuing operations available to ATI after assumed conversions	$	(28.4	)	$	33.4	$	(15.0	)	$	141
	Denominator for basic net income per common share-weighted average shares	106.8			106.2		106.7			106.1
	Effect of dilutive securities:
	Share-based compensation	—			0.9		—			0.9
	4.25% Convertible Notes due 2014	—			9.6		—			9.6
	Denominator for diluted net income per common share – adjusted weighted average shares assuming conversions	106.8			116.7		106.7			116.6
	Basic income (loss) from continuing operations attributable to ATI per common share	$	(0.27	)	$	0.3	$	(0.14	)	$	1.27
	Diluted income (loss) from continuing operations attributable to ATI per common share	$	(0.27	)	$	0.29	$	(0.14	)	$	1.21
	Common stock that would be issuable upon the assumed conversion of the 2014 Convertible Notes and other option equivalents and contingently issuable shares are excluded from the computation of contingently issuable shares, and therefore, from the denominator for diluted earnings per share, if the effect of inclusion is anti-dilutive. Excluded shares for the three and nine month periods ended September 30, 2013 were 10.0 million shares. There were no anti-dilutive shares for the periods ended September 30, 2012.

Financial_Information_for_Subs

Financial Information for Subsidiary and Guarantor Parent	9 Months Ended
	Sep. 30, 2013
Schedule Of Condensed Financial Statements Disclosure [Abstract]	'
Financial Information for Subsidiary and Guarantor Parent	'
	Financial Information for Subsidiary and Guarantor Parent
	The payment obligations under the $150 million 6.95% debentures due 2025 issued by Allegheny Ludlum, LLC (formerly known as Allegheny Ludlum Corporation) (the “Subsidiary”) are fully and unconditionally guaranteed by Allegheny Technologies Incorporated (the “Guarantor Parent”). In accordance with positions established by the Securities and Exchange Commission, the following financial information sets forth separately financial information with respect to the Subsidiary, the Non-guarantor Subsidiaries and the Guarantor Parent. The principal elimination entries eliminate investments in subsidiaries and certain intercompany balances and transactions.
	Allegheny Technologies is the plan sponsor for the U.S. qualified defined benefit pension plan (the “Plan”) which covers certain current and former employees of the Subsidiary and the Non-guarantor Subsidiaries. As a result, the balance sheets presented for the Subsidiary and the Non-guarantor Subsidiaries do not include any Plan assets or liabilities, or the related deferred taxes. The Plan assets, liabilities and related deferred taxes and pension income or expense are recognized by the Guarantor Parent. Management and royalty fees charged to the Subsidiary and to the Non-guarantor Subsidiaries by the Guarantor Parent have been excluded solely for purposes of this presentation.
	Allegheny Technologies Incorporated
	Financial Information for Subsidiary and Guarantor Parent
	Balance Sheets
	September 30, 2013
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Assets:
	Cash and cash equivalents	$	2.6		$	7.3		$	525.8		$	—		$	535.7
	Accounts receivable, net	3.4			187.5			386						576.9
	Intercompany notes receivable	—			—			1,261.40			(1,261.4		)	—
	Inventories, net	—			267.1			1,077.80			—			1,344.90
	Prepaid expenses and other current assets	82.9			9.3			28.4			—			120.6
	Current assets of discontinued operations	—			—			115.4			—			115.4
	Total current assets	88.9			471.2			3,394.80			(1,261.4		)	2,693.50
	Property, plant and equipment, net	3.2			1,211.80			1,529.70			—			2,744.70
	Cost in excess of net assets acquired	—			112.1			616			—			728.1
	Intercompany notes receivable	—			—			200			(200.0		)	—
	Investment in subsidiaries	5,605.50			37.7			—			(5,643.2		)	—
	Other assets	39.5			31.3			277.2			—			348
	Non-current assets of discontinued operations	—			—			85			—			85
	Total assets	$	5,737.10		$	1,864.10		$	6,102.70		$	(7,104.6	)	$	6,599.30
	Liabilities and stockholders’ equity:
	Accounts payable	$	4.6		$	230.8		$	166.5		$	—		$	401.9
	Accrued liabilities	46.9			57			201			—			304.9
	Intercompany notes payable	664.5			596.9			—			(1,261.4		)	—
	Deferred income taxes	8.2			—			—			—			8.2
	Short-term debt and current portion of long-term debt	402.9			0.1			16.9			—			419.9
	Current liabilities of discontinued operations	—			—			33.7			—			33.7
	Total current liabilities	1,127.10			884.8			418.1			(1,261.4		)	1,168.60
	Long-term debt	1,350.90			150.5			40.8			—			1,542.20
	Intercompany notes payable	—			200			—			(200.0		)	—
	Accrued postretirement benefits	—			183.1			291.9			—			475
	Pension liabilities	638.1			4.7			59.6			—			702.4
	Deferred income taxes	52.1			—			—			—			52.1
	Other long-term liabilities	4.8			19.3			70.8			—			94.9
	Total liabilities	3,173.00			1,442.40			881.2			(1,461.4		)	4,035.20
	Total stockholders’ equity	2,564.10			421.7			5,221.50			(5,643.2		)	2,564.10
	Total liabilities and stockholders’ equity	$	5,737.10		$	1,864.10		$	6,102.70		$	(7,104.6	)	$	6,599.30
	Allegheny Technologies Incorporated
	Financial Information for Subsidiary and Guarantor Parent
	Statements of Income and Comprehensive Income
	For the three months ended September 30, 2013
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Sales	$	—		$	422.3		$	550.1		$	—		$	972.4
	Cost of sales	19.4			424.3			475.6			—			919.3
	Selling and administrative expenses	35.4			7.4			27.8			—			70.6
	Income (loss) before interest, other income and income taxes	(54.8		)	(9.4		)	46.7			—			(17.5		)
	Interest expense, net	(17.3		)	(9.7		)	8.8			—			(18.2		)
	Other income (loss) including equity in income of unconsolidated subsidiaries	36.8			0.1			0.3			(36.8		)	0.4
	Income (loss) from continuing operations before income tax provision (benefit)	(35.3		)	(19.0		)	55.8			(36.8		)	(35.3		)
	Income tax provision (benefit)	(8.5		)	(6.6		)	22.4			(15.8		)	(8.5		)
	Income (loss) from continuing operations	(26.8		)	(12.4		)	33.4			(21.0		)	(26.8		)
	Income (loss)from discontinued operations, net of tax	(5.4		)	—			(2.5		)	2.5			(5.4		)
	Net income (loss)	(32.2		)	(12.4		)	30.9			(18.5		)	(32.2		)
	Less: Net income (loss) attributable to noncontrolling interests	—			—			1.6			—			1.6
	Net income (loss) attributable to ATI	$	(32.2	)	$	(12.4	)	$	29.3		$	(18.5	)	$	(33.8	)
	Comprehensive income (loss) attributable to ATI	$	(9.9	)	$	(12.2	)	$	42		$	(31.5	)	$	(11.6	)
	Allegheny Technologies Incorporated
	Financial Information for Subsidiary and Guarantor Parent
Statements of Income and Comprehensive Income
For the nine months ended September 30, 2013
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Sales	$	—		$	1,375.20		$	1,753.00		$	—		$	3,128.20
Cost of sales	55.5			1,359.50			1,471.90			—			2,886.90
Selling and administrative expenses	88.9			27.3			93.9			—			210.1
Income (loss) before interest, other income and income taxes	(144.4		)	(11.6		)	187.2			—			31.2
Interest expense, net	(45.5		)	(27.0		)	26			—			(46.5		)
Other income (loss) including equity in income of unconsolidated subsidiaries	175.9			0.6			0.8			(176.0		)	1.3
Income (loss) from continuing operations before income tax provision (benefit)	(14.0		)	(38.0		)	214			(176.0		)	(14.0		)
Income tax provision (benefit)	(4.4		)	(9.8		)	76.6			(66.8		)	(4.4		)
Income (loss) from continuing operations	(9.6		)	(28.2		)	137.4			(109.2		)	(9.6		)
Income (loss) from discontinued operations, net of tax	(4.4		)	—			(0.2		)	0.2			(4.4		)
Net income (loss)	(14.0		)	(28.2		)	137.2			(109.0		)	(14.0		)
Less: Net income attributable to noncontrolling interests	—			—			5.4			—			5.4
Net income (loss) attributable to ATI	$	(14.0	)	$	(28.2	)	$	131.8		$	(109.0	)	$	(19.4	)
Comprehensive income (loss) attributable to ATI	$	35.3		$	(27.8	)	$	134.8		$	(114.9	)	$	27.4
Condensed Statements of Cash Flows
For the nine months ended September 30, 2013
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Cash flows provided by (used in) operating activities	$	(9.1	)	$	(87.2	)	$	348		$	(24.3	)	$	227.4
Investing Activities:
Purchases of property, plant and equipment	(0.2		)	(359.1		)	(36.2		)	—			(395.5		)
Net receipts/(payments) on intercompany activity	—			—			(31.4		)	31.4			—
Asset disposals and other	0.1			0.1			0.6			—			0.8
Cash flows provided by (used in) investing activities	(0.1		)	(359.0		)	(67.0		)	31.4			(394.7		)
Financing Activities:
Borrowings on long-term debt	500			—			—			—			500
Net receipts/(payments) on intercompany activity	(409.0		)	440.4			—			(31.4		)	—
Dividends paid to stockholders	(57.7		)	—			(24.3		)	24.3			(57.7		)
Other	(27.0		)	—			(16.9		)	—			(43.9		)
Cash flows provided by (used in) financing activities	6.3			440.4			(41.2		)	(7.1		)	398.4
Increase (decrease) in cash and cash equivalents	$	(2.9	)	$	(5.8	)	$	239.8		$	—		$	231.1
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Balance Sheets
December 31, 2012
	Guarantor						Non-guarantor
(In millions)	Parent			Subsidiary			Subsidiaries			Eliminations			Consolidated
Assets:
Cash and cash equivalents	$	5.5		$	13.1		$	286		$	—		$	304.6
Accounts receivable, net	0.4			190.1			422.8			—			613.3
Intercompany notes receivable	—			—			1,289.90			(1,289.9		)	—
Inventories, net	—			311.1			1,225.50			—			1,536.60
Prepaid expenses and other current assets	1.1			10.2			44.8			—			56.1
Total current assets	7			524.5			3,269.00			(1,289.9		)	2,510.60
Property, plant and equipment, net	3.9			882.2			1,673.80			—			2,559.90
Cost in excess of net assets acquired	—			112.1			628			—			740.1
Deferred income taxes	71.5			—			—			—			71.5
Intercompany notes receivable	—			—			200.1			(200.1		)	—
Investment in subsidiaries	5,545.40			33.7			—			(5,579.1		)	—
Other assets	50.5			35.5			279.7			—			365.7
Total assets	$	5,678.30		$	1,588.00		$	6,050.60		$	(7,069.1	)	$	6,247.80
Liabilities and stockholders’ equity:
Accounts payable	$	5.3		$	262.6		$	232		$	—		$	499.9
Accrued liabilities	64			62.2			204.3			—			330.5
Intercompany notes payable	$	1,073.40		$	216.5		$	—		$	(1,289.9	)	—
Deferred income taxes	24			—			—			—			24
Short-term debt and current portion of long-term debt	0.3			0.1			16.7			—			17.1
Total current liabilities	1,167.00			541.4			453			(1,289.9		)	871.5
Long-term debt	1,253.40			150.5			59.1			—			1,463.00
Intercompany notes payable	—			200.1			—			(200.1		)
Accrued postretirement benefits	—			198.2			297			—			495.2
Pension liabilities	651.7			5.1			64.3			—			721.1
Other long-term liabilities	19.1			20.8			70			—			109.9
Total liabilities	3,091.20			1,116.10			943.4			(1,490.0		)	3,660.70
Total stockholders’ equity	2,587.10			471.9			5,107.20			(5,579.1		)	2,587.10
Total liabilities and stockholders’ equity	$	5,678.30		$	1,588.00		$	6,050.60		$	(7,069.1	)	$	6,247.80
The condensed consolidating balance sheets at December 31, 2012 have been restated to revise the presentation of intercompany balances, and to reflect equity elimination entries between Non-guarantor Subsidiaries within the Non-guarantor balance sheet, rather than as part of Eliminations. These revisions increased Non-guarantor balances of total current assets $1,289.9 million and total assets $1,112.7 million, decreased total current liabilities and total liabilities $196.8 million, and increased total stockholders' equity $1,309.5 million. The Subsidiary balances of total assets, total current liabilities and total liabilities were each reduced by $141.1 million to reclassify intercompany balances to a net payable presentation. There was no impact to the consolidated financial statements as a result of these presentation changes.
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Statements of Income and Comprehensive Income
For the three months ended September 30, 2012
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Sales	$	—		$	483.6		$	647.9		$	—		$	1,131.50
Cost of sales	15.1			453.8			519.9			—			988.8
Selling and administrative expenses	33.7			10.8			33.1			—			77.6
Income (loss) before interest, other income and income taxes	(48.8		)	19			94.9			—			65.1
Interest income (expense), net	(14.7		)	(2.7		)	0.2			—			(17.2		)
Other income (loss) including equity in income of unconsolidated subsidiaries	111.6			(5.2		)	7.8			(114.0		)	0.2
Income from continuing operations before income tax provision	48.1			11.1			102.9			(114.0		)	48.1
Income tax provision	14.8			4.6			33.3			(37.9		)	14.8
Income from continuing operations	33.3			6.5			69.6			(76.1		)	33.3
Income from discontinued operations, net of tax	4			—			4.6			(4.6		)	4
Net income	37.3			6.5			74.2			(80.7		)	37.3
Less: Net income attributable to noncontrolling interests	—			—			2			—			2
Net income attributable to ATI	$	37.3		$	6.5		$	72.2		$	(80.7	)	$	35.3
Comprehensive income attributable to ATI	$	74.4		$	6.3		$	87.3		$	(96.2	)	$	71.8
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Statements of Income and Comprehensive Income
For the nine months ended September 30, 2012
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Sales	$	—		$	1,614.20		$	2,031.30		$	—		$	3,645.50
Cost of sales	41.8			1,488.70			1,609.10			—			3,139.60
Selling and administrative expenses	109.1			33.2			101			—			243.3
Income (loss) before interest, other income and income taxes	(150.9		)	92.3			321.2			—			262.6
Interest expense, net	(47.3		)	(7.9		)	(0.5		)	—			(55.7		)
Other income (loss) including equity in income of unconsolidated subsidiaries	405.7			(16.1		)	24.2			(413.2		)	0.6
Income from continuing operations before income tax provision	207.5			68.3			344.9			(413.2		)	207.5
Income tax provision	66.6			26.9			116.9			(143.8		)	66.6
Income from continuing operations	140.9			41.4			228			(269.4		)	140.9
Income from discontinued operations, net of tax	13.4			—			16.1			(16.1		)	13.4
Net income	154.3			41.4			244.1			(285.5		)	154.3
Less: Net income attributable to noncontrolling interests	—			—			6.4			—			6.4
Net income attributable to ATI	$	154.3		$	41.4		$	237.7		$	(285.5	)	$	147.9
Comprehensive income attributable to ATI	$	220		$	40.6		$	249.2		$	(296.2	)	$	213.6
Condensed Statements of Cash Flows
For the nine months ended September 30, 2012
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Cash flows provided by (used in) operating activities	$	(26.1	)	$	4.1		$	267.8		$	—		$	245.8
Investing Activities:
Purchases of property, plant and equipment	(1.0		)	(192.5		)	(52.1		)	—			(245.6		)
Net receipts/(payments) on intercompany activity	—			—			(187.0		)	187			—
Asset disposals and other	—			0.2			1.3			—			1.5
Cash flows used in investing activities	(1.0		)	(192.3		)	(237.8		)	187			(244.1		)
Financing Activities:
Net receipts/(payments) on intercompany activity	103.8			83.2			—			(187.0		)	—
Dividends paid to stockholders	(57.3		)	—			—			—			(57.3		)
Other	(17.0		)	(0.1		)	(26.9		)	—			(44.0		)
Cash flows provided by (used in) financing activities	29.5			83.1			(26.9		)	(187.0		)	(101.3		)
Increase (decrease) in cash and cash equivalents	$	2.4		$	(105.1	)	$	3.1		$	—		$	(99.6	)
The condensed consolidating statements of cash flows for the nine months ended September 30, 2012 have been revised to reclassify intercompany activities between operating, investing and financing activities, rather than entirely as financing activities, as previously presented. These revisions increased (decreased) cash flows provided by (used in) the consolidating statements of cash flows as follows, in millions: operating activities for the Guarantor Parent, Subsidiary, Non-guarantor Subsidiaries and Eliminations, $(4.4), $42.7, $(42.5) and $4.2, respectively; investing activities for the Non-guarantor Subsidiaries and Eliminations, $(187.0) and $187.0, respectively; and financing activities for the Guarantor Parent, Subsidiary, Non-guarantor Subsidiaries and Eliminations, $4.4, $(42.7), $229.5 and $(191.2), respectively.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income Net Of Tax [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Accumulated Other Comprehensive Income (Loss)
	The changes in the accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the three month period ended September 30, 2013 were as follows (in millions):
		Post-				Currency				Unrealized				Derivatives				Total
		retirement				translation				holding gains
		benefit plans				adjustment				on securities
	Attributable to ATI:
	Balance, June 30, 2013	$	(993.5	)		$	(7.5	)		$	(0.1	)		$	(3.7	)		$	(1,004.8	)
	OCI before reclassifications		—				12.3				0.1				(11.1	)		1.3
	Amounts reclassified from AOCI	(a)	18.3			(b)	—			(b)	—			(c)	2.6			20.9
	Net current-period OCI		18.3				12.3				0.1				(8.5	)		22.2
	Balance, September 30, 2013	$	(975.2	)		$	4.8			$	—			$	(12.2	)		$	(982.6	)
	Attributable to noncontrolling interests:
	Balance, June 30, 2013	$	—			$	26.1			$	—			$	—			$	26.1
	OCI before reclassifications		—				0.1				—				—			0.1
	Net current-period OCI		—				0.1				—				—			0.1
	Balance, September 30, 2013	$	—			$	26.2			$	—			$	—			$	26.2
	The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the nine month period ended September 30, 2013 were as follows (in millions):
		Post-				Currency					Unrealized				Derivatives				Total
		retirement				translation					holding gains
		benefit plans				adjustment					on securities
	Attributable to ATI:
	Balance, December 31, 2012	$	(1,030.0	)		$	3.4				$	(0.1	)		$	(2.7	)		$	(1,029.4	)
	OCI before reclassifications		—				1.4					0.1				(12.9	)		(11.4		)
	Amounts reclassified from AOCI	(a)	54.8			(b)	—				(b)	—			(c)	3.4			58.2
	Net current-period OCI		54.8				1.4					0.1				(9.5	)		46.8
	Balance, September 30, 2013	$	(975.2	)		$	4.8				$	—			$	(12.2	)		$	(982.6	)
	Attributable to noncontrolling interests:
	Balance, December 31, 2012	$	—			$	$	23.7			$	—			$	—			$	23.7
	OCI before reclassifications		—				2.5					—				—			2.5
	Amounts reclassified from AOCI		—			(b)	—					—				—			—
	Net current-period OCI		—				2.5					—				—			2.5
	Balance, September 30, 2013	$	—			$	26.2				$	—			$	—			$	26.2
	(a)	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 8).
	(b)	No amounts were reclassified to earnings.
	(c)	Amounts were included in cost of goods sold in the period or periods the hedged item affects earnings (see Note 6).
	Reclassifications out of AOCI for the three and nine month periods ended September 30, 2013 were as follows:
			Amount reclassified from AOCI (c)
	Details about AOCI Components		Three months ended September 30, 2013						Nine months ended September 30, 2013						Affected line item in the
	(in millions)														statement of operations
	Postretirement benefit plans
	Prior service (cost) credit		3.8				(a)		11.4				(a)
	Actuarial losses		(33.5		)		(a)		(100.5		)		(a)
			(29.7		)		(c)		(89.1		)		(c)		Total before tax
			(11.4		)				(34.3		)				Tax provision (benefit)
			$	(18.3	)				$	(54.8	)				Net of tax
	Derivatives
	Nickel and other raw material contracts		$	(2.3	)		(b)		$	(3.8	)		(b)
	Natural gas contracts		(0.9		)		(b)		(2.4		)		(b)
	Electricity contracts		—				(b)		(0.3		)		(b)
	Foreign exchange contracts		(1.1		)		(b)		1				(b)
			(4.3		)		(c)		(5.5		)		(c)		Total before tax
			(1.7		)				(2.1		)				Tax provision (benefit)
			$	(2.6	)				$	(3.4	)				Net of tax
	(a)	Amounts are included in the computation of pension and other postretirement benefit expense, which is reported in both cost of goods sold and selling and administrative expenses. For additional information, see Note 8.
	(b)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings. For additional information, see Note 6.
	(c)	For pretax items, positive amounts are income and negative amounts are expense in terms of the impact to net income. Tax effects are presented in conformity with ATI’s presentation in the consolidated statements of operations.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	The Company is subject to various domestic and international environmental laws and regulations that govern the discharge of pollutants and disposal of wastes, and which may require that it investigate and remediate the effects of the release or disposal of materials at sites associated with past and present operations. The Company could incur substantial cleanup costs, fines, and civil or criminal sanctions, third party property damage or personal injury claims as a result of violations or liabilities under these laws or noncompliance with environmental permits required at its facilities. The Company is currently involved in the investigation and remediation of a number of its current and former sites, as well as third party sites.
	Environmental liabilities are recorded when the Company’s liability is probable and the costs are reasonably estimable. In many cases, however, the Company is not able to determine whether it is liable or, if liability is probable, to reasonably estimate the loss or range of loss. Estimates of the Company’s liability remain subject to additional uncertainties, including the nature and extent of site contamination, available remediation alternatives, the extent of corrective actions that may be required, and the number, participation, and financial condition of other potentially responsible parties (“PRPs”). The Company adjusts its accruals to reflect new information as appropriate. Future adjustments could have a material adverse effect on the Company’s consolidated results of operations in a given period, but the Company cannot reliably predict the amounts of such future adjustments.
	At September 30, 2013, the Company’s reserves for environmental remediation obligations totaled approximately $15 million, of which $9 million was included in other current liabilities. The reserve includes estimated probable future costs of $5 million for federal Superfund and comparable state-managed sites; $7 million for formerly owned or operated sites for which the Company has remediation or indemnification obligations; $2 million for owned or controlled sites at which Company operations have been discontinued; and $1 million for sites utilized by the Company in its ongoing operations. The Company continues to evaluate whether it may be able to recover a portion of past and future costs for environmental liabilities from third parties and to pursue such recoveries where appropriate.
	Future investigation or remediation activities may result in the discovery of additional hazardous materials, potentially higher levels of contamination than discovered during prior investigation, and may impact costs of the success or lack thereof in remedial solutions. Therefore, future developments, administrative actions or liabilities relating to environmental matters could have a material adverse effect on the Company’s consolidated financial condition or results of operations.
	The timing of expenditures depends on a number of factors that vary by site. The Company expects that it will expend present accruals over many years and that remediation of all sites with which it has been identified will be completed within thirty years.
	See Note 16. Commitments and Contingencies to the Company’s consolidated financial statements in the Company’s Annual Report on Form 10-K for its fiscal year ended December 31, 2012 for a discussion of legal proceedings affecting the Company.
	A number of other lawsuits, claims and proceedings have been or may be asserted against the Company relating to the conduct of its currently and formerly owned businesses, including those pertaining to product liability, patent infringement, commercial, government contracting, employment, employee and retiree benefits, taxes, environmental, health and safety and occupational disease, and stockholder and corporate governance matters. While the outcome of litigation cannot be predicted with certainty, and some of these lawsuits, claims or proceedings may be determined adversely to the Company, management does not believe that the disposition of any such pending matters is likely to have a material adverse effect on the Company’s financial condition or liquidity, although the resolution in any reporting period of one or more of these matters could have a material adverse effect on the Company’s consolidated results of operations for that period.
	Based on currently available information, it is reasonably possible that costs for recorded matters may exceed the Company’s recorded reserves by as much as $8 million. In addition, as part of the agreement to sell the tungsten materials business, the Company has agreed to indemnify the buyer for a five year period for conditional asset retirement obligation costs up to $13 million, which is approximately $9.5 million above the Company's recorded reserve for this matter.

Accounting_Policies_Policies

Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Significant Accounting Policies [Abstract]	'
Basis Of Accounting	'
	The interim consolidated financial statements include the accounts of Allegheny Technologies Incorporated and its subsidiaries. Unless the context requires otherwise, “Allegheny Technologies”, “ATI” and “the Company” refer to Allegheny Technologies Incorporated and its subsidiaries.
	These unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions for Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and note disclosures required by U.S. generally accepted accounting principles for complete financial statements. In management’s opinion, all adjustments (which include only normal recurring adjustments) considered necessary for a fair presentation have been included. Certain prior year amounts have been reclassified in order to conform with the fiscal year 2013 presentation. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2012 Annual Report on Form 10-K. The results of operations for these interim periods are not necessarily indicative of the operating results for any future period. The December 31, 2012 financial information has been derived from the Company’s audited consolidated financial statements.
Inventory	'
	Inventories are stated at the lower of cost (last-in, first-out (“LIFO”), first-in, first-out (“FIFO”), and average cost methods) or market, less progress payments. Most of the Company’s inventory is valued utilizing the LIFO costing methodology. Inventory of the Company’s non-U.S. operations is valued using average cost or FIFO methods.
Derivatives	'
	As part of its risk management strategy, the Company, from time-to-time, utilizes derivative financial instruments to manage its exposure to changes in raw material prices, energy costs, foreign currencies, and interest rates. In accordance with applicable accounting standards, the Company accounts for most of these contracts as hedges. In general, hedge effectiveness is determined by examining the relationship between offsetting changes in fair value or cash flows attributable to the item being hedged, and the financial instrument being used for the hedge. Effectiveness is measured utilizing regression analysis and other techniques to determine whether the change in the fair market value or cash flows of the derivative exceeds the change in fair value or cash flow of the hedged item. Calculated ineffectiveness, if any, is immediately recognized in the consolidated statements of income.
	The Company sometimes uses futures and swap contracts to manage exposure to changes in prices for forecasted purchases of raw materials, such as nickel and natural gas. Under these contracts, which are generally accounted for as cash flow hedges, the price of the item being hedged is fixed at the time that the contract is entered into and the Company is obligated to make or receive a payment equal to the net change between this fixed price and the market price at the date the contract matures.
	The majority of ATI’s products are sold utilizing raw material surcharges and index mechanisms. However, as of September 30, 2013, the Company had entered into financial hedging arrangements primarily at the request of its customers, related to firm orders, for an aggregate notional amount of approximately 7% of its estimated annual nickel requirements. These nickel hedges extend to 2020.
	At September 30, 2013, the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas cost hedges for approximately 80% of its annual forecasted domestic requirements for 2013, approximately 75% for 2014, and approximately 30% for 2015, and electricity hedges for Western Pennsylvania operations of approximately 10% of its forecasted on-peak and off-peak requirements for 2014.
	While the majority of the Company’s direct export sales are transacted in U.S. dollars, foreign currency exchange contracts are used, from time-to-time, to limit transactional exposure to changes in currency exchange rates for those transactions denominated in a non-U.S. currency. The Company sometimes purchases foreign currency forward contracts that permit it to sell specified amounts of foreign currencies expected to be received from its export sales for pre-established U.S. dollar amounts at specified dates. The forward contracts are denominated in the same foreign currencies in which export sales are denominated. These contracts are designated as hedges of the variability in cash flows of a portion of the forecasted future export sales transactions which otherwise would expose the Company to foreign currency risk. The Company may also enter into foreign currency forward contracts that are not designated as hedges, which are denominated in the same foreign currency in which export sales are denominated. At September 30, 2013, the outstanding financial derivatives, including both hedges and undesignated derivatives, that are used to manage the Company’s exposure to foreign currency, primarily euros, represented approximately 10% of its forecasted total international sales through 2016. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions.
	The Company may enter into derivative interest rate contracts to maintain a reasonable balance between fixed- and floating-rate debt. There were no unsettled derivative financial instruments related to debt balances for the periods presented.
	There are no credit risk-related contingent features in the Company’s derivative contracts, and the contracts contained no provisions under which the Company has posted, or would be required to post, collateral. The counterparties to the Company’s derivative contracts are substantial and creditworthy commercial banks that are recognized market makers. The Company controls its credit exposure by diversifying across multiple counterparties and by monitoring credit ratings and credit default swap spreads of its counterparties. The Company also enters into master netting agreements with counterparties when possible.
	The fair values of the Company’s derivative financial instruments are presented below, representing the gross amounts recognized which are not offset by counterparty or by type of item hedged. All fair values for these derivatives were measured using Level 2 information as defined by the accounting standard hierarchy, which includes quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs derived principally from or corroborated by observable market data.
	For derivative financial instruments that are designated as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (OCI) and reclassified into earnings in the same period or periods during which the hedged item affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current period results. The Company did not use fair value or net investment hedges for the periods presented. The effects of derivative instruments in the tables below are presented net of related income taxes.
Pension And Other Postretirement Plans	'
	The Company has defined benefit pension plans and defined contribution plans covering substantially all employees. Benefits under the defined benefit pension plans are generally based on years of service and/or final average pay. The Company funds the U.S. pension plans in accordance with the Employee Retirement Income Security Act of 1974, as amended, and the Internal Revenue Code.
	The Company also sponsors several postretirement plans covering certain salaried and hourly employees. The plans provide health care and life insurance benefits for eligible retirees. In most plans, Company contributions towards premiums are capped based on the cost as of a certain date, thereby creating a defined contribution. For the non-collectively bargained plans, the Company maintains the right to amend or terminate the plans at its discretion.
Commitments And Contingencies	'
	Environmental liabilities are recorded when the Company’s liability is probable and the costs are reasonably estimable. In many cases, however, the Company is not able to determine whether it is liable or, if liability is probable, to reasonably estimate the loss or range of loss. Estimates of the Company’s liability remain subject to additional uncertainties, including the nature and extent of site contamination, available remediation alternatives, the extent of corrective actions that may be required, and the number, participation, and financial condition of other potentially responsible parties (“PRPs”). The Company adjusts its accruals to reflect new information as appropriate. Future adjustments could have a material adverse effect on the Company’s consolidated results of operations in a given period, but the Company cannot reliably predict the amounts of such future adjustments.
New Accounting Pronouncements	'
	In January 2013, the Company adopted changes issued by the Financial Accounting Standards Board (FASB) to the disclosure of offsetting assets and liabilities. These changes require an entity to disclose both gross information and net information about both instruments and transactions eligible for offset in the statement of financial position and instruments and transactions subject to an agreement similar to a master netting arrangement. The enhanced disclosures will enable users of an entity’s financial statements to understand and evaluate the effect or potential effect of master netting arrangements on an entity’s financial position, including the effect or potential effect of rights of setoff associated with certain financial instruments and derivative instruments. Other than the additional disclosure requirements, the adoption of these changes had no impact on the consolidated financial statements.
	In January 2013, the Company adopted changes issued by the FASB to the reporting of amounts reclassified out of accumulated other comprehensive income. These changes require an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income if the amount being reclassified is required to be reclassified in its entirety to net income. For other amounts that are not required to be reclassified in their entirety to net income in the same reporting period, an entity is required to cross-reference other disclosures that provide additional detail about those amounts. These requirements are to be applied to each component of accumulated other comprehensive income. Other than the additional disclosure requirements (see Note 13), the adoption of these changes had no impact on the consolidated financial statements.

Inventories_Tables

Inventories (Tables)	9 Months Ended
	Sep. 30, 2013
Inventory Disclosure (Tables) [Abstract]	'
Inventories	'
	Inventories at September 30, 2013 and December 31, 2012 were as follows (in millions):
		September 30,			December 31,
		2013			2012
	Raw materials and supplies	$	330.7		$	351.6
	Work-in-process	900.3			1,063.90
	Finished goods	164.7			209
	Total inventories at current cost	1,395.70			1,624.50
	Less allowances to reduce current cost values to LIFO basis	(12.4		)	(76.9		)
	Progress payments	(38.4		)	(11.0		)
	Total inventories, net	$	1,344.90		$	1,536.60

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2013
Property, Plant and Equipment [Abstract]	'
Property Plant And Equipment	'
	Property, plant and equipment at September 30, 2013 and December 31, 2012 was as follows (in millions):
		September 30,			December 31,
		2013			2012
	Land	$	29.9		$	34.4
	Buildings	947.3			921
	Equipment and leasehold improvements	3,431.90			3,344.40
		4,409.10			4,299.80
	Accumulated depreciation and amortization	(1,664.4		)	(1,739.9		)
	Total property, plant and equipment, net	$	2,744.70		$	2,559.90

Discontinued_Operations_Tables

Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	'
	The following table presents summarized operating results for these discontinued operations (in millions):
		Three months ended September 30,					Nine months ended September 30,
		2013			2012		2013			2012
	Sales	$	77.6		$	89	$	236.7		$	284.9
	Income (loss) before income tax provision	$	(7.1	)	$	6	$	(5.4	)	$	20.4
	Net assets of discontinued operations were $163.4 million at September 30, 2013 and consisted of the following items (in millions):
		30-Sep-13
	Accounts receivable, net of allowances for doubtful accounts	$	47.5
	Inventories, net	65
	Prepaid expenses and other current assets	2.9
	Property, plant and equipment, net	72.9
	Cost in excess of net assets acquired	11.2
	Other long-term assets	0.9
	Total Assets	200.4
	Accounts payable	20.6
	Accrued liabilities	13.1
	Long-term liabilities	3.3
	Total Liabilities	37
	Net Assets	$	163.4

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure (Tables) [Abstract]	'
Schedule of Debt Instruments	'
	Debt at September 30, 2013 and December 31, 2012 was as follows (in millions):
		September 30,		December 31,
		2013		2012
	Allegheny Technologies 5.875% Notes due 2023	$	500	$	—
	Allegheny Technologies 5.95% Notes due 2021	500		500
	Allegheny Technologies 4.25% Convertible Notes due 2014	402.5		402.5
	Allegheny Technologies 9.375% Notes due 2019	350		350
	Allegheny Ludlum 6.95% debentures due 2025	150		150
	ATI Ladish Series B 6.14% Notes due 2016 (a)	18.4		24.8
	ATI Ladish Series C 6.41% Notes due 2015 (b)	21.4		32.5
	Domestic Bank Group $400 million unsecured credit facility	—		—
	Foreign credit facilities	14.3		14.2
	Industrial revenue bonds, due through 2020, and other	5.5		6.1
	Total short-term and long-term debt	1,962.10		1,480.10
	Short-term debt and current portion of long-term debt	419.9		17.1
	Total long-term debt	$	1,542.20	$	1,463.00
	(a)	Includes fair value adjustments of $1.2 million at September 30, 2013 and $1.9 million at December 31, 2012.
	(b)	Includes fair value adjustments of $1.4 million at September 30, 2013 and $2.5 million at December 31, 2012.

Derivative_Financial_Instrumen1

Derivative Financial Instruments and Hedging (Tables)	9 Months Ended
	Sep. 30, 2013
General Discussion of Derivative Instruments and Hedging Activities [Abstract]	'
Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value	'
	The fair values of the Company’s derivative financial instruments are presented below, representing the gross amounts recognized which are not offset by counterparty or by type of item hedged. All fair values for these derivatives were measured using Level 2 information as defined by the accounting standard hierarchy, which includes quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs derived principally from or corroborated by observable market data.
	(in millions):		Balance sheet location		September 30,				December 31,
	Asset derivatives				2013				2012
	Derivatives designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		$	0.3			$	2.9
	Nickel and other raw material contracts		Prepaid expenses and other current assets		—				0.6
	Natural gas contracts		Prepaid expenses and other current assets		0.4				0.4
	Foreign exchange contracts		Other assets		—				0.9
	Nickel and other raw material contracts		Other assets		0.1				0.3
	Natural gas contracts		Other assets		0.2				0.7
	Total derivatives designated as hedging instruments:				1				5.8
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		—				0.4
	Total derivatives not designated as hedging instruments:				—				0.4
	Total asset derivatives				$	1			$	6.2
	Liability derivatives		Balance sheet location
	Derivatives designated as hedging instruments:
	Natural gas contracts		Accrued liabilities		$	2.2			$	4.4
	Nickel and other raw material contracts		Accrued liabilities		9.3				1.1
	Foreign exchange contracts		Accrued liabilities		4				1.7
	Electricity contracts		Accrued liabilities		0.4				0.3
	Natural gas contracts		Other long-term liabilities		0.3				0.6
	Electricity contracts		Other long-term liabilities		0.1				0.4
	Foreign exchange contracts		Other long-term liabilities		3				1.4
	Nickel and other raw material contracts		Other long-term liabilities		1.5				0.3
	Total derivatives designated as hedging instruments:				20.8				10.2
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Accrued liabilities		1.6				1.6
	Total derivatives not designated as hedging instruments:				1.6				1.6
	Total liability derivatives				$	22.4			$	11.8
Schedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance	'
	Activity with regard to derivatives designated as cash flow hedges for the three and nine month periods ended September 30, 2013 and 2012 was as follows (in millions):
		Amount of Gain (Loss)								Amount of Gain (Loss)						Amount of Gain (Loss)
		Recognized in OCI on								Reclassified from						Recognized in Income
		Derivatives								Accumulated OCI						on Derivatives (Ineffective
		(Effective Portion)								into Income						Portion and Amount
										(Effective Portion) (a)						Excluded from
																Effectiveness Testing) (b)
	Derivatives in Cash Flow	Three months ended September 30,								Three months ended September 30,						Three months ended September 30,
	Hedging Relationships	2013				2012				2013			2012			2013		2012
	Nickel and other raw material contracts	$	0.2			$	4.8			$	(1.3	)	$	(1.5	)	$	—	$	—
	Natural gas contracts	0.1				1.2				(0.6		)	(1.8		)	—		—
	Electricity contracts	(0.1		)		0.2				—			(0.5		)	—		—
	Foreign exchange contracts	(11.3		)		(1.4		)		(0.7		)	3.5			—		—
	Total	$	(11.1	)		$	4.8			$	(2.6	)	$	(0.3	)	$	—	$	—
		Amount of Gain (Loss)								Amount of Gain (Loss)						Amount of Gain (Loss)
		Recognized in OCI on								Reclassified from						Recognized in Income
		Derivatives								Accumulated OCI						on Derivatives (Ineffective
		(Effective Portion)								into Income						Portion and Amount
										(Effective Portion) (a)						Excluded from
																Effectiveness Testing) (b)
	Derivatives in Cash Flow	Nine months ended September 30,								Nine months ended September 30,						Nine months ended September 30,
	Hedging Relationships	2013				2012				2013			2012			2013		2012
	Nickel and other raw material contracts	$	(8.6	)		$	0.1			$	(2.3	)	$	(2.3	)	$	—	$	—
	Natural gas contracts	(0.2		)		(2.1		)		(1.5		)	(6.8		)	—		—
	Electricity contracts	(0.1		)		(0.9		)		(0.2		)	(1.6		)	—		—
	Foreign exchange contracts	(4.0		)		6.3				0.6			8.6			—		—
	Total	$	(12.9	)		$	3.4			$	(3.4	)	$	(2.1	)	$	—	$	—
	(a)	The gains (losses) reclassified from accumulated OCI into income related to the effective portion of the derivatives are presented in cost of sales in the same period or periods in which the hedged item affects earnings.
	(b)	The gains (losses) recognized in income on derivatives related to the ineffective portion and the amount excluded from effectiveness testing are presented in selling and administrative expenses.
Schedule Of Derivative Instruments Included In Trading Activities	'
	Derivatives that are not designated as hedging instruments were as follows:
	In millions	Amount of Gain (Loss) Recognized
		in Income on Derivatives
	Derivatives Not Designated	Three months ended September 30,								Nine months ended September 30,
	as Hedging Instruments	2013				2012				2013			2012
	Foreign exchange contracts	$	(0.7	)		$	(1.9	)		$	(0.3	)	$	(2.0	)

Recovered_Sheet1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Of Financial Instruments (Tables) [Abstract]	'
Fair Value By Balance Sheet Grouping	'
	The estimated fair value of financial instruments at September 30, 2013 was as follows:
				Fair Value Measurements at Reporting Date Using
	(In millions)	Total		Total		Quoted Prices in		Significant
		Carrying		Estimated		Active Markets for		Observable
		Amount		Fair Value		Identical Assets(Level 1)		Inputs
								(Level 2)
	Cash and cash equivalents	$	535.7	$	535.7	$	535.7	$	—
	Derivative financial instruments:
	Assets	1		1		—		1
	Liabilities	22.4		22.4		—		22.4
	Debt	1,962.10		2,102.10		2,042.40		59.7
	The estimated fair value of financial instruments at December 31, 2012 was as follows:
				Fair Value Measurements at Reporting Date Using
	(In millions)	Total		Total		Quoted Prices in		Significant
		Carrying		Estimated		Active Markets for		Observable
		Amount		Fair Value		Identical Assets		Inputs
						(Level 1)		(Level 2)
	Cash and cash equivalents	$	304.6	$	304.6	$	304.6	$	—
	Derivative financial instruments:
	Assets	6.2		6.2		—		6.2
	Liabilities	11.8		11.8		—		11.8
	Debt	1,480.10		1,703.20		1,625.60		77.6

Pension_Plans_and_Other_Postre1

Pension Plans and Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2013
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
Schedule Of Defined Benefit Plans Disclosures	'
	For the three month periods ended September 30, 2013 and 2012, the components of pension expense and components of other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions):
		Pension Benefits						Other Postretirement Benefits
		Three months ended September 30,						Three months ended September 30,
		2013			2012			2013			2012
	Service cost - benefits earned during the year	$	10		$	8.8		$	0.8		$	0.8
	Interest cost on benefits earned in prior years	30.3			33.1			5.6			6.5
	Expected return on plan assets	(43.8		)	(45.4		)	(0.1		)	(0.2		)
	Amortization of prior service cost (credit)	0.8			1.6			(4.6		)	(4.5		)
	Amortization of net actuarial loss	29.2			26.3			4.3			3.6
	Total retirement benefit expense	$	26.5		$	24.4		$	6		$	6.2
	For the nine month periods ended September 30, 2013 and 2012, the components of pension expense and components of other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions):
		Pension Benefits						Other Postretirement Benefits
		Nine months ended September 30,						Nine months ended September 30,
		2013			2012			2013			2012
	Service cost - benefits earned during the year	$	30		$	26.3		$	2.4		$	2.4
	Interest cost on benefits earned in prior years	90.9			99.3			16.8			19.5
	Expected return on plan assets	(131.4		)	(136.1		)	(0.3		)	(0.6		)
	Amortization of prior service cost (credit)	2.3			4.8			(13.7		)	(13.6		)
	Amortization of net actuarial loss	87.6			78.9			12.9			10.9
	Total retirement benefit expense	$	79.4		$	73.2		$	18.1		$	18.6

Business_Segments_Tables

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting Tables [Abstract]	'
Schedule Of Segment Reporting Information By Segment	'
	Following is certain financial information with respect to the Company’s business segments for the periods indicated (in millions):
		Three months ended September 30,						Nine months ended September 30,
		2013			2012			2013			2012
	Total sales:
	High Performance Metals	$	481.2		$	591.8		$	1,561.70		$	1,858.00
	Flat-Rolled Products	515.6			573.1			1,644.00			1,892.50
		996.8			1,164.90			3,205.70			3,750.50
	Intersegment sales:
	High Performance Metals	17.3			21.2			53.6			69.1
	Flat-Rolled Products	7.1			12.2			23.9			35.9
		24.4			33.4			77.5			105
	Sales to external customers:
	High Performance Metals	463.9			570.6			1,508.10			1,788.90
	Flat-Rolled Products	508.5			560.9			1,620.10			1,856.60
		$	972.4		$	1,131.50		$	3,128.20		$	3,645.50
	Operating profit (loss):
	High Performance Metals	$	48		$	87.4		$	192		$	303.8
	Flat-Rolled Products	(20.4		)	26.1			(16.7		)	118.4
	Total operating profit	27.6			113.5			175.3			422.2
	Corporate expenses	(8.1		)	(14.9		)	(32.3		)	(52.4		)
	Interest expense, net	(18.2		)	(17.2		)	(46.5		)	(55.7		)
	Closed company and other expenses	(2.1		)	(2.7		)	(11.0		)	(14.8		)
	Retirement benefit expense	(34.5		)	(30.6		)	(99.5		)	(91.8		)
	Income (loss) before income taxes	$	(35.3	)	$	48.1		$	(14.0	)	$	207.5

Per_Share_Information_Tables

Per Share Information (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Schedule Of Earnings Per Share Diluted By Common Class	'
	The following table sets forth the computation of basic and diluted income from continuing operations per common share:
		Three Months Ended					Nine months ended
	(in millions, except per share amounts):	September 30,					September 30,
		2013			2012		2013			2012
	Numerator for basic income (loss) from continuing operations per common share -
	Income (loss) from continuing operations attributable to ATI	$	(28.4	)	$	31.3	$	(15.0	)	$	134.5
	Effect of dilutive securities:
	4.25% Convertible Notes due 2014	—			2.1		—			6.5
	Numerator for diluted income (loss) from continuing operations per common share -
	Income (loss) from continuing operations available to ATI after assumed conversions	$	(28.4	)	$	33.4	$	(15.0	)	$	141
	Denominator for basic net income per common share-weighted average shares	106.8			106.2		106.7			106.1
	Effect of dilutive securities:
	Share-based compensation	—			0.9		—			0.9
	4.25% Convertible Notes due 2014	—			9.6		—			9.6
	Denominator for diluted net income per common share – adjusted weighted average shares assuming conversions	106.8			116.7		106.7			116.6
	Basic income (loss) from continuing operations attributable to ATI per common share	$	(0.27	)	$	0.3	$	(0.14	)	$	1.27
	Diluted income (loss) from continuing operations attributable to ATI per common share	$	(0.27	)	$	0.29	$	(0.14	)	$	1.21

Financial_Information_for_Subs1

Financial Information for Subsidiary and Guarantor Parent (Tables)	9 Months Ended
	Sep. 30, 2013
Condensed Financial Information of Parent Company Only Disclosure [Abstract]	'
Condensed Financial Information of Parent Company Only Disclosure	'
	Allegheny Technologies Incorporated
	Financial Information for Subsidiary and Guarantor Parent
	Balance Sheets
	September 30, 2013
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Assets:
	Cash and cash equivalents	$	2.6		$	7.3		$	525.8		$	—		$	535.7
	Accounts receivable, net	3.4			187.5			386						576.9
	Intercompany notes receivable	—			—			1,261.40			(1,261.4		)	—
	Inventories, net	—			267.1			1,077.80			—			1,344.90
	Prepaid expenses and other current assets	82.9			9.3			28.4			—			120.6
	Current assets of discontinued operations	—			—			115.4			—			115.4
	Total current assets	88.9			471.2			3,394.80			(1,261.4		)	2,693.50
	Property, plant and equipment, net	3.2			1,211.80			1,529.70			—			2,744.70
	Cost in excess of net assets acquired	—			112.1			616			—			728.1
	Intercompany notes receivable	—			—			200			(200.0		)	—
	Investment in subsidiaries	5,605.50			37.7			—			(5,643.2		)	—
	Other assets	39.5			31.3			277.2			—			348
	Non-current assets of discontinued operations	—			—			85			—			85
	Total assets	$	5,737.10		$	1,864.10		$	6,102.70		$	(7,104.6	)	$	6,599.30
	Liabilities and stockholders’ equity:
	Accounts payable	$	4.6		$	230.8		$	166.5		$	—		$	401.9
	Accrued liabilities	46.9			57			201			—			304.9
	Intercompany notes payable	664.5			596.9			—			(1,261.4		)	—
	Deferred income taxes	8.2			—			—			—			8.2
	Short-term debt and current portion of long-term debt	402.9			0.1			16.9			—			419.9
	Current liabilities of discontinued operations	—			—			33.7			—			33.7
	Total current liabilities	1,127.10			884.8			418.1			(1,261.4		)	1,168.60
	Long-term debt	1,350.90			150.5			40.8			—			1,542.20
	Intercompany notes payable	—			200			—			(200.0		)	—
	Accrued postretirement benefits	—			183.1			291.9			—			475
	Pension liabilities	638.1			4.7			59.6			—			702.4
	Deferred income taxes	52.1			—			—			—			52.1
	Other long-term liabilities	4.8			19.3			70.8			—			94.9
	Total liabilities	3,173.00			1,442.40			881.2			(1,461.4		)	4,035.20
	Total stockholders’ equity	2,564.10			421.7			5,221.50			(5,643.2		)	2,564.10
	Total liabilities and stockholders’ equity	$	5,737.10		$	1,864.10		$	6,102.70		$	(7,104.6	)	$	6,599.30
	Allegheny Technologies Incorporated
	Financial Information for Subsidiary and Guarantor Parent
	Statements of Income and Comprehensive Income
	For the three months ended September 30, 2013
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Sales	$	—		$	422.3		$	550.1		$	—		$	972.4
	Cost of sales	19.4			424.3			475.6			—			919.3
	Selling and administrative expenses	35.4			7.4			27.8			—			70.6
	Income (loss) before interest, other income and income taxes	(54.8		)	(9.4		)	46.7			—			(17.5		)
	Interest expense, net	(17.3		)	(9.7		)	8.8			—			(18.2		)
	Other income (loss) including equity in income of unconsolidated subsidiaries	36.8			0.1			0.3			(36.8		)	0.4
	Income (loss) from continuing operations before income tax provision (benefit)	(35.3		)	(19.0		)	55.8			(36.8		)	(35.3		)
	Income tax provision (benefit)	(8.5		)	(6.6		)	22.4			(15.8		)	(8.5		)
	Income (loss) from continuing operations	(26.8		)	(12.4		)	33.4			(21.0		)	(26.8		)
	Income (loss)from discontinued operations, net of tax	(5.4		)	—			(2.5		)	2.5			(5.4		)
	Net income (loss)	(32.2		)	(12.4		)	30.9			(18.5		)	(32.2		)
	Less: Net income (loss) attributable to noncontrolling interests	—			—			1.6			—			1.6
	Net income (loss) attributable to ATI	$	(32.2	)	$	(12.4	)	$	29.3		$	(18.5	)	$	(33.8	)
	Comprehensive income (loss) attributable to ATI	$	(9.9	)	$	(12.2	)	$	42		$	(31.5	)	$	(11.6	)
	Allegheny Technologies Incorporated
	Financial Information for Subsidiary and Guarantor Parent
	Statements of Income and Comprehensive Income
	For the nine months ended September 30, 2013
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
Parent			Subsidiaries
Sales	$	—		$	1,375.20		$	1,753.00		$	—		$	3,128.20
Cost of sales	55.5			1,359.50			1,471.90			—			2,886.90
Selling and administrative expenses	88.9			27.3			93.9			—			210.1
Income (loss) before interest, other income and income taxes	(144.4		)	(11.6		)	187.2			—			31.2
Interest expense, net	(45.5		)	(27.0		)	26			—			(46.5		)
Other income (loss) including equity in income of unconsolidated subsidiaries	175.9			0.6			0.8			(176.0		)	1.3
Income (loss) from continuing operations before income tax provision (benefit)	(14.0		)	(38.0		)	214			(176.0		)	(14.0		)
Income tax provision (benefit)	(4.4		)	(9.8		)	76.6			(66.8		)	(4.4		)
Income (loss) from continuing operations	(9.6		)	(28.2		)	137.4			(109.2		)	(9.6		)
Income (loss) from discontinued operations, net of tax	(4.4		)	—			(0.2		)	0.2			(4.4		)
Net income (loss)	(14.0		)	(28.2		)	137.2			(109.0		)	(14.0		)
Less: Net income attributable to noncontrolling interests	—			—			5.4			—			5.4
Net income (loss) attributable to ATI	$	(14.0	)	$	(28.2	)	$	131.8		$	(109.0	)	$	(19.4	)
Comprehensive income (loss) attributable to ATI	$	35.3		$	(27.8	)	$	134.8		$	(114.9	)	$	27.4
Condensed Statements of Cash Flows
For the nine months ended September 30, 2013
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Cash flows provided by (used in) operating activities	$	(9.1	)	$	(87.2	)	$	348		$	(24.3	)	$	227.4
Investing Activities:
Purchases of property, plant and equipment	(0.2		)	(359.1		)	(36.2		)	—			(395.5		)
Net receipts/(payments) on intercompany activity	—			—			(31.4		)	31.4			—
Asset disposals and other	0.1			0.1			0.6			—			0.8
Cash flows provided by (used in) investing activities	(0.1		)	(359.0		)	(67.0		)	31.4			(394.7		)
Financing Activities:
Borrowings on long-term debt	500			—			—			—			500
Net receipts/(payments) on intercompany activity	(409.0		)	440.4			—			(31.4		)	—
Dividends paid to stockholders	(57.7		)	—			(24.3		)	24.3			(57.7		)
Other	(27.0		)	—			(16.9		)	—			(43.9		)
Cash flows provided by (used in) financing activities	6.3			440.4			(41.2		)	(7.1		)	398.4
Increase (decrease) in cash and cash equivalents	$	(2.9	)	$	(5.8	)	$	239.8		$	—		$	231.1
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Balance Sheets
December 31, 2012
	Guarantor						Non-guarantor
(In millions)	Parent			Subsidiary			Subsidiaries			Eliminations			Consolidated
Assets:
Cash and cash equivalents	$	5.5		$	13.1		$	286		$	—		$	304.6
Accounts receivable, net	0.4			190.1			422.8			—			613.3
Intercompany notes receivable	—			—			1,289.90			(1,289.9		)	—
Inventories, net	—			311.1			1,225.50			—			1,536.60
Prepaid expenses and other current assets	1.1			10.2			44.8			—			56.1
Total current assets	7			524.5			3,269.00			(1,289.9		)	2,510.60
Property, plant and equipment, net	3.9			882.2			1,673.80			—			2,559.90
Cost in excess of net assets acquired	—			112.1			628			—			740.1
Deferred income taxes	71.5			—			—			—			71.5
Intercompany notes receivable	—			—			200.1			(200.1		)	—
Investment in subsidiaries	5,545.40			33.7			—			(5,579.1		)	—
Other assets	50.5			35.5			279.7			—			365.7
Total assets	$	5,678.30		$	1,588.00		$	6,050.60		$	(7,069.1	)	$	6,247.80
Liabilities and stockholders’ equity:
Accounts payable	$	5.3		$	262.6		$	232		$	—		$	499.9
Accrued liabilities	64			62.2			204.3			—			330.5
Intercompany notes payable	$	1,073.40		$	216.5		$	—		$	(1,289.9	)	—
Deferred income taxes	24			—			—			—			24
Short-term debt and current portion of long-term debt	0.3			0.1			16.7			—			17.1
Total current liabilities	1,167.00			541.4			453			(1,289.9		)	871.5
Long-term debt	1,253.40			150.5			59.1			—			1,463.00
Intercompany notes payable	—			200.1			—			(200.1		)
Accrued postretirement benefits	—			198.2			297			—			495.2
Pension liabilities	651.7			5.1			64.3			—			721.1
Other long-term liabilities	19.1			20.8			70			—			109.9
Total liabilities	3,091.20			1,116.10			943.4			(1,490.0		)	3,660.70
Total stockholders’ equity	2,587.10			471.9			5,107.20			(5,579.1		)	2,587.10
Total liabilities and stockholders’ equity	$	5,678.30		$	1,588.00		$	6,050.60		$	(7,069.1	)	$	6,247.80
The condensed consolidating balance sheets at December 31, 2012 have been restated to revise the presentation of intercompany balances, and to reflect equity elimination entries between Non-guarantor Subsidiaries within the Non-guarantor balance sheet, rather than as part of Eliminations. These revisions increased Non-guarantor balances of total current assets $1,289.9 million and total assets $1,112.7 million, decreased total current liabilities and total liabilities $196.8 million, and increased total stockholders' equity $1,309.5 million. The Subsidiary balances of total assets, total current liabilities and total liabilities were each reduced by $141.1 million to reclassify intercompany balances to a net payable presentation. There was no impact to the consolidated financial statements as a result of these presentation changes.
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Statements of Income and Comprehensive Income
For the three months ended September 30, 2012
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Sales	$	—		$	483.6		$	647.9		$	—		$	1,131.50
Cost of sales	15.1			453.8			519.9			—			988.8
Selling and administrative expenses	33.7			10.8			33.1			—			77.6
Income (loss) before interest, other income and income taxes	(48.8		)	19			94.9			—			65.1
Interest income (expense), net	(14.7		)	(2.7		)	0.2			—			(17.2		)
Other income (loss) including equity in income of unconsolidated subsidiaries	111.6			(5.2		)	7.8			(114.0		)	0.2
Income from continuing operations before income tax provision	48.1			11.1			102.9			(114.0		)	48.1
Income tax provision	14.8			4.6			33.3			(37.9		)	14.8
Income from continuing operations	33.3			6.5			69.6			(76.1		)	33.3
Income from discontinued operations, net of tax	4			—			4.6			(4.6		)	4
Net income	37.3			6.5			74.2			(80.7		)	37.3
Less: Net income attributable to noncontrolling interests	—			—			2			—			2
Net income attributable to ATI	$	37.3		$	6.5		$	72.2		$	(80.7	)	$	35.3
Comprehensive income attributable to ATI	$	74.4		$	6.3		$	87.3		$	(96.2	)	$	71.8
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Statements of Income and Comprehensive Income
For the nine months ended September 30, 2012
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Sales	$	—		$	1,614.20		$	2,031.30		$	—		$	3,645.50
Cost of sales	41.8			1,488.70			1,609.10			—			3,139.60
Selling and administrative expenses	109.1			33.2			101			—			243.3
Income (loss) before interest, other income and income taxes	(150.9		)	92.3			321.2			—			262.6
Interest expense, net	(47.3		)	(7.9		)	(0.5		)	—			(55.7		)
Other income (loss) including equity in income of unconsolidated subsidiaries	405.7			(16.1		)	24.2			(413.2		)	0.6
Income from continuing operations before income tax provision	207.5			68.3			344.9			(413.2		)	207.5
Income tax provision	66.6			26.9			116.9			(143.8		)	66.6
Income from continuing operations	140.9			41.4			228			(269.4		)	140.9
Income from discontinued operations, net of tax	13.4			—			16.1			(16.1		)	13.4
Net income	154.3			41.4			244.1			(285.5		)	154.3
Less: Net income attributable to noncontrolling interests	—			—			6.4			—			6.4
Net income attributable to ATI	$	154.3		$	41.4		$	237.7		$	(285.5	)	$	147.9
Comprehensive income attributable to ATI	$	220		$	40.6		$	249.2		$	(296.2	)	$	213.6
Condensed Statements of Cash Flows
For the nine months ended September 30, 2012
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Cash flows provided by (used in) operating activities	$	(26.1	)	$	4.1		$	267.8		$	—		$	245.8
Investing Activities:
Purchases of property, plant and equipment	(1.0		)	(192.5		)	(52.1		)	—			(245.6		)
Net receipts/(payments) on intercompany activity	—			—			(187.0		)	187			—
Asset disposals and other	—			0.2			1.3			—			1.5
Cash flows used in investing activities	(1.0		)	(192.3		)	(237.8		)	187			(244.1		)
Financing Activities:
Net receipts/(payments) on intercompany activity	103.8			83.2			—			(187.0		)	—
Dividends paid to stockholders	(57.3		)	—			—			—			(57.3		)
Other	(17.0		)	(0.1		)	(26.9		)	—			(44.0		)
Cash flows provided by (used in) financing activities	29.5			83.1			(26.9		)	(187.0		)	(101.3		)
Increase (decrease) in cash and cash equivalents	$	2.4		$	(105.1	)	$	3.1		$	—		$	(99.6	)

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2013
Table Text Block Supplement [Abstract]	'
Schedule Of Accumulated Other Comprehensive Income Loss	'
	The changes in the accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the three month period ended September 30, 2013 were as follows (in millions):
		Post-				Currency				Unrealized				Derivatives				Total
		retirement				translation				holding gains
		benefit plans				adjustment				on securities
	Attributable to ATI:
	Balance, June 30, 2013	$	(993.5	)		$	(7.5	)		$	(0.1	)		$	(3.7	)		$	(1,004.8	)
	OCI before reclassifications		—				12.3				0.1				(11.1	)		1.3
	Amounts reclassified from AOCI	(a)	18.3			(b)	—			(b)	—			(c)	2.6			20.9
	Net current-period OCI		18.3				12.3				0.1				(8.5	)		22.2
	Balance, September 30, 2013	$	(975.2	)		$	4.8			$	—			$	(12.2	)		$	(982.6	)
	Attributable to noncontrolling interests:
	Balance, June 30, 2013	$	—			$	26.1			$	—			$	—			$	26.1
	OCI before reclassifications		—				0.1				—				—			0.1
	Net current-period OCI		—				0.1				—				—			0.1
	Balance, September 30, 2013	$	—			$	26.2			$	—			$	—			$	26.2
	The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the nine month period ended September 30, 2013 were as follows (in millions):
		Post-				Currency					Unrealized				Derivatives				Total
		retirement				translation					holding gains
		benefit plans				adjustment					on securities
	Attributable to ATI:
	Balance, December 31, 2012	$	(1,030.0	)		$	3.4				$	(0.1	)		$	(2.7	)		$	(1,029.4	)
	OCI before reclassifications		—				1.4					0.1				(12.9	)		(11.4		)
	Amounts reclassified from AOCI	(a)	54.8			(b)	—				(b)	—			(c)	3.4			58.2
	Net current-period OCI		54.8				1.4					0.1				(9.5	)		46.8
	Balance, September 30, 2013	$	(975.2	)		$	4.8				$	—			$	(12.2	)		$	(982.6	)
	Attributable to noncontrolling interests:
	Balance, December 31, 2012	$	—			$	$	23.7			$	—			$	—			$	23.7
	OCI before reclassifications		—				2.5					—				—			2.5
	Amounts reclassified from AOCI		—			(b)	—					—				—			—
	Net current-period OCI		—				2.5					—				—			2.5
	Balance, September 30, 2013	$	—			$	26.2				$	—			$	—			$	26.2
	(a)	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 8).
	(b)	No amounts were reclassified to earnings.
	(c)	Amounts were included in cost of goods sold in the period or periods the hedged item affects earnings (see Note 6).
	Reclassifications out of AOCI for the three and nine month periods ended September 30, 2013 were as follows:
			Amount reclassified from AOCI (c)
	Details about AOCI Components		Three months ended September 30, 2013						Nine months ended September 30, 2013						Affected line item in the
	(in millions)														statement of operations
	Postretirement benefit plans
	Prior service (cost) credit		3.8				(a)		11.4				(a)
	Actuarial losses		(33.5		)		(a)		(100.5		)		(a)
			(29.7		)		(c)		(89.1		)		(c)		Total before tax
			(11.4		)				(34.3		)				Tax provision (benefit)
			$	(18.3	)				$	(54.8	)				Net of tax
	Derivatives
	Nickel and other raw material contracts		$	(2.3	)		(b)		$	(3.8	)		(b)
	Natural gas contracts		(0.9		)		(b)		(2.4		)		(b)
	Electricity contracts		—				(b)		(0.3		)		(b)
	Foreign exchange contracts		(1.1		)		(b)		1				(b)
			(4.3		)		(c)		(5.5		)		(c)		Total before tax
			(1.7		)				(2.1		)				Tax provision (benefit)
			$	(2.6	)				$	(3.4	)				Net of tax
	(a)	Amounts are included in the computation of pension and other postretirement benefit expense, which is reported in both cost of goods sold and selling and administrative expenses. For additional information, see Note 8.
	(b)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings. For additional information, see Note 6.
	(c)	For pretax items, positive amounts are income and negative amounts are expense in terms of the impact to net income. Tax effects are presented in conformity with ATI’s presentation in the consolidated statements of operations.

Inventories_Details

Inventories (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Inventory Disclosure (Details) [Abstract]	'	'	'
Raw materials and supplies	$330.70	'	$351.60
Work-in-process	900.3	'	1,063.90
Finished goods	164.7	'	209
Total inventories at current cost	1,395.70	'	1,624.50
Less allowances to reduce current cost values to LIFO basis	-12.4	'	-76.9
Progress payments	-38.4	'	-11
Total inventories, net	1,344.90	'	1,536.60
LIFO provision (benefit)	($39.10)	($28.40)	'

Property_Plant_and_Equipment_D

Property, Plant and Equipment (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Property Plant And Equipment Details [Abstract]	'	'
Land	$29.90	$34.40
Buildings	947.3	921
Equipment and leasehold improvements	3,431.90	3,344.40
Property Plant And Equipment	4,409.10	4,299.80
Accumulated depreciation and amortization	-1,664.40	-1,739.90
Total property, plant and equipment, net	2,744.70	2,559.90
Construction in progress	$900.10	'

Discontinued_Operations_Narrat

Discontinued Operations - Narrative (Details) (USD $)	3 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 16, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
		Tungsten Materials Business	Fabricated Components Business	Fabricated Components Business	Fabricated Components Business	Fabricated Components Business	Iron Castings Business
					Minimum	Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'	'	'	'
Estimated Sale Price, Disposed Operation	'	$605	'	'	'	'	'
Restructuring Charge	9.5	'	6.4	'	'	'	3.1
Impairment of Long-Lived Assets to be Disposed of	'	'	5.6	'	'	'	'
Lease Exit Costs	'	'	0.8	'	'	'	'
Restructuring and Related Cost, Expected Cost	'	'	'	'	3.8	4.3	'
Restructuring and Related Cost, Expected Cost, Period to be Incurred	'	'	'	'4 years	'	'	'
Restructuring Charges, Net of Tax	$8.10	'	'	'	'	'	'

Discontinued_Operations_Schedu

Discontinued Operations - Schedule of Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Discontinued Operations and Disposal Groups [Abstract]	'	'	'	'
Sales	$77.60	$89	$236.70	$284.90
Income (loss) before income tax provision	($7.10)	$6	($5.40)	$20.40

Discontinued_Operations_Schedu1

Discontinued Operations - Schedule of Assets and Liabilities (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Discontinued Operations and Disposal Groups [Abstract]	'
Accounts receivable, net of allowances for doubtful accounts	$47.50
Inventories, net	65
Prepaid expenses and other current assets	2.9
Property, plant and equipment, net	72.9
Cost in excess of net assets acquired	11.2
Other long-term assets	0.9
Total Assets	200.4
Accounts payable	20.6
Accrued liabilities	13.1
Long-term liabilities	3.3
Total Liabilities	37
Net Assets	$163.40

Debt_Schedule_of_Debt_Details

Debt Schedule of Debt (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
Total Debt	$1,962,100,000	$1,480,100,000
Short-term debt and current portion of long-term debt	419,900,000	17,100,000
Long-term debt	1,542,200,000	1,463,000,000
Allegheny Technologies 5.875% Notes due 2023	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	500,000,000	0
Debt Instrument, Interest Rate, Stated Percentage	5.88%	'
Allegheny Technologies 5.95% Notes due 2021	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	500,000,000	500,000,000
Allegheny Technologies 4.25% Convertible Notes due 2014	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	402,500,000	402,500,000
Allegheny Technologies 9.375% Notes due 2019	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	350,000,000	350,000,000
Allegheny Ludlum 6.95% debentures due 2025	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	150,000,000	150,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.95%	'
ATI Ladish Series B 6.14% Notes due 2016 (a)	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	18,400,000	24,800,000
Business Acquisition Purchase Price Allocation Notes Payable and L T Debt	1,200,000	1,900,000
ATI Ladish Series C 6.41% Notes due 2015 (b)	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	21,400,000	32,500,000
Business Acquisition Purchase Price Allocation Notes Payable and L T Debt	1,400,000	2,500,000
Domestic Bank Group $400 million unsecured credit facility	'	'
Debt Instrument [Line Items]	'	'
Line of Credit Facility, Maximum Borrowing Capacity	400,000,000	'
Long-term Debt, Gross	0	0
Foreign credit facilities	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	14,300,000	14,200,000
Industrial revenue bonds, due through 2020, and other	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	5,500,000	6,100,000
ATI Ladish Series B 6.14% Notes due 2016 (a)	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Issuer	'ATI Ladish	'
Debt Instrument, Maturity Date	16-May-16	16-May-16
Debt Instrument, Interest Rate, Stated Percentage	6.14%	6.14%
ATI Ladish Series C 6.41% Notes due 2015 (b)	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Issuer	'ATI Ladish	'
Debt Instrument, Maturity Date	2-Sep-15	2-Sep-15
Debt Instrument, Interest Rate, Stated Percentage	6.41%	6.41%
Allegheny Technologies 5.95% Notes due 2021	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Issuer	'Allegheny Technologies	'
Debt Instrument, Maturity Date	15-Jan-21	15-Jan-21
Debt Instrument, Interest Rate, Stated Percentage	5.95%	5.95%
Allegheny Technologies 4.25% Convertible Notes due 2014	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Issuer	'Allegheny Technologies	'
Debt Instrument, Maturity Date	1-Jun-14	1-Jun-14
Debt Instrument, Interest Rate, Stated Percentage	4.25%	4.25%
Industrial revenue bonds, due through 2020, and other	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Maturity Date Range, End	1-Jan-20	1-Jan-20
Allegheny Ludlum 6.95% debentures due 2025	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Issuer	'Allegheny Ludlum	'
Debt Instrument, Maturity Date	15-Dec-25	15-Dec-25
Debt Instrument, Interest Rate, Stated Percentage	'	6.95%
Allegheny Technologies 9.375% Notes due 2019	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Issuer	'Allegheny Technologies	'
Debt Instrument, Maturity Date	1-Jun-19	1-Jun-19
Debt Instrument, Interest Rate, Stated Percentage	9.38%	9.38%
Domestic Bank Group $400 million unsecured credit facility	'	'
Debt Instrument [Line Items]	'	'
Line of Credit Facility, Maximum Borrowing Capacity	'	$400,000,000

Debt_Narrative_Details

Debt Narrative (Details)	Sep. 30, 2013	Jul. 12, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	Allegheny Technologies 5.875% Notes due 2023	Allegheny Technologies 5.875% Notes due 2023	Allegheny Technologies 5.875% Notes due 2023	Domestic Bank Group $400 million unsecured credit facility	Domestic Bank Group $400 million unsecured credit facility	Seperateletter of Credit Facility	STAL Revolving Credit Facility	STAL Revolving Credit Facility	STAL Precision Stainless Steel Company Limited	STAL Revolving Credit Facility
	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	CNY
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'	'
Debt Instrument, Face Amount	'	$500,000,000	'	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	5.88%	'	'	'	'	'	'	'	'	'
Line of Credit Facility, Maximum Borrowing Capacity	'	'	'	400,000,000	'	'	33,000,000	205,000,000	'	'
Line of Credit Facility, Borrowing Capacity Increase Limit	'	'	'	100,000,000	'	'	'	'	'	'
Debt Instrument, Covenant, Maximum Leverage Ratio, Period One	'	'	'	4.5	'	'	'	'	'	'
Debt Instrument, Covenant, Maximum Leverage Ratio, Period Two	'	'	'	4	'	'	'	'	'	'
Debt Instrument, Covenant, Maximum Leverage Ratio, Period Three	'	'	'	3.75	'	'	'	'	'	'
Debt Instrument, Covenant, Maximum Leverage Ratio, Period Four	'	'	'	3.5	'	'	'	'	'	'
Debt Instrument, Covenant, Maximum Interest Coverage Ratio, Period One	'	'	'	2	'	'	'	'	'	'
Debt Instrument, Covenant, Maximum Interest Coverage Ratio, Period Two	'	'	'	1.75	'	'	'	'	'	'
Debt Instrument, Covenant, Maximum Interest Coverage Ratio, Period Three	'	'	'	2	'	'	'	'	'	'
Debt Instrument, Covenant, Leverage Ratio	'	'	'	4.18	'	'	'	'	'	'
Debt Instrument, Covenant, Interest Coverage Ratio	'	'	'	2.71	'	'	'	'	'	'
Amount of Cash on Hand Used to Reduce the Indebtness Figure used in the Leverage Ratio Calculation	'	'	'	50,000,000	'	'	'	'	'	'
Long-term Debt, Gross	500,000,000	'	0	0	0	'	'	'	'	'
Line of Credit Facility, Amount Outstanding	'	'	'	4,000,000	'	'	0	'	'	'
Sublimit for letters of credit	'	'	'	200,000,000	'	'	'	'	'	'
Letters of Credit Outstanding, Amount	'	'	'	'	'	$32,000,000	'	'	'	'
Noncontrolling Interest, Ownership Percentage by Parent	'	'	'	'	'	'	'	'	60.00%	'
Line of Credit Facility, Expiration Date	'	'	'	'	'	'	'	'	'	1-Aug-14

Derivative_Financial_Instrumen2

Derivative Financial Instruments and Hedging (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	$2.60	'	$3.40	'
Notional Amount of Derivatives, by Category of Derivative [Abstract]	'	'	'	'
Percentage of estimated annual nickel requirements	'	'	7.00%	'
Percentage of forecasted natural gas usage hedged for 2013	'	'	80.00%	'
Percentage Of Forecasted Natural Gas Usage Hedged for 2014	'	'	75.00%	'
Percentage Of Forecasted Natural Gas Usage Hedged for 2015	'	'	30.00%	'
Percentage of on-peak and off-peak electricity hedged	'	'	10.00%	'
Percentage of forecasted international sales hedged	'	'	10.00%	'
Reclassification of Cash Flow Hedge Gain (Loss) [Abstract]	'	'	'	'
Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months	'	'	-9.4	'
Other Comprehensive Income | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	-11.1	4.8	-12.9	3.4
Cost Of Sales | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	-2.6	-0.3	-3.4	-2.1
Selling And Administrative Expenses | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
Nickel and other raw material contracts | Other Comprehensive Income | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	0.2	4.8	-8.6	0.1
Nickel and other raw material contracts | Cost Of Sales | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	-1.3	-1.5	-2.3	-2.3
Nickel and other raw material contracts | Selling And Administrative Expenses | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
Natural gas contracts | Other Comprehensive Income | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	0.1	1.2	-0.2	-2.1
Natural gas contracts | Cost Of Sales | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	-0.6	-1.8	-1.5	-6.8
Natural gas contracts | Selling And Administrative Expenses | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
Electricity contracts | Other Comprehensive Income | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	-0.1	0.2	-0.1	-0.9
Electricity contracts | Cost Of Sales | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	0	-0.5	-0.2	-1.6
Electricity contracts | Selling And Administrative Expenses | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
Foreign exchange contracts | Other Comprehensive Income | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	-11.3	-1.4	-4	6.3
Foreign exchange contracts | Cost Of Sales | Derivatives not designated as hedging instruments:	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Income Net	-0.7	-1.9	-0.3	-2
Foreign exchange contracts | Cost Of Sales | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	-0.7	3.5	0.6	8.6
Foreign exchange contracts | Selling And Administrative Expenses | Cash Flow Hedging	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	$0	$0	$0	$0

Derivative_Financial_Instrumen3

Derivative Financial Instruments and Hedging (Details2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	$1	$6.20
Derivative Fair Value Of Derivative Liability	22.4	11.8
Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	1	5.8
Derivative Fair Value Of Derivative Liability	20.8	10.2
Derivatives not designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0	0.4
Derivative Fair Value Of Derivative Liability	1.6	1.6
Prepaid expenses and other current assets | Nickel and other raw material contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0	0.6
Prepaid expenses and other current assets | Natural gas contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0.4	0.4
Prepaid expenses and other current assets | Electricity contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0	0
Prepaid expenses and other current assets | Foreign exchange contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0.3	2.9
Prepaid expenses and other current assets | Foreign exchange contracts | Derivatives not designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0	0.4
Other assets | Nickel and other raw material contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0.1	0.3
Other assets | Natural gas contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0.2	0.7
Other assets | Electricity contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0	0
Other assets | Foreign exchange contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Asset	0	0.9
Accrued liabilities | Nickel and other raw material contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	9.3	1.1
Accrued liabilities | Natural gas contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	2.2	4.4
Accrued liabilities | Electricity contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	0.4	0.3
Accrued liabilities | Foreign exchange contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	4	1.7
Accrued liabilities | Foreign exchange contracts | Derivatives not designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	1.6	1.6
Other long-term liabilities | Nickel and other raw material contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	1.5	0.3
Other long-term liabilities | Natural gas contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	0.3	0.6
Other long-term liabilities | Electricity contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	0.1	0.4
Other long-term liabilities | Foreign exchange contracts | Derivatives designated as hedging instruments:	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative Fair Value Of Derivative Liability	$3	$1.40

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Carrying Reported Amount Fair Value Disclosure	'	'
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Cash and cash equivalents	$535.70	$304.60
Derivative financial instruments, Assets	1	6.2
Derivative Financial Instruments, liabilities	22.4	11.8
Debt	1,962.10	1,480.10
Estimate Of Fair Value Fair Value Disclosure	'	'
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Cash and cash equivalents	535.7	304.6
Derivative financial instruments, Assets	1	6.2
Derivative Financial Instruments, liabilities	22.4	11.8
Debt	2,102.10	1,703.20
Fair Value Inputs Level 1	'	'
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Cash and cash equivalents	535.7	304.6
Derivative financial instruments, Assets	0	0
Derivative Financial Instruments, liabilities	0	0
Debt	2,042.40	1,625.60
Fair Value Inputs Level 2	'	'
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Cash and cash equivalents	0	0
Derivative financial instruments, Assets	1	6.2
Derivative Financial Instruments, liabilities	22.4	11.8
Debt	$59.70	$77.60

Pension_Plans_and_Other_Postre2

Pension Plans and Other Postretirement Benefits (Details1) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Plans Defined Benefit	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost - benefits earned during the year	$10	$8.80	$30	$26.30
Interest cost on benefits earned in prior years	30.3	33.1	90.9	99.3
Expected return on plan assets	-43.8	-45.4	-131.4	-136.1
Amortization of prior service cost (credit)	0.8	1.6	2.3	4.8
Amortization of net actuarial loss	29.2	26.3	87.6	78.9
Total retirement benefit expense	26.5	24.4	79.4	73.2
Other Postretirement Benefit Plans Defined Benefit	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost - benefits earned during the year	0.8	0.8	2.4	2.4
Interest cost on benefits earned in prior years	5.6	6.5	16.8	19.5
Expected return on plan assets	-0.1	-0.2	-0.3	-0.6
Amortization of prior service cost (credit)	-4.6	-4.5	-13.7	-13.6
Amortization of net actuarial loss	4.3	3.6	12.9	10.9
Total retirement benefit expense	$6	$6.20	$18.10	$18.60

Pension_Plans_and_Other_Postre3

Pension Plans and Other Postretirement Benefits - Narrative (Details) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Pension and Other Postemployment Benefits [Abstract]	'	'
Defined Contribution Plan, Cost Recognized	$2	$2

Income_Taxes_Quarterly_Disclos

Income Taxes - Quarterly Disclosure (Details9) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Expense (Benefit) [Abstract]	'	'	'	'
Income tax (provision) benefit	$8.50	($14.80)	$4.40	($66.60)
Effective Income Tax Rate Continuing Operations	24.10%	30.80%	31.40%	32.10%
Income Tax Reconciliation Other Adjustments	'	'	($6.70)	($4.20)

Business_Segments_Details

Business Segments (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Total sales:	$996.80	$1,164.90	$3,205.70	$3,750.50
Intersegment sales:	24.4	33.4	77.5	105
Sales to external customers:	972.4	1,131.50	3,128.20	3,645.50
Operating profit (loss):	27.6	113.5	175.3	422.2
Corporate expenses	-8.1	-14.9	-32.3	-52.4
Interest expense, net	-18.2	-17.2	-46.5	-55.7
Closed company and other expenses	-2.1	-2.7	-11	-14.8
Retirement benefit expense	-34.5	-30.6	-99.5	-91.8
Income (loss) before income taxes	-35.3	48.1	-14	207.5
Interest Costs Capitalized	12.7	6.6	'	'
High Performance Metals	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total sales:	481.2	591.8	1,561.70	1,858
Intersegment sales:	17.3	21.2	53.6	69.1
Sales to external customers:	463.9	570.6	1,508.10	1,788.90
Operating profit (loss):	48	87.4	192	303.8
Flat-Rolled Products	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total sales:	515.6	573.1	1,644	1,892.50
Intersegment sales:	7.1	12.2	23.9	35.9
Sales to external customers:	508.5	560.9	1,620.10	1,856.60
Operating profit (loss):	($20.40)	$26.10	($16.70)	$118.40

Per_Share_Information_Details

Per Share Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount	10,000,000	0	10,000,000	0
Earnings Per Share Reconciliation [Abstract]	'	'	'	'
Income (loss) from continuing operations attributable to ATI	($28.40)	$31.30	($15)	$134.50
4.25% Convertible Notes due 2014	0	2.1	0	6.5
Income (loss) from continuing operations available to ATI after assumed conversions	($28.40)	$33.40	($15)	$141
Denominator for basic net income per common share-weighted average shares	106,800,000	106,200,000	106,700,000	106,100,000
Share-based compensation	0	900,000	0	900,000
4.25% Convertible Notes due 2014	0	9,600,000	0	9,600,000
Denominator for diluted net income per common share – adjusted weighted average shares assuming conversions	106,800,000	116,700,000	106,700,000	116,600,000
Basic income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	($0.27)	$0.30	($0.14)	$1.27
Diluted income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	($0.27)	$0.29	($0.14)	$1.21

Financial_Information_for_Subs2

Financial Information for Subsidiary and Guarantor Parent Financial Information for Subsidiary and Guarantor Parent (Narrative) (Details) (Allegheny Ludlum 6.95% debentures due 2025, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Allegheny Ludlum 6.95% debentures due 2025	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	$150	$150
Interest rate	6.95%	'

Financial_Information_for_Subs3

Financial Information for Subsidiary and Guarantor Parent (B.S.) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
ASSETS	'	'	'	'
Cash and cash equivalents	$535.70	$304.60	$281	$380.60
Accounts receivable, net	576.9	613.3	'	'
Intercompany notes receivable	0	0	'	'
Inventories, net	1,344.90	1,536.60	'	'
Prepaid expenses and other current assets	120.6	56.1	'	'
Current assets of discontinued operations	115.4	0	'	'
Total current assets	2,693.50	2,510.60	'	'
Property, plant and equipment, net	2,744.70	2,559.90	'	'
Cost in excess of net assets acquired	728.1	740.1	'	'
Deferred income taxes	0	71.5	'	'
Intercompany notes receivable	0	0	'	'
Investment in subsidiaries	0	0	'	'
Other assets	348	365.7	'	'
Non-current assets of discontinued operations	85	0	'	'
Total assets	6,599.30	6,247.80	'	'
LIABILITIES AND EQUITY	'	'	'	'
Accounts payable	401.9	499.9	'	'
Accrued liabilities	304.9	330.5	'	'
Intercompany notes payable	0	0	'	'
Deferred income taxes	8.2	24	'	'
Short-term debt and current portion of long-term debt	419.9	17.1	'	'
Current liabilities of discontinued operations	33.7	0	'	'
Total current liabilities	1,168.60	871.5	'	'
Long-term debt	1,542.20	1,463	'	'
Intercompany notes payable	0	'	'	'
Accrued postretirement benefits	475	495.2	'	'
Pension liabilities	702.4	721.1	'	'
Deferred income taxes	52.1	0	'	'
Other long-term liabilities	94.9	109.9	'	'
Total liabilities	4,035.20	3,660.70	'	'
Total stockholders’ equity	2,564.10	2,587.10	2,744.90	2,571.60
Total Liabilities and Equity	6,599.30	6,247.80	'	'
Parent Company	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	2.6	5.5	'	'
Accounts receivable, net	3.4	0.4	'	'
Intercompany notes receivable	0	0	'	'
Inventories, net	0	0	'	'
Prepaid expenses and other current assets	82.9	1.1	'	'
Current assets of discontinued operations	0	'	'	'
Total current assets	88.9	7	'	'
Property, plant and equipment, net	3.2	3.9	'	'
Cost in excess of net assets acquired	0	0	'	'
Deferred income taxes	'	71.5	'	'
Intercompany notes receivable	0	0	'	'
Investment in subsidiaries	5,605.50	5,545.40	'	'
Other assets	39.5	50.5	'	'
Non-current assets of discontinued operations	0	'	'	'
Total assets	5,737.10	5,678.30	'	'
LIABILITIES AND EQUITY	'	'	'	'
Accounts payable	4.6	5.3	'	'
Accrued liabilities	46.9	64	'	'
Intercompany notes payable	664.5	1,073.40	'	'
Deferred income taxes	8.2	24	'	'
Short-term debt and current portion of long-term debt	402.9	0.3	'	'
Current liabilities of discontinued operations	0	'	'	'
Total current liabilities	1,127.10	1,167	'	'
Long-term debt	1,350.90	1,253.40	'	'
Intercompany notes payable	0	0	'	'
Accrued postretirement benefits	0	0	'	'
Pension liabilities	638.1	651.7	'	'
Deferred income taxes	52.1	'	'	'
Other long-term liabilities	4.8	19.1	'	'
Total liabilities	3,173	3,091.20	'	'
Total stockholders’ equity	2,564.10	2,587.10	'	'
Total Liabilities and Equity	5,737.10	5,678.30	'	'
Subsidiaries	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	7.3	13.1	'	'
Accounts receivable, net	187.5	190.1	'	'
Intercompany notes receivable	0	0	'	'
Inventories, net	267.1	311.1	'	'
Prepaid expenses and other current assets	9.3	10.2	'	'
Current assets of discontinued operations	0	'	'	'
Total current assets	471.2	524.5	'	'
Property, plant and equipment, net	1,211.80	882.2	'	'
Cost in excess of net assets acquired	112.1	112.1	'	'
Deferred income taxes	'	0	'	'
Intercompany notes receivable	0	0	'	'
Investment in subsidiaries	37.7	33.7	'	'
Other assets	31.3	35.5	'	'
Non-current assets of discontinued operations	0	'	'	'
Total assets	1,864.10	1,588	'	'
LIABILITIES AND EQUITY	'	'	'	'
Accounts payable	230.8	262.6	'	'
Accrued liabilities	57	62.2	'	'
Intercompany notes payable	596.9	216.5	'	'
Deferred income taxes	0	0	'	'
Short-term debt and current portion of long-term debt	0.1	0.1	'	'
Current liabilities of discontinued operations	0	'	'	'
Total current liabilities	884.8	541.4	'	'
Long-term debt	150.5	150.5	'	'
Intercompany notes payable	200	200.1	'	'
Accrued postretirement benefits	183.1	198.2	'	'
Pension liabilities	4.7	5.1	'	'
Deferred income taxes	0	'	'	'
Other long-term liabilities	19.3	20.8	'	'
Total liabilities	1,442.40	1,116.10	'	'
Total stockholders’ equity	421.7	471.9	'	'
Total Liabilities and Equity	1,864.10	1,588	'	'
NonGuarantor Subsidiaries	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	525.8	286	'	'
Accounts receivable, net	386	422.8	'	'
Intercompany notes receivable	1,261.40	1,289.90	'	'
Inventories, net	1,077.80	1,225.50	'	'
Prepaid expenses and other current assets	28.4	44.8	'	'
Current assets of discontinued operations	115.4	'	'	'
Total current assets	3,394.80	3,269	'	'
Property, plant and equipment, net	1,529.70	1,673.80	'	'
Cost in excess of net assets acquired	616	628	'	'
Deferred income taxes	'	0	'	'
Intercompany notes receivable	200	200.1	'	'
Investment in subsidiaries	0	0	'	'
Other assets	277.2	279.7	'	'
Non-current assets of discontinued operations	85	'	'	'
Total assets	6,102.70	6,050.60	'	'
LIABILITIES AND EQUITY	'	'	'	'
Accounts payable	166.5	232	'	'
Accrued liabilities	201	204.3	'	'
Intercompany notes payable	0	0	'	'
Deferred income taxes	0	0	'	'
Short-term debt and current portion of long-term debt	16.9	16.7	'	'
Current liabilities of discontinued operations	33.7	'	'	'
Total current liabilities	418.1	453	'	'
Long-term debt	40.8	59.1	'	'
Intercompany notes payable	0	0	'	'
Accrued postretirement benefits	291.9	297	'	'
Pension liabilities	59.6	64.3	'	'
Deferred income taxes	0	'	'	'
Other long-term liabilities	70.8	70	'	'
Total liabilities	881.2	943.4	'	'
Total stockholders’ equity	5,221.50	5,107.20	'	'
Total Liabilities and Equity	6,102.70	6,050.60	'	'
Consolidation Eliminations	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	0	0	'	'
Accounts receivable, net	'	0	'	'
Intercompany notes receivable	-1,261.40	-1,289.90	'	'
Inventories, net	0	0	'	'
Prepaid expenses and other current assets	0	0	'	'
Current assets of discontinued operations	0	'	'	'
Total current assets	-1,261.40	-1,289.90	'	'
Property, plant and equipment, net	0	0	'	'
Cost in excess of net assets acquired	0	0	'	'
Deferred income taxes	'	0	'	'
Intercompany notes receivable	-200	-200.1	'	'
Investment in subsidiaries	-5,643.20	-5,579.10	'	'
Other assets	0	0	'	'
Non-current assets of discontinued operations	0	'	'	'
Total assets	-7,104.60	-7,069.10	'	'
LIABILITIES AND EQUITY	'	'	'	'
Accounts payable	0	0	'	'
Accrued liabilities	0	0	'	'
Intercompany notes payable	-1,261.40	-1,289.90	'	'
Deferred income taxes	0	0	'	'
Short-term debt and current portion of long-term debt	0	0	'	'
Current liabilities of discontinued operations	0	'	'	'
Total current liabilities	-1,261.40	-1,289.90	'	'
Long-term debt	0	0	'	'
Intercompany notes payable	-200	-200.1	'	'
Accrued postretirement benefits	0	0	'	'
Pension liabilities	0	0	'	'
Deferred income taxes	0	'	'	'
Other long-term liabilities	0	0	'	'
Total liabilities	-1,461.40	-1,490	'	'
Total stockholders’ equity	-5,643.20	-5,579.10	'	'
Total Liabilities and Equity	($7,104.60)	($7,069.10)	'	'

Financial_Information_for_Subs4

Financial Information for Subsidiary and Guarantor Parent (I.S.) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]	'	'	'	'
Sales	$972.40	$1,131.50	$3,128.20	$3,645.50
Cost of sales	919.3	988.8	2,886.90	3,139.60
Selling and administrative expenses	70.6	77.6	210.1	243.3
Income (loss) before interest, other income and income taxes	-17.5	65.1	31.2	262.6
Interest expense, net	-18.2	-17.2	-46.5	-55.7
Other income (loss) including equity in income of unconsolidated subsidiaries	0.4	0.2	1.3	0.6
Income (loss) before income taxes	-35.3	48.1	-14	207.5
Income tax provision (benefit)	-8.5	14.8	-4.4	66.6
Income (loss) from continuing operations	-26.8	33.3	-9.6	140.9
Income (loss)from discontinued operations, net of tax	-5.4	4	-4.4	13.4
Net income (loss)	-32.2	37.3	-14	154.3
Less: Net income (loss) attributable to noncontrolling interests	1.6	2	5.4	6.4
Net income (loss) attributable to ATI	-33.8	35.3	-19.4	147.9
Comprehensive income (loss) attributable to ATI	-11.6	71.8	27.4	213.6
Parent Company	'	'	'	'
Income Statement [Abstract]	'	'	'	'
Sales	0	0	0	0
Cost of sales	19.4	15.1	55.5	41.8
Selling and administrative expenses	35.4	33.7	88.9	109.1
Income (loss) before interest, other income and income taxes	-54.8	-48.8	-144.4	-150.9
Interest expense, net	-17.3	-14.7	-45.5	-47.3
Other income (loss) including equity in income of unconsolidated subsidiaries	36.8	111.6	175.9	405.7
Income (loss) before income taxes	-35.3	48.1	-14	207.5
Income tax provision (benefit)	-8.5	14.8	-4.4	66.6
Income (loss) from continuing operations	-26.8	33.3	-9.6	140.9
Income (loss)from discontinued operations, net of tax	-5.4	4	-4.4	13.4
Net income (loss)	-32.2	37.3	-14	154.3
Less: Net income (loss) attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	-32.2	37.3	-14	154.3
Comprehensive income (loss) attributable to ATI	-9.9	74.4	35.3	220
Subsidiaries	'	'	'	'
Income Statement [Abstract]	'	'	'	'
Sales	422.3	483.6	1,375.20	1,614.20
Cost of sales	424.3	453.8	1,359.50	1,488.70
Selling and administrative expenses	7.4	10.8	27.3	33.2
Income (loss) before interest, other income and income taxes	-9.4	19	-11.6	92.3
Interest expense, net	-9.7	-2.7	-27	-7.9
Other income (loss) including equity in income of unconsolidated subsidiaries	0.1	-5.2	0.6	-16.1
Income (loss) before income taxes	-19	11.1	-38	68.3
Income tax provision (benefit)	-6.6	4.6	-9.8	26.9
Income (loss) from continuing operations	-12.4	6.5	-28.2	41.4
Income (loss)from discontinued operations, net of tax	0	0	0	0
Net income (loss)	-12.4	6.5	-28.2	41.4
Less: Net income (loss) attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	-12.4	6.5	-28.2	41.4
Comprehensive income (loss) attributable to ATI	-12.2	6.3	-27.8	40.6
NonGuarantor Subsidiaries	'	'	'	'
Income Statement [Abstract]	'	'	'	'
Sales	550.1	647.9	1,753	2,031.30
Cost of sales	475.6	519.9	1,471.90	1,609.10
Selling and administrative expenses	27.8	33.1	93.9	101
Income (loss) before interest, other income and income taxes	46.7	94.9	187.2	321.2
Interest expense, net	8.8	0.2	26	-0.5
Other income (loss) including equity in income of unconsolidated subsidiaries	0.3	7.8	0.8	24.2
Income (loss) before income taxes	55.8	102.9	214	344.9
Income tax provision (benefit)	22.4	33.3	76.6	116.9
Income (loss) from continuing operations	33.4	69.6	137.4	228
Income (loss)from discontinued operations, net of tax	-2.5	4.6	-0.2	16.1
Net income (loss)	30.9	74.2	137.2	244.1
Less: Net income (loss) attributable to noncontrolling interests	1.6	2	5.4	6.4
Net income (loss) attributable to ATI	29.3	72.2	131.8	237.7
Comprehensive income (loss) attributable to ATI	42	87.3	134.8	249.2
Consolidation Eliminations	'	'	'	'
Income Statement [Abstract]	'	'	'	'
Sales	0	0	0	0
Cost of sales	0	0	0	0
Selling and administrative expenses	0	0	0	0
Income (loss) before interest, other income and income taxes	0	0	0	0
Interest expense, net	0	0	0	0
Other income (loss) including equity in income of unconsolidated subsidiaries	-36.8	-114	-176	-413.2
Income (loss) before income taxes	-36.8	-114	-176	-413.2
Income tax provision (benefit)	-15.8	-37.9	-66.8	-143.8
Income (loss) from continuing operations	-21	-76.1	-109.2	-269.4
Income (loss)from discontinued operations, net of tax	2.5	-4.6	0.2	-16.1
Net income (loss)	-18.5	-80.7	-109	-285.5
Less: Net income (loss) attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	-18.5	-80.7	-109	-285.5
Comprehensive income (loss) attributable to ATI	($31.50)	($96.20)	($114.90)	($296.20)

Financial_Information_for_Subs5

Financial Information for Subsidiary and Guarantor Parent (Cash Flow) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Statement of Cash Flows	'	'
Cash flows provided by (used in) operating activities	$227.40	$245.80
Investing Activities:	'	'
Purchases of property, plant and equipment	-395.5	-245.6
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0.8	1.5
Cash used in investing activities	-394.7	-244.1
Financing Activities:	'	'
Borrowings on long-term debt	500	0
Net receipts/(payments) on intercompany activity	0	0
Dividends paid to stockholders	-57.7	-57.3
Other	-43.9	-44
Cash provided by (used in) financing activities	398.4	-101.3
Increase (decrease) in cash and cash equivalents	231.1	-99.6
Parent Company	'	'
Statement of Cash Flows	'	'
Cash flows provided by (used in) operating activities	-9.1	-26.1
Investing Activities:	'	'
Purchases of property, plant and equipment	-0.2	-1
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0.1	0
Cash used in investing activities	-0.1	-1
Financing Activities:	'	'
Borrowings on long-term debt	500	'
Net receipts/(payments) on intercompany activity	-409	103.8
Dividends paid to stockholders	-57.7	-57.3
Other	-27	-17
Cash provided by (used in) financing activities	6.3	29.5
Increase (decrease) in cash and cash equivalents	-2.9	2.4
Subsidiaries	'	'
Statement of Cash Flows	'	'
Cash flows provided by (used in) operating activities	-87.2	4.1
Investing Activities:	'	'
Purchases of property, plant and equipment	-359.1	-192.5
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0.1	0.2
Cash used in investing activities	-359	-192.3
Financing Activities:	'	'
Borrowings on long-term debt	0	'
Net receipts/(payments) on intercompany activity	440.4	83.2
Dividends paid to stockholders	0	0
Other	0	-0.1
Cash provided by (used in) financing activities	440.4	83.1
Increase (decrease) in cash and cash equivalents	-5.8	-105.1
NonGuarantor Subsidiaries	'	'
Statement of Cash Flows	'	'
Cash flows provided by (used in) operating activities	348	267.8
Investing Activities:	'	'
Purchases of property, plant and equipment	-36.2	-52.1
Net receipts/(payments) on intercompany activity	-31.4	-187
Asset disposals and other	0.6	1.3
Cash used in investing activities	-67	-237.8
Financing Activities:	'	'
Borrowings on long-term debt	0	'
Net receipts/(payments) on intercompany activity	0	0
Dividends paid to stockholders	-24.3	0
Other	-16.9	-26.9
Cash provided by (used in) financing activities	-41.2	-26.9
Increase (decrease) in cash and cash equivalents	239.8	3.1
Consolidation Eliminations	'	'
Statement of Cash Flows	'	'
Cash flows provided by (used in) operating activities	-24.3	0
Investing Activities:	'	'
Purchases of property, plant and equipment	0	0
Net receipts/(payments) on intercompany activity	31.4	187
Asset disposals and other	0	0
Cash used in investing activities	31.4	187
Financing Activities:	'	'
Borrowings on long-term debt	0	'
Net receipts/(payments) on intercompany activity	-31.4	-187
Dividends paid to stockholders	24.3	0
Other	0	0
Cash provided by (used in) financing activities	-7.1	-187
Increase (decrease) in cash and cash equivalents	$0	$0

Financial_Information_for_Subs6

Financial Information for Subsidiary and Guarantor Parent Financial Information for Subsidiary and Guarantor Parent (Changes) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Current assets	$2,693.50	'	$2,510.60	'
Assets	6,599.30	'	6,247.80	'
Current liabilities	1,168.60	'	871.5	'
Liabilities	4,035.20	'	3,660.70	'
Stockholders' equity	2,564.10	2,744.90	2,587.10	2,571.60
Cash flows provided by (used in) operating activities	227.4	245.8	'	'
Net Cash Provided by (Used in) Investing Activities	-394.7	-244.1	'	'
Cash provided by (used in) financing activities	398.4	-101.3	'	'
NonGuarantor Subsidiaries	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Current assets	3,394.80	'	3,269	'
Assets	6,102.70	'	6,050.60	'
Current liabilities	418.1	'	453	'
Liabilities	881.2	'	943.4	'
Stockholders' equity	5,221.50	'	5,107.20	'
Cash flows provided by (used in) operating activities	348	267.8	'	'
Net Cash Provided by (Used in) Investing Activities	-67	-237.8	'	'
Cash provided by (used in) financing activities	-41.2	-26.9	'	'
Subsidiaries	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Current assets	471.2	'	524.5	'
Assets	1,864.10	'	1,588	'
Current liabilities	884.8	'	541.4	'
Liabilities	1,442.40	'	1,116.10	'
Stockholders' equity	421.7	'	471.9	'
Cash flows provided by (used in) operating activities	-87.2	4.1	'	'
Net Cash Provided by (Used in) Investing Activities	-359	-192.3	'	'
Cash provided by (used in) financing activities	440.4	83.1	'	'
Parent Company	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Current assets	88.9	'	7	'
Assets	5,737.10	'	5,678.30	'
Current liabilities	1,127.10	'	1,167	'
Liabilities	3,173	'	3,091.20	'
Stockholders' equity	2,564.10	'	2,587.10	'
Cash flows provided by (used in) operating activities	-9.1	-26.1	'	'
Net Cash Provided by (Used in) Investing Activities	-0.1	-1	'	'
Cash provided by (used in) financing activities	6.3	29.5	'	'
Consolidation Eliminations	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Current assets	-1,261.40	'	-1,289.90	'
Assets	-7,104.60	'	-7,069.10	'
Current liabilities	-1,261.40	'	-1,289.90	'
Liabilities	-1,461.40	'	-1,490	'
Stockholders' equity	-5,643.20	'	-5,579.10	'
Cash flows provided by (used in) operating activities	-24.3	0	'	'
Net Cash Provided by (Used in) Investing Activities	31.4	187	'	'
Cash provided by (used in) financing activities	-7.1	-187	'	'
Restatement Adjustment | NonGuarantor Subsidiaries	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Current assets	'	'	1,289.90	'
Assets	'	'	1,112.70	'
Current liabilities	'	'	-196.8	'
Liabilities	'	'	-196.8	'
Stockholders' equity	'	'	1,309.50	'
Cash flows provided by (used in) operating activities	'	-42.5	'	'
Net Cash Provided by (Used in) Investing Activities	'	-187	'	'
Cash provided by (used in) financing activities	'	229.5	'	'
Restatement Adjustment | Subsidiaries	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Assets	'	'	-141.1	'
Current liabilities	'	'	-141.1	'
Liabilities	'	'	-141.1	'
Cash flows provided by (used in) operating activities	'	42.7	'	'
Cash provided by (used in) financing activities	'	-42.7	'	'
Restatement Adjustment | Parent Company	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Cash flows provided by (used in) operating activities	'	-4.4	'	'
Cash provided by (used in) financing activities	'	4.4	'	'
Restatement Adjustment | Consolidation Eliminations	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Cash flows provided by (used in) operating activities	'	4.2	'	'
Net Cash Provided by (Used in) Investing Activities	'	187	'	'
Cash provided by (used in) financing activities	'	($191.20)	'	'

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent [Abstract]	'	'	'	'
Post-retirement benefit plans, Opening balance, Attributable to parent	($993.50)	'	($1,030)	'
Post-retirement benefit plans, OCI before reclassifications, Attributable to parent	0	'	0	'
Post-retirement benefit plans, Amounts reclassified from AOCI, Attributable to parent	18.3	16.7	54.8	50
Post-retirement benefit plans, Net current-period OCI, Attributable to parent	18.3	'	54.8	'
Post-retirement benefit plans, Closing balance, Attributable to parent	-975.2	'	-975.2	'
Accumulated Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent [Abstract]	'	'	'	'
Currency translation adjustment, Opening balance, Attributable to parent	-7.5	'	3.4	'
Currency translation adjustment, OCI before reclassification, Attributable to parent	12.3	'	1.4	'
Currency translation adjustment, Amounts reclassified from AOCI, Attributable to parent	0	'	0	'
Currency translation adjustment, Net current-period OCI, Attributable to parent	12.3	'	1.4	'
Currency translation adjustment, Closing balance, Attributable to parent	4.8	'	4.8	'
Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax Attributable to Parent [Abstract]	'	'	'	'
Unrealized holding gains on securities, Opening Balance, Attributable to parent	-0.1	'	-0.1	'
Unrealized holding gains on securities, OCI before reclassifications, Attributable to parent	0.1	'	0.1	'
Unrealized holding gains on securities, Amounts reclassified from AOCI, Attributable to parent	0	'	0	'
Unrealized holding gains on securities, Net current-period OCI, Attributable to parent	0.1	'	0.1	'
Unrealized holding gains on securities, Closing Balance, Attributable to parent	0	'	0	'
AOCI Derivative Financial Instruments Attributable to Parent [Abstract]	'	'	'	'
Derivatives, Opening balance, Attributable to parent	-3.7	'	-2.7	'
Derivatives, OCI before reclassifications, Attributable to parent	-11.1	'	-12.9	'
Derivatives, Amounts reclassified from AOCI, Attributable to parent	2.6	'	3.4	'
Derivatives, Net current-period OCI,, Attributable to parent	-8.5	'	-9.5	'
Derivatives, Closing balance, Attributable to parent	-12.2	'	-12.2	'
Accumulated Other Comprehensive Income Loss Attributable To ATI [Abstract]	'	'	'	'
Total, Opening balance, Attributable to parent	-1,004.80	'	-1,029.40	'
Total, OCI before reclassifications, Attributable to parent	1.3	'	-11.4	'
Total, Amounts reclassified from AOCI, Attributable to parent	20.9	'	58.2	'
Total, Net current-period OCI, Attributable to parent	22.2	'	46.8	'
Total, Closing balance, Attributable to parent	-982.6	'	-982.6	'
Accumulated Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Noncontrolling Interest [Abstract]	'	'	'	'
Post-retirement benefit plans, Opening balance, Attributable to noncontrolling interest	0	'	0	'
Post-retirement benefit plans, OCI before reclassifications, Attributable to noncontrolling interest	0	'	0	'
Post-retirement benefit plans, Amounts reclassified from AOCI, Attributable to noncontrolling interest	'	'	0	'
Post-retirement benefit plans, Net current-period OCI, Attributable to noncontrolling interest	0	'	0	'
Post-retirement benefit plans, Closing balance, Attributable to noncontrolling interest	0	'	0	'
Accumulated Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Noncontrolling Interest [Abstract]	'	'	'	'
Currency translation adjustment, Opening balance, Attributable to noncontrolling interests	26.1	'	23.7	'
Currency translation adjustment, OCI before reclassifications, Attributable to noncontrolling interests	0.1	'	2.5	'
Currency translation adjustment, Amounts reclassified from AOCI, Attributable to noncontrolling interest	'	'	0	'
Foreign Currency adjustment, Net current-period OCI, Attributable to noncontrolling interests	0.1	'	2.5	'
Currency translation adjustment, Closing balance, Attributable to noncontrolling interests	26.2	'	26.2	'
Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax Attributable to Noncontrolling Interest [Abstract]	'	'	'	'
Unrealized holding gains on securities, Opening balance, Attributable to noncontrolling interests	0	'	0	'
Unrealized holding gains on securities, OCI before reclassifications, Attributable to noncontrolling interests	0	'	0	'
Unrealized holding gains on securities, Amounts reclassified from AOCI, Attributable to noncontrolling interest	'	'	0	'
Unrealized holding gains on securities, Net current-period OCI, Attributable to noncontrolling interests	0	'	0	'
Unrealized holding gains on securities, Closing balance, Attributable to noncontrolling interests	0	'	0	'
AOCI Derivative Financial Instruments Attributable to Noncontrolling Interest [Abstract]	'	'	'	'
Derivatives, Opening balance, Attributable to noncontrolling interests	0	'	0	'
Derivatives, OCI before reclassifications, Attributable to noncontrolling interests	0	'	0	'
Derivatives, Amounts reclassified from AOCI, Attributable to Noncontrolling Interest	'	'	0	'
Derivatives, OCI before reclassifications, Attributable to noncontrolling interests	0	'	0	'
Derivatives, Closing balance, Attributable to noncontrolling interests	0	'	0	'
Accumulated Other Comprehensive Income Loss Attributable To Noncontrolling interest [Roll Forward]	'	'	'	'
Total, Opening balance, Attributable to Noncontrolling Interest	26.1	'	23.7	'
Total, OCI before reclassifications, Attributable to noncontrolling interest	0.1	'	2.5	'
Total, Amounts reclassified from AOCI, Attributable To Noncontrolling Interest	'	'	0	'
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest	0.1	'	2.5	'
Total, Closing balance, Attributable to Noncontrolling Interest	$26.20	'	$26.20	'

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Amount reclassified from AOCI, Derivatives	($4.30)	($0.60)	($5.50)	($3.50)
Amount reclassified from AOCI, Derivatives, Tax provision (benefit)	-1.7	'	-2.1	'
Amount reclassified from AOCI, Derivatives, Net of tax	-2.6	'	-3.4	'
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments and Tax [Abstract]	'	'	'	'
Amount reclassified from AOCI, Postretirement benefit plans, Prior service (cost) credit	3.8	2.9	11.4	8.8
Amount reclassified from AOCI, Postretirement benefit plans, Actuarial costs	-33.5	-29.9	-100.5	-89.8
Amount reclassified from AOCI, Postretirement benefit plans, Total before tax	-29.7	'	-89.1	'
Amount reclassified from AOCI, Postretirement benefit plans, Tax provision (benefit)	-11.4	-10.3	-34.3	-31
Amount reclassified from AOCI, Postretirement benefit plans, Net of tax	-18.3	-16.7	-54.8	-50
Nickel and other raw material contracts	'	'	'	'
Amount reclassified from AOCI, Derivatives	-2.3	'	-3.8	'
Natural gas contracts	'	'	'	'
Amount reclassified from AOCI, Derivatives	-0.9	'	-2.4	'
Electricity contracts	'	'	'	'
Amount reclassified from AOCI, Derivatives	0	'	-0.3	'
Foreign exchange contracts	'	'	'	'
Amount reclassified from AOCI, Derivatives	($1.10)	'	$1	'

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Components of Environmental Loss Accrual [Abstract]	'
Accrual For Environmental Loss Contingencies	$15
Accrued Environmental Loss Contingencies Current	9
Federal Superfund and comparable state-managed sites	5
Formerly owned or operated sites	7
Owned or controlled sites at which Company operations have been discontinued	2
Sites utilized by the company in its ongoing operations	1
Loss Contingency, Estimate [Abstract]	'
Loss contingency maximum possible loss	8
Tungsten Materials Business	'
Loss Contingency, Estimate [Abstract]	'
Conditional asset retirement obligation costs, Idenmity Maximum	13
Conditional asset retirement obligation costs, Unreserved portion of Maximum	$9.50