ATI (ATI) 10-Q 4 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	3 Months Ended
	Mar. 31, 2015	Apr. 24, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	31-Mar-15
Amendment Flag	FALSE
Entity Registrant Name	ALLEGHENY TECHNOLOGIES INCORPORATED
Entity Central Index Key	1018963
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		109,215,499
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Entity Public Float			$4,900,000,000

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Current Assets:
Cash and cash equivalents	$238	$269.50
Accounts receivable, net of allowances for doubtful accounts of $4.8 as of March 31, 2015 and December 31, 2014	690.9	603.6
Inventories, net	1,472.60	1,472.80
Prepaid expenses and other current assets	64.1	136.2
Total current assets	2,465.60	2,482.10
Property, plant and equipment, net	2,943.70	2,961.80
Cost in excess of net assets acquired	777.9	780.4
Other assets	369.6	358.3
Total assets	6,556.80	6,582.60
Current Liabilities:
Accounts payable	559.5	556.7
Accrued liabilities	288.8	323.2
Deferred income taxes	70.8	62.2
Short-term debt and current portion of long-term debt	17.9	17.8
Total current liabilities	937	959.9
Long-term debt	1,509.10	1,509.10
Accrued postretirement benefits	407.1	415.8
Pension liabilities	730.2	739.3
Deferred income taxes	91.3	80.9
Other long-term liabilities	162	156.2
Total liabilities	3,836.70	3,861.20
Redeemable noncontrolling interest	12.1	12.1
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 March 31, 2015 and December 31, 2014; outstanding- 109,172,045 shares at March 31, 2015 and 108,710,914 shares at December 31, 2014	11	11
Additional paid-in capital	1,154.20	1,164.20
Retained earnings	2,382.40	2,398.90
Treasury stock: 523,126 shares at March 31, 2015 and 984,257 shares at December 31, 2014	-22.2	-44.3
Accumulated other comprehensive loss, net of tax	-930.8	-931.4
Total ATI stockholders’ equity	2,594.60	2,598.40
Noncontrolling interests
Noncontrolling interests	113.4	110.9
Total Equity	2,708	2,709.30
Total Liabilities and Equity	$6,556.80	$6,582.60

CONSOLIDATED_BALANCE_SHEETS_PA

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Allowances for doubtful accounts	$4.80	$4.80
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	109,172,045	108,710,914
Treasury stock	523,126	984,257

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Sales	$1,125.50	$987.30
Costs and expenses:
Cost of sales	1,016	917.1
Selling and administrative expenses	63.1	67.7
Income before interest, other income and income taxes	46.4	2.5
Interest expense, net	-26.7	-29.1
Other income, net	0.9	0.6
Income (loss) from continuing operations before income taxes	20.6	-26
Income tax provision (benefit)	8	-10
Income (loss) from continuing operations	12.6	-16
Income (loss) from discontinued operations, net of tax	0	-1.9
Net income (loss)	12.6	-17.9
Less: Net income attributable to noncontrolling interests	2.6	2.1
Net income (loss) attributable to ATI	10	-20
Continuing operations attributable to ATI per common share (in dollars per share)	$0.09	($0.17)
Discontinued operations attributable to ATI per common share (in dollars per share)	$0	($0.02)
Basic net income (loss) attributable to ATI per common share (in dollars per share)	$0.09	($0.19)
Continuing operations attributable to ATI per common share (in dollars per share)	$0.09	($0.17)
Discontinued operations attributable to ATI per common share (in dollars per share)	$0	($0.02)
Diluted net income (loss) attributable to ATI per common share (in dollars per share)	$0.09	($0.19)
Dividends declared per common share (in dollars per share)	$0.18	$0.18
Income (loss) from continuing operations, net of tax	10	-18.1
Loss from discontinued operations, net of tax	$0	($1.90)

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$12.60	($17.90)
Currency translation adjustment
Unrealized net change arising during the period	-21.8	-3.3
Unrealized holding gain on securities
Net gain (loss) arising during the period	0	0
Derivatives
Net derivatives gain on hedge transactions	18.5	9.3
Reclassification to net income of net realized loss (gain)	-2.7	2.1
Income taxes on derivative transactions	6.1	4.4
Total	9.7	7
Postretirement benefit plans
Amortization of net actuarial loss	18.7	22
Amortization to net income of net prior service cost (credits)	1.5	-0.2
Income taxes on postretirement benefit plans	7.7	8.4
Total	12.5	13.4
Other comprehensive income, net of tax	0.4	17.1
Comprehensive income (loss)	13	-0.8
Less: Comprehensive income attributable to noncontrolling interests	2.4	0.2
Comprehensive income (loss) attributable to ATI	$10.60	($1)

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating Activities:
Net income (loss)	$12.60	($17.90)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	45.6	44
Deferred taxes	5	-1.7
Changes in operating asset and liabilities:
Inventories	0.3	-82.6
Accounts receivable	-87.3	-28.6
Accounts payable	2.7	45.9
Retirement benefits	2.5	4.2
Accrued income taxes	60.6	-10.9
Accrued liabilities and other	-30	-9.3
Cash provided by (used in) operating activities	12	-56.9
Investing Activities:
Purchases of property, plant and equipment	-22.6	-39.6
Purchases of businesses, net of cash acquired	0	-71.1
Asset disposals and other	0.1	1.8
Cash used in investing activities	-22.5	-108.9
Financing Activities:
Payments on long-term debt and capital leases	-0.3	-0.1
Dividends paid to stockholders	-19.3	-19.3
Shares repurchased for income tax withholding on share-based compensation	-1.4	-3.9
Cash used in financing activities	-21	-23.3
Increase (decrease) in cash and cash equivalents
Decrease in cash and cash equivalents	-31.5	-189.1
Cash and cash equivalents at beginning of period	269.5	1,026.80
Cash and cash equivalents at end of period	$238	$837.70

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, 2013	$2,994.70	$11	$1,185.90	$2,490.10	($79.60)	($713.20)	$100.50
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	-17.9			-20			2.1
Other comprehensive income (loss)	17.1					18.9	-1.8
Cash dividends on common stock ($0.18 per share)	-19.3			-19.3
Employee stock plans	-7.5		-25.7	-10.1	28.3
Total Stockholders' Equity at Mar. 31, 2014	2,967.10	11	1,160.20	2,440.70	-51.3	-694.3	100.8
Total Stockholders' Equity at Dec. 31, 2014	2,709.30	11	1,164.20	2,398.90	-44.3	-931.4	110.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	12.6			10			2.6
Other comprehensive income (loss)	0.4					0.6	-0.2
Cash dividends on common stock ($0.18 per share)	-19.3			-19.3
Redeemable noncontrolling interest	0			-0.1			0.1
Employee stock plans	5		-10	-7.1	22.1
Total Stockholders' Equity at Mar. 31, 2015	$2,708	$11	$1,154.20	$2,382.40	($22.20)	($930.80)	$113.40

STATEMENTS_OF_CHANGES_IN_CONSO1

STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY (PARENTHETICAL) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Cash dividends on common stock per share	$0.18	$0.18

Accounting_Policies

Accounting Policies	3 Months Ended
	Mar. 31, 2015
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. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2014 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, 2014 financial information has been derived from the Company’s audited consolidated financial statements.
	In 2013, the Company sold or announced closures of certain businesses that are reported as discontinued operations. Remaining closure activities were completed in 2014. Financial results for discontinued operations for the first quarter of 2014 were sales of $5.2 million, pretax losses of $2.8 million, and net assets of $2.9 million as of March 31, 2014.
	New Accounting Pronouncements Adopted
	In January 2015, the Company adopted changes issued by the Financial Accounting Standards Board (FASB) to the criteria for reporting discontinued operations. Under the new criteria, a disposal of a component of an entity is required to be reported as discontinued operations only if the disposal represents a strategic shift that has, or will have, a major effect on an entity’s operations and financial results. The criteria that there be no significant continuing involvement in the operations of the component after the disposal transaction has been removed under the new guidance. The new guidance also requires the presentation of the assets and liabilities of a disposal group that includes a discontinued operation for each comparative period and requires additional disclosures about discontinued operations, including the major line items constituting the pretax profit or loss of the discontinued operation, certain cash flow information for the discontinued operation, expanded disclosures about an entity’s significant continuing involvement in a discontinued operation, and disclosures about a disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation. The provisions of the new guidance are effective for all disposals that occur for the Company beginning in fiscal year 2015. The adoption of these changes had no impact on the consolidated financial statements.
	Pending Accounting Pronouncements
	In April 2015, the FASB issued new guidance on presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this guidance. This update will be effective for the Company beginning in fiscal year 2016, with early adoption permitted, and is applied on a retrospective basis. As of March 31, 2015 and December 31, 2014, the Company had $10.6 million and $10.9 million, respectively, of debt issuance costs reported as assets on the consolidated balance sheet that will be reclassified to a reduction of the carrying amount of the debt liability upon the Company’s adoption of this new guidance.
	In May 2014, the FASB issued changes to revenue recognition with customers. This update provides a five-step analysis of transactions to determine when and how revenue is recognized. An entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update will be effective for the Company beginning in fiscal year 2017. This update may be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying this update recognized at the date of initial application. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories
	Inventories at March 31, 2015 and December 31, 2014 were as follows (in millions):
		March 31,			December 31,
		2015			2014
	Raw materials and supplies	$	234.5		$	249.3
	Work-in-process	1,186.30			1,184.10
	Finished goods	177			172.2
	Total inventories at current cost	1,597.80			1,605.60
	Adjustment from current cost to LIFO cost basis	4.3			4.8
	Inventory valuation reserves	(66.4		)	(68.8		)
	Progress payments	(63.1		)	(68.8		)
	Total inventories, net	$	1,472.60		$	1,472.80
	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, increased cost of sales by $0.5 million for the first three months of 2015, which was offset by a $0.5 million reduction in net realizable value reserves on the carrying value of LIFO-based inventory. The first three months of 2014 results included a $9.0 million increase in cost of sales from using the LIFO costing methodology, which was offset by a $9.0 million reduction in net realizable value reserves on the carrying value of LIFO-based inventory. The first three months of 2015 and 2014 results included $5.3 million and $8.3 million, respectively, in inventory valuation charges related to the market-based valuation of industrial titanium products in the Flat Rolled Products segment.

Property_Plant_And_Equipment

Property Plant And Equipment	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Property Plant and Equipment	Property, Plant and Equipment
	Property, plant and equipment at March 31, 2015 and December 31, 2014 was as follows (in millions):
		March 31,			December 31,
		2015			2014
	Land	$	30		$	30.2
	Buildings	1,053.10			1,048.90
	Equipment and leasehold improvements	3,714.60			3,702.50
		4,797.70			4,781.60
	Accumulated depreciation and amortization	(1,854.0		)	(1,819.8		)
	Total property, plant and equipment, net	$	2,943.70		$	2,961.80
	The construction in progress portion of property, plant and equipment at March 31, 2015 was $57.2 million.

Debt

Debt	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Debt	Debt
	Debt at March 31, 2015 and December 31, 2014 was as follows (in millions):
		March 31,		December 31,
		2015		2014
	Allegheny Technologies 5.875% Notes due 2023 (a)	$	500	$	500
	Allegheny Technologies 5.95% Notes due 2021	500		500
	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 (b)	11.7		11.9
	ATI Ladish Series C 6.41% Notes due 2015 (c)	10.2		10.3
	Domestic Bank Group $400 million credit facility	—		—
	Foreign credit facilities	—		—
	Industrial revenue bonds, due through 2020, and other	5.1		4.7
	Total short-term and long-term debt	1,527.00		1,526.90
	Short-term debt and current portion of long-term debt	17.9		17.8
	Total long-term debt	$	1,509.10	$	1,509.10
	(a)	Bearing interest at 6.375% effective February 15, 2015.
	(b)	Includes fair value adjustments of $0.3 million at March 31, 2015 and $0.4 million at December 31, 2014.
	(c)	Includes fair value adjustments of $0.2 million at March 31, 2015 and $0.3 million at December 31, 2014.
	During the first quarter of 2015, Standard & Poor’s (“S&P”) downgraded the Company’s credit rating one notch to BB+ from BBB-, resulting in an increase of the interest rate on the Senior Notes due 2023 (the “2023 Notes”) from 6.125% as of December 31, 2014 to 6.375% effective with the interest period beginning February 15, 2015. Future downgrades of the Company’s credit ratings could result in additional increases to the interest cost with respect to the 2023 Notes.
	There were no outstanding borrowings made under the Company’s $400 million senior domestic credit facility (“credit facility”) expiring May 31, 2018 as of March 31, 2015, although approximately $4.7 million has been utilized to support the issuance of letters of credit. Average borrowings under the credit facility for the first quarter of 2015 were $73.7 million, bearing an average annual interest rate of 1.9%. The credit facility provides for a springing lien on certain of the Company’s accounts receivable and inventory. This springing lien became effective during the first quarter of 2015 as the Company’s credit ratings from both S&P’s and Moody’s are now below investment grade following S&P’s downgrade in the first quarter 2015 discussed above. This springing lien will be subsequently released if the Company’s credit rating returns to investment grade from either rating agency, assuming no event of default condition exists. The credit facility requires the Company to maintain a leverage ratio (measured as consolidated total indebtedness net of cash on hand in excess of $50 million, divided by consolidated EBITDA, defined as earnings before interest, taxes, depreciation and amortization, and non-cash pension expense, with the definition of consolidated EBIT excluding any gain or loss attributable to sale or other dispositions of assets outside the ordinary course of business, for the four prior fiscal quarters) of not greater than 5.00 for the quarter ended March 31, 2015, 4.50 for the quarter ended June 30, 2015, 3.75 for the quarter ended September 30, 2015, and 3.50 for the quarter ended December 31, 2015 and for each fiscal quarter thereafter. The credit facility also requires the Company to maintain an interest coverage ratio (consolidated EBITDA as calculated for the leverage ratio, divided by interest expense) of not less than 2.50 for the quarter ended March 31, 2015, 3.00 for the quarter ended June 30, 2015, 3.25 for the quarter ended September 30, 2015, and 3.50 for the quarter ended December 31, 2015 and for each fiscal quarter thereafter. At March 31, 2015, the leverage ratio was 3.73 and the interest coverage ratio was 3.26. The Company was in compliance with these required ratios during all applicable periods.
	The Company has an additional separate credit facility for the issuance of letters of credit. As of March 31, 2015, $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, entered into a 125 million renminbi (approximately $20 million at March 31, 2015 exchange rates) revolving credit facility in April 2015, replacing a previous revolving credit facility that expired in 2014. Borrowings may be either in renminbi or U.S. dollars, with interest rates based on published Chinese or U.S. interbank offer rates, respectively. The credit facility is supported solely by STAL’s financial capability without any guarantees from the joint venture partners. The credit facility requires STAL to maintain a minimum level of shareholders’ equity, and certain financial ratios.
	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	3 Months Ended
	Mar. 31, 2015
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 operations.
	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 March 31, 2015, 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 20% of its estimated annual nickel requirements. These nickel hedges extend to 2020.
	At March 31, 2015, 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 2015, approximately 75% for 2016, and approximately 45% for 2017.
	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, primarily euros. At March 31, 2015, the Company held euro forward sales contracts designated as hedges with a notional value of approximately 375 million euro with maturity dates through February 2018, including approximately 157 million euro with maturities in 2015. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions.
	During the first quarter of 2015, the Company net settled 126.5 million euro notional value of foreign currency forward contracts designated as cash flow hedges with 2015 maturity dates, receiving cash proceeds of $26.1 million which is reported in cash provided by operating activities on the consolidated cash flow statement. Deferred gains on these settled cash flow hedges currently recognized in accumulated other comprehensive income will be reclassified to earnings when the underlying transactions occur. The Company subsequently entered into 115 million euro notional value of foreign currency forward contracts designated as fair value hedges in the first quarter of 2015, all with 2015 maturity dates, and recorded a $5.0 million benefit in costs of sales on the consolidated statement of operations in the first quarter of 2015 for subsequent mark-to-market changes on these fair value hedges.
	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		March 31,				December 31,
	Asset derivatives				2015				2014
	Derivatives designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		$	23.1			$	23.6
	Nickel and other raw material contracts		Prepaid expenses and other current assets		—				1.1
	Foreign exchange contracts		Other assets		46				28.3
	Nickel and other raw material contracts		Other assets		—				0.5
	Total derivatives designated as hedging instruments				69.1				53.5
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		—				6.4
	Total derivatives not designated as hedging instruments				—				6.4
	Total asset derivatives				$	69.1			$	59.9
	Liability derivatives		Balance sheet location
	Derivatives designated as hedging instruments:
	Natural gas contracts		Accrued liabilities		$	12.1			$	10.2
	Nickel and other raw material contracts		Accrued liabilities		9.9				5.8
	Electricity contracts		Accrued liabilities		—				0.1
	Natural gas contracts		Other long-term liabilities		11.8				7.9
	Nickel and other raw material contracts		Other long-term liabilities		9.4				3
	Total derivatives designated as hedging instruments				43.2				27
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Accrued liabilities		0.4				—
	Total derivatives not designated as hedging instruments				0.4				—
	Total liability derivatives				$	43.6			$	27
	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. For derivative financial instruments that are designated as fair value hedges, changes in the fair value of these derivatives are recognized in current period results. The Company did not use 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 month periods ended March 31, 2015 and 2014 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 March 31,								Three months ended March 31,						Three months ended March 31,
	Hedging Relationships	2015				2014				2015			2014			2015		2014
	Nickel and other raw material contracts	$	(9.6	)		$	3			$	(2.2	)	$	(1.7	)	$	—	$	—
	Natural gas contracts	(6.0		)		2.3				(2.4		)	1.4			—		—
	Electricity contracts	—				0.9				(0.1		)	0.4			—		—
	Foreign exchange contracts	27				(0.5		)		6.4			(1.4		)	—		—
	Total	$	11.4			$	5.7			$	1.7		$	(1.3	)	$	—	$	—
	(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 March 31, 2015, a gain of $0.7 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.
	During the first quarter of 2015, the Company net settled 40.3 million euro notional value of foreign currency forward contracts that were not designated as hedges, receiving cash proceeds of $11.8 million which is reported in cash provided by operating activities on the consolidated cash flow statement. The Company also entered into 30 million euro notional value of foreign currency forward contracts not designated as hedges in the first quarter of 2015 with maturity dates through February 2016.
	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 March 31,
	as Hedging Instruments	2015				2014
	Foreign exchange contracts	$	3.5			$	0.2
	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	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	Fair Value of Financial Instruments
	The estimated fair value of financial instruments at March 31, 2015 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	$	238	$	238	$	238	$	—
	Derivative financial instruments:
	Assets	69.1		69.1		—		69.1
	Liabilities	43.6		43.6		—		43.6
	Debt	1,527.00		1,679.60		1,652.60		27
	The estimated fair value of financial instruments at December 31, 2014 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	$	269.5	$	269.5	$	269.5	$	—
	Derivative financial instruments:
	Assets	59.9		59.9		—		59.9
	Liabilities	27		27		—		27
	Debt	1,526.90		1,616.00		1,589.10		26.9
	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 availability of observable market data is monitored to assess the appropriate classification of financial instruments within the fair value hierarchy. Changes in economic conditions or model-based valuation techniques may require the transfer of financial instruments from one fair value level to another. In such instances, the transfer is reported at the beginning of the reporting period. No transfers between levels were reported in 2015 or 2014.
	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	3 Months Ended
	Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Pension Plans and Other Postretirement Benefits	Pension Plans and Other Postretirement Benefits
	The Company has defined benefit pension plans or 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 March 31, 2015 and 2014, 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 March 31,						Three months ended March 31,
		2015			2014			2015		2014
	Service cost - benefits earned during the year	$	5.7		$	7.4		$	0.7	$	0.7
	Interest cost on benefits earned in prior years	30.3			33.4			4.5		6
	Expected return on plan assets	(42.1		)	(46.1		)	—		—
	Amortization of prior service cost (credit)	0.3			0.6			1.2		(0.8		)
	Amortization of net actuarial loss	15.1			18.5			3.6		3.5
	Total retirement benefit expense	$	9.3		$	13.8		$	10	$	9.4
	Other postretirement benefit costs for a defined contribution plan were $0.7 million for the three months ended March 31, 2014.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	First quarter 2015 results included a provision for income taxes of $8.0 million, or 38.8% of income from continuing operations before income tax, compared to a benefit of $10.0 million, or 38.5% of loss from continuing operations before income tax, for the 2014 comparable period. The income tax rate in 2015 is higher than normal due to the Company’s inability to use the federal domestic manufacturing deduction tax benefit due to net operating loss carryforwards. A federal income tax refund of $59.9 million was received in the first quarter of 2015. Income taxes in the first quarter 2014 included discrete tax benefits of $2.2 million primarily associated with adjustments to prior years’ and foreign taxes.

Business_Segments

Business Segments	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Business Segments	Business Segments
	The Company operates in two business segments: High Performance Materials & Components and Flat Rolled Products. The measure of segment operating profit, which is used to analyze the performance and results of the business segments, excludes income taxes, corporate expenses, net interest expense, retirement benefit expense, closed company expenses and restructuring costs, if any. Discontinued operations are also excluded. Management believes segment operating profit, as defined, provides an appropriate measure of controllable operating results at the business segment level. Following is certain financial information with respect to the Company’s business segments for the periods indicated (in millions):
		Three months ended March 31,
		2015			2014
	Total sales:
	High Performance Materials & Components	$	564.9		$	504.1
	Flat Rolled Products	604.7			529.6
		1,169.60			1,033.70
	Intersegment sales:
	High Performance Materials & Components	22.1			19.7
	Flat Rolled Products	22			26.7
		44.1			46.4
	Sales to external customers:
	High Performance Materials & Components	542.8			484.4
	Flat Rolled Products	582.7			502.9
		$	1,125.50		$	987.3
	Operating profit (loss):
	High Performance Materials & Components	$	75.9		$	69.1
	Flat Rolled Products	7.9			(25.6		)
	Total operating profit	83.8			43.5
	Corporate expenses	(11.8		)	(11.5		)
	Interest expense, net	(26.7		)	(29.1		)
	Closed company and other expenses	(5.4		)	(5.0		)
	Retirement benefit expense	(19.3		)	(23.9		)
	Income (loss) from continuing operations before income taxes	$	20.6		$	(26.0	)
	Retirement benefit expense represents defined benefit 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 retirement plans are included in segment operating profit or corporate expenses, as applicable.
	Interest expense, net of interest income, in the first quarter 2015 was $26.7 million, compared to net interest expense of $29.1 million in the first quarter 2014. The decrease in interest expense was primarily due to lower debt levels. Interest expense benefited from the capitalization of interest costs of $0.6 million in the first quarter 2015 compared to $2.3 million in the first quarter 2014. The decrease in capitalized interest primarily related to the Flat Rolled Products segment Hot-Rolling and Processing Facility.

Redeemable_Noncontrolling_Inte

Redeemable Noncontrolling Interest Redeemable Noncontrolling Interest	3 Months Ended
	Mar. 31, 2015
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interest
	The holders of the 15% noncontrolling interest in ATI Flowform Products have a put option to require the Company to purchase their equity interest at a redemption value determinable from a specified formula based on a multiple of EBITDA (subject to a fixed minimum linked to the original acquisition date value). The put option is fully exercisable beginning in the second quarter of 2017, and is also exercisable under certain other circumstances. The put option cannot be separated from the noncontrolling interest, and the combination of a noncontrolling interest and the redemption feature requires classification as redeemable noncontrolling interest in the consolidated balance sheet, separate from Stockholders’ Equity.
	The carrying amount of the redeemable noncontrolling interest approximates its maximum redemption value. Any subsequent change in maximum redemption value is adjusted through retained earnings. The adjustment to the carrying amount for the quarter ended March 31, 2015 reduced retained earnings by $0.1 million. The Company applied the two-class method of calculating earnings per share, and as such this adjustment to the carrying amount was reflected in earnings per share. The redeemable noncontrolling interest was $12.1 million as of March 31, 2015 and December 31, 2014, which was unchanged from the acquisition date value.

Per_Share_Information

Per Share Information	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [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
	(In millions, except per share amounts)	March 31,
		2015			2014
	Numerator for basic income (loss) from continuing operations per common share –
	Income (loss) from continuing operations attributable to ATI	$	10		$	(18.1	)
	Redeemable noncontrolling interest (Note 10)	(0.1		)	—
	Numerator for diluted income (loss) from continuing operations per common share –
	Income (loss) from continuing operations available to ATI after assumed conversions	$	9.9		$	(18.1	)
	Denominator for basic net income (loss) per common share-weighted average shares	107.2			107
	Effect of dilutive securities:
	Share-based compensation	0.8			—
	4.25% Convertible Notes due 2014	—			—
	Denominator for diluted net income (loss) per common share – adjusted weighted average shares assuming conversions	108			107
	Basic income (loss) from continuing operations attributable to ATI per common share	$	0.09		$	(0.17	)
	Diluted income (loss) from continuing operations attributable to ATI per common share	$	0.09		$	(0.17	)
	Common stock that would be issuable upon the assumed conversion of the 2014 Convertible Notes (prior to maturity on June 2, 2014) 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. There were no anti-dilutive shares for the three month period ended March 31, 2015 and 10.0 million anti-dilutive shares for the three month period ended March 31, 2014.

Financial_Information_for_Subs

Financial Information for Subsidiary and Guarantor Parent	3 Months Ended
	Mar. 31, 2015
Condensed Financial Information of Parent Company Only 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 (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.
	ATI 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
	March 31, 2015
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Assets:
	Cash and cash equivalents	$	2.5		$	12		$	223.5		$	—		$	238
	Accounts receivable, net	0.1			222.4			468.4			—			690.9
	Intercompany notes receivable	—			—			2,367.90			(2,367.9		)	—
	Inventories, net	—			399.6			1,073.00			—			1,472.60
	Prepaid expenses and other current assets	3			8.9			52.2			—			64.1
	Total current assets	5.6			642.9			4,185.00			(2,367.9		)	2,465.60
	Property, plant and equipment, net	2.5			1,544.90			1,396.30			—			2,943.70
	Cost in excess of net assets acquired	—			126.6			651.3			—			777.9
	Intercompany notes receivable	—			—			200			(200.0		)	—
	Investment in subsidiaries	6,149.20			37.7			—			(6,186.9		)	—
	Other assets	23.5			27.7			318.4			—			369.6
	Total assets	$	6,180.80		$	2,379.80		$	6,751.00		$	(8,754.8	)	$	6,556.80
	Liabilities and stockholders’ equity:
	Accounts payable	$	2.8		$	336.9		$	219.8		$	—		$	559.5
	Accrued liabilities	31.7			60.3			196.8			—			288.8
	Intercompany notes payable	1,179.00			1,188.90			—			(2,367.9		)	—
	Deferred income taxes	70.8			—			—			—			70.8
	Short-term debt and current portion of long-term debt	0.6			0.1			17.2			—			17.9
	Total current liabilities	1,284.90			1,586.20			433.8			(2,367.9		)	937
	Long-term debt	1,351.00			150.3			7.8			—			1,509.10
	Intercompany notes payable	—			200			—			(200.0		)	—
	Accrued postretirement benefits	—			150.9			256.2			—			407.1
	Pension liabilities	668.7			5.8			55.7			—			730.2
	Deferred income taxes	91.3			—			—			—			91.3
	Other long-term liabilities	76.9			20.9			64.2			—			162
	Total liabilities	3,472.80			2,114.10			817.7			(2,567.9		)	3,836.70
	Redeemable noncontrolling interest	—			—			12.1			—			12.1
	Total stockholders’ equity	2,708.00			265.7			5,921.20			(6,186.9		)	2,708.00
	Total liabilities and stockholders’ equity	$	6,180.80		$	2,379.80		$	6,751.00		$	(8,754.8	)	$	6,556.80
	Allegheny Technologies Incorporated
	Financial Information for Subsidiary and Guarantor Parent
	Statements of Operations and Comprehensive Income
	For the three months ended March 31, 2015
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Sales	$	—		$	508.5		$	617		$	—		$	1,125.50
	Cost of sales	2.2			504			509.8			—			1,016.00
	Selling and administrative expenses	25.8			11.7			25.6			—			63.1
	Income (loss) before interest, other income and income taxes	(28.0		)	(7.2		)	81.6			—			46.4
	Interest income (expense), net	(28.0		)	(12.2		)	13.5			—			(26.7		)
	Other income (loss) including equity in income of unconsolidated subsidiaries	76.6			0.4			0.6			(76.7		)	0.9
	Income (loss) from continuing operations before income tax provision (benefit)	20.6			(19.0		)	95.7			(76.7		)	20.6
	Income tax provision (benefit)	8			(6.6		)	34.1			(27.5		)	8
	Income (loss) from continuing operations	12.6			(12.4		)	61.6			(49.2		)	12.6
	Income (loss) from discontinued operations, net of tax	—			—			—			—			—
	Net income (loss)	12.6			(12.4		)	61.6			(49.2		)	12.6
	Less: Net income attributable to noncontrolling interests	—			—			2.6			—			2.6
	Net income (loss) attributable to ATI	$	12.6		$	(12.4	)	$	59		$	(49.2	)	$	10
	Comprehensive income (loss) attributable to ATI	$	13		$	(9.1	)	$	37.8		$	(31.1	)	$	10.6
	Condensed Statements of Cash Flows
	For the three months ended March 31, 2015
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Cash flows provided by (used in) operating activities	$	(26.3	)	$	(42.3	)	$	80.6		$	—		$	12
Investing Activities:
Purchases of property, plant and equipment	—			(9.1		)	(13.5		)	—			(22.6		)
Net receipts/(payments) on intercompany activity	—			—			(96.9		)	96.9			—
Asset disposals and other	—			0.1			—			—			0.1
Cash flows provided by (used in) investing activities	—			(9.0		)	(110.4		)	96.9			(22.5		)
Financing Activities:
Net receipts/(payments) on intercompany activity	47.4			49.5			—			(96.9		)	—
Dividends paid to stockholders	(19.3		)	—			—			—			(19.3		)
Other	(1.5		)	—			(0.2		)	—			(1.7		)
Cash flows provided by (used in) financing activities	26.6			49.5			(0.2		)	(96.9		)	(21.0		)
Increase (decrease) in cash and cash equivalents	$	0.3		$	(1.8	)	$	(30.0	)	$	—		$	(31.5	)
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Balance Sheets
December 31, 2014
	Guarantor						Non-guarantor
(In millions)	Parent			Subsidiary			Subsidiaries			Eliminations			Consolidated
Assets:
Cash and cash equivalents	$	2.2		$	13.8		$	253.5		$	—		$	269.5
Accounts receivable, net	0.1			209.1			394.4			—			603.6
Intercompany notes receivable	—			—			2,390.80			(2,390.8		)	—
Inventories, net	—			387.7			1,085.10			—			1,472.80
Prepaid expenses and other current assets	63.7			13.2			59.3			—			136.2
Total current assets	66			623.8			4,183.10			(2,390.8		)	2,482.10
Property, plant and equipment, net	2.2			1,545.10			1,414.50			—			2,961.80
Cost in excess of net assets acquired	—			126.6			653.8			—			780.4
Intercompany notes receivable	—			—			200			(200.0		)	—
Investment in subsidiaries	6,149.40			37.7			—			(6,187.1		)	—
Other assets	23.7			28			306.6			—			358.3
Total assets	$	6,241.30		$	2,361.20		$	6,758.00		$	(8,777.9	)	$	6,582.60
Liabilities and stockholders’ equity:
Accounts payable	$	4.5		$	302		$	250.2		$	—		$	556.7
Accrued liabilities	47.5			72			203.7			—			323.2
Intercompany notes payable	1,232.60			1,158.20			—			(2,390.8		)	—
Deferred income taxes	62.2			—			—			—			62.2
Short-term debt and current portion of long-term debt	0.5			0.1			17.2			—			17.8
Total current liabilities	1,347.30			1,532.30			471.1			(2,390.8		)	959.9
Long-term debt	1,350.60			150.3			8.2			—			1,509.10
Intercompany notes payable	—			200			—			(200.0		)	—
Accrued postretirement benefits	—			153			262.8			—			415.8
Pension liabilities	675.5			6			57.8			—			739.3
Deferred income taxes	80.9			—			—			—			80.9
Other long-term liabilities	77.7			22.5			56			—			156.2
Total liabilities	3,532.00			2,064.10			855.9			(2,590.8		)	3,861.20
Redeemable noncontrolling interest	—			—			12.1			—			12.1
Total stockholders’ equity	2,709.30			297.1			5,890.00			(6,187.1		)	2,709.30
Total liabilities and stockholders’ equity	$	6,241.30		$	2,361.20		$	6,758.00		$	(8,777.9	)	$	6,582.60
Allegheny Technologies Incorporated
Financial Information for Subsidiary and Guarantor Parent
Statements of Operations and Comprehensive Income
For the three months ended March 31, 2014
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Sales	$	—		$	427.9		$	559.4		$	—		$	987.3
Cost of sales	12.3			439.6			465.2			—			917.1
Selling and administrative expenses	27.1			10.1			30.5			—			67.7
Income (loss) before interest, other income and income taxes	(39.4		)	(21.8		)	63.7			—			2.5
Interest income (expense), net	(28.5		)	(10.6		)	10			—			(29.1		)
Other income (loss) including equity in income of unconsolidated subsidiaries	41.9			0.3			0.6			(42.2		)	0.6
Income (loss) from continuing operations before income tax provision (benefit)	(26.0		)	(32.1		)	74.3			(42.2		)	(26.0		)
Income tax provision (benefit)	(10.0		)	(11.3		)	26.4			(15.1		)	(10.0		)
Income (loss) from continuing operations	(16.0		)	(20.8		)	47.9			(27.1		)	(16.0		)
Income (loss) from discontinued operations, net of tax	(1.9		)	—			(1.9		)	1.9			(1.9		)
Net income (loss)	(17.9		)	(20.8		)	46			(25.2		)	(17.9		)
Less: Net income attributable to noncontrolling interests	—			—			2.1			—			2.1
Net income (loss) attributable to ATI	$	(17.9	)	$	(20.8	)	$	43.9		$	(25.2	)	$	(20.0	)
Comprehensive income (loss) attributable to ATI	$	(0.8	)	$	(18.8	)	$	42.5		$	(23.9	)	$	(1.0	)
Condensed Statements of Cash Flows
For the three months ended March 31, 2014
(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
	Parent						Subsidiaries
Cash flows provided by (used in) operating activities	$	(29.7	)	$	(125.6	)	$	98.4		$	—		$	(56.9	)
Investing Activities:
Purchases of property, plant and equipment	—			(26.3		)	(13.3		)	—			(39.6		)
Purchase of business, net of cash acquired	—			—			(71.1		)	—			(71.1		)
Net receipts/(payments) on intercompany activity	—			—			(208.9		)	208.9			—
Asset disposals and other	—			1.4			0.4			—			1.8
Cash flows provided by (used in) investing activities	—			(24.9		)	(292.9		)	208.9			(108.9		)
Financing Activities:
Net receipts/(payments) on intercompany activity	58.9			150			—			(208.9		)	—
Dividends paid to stockholders	(19.3		)	—			—			—			(19.3		)
Other	(4.0		)	—			—			—			(4.0		)
Cash flows provided by (used in) financing activities	35.6			150			—			(208.9		)	(23.3		)
Increase (decrease) in cash and cash equivalents	$	5.9		$	(0.5	)	$	(194.5	)	$	—		$	(189.1	)

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)
	The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the three month period ended March 31, 2015 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, 2014	$	(931.5	)		$	(16.2		)		$	—			$	16.3			$	(931.4	)
	OCI before reclassifications		—				(21.6		)			—				11.4			(10.2		)
	Amounts reclassified from AOCI	(a)	12.5			(b)	—				(b)	—			(c)	(1.7	)		10.8
	Net current-period OCI		12.5				(21.6		)			—				9.7			0.6
	Balance, March 31, 2015	$	(919.0	)		$	(37.8		)		$	—			$	26			$	(930.8	)
	Attributable to noncontrolling interests:
	Balance, December 31, 2014	$	—			$	$	25			$	—			$	—			$	25
	OCI before reclassifications		—				(0.2		)			—				—			(0.2		)
	Amounts reclassified from AOCI		—			(b)	—					—				—			—
	Net current-period OCI		—				(0.2		)			—				—			(0.2		)
	Balance, March 31, 2015	$	—			$	24.8				$	—			$	—			$	24.8
	(a)	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 7).
	(b)	No amounts were reclassified to earnings.
	(c)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings (see Note 5).
	The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the three month period ended March 31, 2014 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, 2013	$	(718.9	)		$	15.3			$	—			$	(9.6	)		$	(713.2	)
	OCI before reclassifications		—				(1.5	)			—				5.7			4.2
	Amounts reclassified from AOCI	(a)	13.4			(b)	—			(b)	—			(c)	1.3			14.7
	Net current-period OCI		13.4				(1.5	)			—				7			18.9
	Balance, March 31, 2014	$	(705.5	)		$	13.8			$	—			$	(2.6	)		$	(694.3	)
	Attributable to noncontrolling interests:
	Balance, December 31, 2013	$	—			$	27.1			$	—			$	—			$	27.1
	OCI before reclassifications		—				(1.8	)			—				—			(1.8		)
	Amounts reclassified from AOCI		—			(b)	—				—				—			—
	Net current-period OCI		—				(1.8	)			—				—			$	(1.8	)
	Balance, March 31, 2013	$	—			$	25.3			$	—			$	—			$	25.3
	(a)	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 7).
	(b)	No amounts were reclassified to earnings.
	(c)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings (see Note 5).
	Reclassifications out of AOCI for the three month periods ended March 31, 2015 and 2014 were as follows:
			Amount reclassified from AOCI
	Details about AOCI Components		Three months ended March 31, 2015					Three months ended March 31, 2014					Affected line item in the
	(In millions)												statements of operations
	Postretirement benefit plans
	Prior service (cost) credit		$	(1.5	)	(a)		$	0.2		(a)
	Actuarial losses		(18.7		)	(a)		(22.0		)	(a)
			(20.2		)	(c)		(21.8		)	(c)		Total before tax
			(7.7		)			(8.4		)			Tax provision (benefit)
			$	(12.5	)			$	(13.4	)			Net of tax
	Derivatives
	Nickel and other raw material contracts		$	(3.6	)	(b)		$	(2.8	)	(b)
	Natural gas contracts		(3.9		)	(b)		2.3			(b)
	Electricity contracts		(0.2		)	(b)		0.7			(b)
	Foreign exchange contracts		10.4			(b)		(2.3		)	(b)
			2.7			(c)		(2.1		)	(c)		Total before tax
			1					(0.8		)			Tax provision (benefit)
			$	1.7				$	(1.3	)			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 7.
	(b)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings. For additional information, see Note 5.
	(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	3 Months Ended
	Mar. 31, 2015
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 March 31, 2015, the Company’s reserves for environmental remediation obligations totaled approximately $17 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; $10 million for formerly owned or operated sites for which the Company has remediation or indemnification obligations; $1 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.
	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 $19 million. However, 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 20. 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, 2014 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, construction, 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.

Accounting_Policies_Policies

Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
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. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2014 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, 2014 financial information has been derived from the Company’s audited consolidated financial statements.
	In 2013, the Company sold or announced closures of certain businesses that are reported as discontinued operations. Remaining closure activities were completed in 2014. Financial results for discontinued operations for the first quarter of 2014 were sales of $5.2 million, pretax losses of $2.8 million, and net assets of $2.9 million as of March 31, 2014.
New Accounting Pronouncements	New Accounting Pronouncements Adopted
	In January 2015, the Company adopted changes issued by the Financial Accounting Standards Board (FASB) to the criteria for reporting discontinued operations. Under the new criteria, a disposal of a component of an entity is required to be reported as discontinued operations only if the disposal represents a strategic shift that has, or will have, a major effect on an entity’s operations and financial results. The criteria that there be no significant continuing involvement in the operations of the component after the disposal transaction has been removed under the new guidance. The new guidance also requires the presentation of the assets and liabilities of a disposal group that includes a discontinued operation for each comparative period and requires additional disclosures about discontinued operations, including the major line items constituting the pretax profit or loss of the discontinued operation, certain cash flow information for the discontinued operation, expanded disclosures about an entity’s significant continuing involvement in a discontinued operation, and disclosures about a disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation. The provisions of the new guidance are effective for all disposals that occur for the Company beginning in fiscal year 2015. The adoption of these changes had no impact on the consolidated financial statements.
	Pending Accounting Pronouncements
	In April 2015, the FASB issued new guidance on presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this guidance. This update will be effective for the Company beginning in fiscal year 2016, with early adoption permitted, and is applied on a retrospective basis. As of March 31, 2015 and December 31, 2014, the Company had $10.6 million and $10.9 million, respectively, of debt issuance costs reported as assets on the consolidated balance sheet that will be reclassified to a reduction of the carrying amount of the debt liability upon the Company’s adoption of this new guidance.
	In May 2014, the FASB issued changes to revenue recognition with customers. This update provides a five-step analysis of transactions to determine when and how revenue is recognized. An entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update will be effective for the Company beginning in fiscal year 2017. This update may be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying this update recognized at the date of initial application. The Company is currently evaluating the impact of the new guidance on its 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 operations.
	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 March 31, 2015, 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 20% of its estimated annual nickel requirements. These nickel hedges extend to 2020.
	At March 31, 2015, 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 2015, approximately 75% for 2016, and approximately 45% for 2017.
	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, primarily euros. At March 31, 2015, the Company held euro forward sales contracts designated as hedges with a notional value of approximately 375 million euro with maturity dates through February 2018, including approximately 157 million euro with maturities in 2015. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions.
	During the first quarter of 2015, the Company net settled 126.5 million euro notional value of foreign currency forward contracts designated as cash flow hedges with 2015 maturity dates, receiving cash proceeds of $26.1 million which is reported in cash provided by operating activities on the consolidated cash flow statement. Deferred gains on these settled cash flow hedges currently recognized in accumulated other comprehensive income will be reclassified to earnings when the underlying transactions occur. The Company subsequently entered into 115 million euro notional value of foreign currency forward contracts designated as fair value hedges in the first quarter of 2015, all with 2015 maturity dates, and recorded a $5.0 million benefit in costs of sales on the consolidated statement of operations in the first quarter of 2015 for subsequent mark-to-market changes on these fair value hedges.
	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. For derivative financial instruments that are designated as fair value hedges, changes in the fair value of these derivatives are recognized in current period results. The Company did not use 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 or 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.

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories at March 31, 2015 and December 31, 2014 were as follows (in millions):
		March 31,			December 31,
		2015			2014
	Raw materials and supplies	$	234.5		$	249.3
	Work-in-process	1,186.30			1,184.10
	Finished goods	177			172.2
	Total inventories at current cost	1,597.80			1,605.60
	Adjustment from current cost to LIFO cost basis	4.3			4.8
	Inventory valuation reserves	(66.4		)	(68.8		)
	Progress payments	(63.1		)	(68.8		)
	Total inventories, net	$	1,472.60		$	1,472.80

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Property Plant And Equipment	Property, plant and equipment at March 31, 2015 and December 31, 2014 was as follows (in millions):
		March 31,			December 31,
		2015			2014
	Land	$	30		$	30.2
	Buildings	1,053.10			1,048.90
	Equipment and leasehold improvements	3,714.60			3,702.50
		4,797.70			4,781.60
	Accumulated depreciation and amortization	(1,854.0		)	(1,819.8		)
	Total property, plant and equipment, net	$	2,943.70		$	2,961.80

Debt_Tables

Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Schedule of Debt Instruments	Debt at March 31, 2015 and December 31, 2014 was as follows (in millions):
		March 31,		December 31,
		2015		2014
	Allegheny Technologies 5.875% Notes due 2023 (a)	$	500	$	500
	Allegheny Technologies 5.95% Notes due 2021	500		500
	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 (b)	11.7		11.9
	ATI Ladish Series C 6.41% Notes due 2015 (c)	10.2		10.3
	Domestic Bank Group $400 million credit facility	—		—
	Foreign credit facilities	—		—
	Industrial revenue bonds, due through 2020, and other	5.1		4.7
	Total short-term and long-term debt	1,527.00		1,526.90
	Short-term debt and current portion of long-term debt	17.9		17.8
	Total long-term debt	$	1,509.10	$	1,509.10
	(a)	Bearing interest at 6.375% effective February 15, 2015.
	(b)	Includes fair value adjustments of $0.3 million at March 31, 2015 and $0.4 million at December 31, 2014.
	(c)	Includes fair value adjustments of $0.2 million at March 31, 2015 and $0.3 million at December 31, 2014.

Derivative_Financial_Instrumen1

Derivative Financial Instruments and Hedging (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [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		March 31,				December 31,
	Asset derivatives				2015				2014
	Derivatives designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		$	23.1			$	23.6
	Nickel and other raw material contracts		Prepaid expenses and other current assets		—				1.1
	Foreign exchange contracts		Other assets		46				28.3
	Nickel and other raw material contracts		Other assets		—				0.5
	Total derivatives designated as hedging instruments				69.1				53.5
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Prepaid expenses and other current assets		—				6.4
	Total derivatives not designated as hedging instruments				—				6.4
	Total asset derivatives				$	69.1			$	59.9
	Liability derivatives		Balance sheet location
	Derivatives designated as hedging instruments:
	Natural gas contracts		Accrued liabilities		$	12.1			$	10.2
	Nickel and other raw material contracts		Accrued liabilities		9.9				5.8
	Electricity contracts		Accrued liabilities		—				0.1
	Natural gas contracts		Other long-term liabilities		11.8				7.9
	Nickel and other raw material contracts		Other long-term liabilities		9.4				3
	Total derivatives designated as hedging instruments				43.2				27
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts		Accrued liabilities		0.4				—
	Total derivatives not designated as hedging instruments				0.4				—
	Total liability derivatives				$	43.6			$	27
Schedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance	Activity with regard to derivatives designated as cash flow hedges for the three month periods ended March 31, 2015 and 2014 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 March 31,								Three months ended March 31,						Three months ended March 31,
	Hedging Relationships	2015				2014				2015			2014			2015		2014
	Nickel and other raw material contracts	$	(9.6	)		$	3			$	(2.2	)	$	(1.7	)	$	—	$	—
	Natural gas contracts	(6.0		)		2.3				(2.4		)	1.4			—		—
	Electricity contracts	—				0.9				(0.1		)	0.4			—		—
	Foreign exchange contracts	27				(0.5		)		6.4			(1.4		)	—		—
	Total	$	11.4			$	5.7			$	1.7		$	(1.3	)	$	—	$	—
	(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 Not Designated as Hedging Instruments	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 March 31,
	as Hedging Instruments	2015				2014
	Foreign exchange contracts	$	3.5			$	0.2

Recovered_Sheet1

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value By Balance Sheet Grouping	The estimated fair value of financial instruments at March 31, 2015 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	$	238	$	238	$	238	$	—
	Derivative financial instruments:
	Assets	69.1		69.1		—		69.1
	Liabilities	43.6		43.6		—		43.6
	Debt	1,527.00		1,679.60		1,652.60		27
	The estimated fair value of financial instruments at December 31, 2014 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	$	269.5	$	269.5	$	269.5	$	—
	Derivative financial instruments:
	Assets	59.9		59.9		—		59.9
	Liabilities	27		27		—		27
	Debt	1,526.90		1,616.00		1,589.10		26.9

Pension_Plans_and_Other_Postre1

Pension Plans and Other Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Schedule Of Defined Benefit Plans Disclosures	For the three month periods ended March 31, 2015 and 2014, 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 March 31,						Three months ended March 31,
		2015			2014			2015		2014
	Service cost - benefits earned during the year	$	5.7		$	7.4		$	0.7	$	0.7
	Interest cost on benefits earned in prior years	30.3			33.4			4.5		6
	Expected return on plan assets	(42.1		)	(46.1		)	—		—
	Amortization of prior service cost (credit)	0.3			0.6			1.2		(0.8		)
	Amortization of net actuarial loss	15.1			18.5			3.6		3.5
	Total retirement benefit expense	$	9.3		$	13.8		$	10	$	9.4

Business_Segments_Tables

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [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 March 31,
		2015			2014
	Total sales:
	High Performance Materials & Components	$	564.9		$	504.1
	Flat Rolled Products	604.7			529.6
		1,169.60			1,033.70
	Intersegment sales:
	High Performance Materials & Components	22.1			19.7
	Flat Rolled Products	22			26.7
		44.1			46.4
	Sales to external customers:
	High Performance Materials & Components	542.8			484.4
	Flat Rolled Products	582.7			502.9
		$	1,125.50		$	987.3
	Operating profit (loss):
	High Performance Materials & Components	$	75.9		$	69.1
	Flat Rolled Products	7.9			(25.6		)
	Total operating profit	83.8			43.5
	Corporate expenses	(11.8		)	(11.5		)
	Interest expense, net	(26.7		)	(29.1		)
	Closed company and other expenses	(5.4		)	(5.0		)
	Retirement benefit expense	(19.3		)	(23.9		)
	Income (loss) from continuing operations before income taxes	$	20.6		$	(26.0	)

Per_Share_Information_Tables

Per Share Information (Tables)	3 Months Ended
	Mar. 31, 2015
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
	(In millions, except per share amounts)	March 31,
		2015			2014
	Numerator for basic income (loss) from continuing operations per common share –
	Income (loss) from continuing operations attributable to ATI	$	10		$	(18.1	)
	Redeemable noncontrolling interest (Note 10)	(0.1		)	—
	Numerator for diluted income (loss) from continuing operations per common share –
	Income (loss) from continuing operations available to ATI after assumed conversions	$	9.9		$	(18.1	)
	Denominator for basic net income (loss) per common share-weighted average shares	107.2			107
	Effect of dilutive securities:
	Share-based compensation	0.8			—
	4.25% Convertible Notes due 2014	—			—
	Denominator for diluted net income (loss) per common share – adjusted weighted average shares assuming conversions	108			107
	Basic income (loss) from continuing operations attributable to ATI per common share	$	0.09		$	(0.17	)
	Diluted income (loss) from continuing operations attributable to ATI per common share	$	0.09		$	(0.17	)

Financial_Information_for_Subs1

Financial Information for Subsidiary and Guarantor Parent (Tables)	3 Months Ended
	Mar. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Balance Sheets	Balance Sheets
	December 31, 2014
		Guarantor						Non-guarantor
	(In millions)	Parent			Subsidiary			Subsidiaries			Eliminations			Consolidated
	Assets:
	Cash and cash equivalents	$	2.2		$	13.8		$	253.5		$	—		$	269.5
	Accounts receivable, net	0.1			209.1			394.4			—			603.6
	Intercompany notes receivable	—			—			2,390.80			(2,390.8		)	—
	Inventories, net	—			387.7			1,085.10			—			1,472.80
	Prepaid expenses and other current assets	63.7			13.2			59.3			—			136.2
	Total current assets	66			623.8			4,183.10			(2,390.8		)	2,482.10
	Property, plant and equipment, net	2.2			1,545.10			1,414.50			—			2,961.80
	Cost in excess of net assets acquired	—			126.6			653.8			—			780.4
	Intercompany notes receivable	—			—			200			(200.0		)	—
	Investment in subsidiaries	6,149.40			37.7			—			(6,187.1		)	—
	Other assets	23.7			28			306.6			—			358.3
	Total assets	$	6,241.30		$	2,361.20		$	6,758.00		$	(8,777.9	)	$	6,582.60
	Liabilities and stockholders’ equity:
	Accounts payable	$	4.5		$	302		$	250.2		$	—		$	556.7
	Accrued liabilities	47.5			72			203.7			—			323.2
	Intercompany notes payable	1,232.60			1,158.20			—			(2,390.8		)	—
	Deferred income taxes	62.2			—			—			—			62.2
	Short-term debt and current portion of long-term debt	0.5			0.1			17.2			—			17.8
	Total current liabilities	1,347.30			1,532.30			471.1			(2,390.8		)	959.9
	Long-term debt	1,350.60			150.3			8.2			—			1,509.10
	Intercompany notes payable	—			200			—			(200.0		)	—
	Accrued postretirement benefits	—			153			262.8			—			415.8
	Pension liabilities	675.5			6			57.8			—			739.3
	Deferred income taxes	80.9			—			—			—			80.9
	Other long-term liabilities	77.7			22.5			56			—			156.2
	Total liabilities	3,532.00			2,064.10			855.9			(2,590.8		)	3,861.20
	Redeemable noncontrolling interest	—			—			12.1			—			12.1
	Total stockholders’ equity	2,709.30			297.1			5,890.00			(6,187.1		)	2,709.30
	Total liabilities and stockholders’ equity	$	6,241.30		$	2,361.20		$	6,758.00		$	(8,777.9	)	$	6,582.60
	Balance Sheets
	March 31, 2015
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Assets:
	Cash and cash equivalents	$	2.5		$	12		$	223.5		$	—		$	238
	Accounts receivable, net	0.1			222.4			468.4			—			690.9
	Intercompany notes receivable	—			—			2,367.90			(2,367.9		)	—
	Inventories, net	—			399.6			1,073.00			—			1,472.60
	Prepaid expenses and other current assets	3			8.9			52.2			—			64.1
	Total current assets	5.6			642.9			4,185.00			(2,367.9		)	2,465.60
	Property, plant and equipment, net	2.5			1,544.90			1,396.30			—			2,943.70
	Cost in excess of net assets acquired	—			126.6			651.3			—			777.9
	Intercompany notes receivable	—			—			200			(200.0		)	—
	Investment in subsidiaries	6,149.20			37.7			—			(6,186.9		)	—
	Other assets	23.5			27.7			318.4			—			369.6
	Total assets	$	6,180.80		$	2,379.80		$	6,751.00		$	(8,754.8	)	$	6,556.80
	Liabilities and stockholders’ equity:
	Accounts payable	$	2.8		$	336.9		$	219.8		$	—		$	559.5
	Accrued liabilities	31.7			60.3			196.8			—			288.8
	Intercompany notes payable	1,179.00			1,188.90			—			(2,367.9		)	—
	Deferred income taxes	70.8			—			—			—			70.8
	Short-term debt and current portion of long-term debt	0.6			0.1			17.2			—			17.9
	Total current liabilities	1,284.90			1,586.20			433.8			(2,367.9		)	937
	Long-term debt	1,351.00			150.3			7.8			—			1,509.10
	Intercompany notes payable	—			200			—			(200.0		)	—
	Accrued postretirement benefits	—			150.9			256.2			—			407.1
	Pension liabilities	668.7			5.8			55.7			—			730.2
	Deferred income taxes	91.3			—			—			—			91.3
	Other long-term liabilities	76.9			20.9			64.2			—			162
Total liabilities	3,472.80			2,114.10			817.7			(2,567.9		)	3,836.70
Redeemable noncontrolling interest	—			—			12.1			—			12.1
Total stockholders’ equity	2,708.00			265.7			5,921.20			(6,186.9		)	2,708.00
Total liabilities and stockholders’ equity	$	6,180.80		$	2,379.80		$	6,751.00		$	(8,754.8	)	$	6,556.80
Statements of Operations and Comprehensive Income	Statements of Operations and Comprehensive Income
	For the three months ended March 31, 2015
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Sales	$	—		$	508.5		$	617		$	—		$	1,125.50
	Cost of sales	2.2			504			509.8			—			1,016.00
	Selling and administrative expenses	25.8			11.7			25.6			—			63.1
	Income (loss) before interest, other income and income taxes	(28.0		)	(7.2		)	81.6			—			46.4
	Interest income (expense), net	(28.0		)	(12.2		)	13.5			—			(26.7		)
	Other income (loss) including equity in income of unconsolidated subsidiaries	76.6			0.4			0.6			(76.7		)	0.9
	Income (loss) from continuing operations before income tax provision (benefit)	20.6			(19.0		)	95.7			(76.7		)	20.6
	Income tax provision (benefit)	8			(6.6		)	34.1			(27.5		)	8
	Income (loss) from continuing operations	12.6			(12.4		)	61.6			(49.2		)	12.6
	Income (loss) from discontinued operations, net of tax	—			—			—			—			—
	Net income (loss)	12.6			(12.4		)	61.6			(49.2		)	12.6
	Less: Net income attributable to noncontrolling interests	—			—			2.6			—			2.6
	Net income (loss) attributable to ATI	$	12.6		$	(12.4	)	$	59		$	(49.2	)	$	10
	Comprehensive income (loss) attributable to ATI	$	13		$	(9.1	)	$	37.8		$	(31.1	)	$	10.6
	Statements of Operations and Comprehensive Income
	For the three months ended March 31, 2014
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Sales	$	—		$	427.9		$	559.4		$	—		$	987.3
	Cost of sales	12.3			439.6			465.2			—			917.1
	Selling and administrative expenses	27.1			10.1			30.5			—			67.7
	Income (loss) before interest, other income and income taxes	(39.4		)	(21.8		)	63.7			—			2.5
	Interest income (expense), net	(28.5		)	(10.6		)	10			—			(29.1		)
	Other income (loss) including equity in income of unconsolidated subsidiaries	41.9			0.3			0.6			(42.2		)	0.6
	Income (loss) from continuing operations before income tax provision (benefit)	(26.0		)	(32.1		)	74.3			(42.2		)	(26.0		)
	Income tax provision (benefit)	(10.0		)	(11.3		)	26.4			(15.1		)	(10.0		)
	Income (loss) from continuing operations	(16.0		)	(20.8		)	47.9			(27.1		)	(16.0		)
	Income (loss) from discontinued operations, net of tax	(1.9		)	—			(1.9		)	1.9			(1.9		)
	Net income (loss)	(17.9		)	(20.8		)	46			(25.2		)	(17.9		)
	Less: Net income attributable to noncontrolling interests	—			—			2.1			—			2.1
	Net income (loss) attributable to ATI	$	(17.9	)	$	(20.8	)	$	43.9		$	(25.2	)	$	(20.0	)
	Comprehensive income (loss) attributable to ATI	$	(0.8	)	$	(18.8	)	$	42.5		$	(23.9	)	$	(1.0	)
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows
	For the three months ended March 31, 2015
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Cash flows provided by (used in) operating activities	$	(26.3	)	$	(42.3	)	$	80.6		$	—		$	12
	Investing Activities:
	Purchases of property, plant and equipment	—			(9.1		)	(13.5		)	—			(22.6		)
	Net receipts/(payments) on intercompany activity	—			—			(96.9		)	96.9			—
	Asset disposals and other	—			0.1			—			—			0.1
	Cash flows provided by (used in) investing activities	—			(9.0		)	(110.4		)	96.9			(22.5		)
	Financing Activities:
	Net receipts/(payments) on intercompany activity	47.4			49.5			—			(96.9		)	—
	Dividends paid to stockholders	(19.3		)	—			—			—			(19.3		)
	Other	(1.5		)	—			(0.2		)	—			(1.7		)
	Cash flows provided by (used in) financing activities	26.6			49.5			(0.2		)	(96.9		)	(21.0		)
	Increase (decrease) in cash and cash equivalents	$	0.3		$	(1.8	)	$	(30.0	)	$	—		$	(31.5	)
	Condensed Statements of Cash Flows
	For the three months ended March 31, 2014
	(In millions)	Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated
		Parent						Subsidiaries
	Cash flows provided by (used in) operating activities	$	(29.7	)	$	(125.6	)	$	98.4		$	—		$	(56.9	)
	Investing Activities:
	Purchases of property, plant and equipment	—			(26.3		)	(13.3		)	—			(39.6		)
	Purchase of business, net of cash acquired	—			—			(71.1		)	—			(71.1		)
	Net receipts/(payments) on intercompany activity	—			—			(208.9		)	208.9			—
	Asset disposals and other	—			1.4			0.4			—			1.8
	Cash flows provided by (used in) investing activities	—			(24.9		)	(292.9		)	208.9			(108.9		)
	Financing Activities:
	Net receipts/(payments) on intercompany activity	58.9			150			—			(208.9		)	—
	Dividends paid to stockholders	(19.3		)	—			—			—			(19.3		)
	Other	(4.0		)	—			—			—			(4.0		)
	Cash flows provided by (used in) financing activities	35.6			150			—			(208.9		)	(23.3		)
	Increase (decrease) in cash and cash equivalents	$	5.9		$	(0.5	)	$	(194.5	)	$	—		$	(189.1	)

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule Of Accumulated Other Comprehensive Income Loss	The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the three month period ended March 31, 2015 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, 2014	$	(931.5	)		$	(16.2		)		$	—			$	16.3			$	(931.4	)
	OCI before reclassifications		—				(21.6		)			—				11.4			(10.2		)
	Amounts reclassified from AOCI	(a)	12.5			(b)	—				(b)	—			(c)	(1.7	)		10.8
	Net current-period OCI		12.5				(21.6		)			—				9.7			0.6
	Balance, March 31, 2015	$	(919.0	)		$	(37.8		)		$	—			$	26			$	(930.8	)
	Attributable to noncontrolling interests:
	Balance, December 31, 2014	$	—			$	$	25			$	—			$	—			$	25
	OCI before reclassifications		—				(0.2		)			—				—			(0.2		)
	Amounts reclassified from AOCI		—			(b)	—					—				—			—
	Net current-period OCI		—				(0.2		)			—				—			(0.2		)
	Balance, March 31, 2015	$	—			$	24.8				$	—			$	—			$	24.8
	(a)	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 7).
	(b)	No amounts were reclassified to earnings.
	(c)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings (see Note 5).
	The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the three month period ended March 31, 2014 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, 2013	$	(718.9	)		$	15.3			$	—			$	(9.6	)		$	(713.2	)
	OCI before reclassifications		—				(1.5	)			—				5.7			4.2
	Amounts reclassified from AOCI	(a)	13.4			(b)	—			(b)	—			(c)	1.3			14.7
	Net current-period OCI		13.4				(1.5	)			—				7			18.9
	Balance, March 31, 2014	$	(705.5	)		$	13.8			$	—			$	(2.6	)		$	(694.3	)
	Attributable to noncontrolling interests:
	Balance, December 31, 2013	$	—			$	27.1			$	—			$	—			$	27.1
	OCI before reclassifications		—				(1.8	)			—				—			(1.8		)
	Amounts reclassified from AOCI		—			(b)	—				—				—			—
	Net current-period OCI		—				(1.8	)			—				—			$	(1.8	)
	Balance, March 31, 2013	$	—			$	25.3			$	—			$	—			$	25.3
	(a)	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 7).
	(b)	No amounts were reclassified to earnings.
	(c)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings (see Note 5).
Reclassification out of Accumulated Other Comprehensive Income	Reclassifications out of AOCI for the three month periods ended March 31, 2015 and 2014 were as follows:
			Amount reclassified from AOCI
	Details about AOCI Components		Three months ended March 31, 2015					Three months ended March 31, 2014					Affected line item in the
	(In millions)												statements of operations
	Postretirement benefit plans
	Prior service (cost) credit		$	(1.5	)	(a)		$	0.2		(a)
	Actuarial losses		(18.7		)	(a)		(22.0		)	(a)
			(20.2		)	(c)		(21.8		)	(c)		Total before tax
			(7.7		)			(8.4		)			Tax provision (benefit)
			$	(12.5	)			$	(13.4	)			Net of tax
	Derivatives
	Nickel and other raw material contracts		$	(3.6	)	(b)		$	(2.8	)	(b)
	Natural gas contracts		(3.9		)	(b)		2.3			(b)
	Electricity contracts		(0.2		)	(b)		0.7			(b)
	Foreign exchange contracts		10.4			(b)		(2.3		)	(b)
			2.7			(c)		(2.1		)	(c)		Total before tax
			1					(0.8		)			Tax provision (benefit)
			$	1.7				$	(1.3	)			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 7.
	(b)	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings. For additional information, see Note 5.
	(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.

Accounting_Policies_Discontinu

Accounting Policies (Discontinued Operations) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Accounting Policies [Abstract]
Discontinued operations sales	$5.20
Discontinued operations pretax loss	-2.8
Discontinued operation assets	$2.90

Accounting_Policies_Accounting

Accounting Policies (Accounting Pronouncements) (Details) (Accounting Standard Update 2015-03, USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Accounting Standard Update 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt issuance costs to be reclassified	$10.60	$10.90

Inventories_Details

Inventories (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials and supplies	$234.50		$249.30
Work-in-process	1,186.30		1,184.10
Finished goods	177		172.2
Total inventories at current cost	1,597.80		1,605.60
Adjustment from current cost to LIFO cost basis	4.3		4.8
Inventory valuation reserves	-66.4		-68.8
Progress payments	-63.1		-68.8
Total inventories, net	1,472.60		1,472.80
Inventory [Line Items]
Lifo Provision (Benefit)	0.5	9
High Performance Materials & Components
Inventory [Line Items]
Change in inventory valuation reserve	-0.5	-9
Flat Rolled Products
Inventory [Line Items]
Change in inventory valuation reserve	$5.30	$8.30

Property_Plant_and_Equipment_D

Property, Plant and Equipment (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Property, Plant and Equipment [Abstract]
Land	$30	$30.20
Buildings	1,053.10	1,048.90
Equipment and leasehold improvements	3,714.60	3,702.50
Property Plant And Equipment	4,797.70	4,781.60
Accumulated depreciation and amortization	-1,854	-1,819.80
Total property, plant and equipment, net	2,943.70	2,961.80
Construction in progress	$57.20

Debt_Schedule_of_Debt_Details

Debt Schedule of Debt (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015		Dec. 31, 2014		Feb. 15, 2015	Dec. 31, 2013
Debt Instrument [Line Items]
Total Debt	$1,527,000,000		$1,526,900,000
Short-term debt and current portion of long-term debt	17,900,000		17,800,000
Long-term debt	1,509,100,000		1,509,100,000
Allegheny Technologies 5.875% Notes due 2023 (a)
Debt Instrument [Line Items]
Long-term Debt, Gross	500,000,000	[1]	500,000,000	[1]
Debt Instrument, Issuer	Allegheny Technologies
Debt Instrument, Maturity Date	15-Aug-23		15-Aug-23
Interest rate	6.38%		6.13%		6.38%	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 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
Interest rate	6.95%
ATI Ladish Series B 6.14% Notes due 2016 (b)
Debt Instrument [Line Items]
Long-term Debt, Gross	11,700,000	[2]	11,900,000	[2]
Business Acquisition Purchase Price Allocation Notes Payable and L T Debt	300,000		400,000
ATI Ladish Series C 6.41% Notes due 2015 (c)
Debt Instrument [Line Items]
Long-term Debt, Gross	10,200,000	[3]	10,300,000	[3]
Business Acquisition Purchase Price Allocation Notes Payable and L T Debt	200,000		300,000
Domestic Bank Group $400 million credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity	400,000,000
Long-term Debt, Gross	0		0
Foreign credit facilities
Debt Instrument [Line Items]
Long-term Debt, Gross	0		0
Industrial revenue bonds, due through 2020, and other
Debt Instrument [Line Items]
Long-term Debt, Gross	5,100,000		4,700,000
ATI Ladish Series B 6.14% Notes due 2016 (b)
Debt Instrument [Line Items]
Debt Instrument, Issuer	ATI Ladish
Debt Instrument, Maturity Date	16-May-16		16-May-16
Interest rate	6.14%		6.14%
ATI Ladish Series C 6.41% Notes due 2015 (c)
Debt Instrument [Line Items]
Debt Instrument, Issuer	ATI Ladish
Debt Instrument, Maturity Date	2-Sep-15		2-Sep-15
Interest rate	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
Interest rate	5.95%		5.95%
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
Interest rate			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
Interest rate	9.38%		9.38%
Domestic Bank Group $400 million credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity			$400,000,000
[1]	Bearing interest at 6.375% effective February 15, 2015.
[2]	Includes fair value adjustments of $0.3 million at March 31, 2015 and $0.4 million at December 31, 2014.
[3]	Includes fair value adjustments of $0.2 million at March 31, 2015 and $0.3 million at December 31, 2014.

Debt_Narrative_Details

Debt Narrative (Details)

3 Months Ended

3 Months Ended

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Feb. 15, 2015

Dec. 31, 2014

Dec. 31, 2013

Mar. 31, 2015

Dec. 31, 2014

Mar. 31, 2015

Apr. 30, 2015

Apr. 30, 2015

Mar. 31, 2015

USD ($)

USD ($)

Allegheny Technologies 5.875% Notes due 2023 (a)

Allegheny Technologies 5.875% Notes due 2023 (a)

Allegheny Technologies 5.875% Notes due 2023 (a)

Allegheny Technologies 5.875% Notes due 2023 (a)

Domestic Bank Group $400 million credit facility

Domestic Bank Group $400 million credit facility

Seperateletter of Credit Facility

STAL Revolving Credit Facility

STAL Revolving Credit Facility

STAL Precision Stainless Steel Company Limited

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Subsequent Event

Subsequent Event

USD ($)

CNY

Debt Instrument [Line Items]

Interest rate

6.38%

6.38%

6.13%

5.88%

Long-term Debt, Gross

$500,000,000

[1]

$500,000,000

[1]

$0

$0

Maximum borrowing capacity

400,000,000

20,000,000

125,000,000

Amount utilized to support the issuance of letters of credit

4,700,000

Average borrowings during period

73,700,000

Line of Credit Facility, Interest Rate During Period

1.90%

Amount of Cash on Hand Used to Reduce the Indebtness Figure used in the Leverage Ratio Calculation

50,000,000

Maximum leverage ratio for the quarter ended March 31, 2015

5

Maximum leverage ratio for the quarter ended June 30, 2015

4.5

Maximum leverage ratio for the quarter ended September 30, 2015

3.75

Maximum leverage ratio for the quarter ended December 31, 2015 and for each fiscal quarter thereafter

3.5

Minimum interest coverage ratio for the quarter ended March 31, 2015

2.5

Minimum interest coverage ratio for the quarter ended June 30, 2015

3

Minimum interest coverage ratio for the quarter ended September 30, 2015

3.25

Minimum interest coverage ratio for the quarter ended December 31, 2015 and for each fiscal quarter thereafter

3.5

Actual leverage ratio

3.73

Actual interest coverage ratio

3.26

Letters of credit outstanding

32,000,000

Noncontrolling Interest, Ownership Percentage by Parent

60.00%

Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities

$300,000

$100,000

[1]

Bearing interest at 6.375% effective February 15, 2015.

Derivative_Financial_Instrumen2

Derivative Financial Instruments and Hedging (Details)

3 Months Ended

3 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2014

USD ($)

Other Comprehensive Income

Other Comprehensive Income

Cost Of Sales

Cost Of Sales

Selling And Administrative Expenses

Selling And Administrative Expenses

Nickel and other raw material contracts

Nickel and other raw material contracts

Nickel and other raw material contracts

Nickel and other raw material contracts

Nickel and other raw material contracts

Nickel and other raw material contracts

Natural gas contracts

Natural gas contracts

Natural gas contracts

Natural gas contracts

Natural gas contracts

Natural gas contracts

Electricity contracts

Electricity contracts

Electricity contracts

Electricity contracts

Electricity contracts

Electricity contracts

Foreign exchange contracts

Foreign exchange contracts

Foreign exchange contracts

Foreign exchange contracts

Foreign exchange contracts

Foreign exchange contracts

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Other Comprehensive Income

Other Comprehensive Income

Cost Of Sales

Cost Of Sales

Selling And Administrative Expenses

Selling And Administrative Expenses

Other Comprehensive Income

Other Comprehensive Income

Cost Of Sales

Cost Of Sales

Selling And Administrative Expenses

Selling And Administrative Expenses

Other Comprehensive Income

Other Comprehensive Income

Cost Of Sales

Cost Of Sales

Selling And Administrative Expenses

Selling And Administrative Expenses

Other Comprehensive Income

Other Comprehensive Income

Cost Of Sales

Cost Of Sales

Selling And Administrative Expenses

Selling And Administrative Expenses

Foreign exchange forward

Foreign exchange forward

Foreign exchange forward

Foreign exchange forward

Foreign exchange forward

Foreign exchange forward

Foreign exchange forward

Foreign exchange forward

Foreign exchange forward

Foreign exchange contracts

Foreign exchange contracts

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cash Flow Hedging

Cost Of Sales

Maturity dates Through February 2018

Maturity Dates Through 2015

Maturity Dates Through 2015

USD ($)

EUR (€)

Maturity Dates Through February 2016

Cost Of Sales

Cost Of Sales

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

EUR (€)

Fair Value Hedging

EUR (€)

EUR (€)

Fair Value Hedging

EUR (€)

USD ($)

USD ($)

USD ($)

EUR (€)

Notional Disclosures [Abstract]

Percentage of estimated annual nickel requirements

20.00%

Percentage of forecasted natural gas usage hedged for 2015

80.00%

Percentage Of Forecasted Natural Gas Usage Hedged for 2016

75.00%

Percentage Of Forecasted Natural Gas Usage Hedged for 2017

45.00%

Derivative Instruments Gain Loss [Line Items]

Notional amount of derivative

€ 375

€ 157

€ 115

€ 30

Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net

11.4

5.7

-9.6

3

-6

2.3

0

0.9

27

-0.5

Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net

1.7

-1.3

-2.2

-1.7

-2.4

1.4

-0.1

0.4

6.4

-1.4

Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net

0

0

0

0

0

0

0

0

0

0

Derivative Instruments Gain Loss Recognized In Income Net

3.5

0.2

Notional amount of derivatives net settled

126.5

40.3

Cash proceeds from settlement of hedge

26.1

11.8

Gain on derivative

5

Reclassification of Cash Flow Hedge Gain (Loss) [Abstract]

Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months

$0.70

Derivative_Financial_Instrumen3

Derivative Financial Instruments and Hedging (Details2) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	$69.10	$59.90
Derivative Fair Value Of Derivative Liability	43.6	27
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	69.1	53.5
Derivative Fair Value Of Derivative Liability	43.2	27
Not Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	6.4
Derivative Fair Value Of Derivative Liability	0.4	0
Prepaid expenses and other current assets | Nickel and other raw material contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	1.1
Prepaid expenses and other current assets | Foreign exchange contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	23.1	23.6
Prepaid expenses and other current assets | Foreign exchange contracts | Not Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	6.4
Other assets | Nickel and other raw material contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.5
Other assets | Foreign exchange contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	46	28.3
Accrued liabilities | Nickel and other raw material contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	9.9	5.8
Accrued liabilities | Natural gas contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	12.1	10.2
Accrued liabilities | Electricity contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0	0.1
Accrued liabilities | Foreign exchange contracts | Not Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.4	0
Other long-term liabilities | Nickel and other raw material contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	9.4	3
Other long-term liabilities | Natural gas contracts | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	$11.80	$7.90

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
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	$238	$269.50
Derivative financial instruments, Assets	69.1	59.9
Derivative Financial Instruments, liabilities	43.6	27
Debt	1,527	1,526.90
Estimate Of Fair Value Fair Value Disclosure
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	238	269.5
Derivative financial instruments, Assets	69.1	59.9
Derivative Financial Instruments, liabilities	43.6	27
Debt	1,679.60	1,616
Estimate Of Fair Value Fair Value Disclosure | Fair Value Inputs Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	238	269.5
Derivative financial instruments, Assets	0	0
Derivative Financial Instruments, liabilities	0	0
Debt	1,652.60	1,589.10
Estimate Of Fair Value Fair Value Disclosure | 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	69.1	59.9
Derivative Financial Instruments, liabilities	43.6	27
Debt	$27	$26.90

Pension_Plans_and_Other_Postre2

Pension Plans and Other Postretirement Benefits (Details1) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Pension Plans Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	$5.70	$7.40
Interest cost on benefits earned in prior years	30.3	33.4
Expected return on plan assets	-42.1	-46.1
Amortization of prior service cost (credit)	0.3	0.6
Amortization of net actuarial loss	15.1	18.5
Total retirement benefit expense	9.3	13.8
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	0.7	0.7
Interest cost on benefits earned in prior years	4.5	6
Expected return on plan assets	0	0
Amortization of prior service cost (credit)	1.2	-0.8
Amortization of net actuarial loss	3.6	3.5
Total retirement benefit expense	$10	$9.40

Pension_Plans_and_Other_Postre3

Pension Plans and Other Postretirement Benefits Narrative (Details) (Other Postretirement Benefit Plan, Defined Benefit [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, cost recognized	$0.70

Income_Taxes_Quarterly_Disclos

Income Taxes - Quarterly Disclosure (Details9) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Investments, Owned, Federal Income Tax Note [Line Items]
Income tax (provision) benefit	($8)	$10
Effective Income Tax Rate Continuing Operations	38.80%	38.50%
Income Tax Reconciliation Other Adjustments		2.2
Federal
Investments, Owned, Federal Income Tax Note [Line Items]
Proceeds from Income Tax Refunds	$59.90

Business_Segments_Details

Business Segments (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Sales	$1,125.50	$987.30
Operating profit (loss):	83.8	43.5
Corporate expenses	-11.8	-11.5
Interest expense, net	-26.7	-29.1
Closed company and other expenses	-5.4	-5
Retirement benefit expense	-19.3	-23.9
Income (loss) from continuing operations before income tax provision (benefit)	20.6	-26
Interest Costs Capitalized	0.6	2.3
High Performance Materials & Components
Segment Reporting Information [Line Items]
Total sales:	542.8	484.4
Operating profit (loss):	75.9	69.1
Flat Rolled Products
Segment Reporting Information [Line Items]
Total sales:	582.7	502.9
Operating profit (loss):	7.9	-25.6
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total sales:	1,169.60	1,033.70
Operating Segments [Member] | High Performance Materials & Components
Segment Reporting Information [Line Items]
Total sales:	564.9	504.1
Operating Segments [Member] | Flat Rolled Products
Segment Reporting Information [Line Items]
Total sales:	604.7	529.6
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total sales:	44.1	46.4
Intersegment Eliminations [Member] | High Performance Materials & Components
Segment Reporting Information [Line Items]
Total sales:	22.1	19.7
Intersegment Eliminations [Member] | Flat Rolled Products
Segment Reporting Information [Line Items]
Total sales:	$22	$26.70

Redeemable_Noncontrolling_Inte1

Redeemable Noncontrolling Interest Redeemable Noncontrolling Interest (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Feb. 07, 2014
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interest	$0
Redeemable noncontrolling interest	12.1	12.1
Dynamic Flowform [Member]
Redeemable Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			15.00%
[RetainedEarningsMember]
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interest	($0.10)

Per_Share_Information_Details

Per Share Information (Details) (USD $)	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share Reconciliation [Abstract]
Income (loss) from continuing operations attributable to ATI	$10	($18.10)
Redeemable noncontrolling interest	-0.1	0
Income (loss) from continuing operations available to ATI after assumed conversions	$9.90	($18.10)
Denominator for basic net income (loss) per common share-weighted average shares	107,200,000	107,000,000
Share-based compensation	800,000	0
4.25% Convertible Notes due 2014	0	0
Denominator for diluted net income (loss) per common share – adjusted weighted average shares assuming conversions	108,000,000	107,000,000
Basic income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	$0.09	($0.17)
Diluted income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	$0.09	($0.17)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount	0	10,000,000

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 $)	Mar. 31, 2015	Dec. 31, 2014
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 $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
ASSETS
Cash and cash equivalents	$238	$269.50	$837.70	$1,026.80
Accounts receivable, net	690.9	603.6
Intercompany notes receivable	0	0
Inventories, net	1,472.60	1,472.80
Prepaid expenses and other current assets	64.1	136.2
Total current assets	2,465.60	2,482.10
Property, plant and equipment, net	2,943.70	2,961.80
Cost in excess of net assets acquired	777.9	780.4
Intercompany notes receivable	0	0
Investment in subsidiaries	0	0
Other assets	369.6	358.3
Total assets	6,556.80	6,582.60
LIABILITIES AND EQUITY
Accounts payable	559.5	556.7
Accrued liabilities	288.8	323.2
Intercompany notes payable	0	0
Deferred income taxes	70.8	62.2
Short-term debt and current portion of long-term debt	17.9	17.8
Total current liabilities	937	959.9
Long-term debt	1,509.10	1,509.10
Intercompany notes payable	0	0
Accrued postretirement benefits	407.1	415.8
Pension liabilities	730.2	739.3
Deferred income taxes	91.3	80.9
Other long-term liabilities	162	156.2
Total liabilities	3,836.70	3,861.20
Redeemable noncontrolling interest	12.1	12.1
Total stockholders’ equity	2,708	2,709.30	2,967.10	2,994.70
Total Liabilities and Equity	6,556.80	6,582.60
Parent Company
ASSETS
Cash and cash equivalents	2.5	2.2
Accounts receivable, net	0.1	0.1
Intercompany notes receivable	0	0
Inventories, net	0	0
Prepaid expenses and other current assets	3	63.7
Total current assets	5.6	66
Property, plant and equipment, net	2.5	2.2
Cost in excess of net assets acquired	0	0
Intercompany notes receivable	0	0
Investment in subsidiaries	6,149.20	6,149.40
Other assets	23.5	23.7
Total assets	6,180.80	6,241.30
LIABILITIES AND EQUITY
Accounts payable	2.8	4.5
Accrued liabilities	31.7	47.5
Intercompany notes payable	1,179	1,232.60
Deferred income taxes	70.8	62.2
Short-term debt and current portion of long-term debt	0.6	0.5
Total current liabilities	1,284.90	1,347.30
Long-term debt	1,351	1,350.60
Intercompany notes payable	0	0
Accrued postretirement benefits	0	0
Pension liabilities	668.7	675.5
Deferred income taxes	91.3	80.9
Other long-term liabilities	76.9	77.7
Total liabilities	3,472.80	3,532
Redeemable noncontrolling interest	0	0
Total stockholders’ equity	2,708	2,709.30
Total Liabilities and Equity	6,180.80	6,241.30
Subsidiaries
ASSETS
Cash and cash equivalents	12	13.8
Accounts receivable, net	222.4	209.1
Intercompany notes receivable	0	0
Inventories, net	399.6	387.7
Prepaid expenses and other current assets	8.9	13.2
Total current assets	642.9	623.8
Property, plant and equipment, net	1,544.90	1,545.10
Cost in excess of net assets acquired	126.6	126.6
Intercompany notes receivable	0	0
Investment in subsidiaries	37.7	37.7
Other assets	27.7	28
Total assets	2,379.80	2,361.20
LIABILITIES AND EQUITY
Accounts payable	336.9	302
Accrued liabilities	60.3	72
Intercompany notes payable	1,188.90	1,158.20
Deferred income taxes	0	0
Short-term debt and current portion of long-term debt	0.1	0.1
Total current liabilities	1,586.20	1,532.30
Long-term debt	150.3	150.3
Intercompany notes payable	200	200
Accrued postretirement benefits	150.9	153
Pension liabilities	5.8	6
Deferred income taxes	0	0
Other long-term liabilities	20.9	22.5
Total liabilities	2,114.10	2,064.10
Redeemable noncontrolling interest	0	0
Total stockholders’ equity	265.7	297.1
Total Liabilities and Equity	2,379.80	2,361.20
NonGuarantor Subsidiaries
ASSETS
Cash and cash equivalents	223.5	253.5
Accounts receivable, net	468.4	394.4
Intercompany notes receivable	2,367.90	2,390.80
Inventories, net	1,073	1,085.10
Prepaid expenses and other current assets	52.2	59.3
Total current assets	4,185	4,183.10
Property, plant and equipment, net	1,396.30	1,414.50
Cost in excess of net assets acquired	651.3	653.8
Intercompany notes receivable	200	200
Investment in subsidiaries	0	0
Other assets	318.4	306.6
Total assets	6,751	6,758
LIABILITIES AND EQUITY
Accounts payable	219.8	250.2
Accrued liabilities	196.8	203.7
Intercompany notes payable	0	0
Deferred income taxes	0	0
Short-term debt and current portion of long-term debt	17.2	17.2
Total current liabilities	433.8	471.1
Long-term debt	7.8	8.2
Intercompany notes payable	0	0
Accrued postretirement benefits	256.2	262.8
Pension liabilities	55.7	57.8
Deferred income taxes	0	0
Other long-term liabilities	64.2	56
Total liabilities	817.7	855.9
Redeemable noncontrolling interest	12.1	12.1
Total stockholders’ equity	5,921.20	5,890
Total Liabilities and Equity	6,751	6,758
Consolidation Eliminations
ASSETS
Cash and cash equivalents	0	0
Accounts receivable, net	0	0
Intercompany notes receivable	-2,367.90	-2,390.80
Inventories, net	0	0
Prepaid expenses and other current assets	0	0
Total current assets	-2,367.90	-2,390.80
Property, plant and equipment, net	0	0
Cost in excess of net assets acquired	0	0
Intercompany notes receivable	-200	-200
Investment in subsidiaries	-6,186.90	-6,187.10
Other assets	0	0
Total assets	-8,754.80	-8,777.90
LIABILITIES AND EQUITY
Accounts payable	0	0
Accrued liabilities	0	0
Intercompany notes payable	-2,367.90	-2,390.80
Deferred income taxes	0	0
Short-term debt and current portion of long-term debt	0	0
Total current liabilities	-2,367.90	-2,390.80
Long-term debt	0	0
Intercompany notes payable	-200	-200
Accrued postretirement benefits	0	0
Pension liabilities	0	0
Deferred income taxes	0	0
Other long-term liabilities	0	0
Total liabilities	-2,567.90	-2,590.80
Redeemable noncontrolling interest	0	0
Total stockholders’ equity	-6,186.90	-6,187.10
Total Liabilities and Equity	($8,754.80)	($8,777.90)

Financial_Information_for_Subs4

Financial Information for Subsidiary and Guarantor Parent (I.S.) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Sales	$1,125.50	$987.30
Cost of sales	1,016	917.1
Selling and administrative expenses	63.1	67.7
Income (loss) before interest, other income and income taxes	46.4	2.5
Interest income (expense), net	-26.7	-29.1
Other income (loss) including equity in income of unconsolidated subsidiaries	0.9	0.6
Income (loss) from continuing operations before income tax provision (benefit)	20.6	-26
Income tax provision (benefit)	8	-10
Income (loss) from continuing operations	12.6	-16
Income (loss) from discontinued operations, net of tax	0	-1.9
Net income (loss)	12.6	-17.9
Less: Net income attributable to noncontrolling interests	2.6	2.1
Net income (loss) attributable to ATI	10	-20
Comprehensive income (loss) attributable to ATI	10.6	-1
Parent Company
Income Statement [Abstract]
Sales	0	0
Cost of sales	2.2	12.3
Selling and administrative expenses	25.8	27.1
Income (loss) before interest, other income and income taxes	-28	-39.4
Interest income (expense), net	-28	-28.5
Other income (loss) including equity in income of unconsolidated subsidiaries	76.6	41.9
Income (loss) from continuing operations before income tax provision (benefit)	20.6	-26
Income tax provision (benefit)	8	-10
Income (loss) from continuing operations	12.6	-16
Income (loss) from discontinued operations, net of tax	0	-1.9
Net income (loss)	12.6	-17.9
Less: Net income attributable to noncontrolling interests	0	0
Net income (loss) attributable to ATI	12.6	-17.9
Comprehensive income (loss) attributable to ATI	13	-0.8
Subsidiaries
Income Statement [Abstract]
Sales	508.5	427.9
Cost of sales	504	439.6
Selling and administrative expenses	11.7	10.1
Income (loss) before interest, other income and income taxes	-7.2	-21.8
Interest income (expense), net	-12.2	-10.6
Other income (loss) including equity in income of unconsolidated subsidiaries	0.4	0.3
Income (loss) from continuing operations before income tax provision (benefit)	-19	-32.1
Income tax provision (benefit)	-6.6	-11.3
Income (loss) from continuing operations	-12.4	-20.8
Income (loss) from discontinued operations, net of tax	0	0
Net income (loss)	-12.4	-20.8
Less: Net income attributable to noncontrolling interests	0	0
Net income (loss) attributable to ATI	-12.4	-20.8
Comprehensive income (loss) attributable to ATI	-9.1	-18.8
NonGuarantor Subsidiaries
Income Statement [Abstract]
Sales	617	559.4
Cost of sales	509.8	465.2
Selling and administrative expenses	25.6	30.5
Income (loss) before interest, other income and income taxes	81.6	63.7
Interest income (expense), net	13.5	10
Other income (loss) including equity in income of unconsolidated subsidiaries	0.6	0.6
Income (loss) from continuing operations before income tax provision (benefit)	95.7	74.3
Income tax provision (benefit)	34.1	26.4
Income (loss) from continuing operations	61.6	47.9
Income (loss) from discontinued operations, net of tax	0	-1.9
Net income (loss)	61.6	46
Less: Net income attributable to noncontrolling interests	2.6	2.1
Net income (loss) attributable to ATI	59	43.9
Comprehensive income (loss) attributable to ATI	37.8	42.5
Consolidation Eliminations
Income Statement [Abstract]
Sales	0	0
Cost of sales	0	0
Selling and administrative expenses	0	0
Income (loss) before interest, other income and income taxes	0	0
Interest income (expense), net	0	0
Other income (loss) including equity in income of unconsolidated subsidiaries	-76.7	-42.2
Income (loss) from continuing operations before income tax provision (benefit)	-76.7	-42.2
Income tax provision (benefit)	-27.5	-15.1
Income (loss) from continuing operations	-49.2	-27.1
Income (loss) from discontinued operations, net of tax	0	1.9
Net income (loss)	-49.2	-25.2
Less: Net income attributable to noncontrolling interests	0	0
Net income (loss) attributable to ATI	-49.2	-25.2
Comprehensive income (loss) attributable to ATI	($31.10)	($23.90)

Financial_Information_for_Subs5

Financial Information for Subsidiary and Guarantor Parent (Cash Flow) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Cash Flows
Cash flows provided by (used in) operating activities	$12	($56.90)
Investing Activities:
Purchases of property, plant and equipment	-22.6	-39.6
Purchases of businesses, net of cash acquired	0	-71.1
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0.1	1.8
Cash used in investing activities	-22.5	-108.9
Financing Activities:
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities	-0.3	-0.1
Net receipts/(payments) on intercompany activity	0	0
Dividends paid to stockholders	-19.3	-19.3
Other	-1.7	-4
Cash used in financing activities	-21	-23.3
Decrease in cash and cash equivalents	-31.5	-189.1
Parent Company
Statement of Cash Flows
Cash flows provided by (used in) operating activities	-26.3	-29.7
Investing Activities:
Purchases of property, plant and equipment	0	0
Purchases of businesses, net of cash acquired		0
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0	0
Cash used in investing activities	0	0
Financing Activities:
Net receipts/(payments) on intercompany activity	47.4	58.9
Dividends paid to stockholders	-19.3	-19.3
Other	-1.5	-4
Cash used in financing activities	26.6	35.6
Decrease in cash and cash equivalents	0.3	5.9
Subsidiaries
Statement of Cash Flows
Cash flows provided by (used in) operating activities	-42.3	-125.6
Investing Activities:
Purchases of property, plant and equipment	-9.1	-26.3
Purchases of businesses, net of cash acquired		0
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0.1	1.4
Cash used in investing activities	-9	-24.9
Financing Activities:
Net receipts/(payments) on intercompany activity	49.5	150
Dividends paid to stockholders	0	0
Other	0	0
Cash used in financing activities	49.5	150
Decrease in cash and cash equivalents	-1.8	-0.5
NonGuarantor Subsidiaries
Statement of Cash Flows
Cash flows provided by (used in) operating activities	80.6	98.4
Investing Activities:
Purchases of property, plant and equipment	-13.5	-13.3
Purchases of businesses, net of cash acquired		-71.1
Net receipts/(payments) on intercompany activity	-96.9	-208.9
Asset disposals and other	0	0.4
Cash used in investing activities	-110.4	-292.9
Financing Activities:
Net receipts/(payments) on intercompany activity	0	0
Dividends paid to stockholders	0	0
Other	-0.2	0
Cash used in financing activities	-0.2	0
Decrease in cash and cash equivalents	-30	-194.5
Consolidation Eliminations
Statement of Cash Flows
Cash flows provided by (used in) operating activities	0	0
Investing Activities:
Purchases of property, plant and equipment	0	0
Purchases of businesses, net of cash acquired		0
Net receipts/(payments) on intercompany activity	96.9	208.9
Asset disposals and other	0	0
Cash used in investing activities	96.9	208.9
Financing Activities:
Net receipts/(payments) on intercompany activity	-96.9	-208.9
Dividends paid to stockholders	0	0
Other	0	0
Cash used in financing activities	-96.9	-208.9
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 $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Current assets	$2,465.60		$2,482.10
Assets	6,556.80		6,582.60
Current liabilities	937		959.9
Liabilities	3,836.70		3,861.20
Stockholders' equity	2,708	2,967.10	2,709.30	2,994.70
Cash flows provided by (used in) operating activities	12	-56.9
Net Cash Provided by (Used in) Investing Activities	-22.5	-108.9
Cash used in financing activities	-21	-23.3
NonGuarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Current assets	4,185		4,183.10
Assets	6,751		6,758
Current liabilities	433.8		471.1
Liabilities	817.7		855.9
Stockholders' equity	5,921.20		5,890
Cash flows provided by (used in) operating activities	80.6	98.4
Net Cash Provided by (Used in) Investing Activities	-110.4	-292.9
Cash used in financing activities	-0.2	0
Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Current assets	642.9		623.8
Assets	2,379.80		2,361.20
Current liabilities	1,586.20		1,532.30
Liabilities	2,114.10		2,064.10
Stockholders' equity	265.7		297.1
Cash flows provided by (used in) operating activities	-42.3	-125.6
Net Cash Provided by (Used in) Investing Activities	-9	-24.9
Cash used in financing activities	49.5	150
Parent Company
Condensed Financial Statements, Captions [Line Items]
Current assets	5.6		66
Assets	6,180.80		6,241.30
Current liabilities	1,284.90		1,347.30
Liabilities	3,472.80		3,532
Stockholders' equity	2,708		2,709.30
Cash flows provided by (used in) operating activities	-26.3	-29.7
Net Cash Provided by (Used in) Investing Activities	0	0
Cash used in financing activities	26.6	35.6
Consolidation Eliminations
Condensed Financial Statements, Captions [Line Items]
Current assets	-2,367.90		-2,390.80
Assets	-8,754.80		-8,777.90
Current liabilities	-2,367.90		-2,390.80
Liabilities	-2,567.90		-2,590.80
Stockholders' equity	-6,186.90		-6,187.10
Cash flows provided by (used in) operating activities	0	0
Net Cash Provided by (Used in) Investing Activities	96.9	208.9
Cash used in financing activities	($96.90)	($208.90)

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	($931.40)		($713.20)
OCI before reclassifications	-10.2		4.2
Amounts reclassified from AOCI	10.8		14.7
Net current-period OCI	0.6		18.9
Ending balance	-930.8		-694.3
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	25		27.1
OCI before reclassifications	-0.2		-1.8
Amounts reclassified from AOCI	0		0
Net current-period OCI	-0.2		-1.8
Ending balance	24.8		25.3
Post- retirement benefit plans [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	-931.5		-718.9
OCI before reclassifications	0		0
Amounts reclassified from AOCI	12.5	[1]	13.4	[1]
Net current-period OCI	12.5		13.4
Ending balance	-919		-705.5
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	0		0
OCI before reclassifications	0		0
Amounts reclassified from AOCI	0		0
Net current-period OCI	0		0
Ending balance	0		0
Currency translation adjustment [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	-16.2		15.3
OCI before reclassifications	-21.6		-1.5
Amounts reclassified from AOCI	0	[2]	0	[2]
Net current-period OCI	-21.6		-1.5
Ending balance	-37.8		13.8
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	25		27.1
OCI before reclassifications	-0.2		-1.8
Amounts reclassified from AOCI	0	[2]	0	[2]
Net current-period OCI	-0.2		-1.8
Ending balance	24.8		25.3
Unrealized holding gains on securities [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0		0
OCI before reclassifications	0		0
Amounts reclassified from AOCI	0	[2]	0	[2]
Net current-period OCI	0		0
Ending balance	0		0
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	0		0
OCI before reclassifications	0		0
Amounts reclassified from AOCI	0		0
Net current-period OCI	0		0
Ending balance	0		0
Derivatives [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	16.3		-9.6
OCI before reclassifications	11.4		5.7
Amounts reclassified from AOCI	-1.7	[3]	1.3	[3]
Net current-period OCI	9.7		7
Ending balance	26		-2.6
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	0		0
OCI before reclassifications	0		0
Amounts reclassified from AOCI	0		0
Net current-period OCI	0		0
Ending balance	$0		$0
[1]	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 7).
[2]	No amounts were reclassified to earnings.
[3]	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings (see Note 5).

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization to net income of net prior service cost (credits)	$1.50		($0.20)
Amount reclassified from AOCI, Postretirement benefit plans, Actuarial losses	18.7		22
Income (loss) from continuing operations before income tax provision (benefit)	20.6		-26
Income tax provision (benefit)	8		-10
Income (loss) from continuing operations	12.6		-16
Amount reclassified from AOCI, Gain (loss) on derivatives	-1,016		-917.1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Post- retirement benefit plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization to net income of net prior service cost (credits)	-1.5	[1]	0.2	[1]
Amount reclassified from AOCI, Postretirement benefit plans, Actuarial losses	-18.7	[1]	-22	[1]
Income (loss) from continuing operations before income tax provision (benefit)	-20.2	[2]	-21.8	[2]
Income tax provision (benefit)	-7.7		-8.4
Income (loss) from continuing operations	-12.5		-13.4
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before income tax provision (benefit)	2.7	[2]	-2.1	[2]
Income tax provision (benefit)	1		-0.8
Income (loss) from continuing operations	1.7		-1.3
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Nickel and other raw material contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCI, Gain (loss) on derivatives	-3.6	[3]	-2.8	[3]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Natural gas contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCI, Gain (loss) on derivatives	-3.9	[3]	2.3	[3]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Electricity contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCI, Gain (loss) on derivatives	-0.2	[3]	0.7	[3]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCI, Gain (loss) on derivatives	$10.40	[3]	($2.30)	[3]
[1]	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 7.
[2]	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.
[3]	Amounts are included in cost of goods sold in the period or periods the hedged item affects earnings. For additional information, see Note 5.

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified
Components of Environmental Loss Accrual [Abstract]
Accrual For Environmental Loss Contingencies	$17
Accrued Environmental Loss Contingencies Current	9
Federal Superfund and comparable state-managed sites	5
Formerly owned or operated sites	10
Owned or controlled sites at which Company operations have been discontinued	1
Sites utilized by the company in its ongoing operations	1
Loss Contingency, Estimate [Abstract]
Loss contingency maximum possible loss	$19