ATI (ATI) 10-Q 2 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	9 Months Ended
	Sep. 30, 2016	Oct. 21, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Amendment Flag	false
Entity Registrant Name	ALLEGHENY TECHNOLOGIES INCORPORATED
Entity Central Index Key	1,018,963
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		108,927,240
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Entity Public Float			$ 3,300,000,000

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 188.4	$ 149.8
Accounts receivable, net	454	400.3
Inventories, net	1,078.9	1,271.6
Prepaid expenses and other current assets	40.8	45.9
Total current assets	1,762.1	1,867.6
Property, plant and equipment, net	2,514.4	2,928.2
Goodwill	644.4	651.4
Other assets	271.4	304.5
Total assets	5,192.3	5,751.7
Current Liabilities:
Accounts payable	285.2	380.8
Accrued liabilities	310.9	301.8
Short-term debt and current portion of long-term debt	5.4	3.9
Total current liabilities	601.5	686.5
Long-term debt	1,870.4	1,491.8
Accrued postretirement benefits	311.6	359.2
Pension liabilities	708.6	833.8
Deferred income taxes	51.3	75.6
Other long-term liabilities	86.2	108.3
Total liabilities	3,629.6	3,555.2
Redeemable noncontrolling interest	0	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 September 30, 2016 and December 31, 2015; outstanding-108,927,240 shares at September 30, 2016 and 109,174,882 shares at December 31, 2015	11	11
Additional paid-in capital	1,183.3	1,161.7
Retained earnings	1,267.1	1,945.9
Treasury stock: 767,931 shares at September 30, 2016 and 520,289 shares at December 31, 2015	(27.9)	(21.3)
Accumulated other comprehensive loss, net of tax	(961.7)	(1,014.5)
Total ATI stockholders’ equity	1,471.8	2,082.8
Noncontrolling interests
Noncontrolling interests	90.9	101.6
Total Equity	1,562.7	2,184.4
Total Liabilities and Equity	$ 5,192.3	$ 5,751.7

CONSOLIDATED BALANCE SHEETS (PA

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, authorized	50,000,000	50,000,000
Preferred stock, issued	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, authorized	500,000,000	500,000,000
Common stock, issued	109,695,171	109,695,171
Common stock, oustanding	108,927,240	109,174,882
Treasury stock	767,931	520,289

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Sales	$ 770.5	$ 832.7	$ 2,338.5	$ 2,980.7
Cost of sales	720.3	861.4	2,273.3	2,822.9
Gross profit (loss)	50.2	(28.7)	65.2	157.8
Selling and administrative expenses	60.5	62.5	182.4	198
Restructuring charges	488.6	0	498.6	0
Operating loss	(498.9)	(91.2)	(615.8)	(40.2)
Interest expense, net	(32.6)	(27.5)	(91.2)	(81)
Other income, net	0	0.8	1.8	2.3
Loss before income taxes	(531.5)	(117.9)	(705.2)	(118.9)
Income tax provision (benefit)	(4.3)	23.4	(64.4)	23.7
Net income (loss)	(527.2)	(141.3)	(640.8)	(142.6)
Less: Net income attributable to noncontrolling interests	3.6	3.3	10	8.4
Net income (loss) attributable to ATI	$ (530.8)	$ (144.6)	$ (650.8)	$ (151)
Basic net loss attributable to ATI per common share (in dollars per share)	$ (4.95)	$ (1.35)	$ (6.07)	$ (1.41)
Diluted net loss attributable to ATI per common share (in dollars per share)	(4.95)	(1.35)	(6.07)	(1.41)
Dividends declared per common share (in dollars per share)	$ 0.08	$ 0.18	$ 0.24	$ 0.54

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (527.2)	$ (141.3)	$ (640.8)	$ (142.6)
Currency translation adjustment
Unrealized net change arising during the period	(4.4)	(16.2)	(19.6)	(18.7)
Unrealized holding gain on securities
Net loss arising during the period	0	0	0	(0.1)
Derivatives
Net derivatives gain (loss) on hedge transactions	4.8	(26.8)	21.9	(18.7)
Reclassification to net income (loss) of net realized loss (gain)	0.6	(3.3)	8.5	(8.1)
Income taxes on derivative transactions	2	(11.6)	11.5	(10.3)
Total	3.4	(18.5)	18.9	(16.5)
Postretirement benefit plans
Amortization of net actuarial loss	18.7	18.8	56.2	56.2
Net gain arising during period	0	0	22.5	0
Amortization to net income (loss) of net prior service cost (credit)	(0.4)	1.5	0	4.5
Income taxes on postretirement benefit plans	6.9	7.8	29.8	23.2
Total	11.4	12.5	48.9	37.5
Other comprehensive income (loss), net of tax	10.4	(22.2)	48.2	2.2
Comprehensive loss	(516.8)	(163.5)	(592.6)	(140.4)
Less: Comprehensive income (loss) attributable to noncontrolling interests	2	(0.8)	5.4	4.6
Comprehensive loss attributable to ATI	$ (518.8)	$ (162.7)	$ (598)	$ (145)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015
Operating Activities:
Net loss		$ (640.8)	$ (142.6)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization		130.2	141.4
Deferred taxes		(78.1)	9.6
Non-cash restructuring charges		471.3	0
Changes in operating assets and liabilities:
Inventories		192.7	116.7
Accounts receivable		(53.7)	106.1
Accounts payable		(60.2)	(189.7)
Retirement benefits	[1]	(94.6)	7.9
Accrued income taxes		7.7	61
Accrued liabilities and other		13.8	(1.5)
Cash provided by (used in) operating activities		(111.7)	108.9
Investing Activities:
Purchases of property, plant and equipment		(174.9)	(99.5)
Purchases of businesses, net of cash acquired		0	(0.5)
Asset disposals and other		2.1	0
Cash used in investing activities		(172.8)	(100)
Financing Activities:
Borrowings on long-term debt		387.5	0
Payments on long-term debt and capital leases		(2.4)	(23.3)
Net borrowings under credit facilities		2.4	1.7
Debt issuance costs		(10.4)	0
Dividends paid to stockholders		(25.8)	(57.9)
Dividends paid to noncontrolling interests		(16)	0
Acquisition of noncontrolling interests		(12.2)	0
Shares repurchased for income tax withholding on share-based compensation		0	(1.4)
Cash provided by (used in) financing activities		323.1	(80.9)
Increase (decrease) in cash and cash equivalents
Increase (decrease) in cash and cash equivalents		38.6	(72)
Cash and cash equivalents at beginning of period		149.8	269.5
Cash and cash equivalents at end of period		$ 188.4	$ 197.5
[1]	Includes a $(115) million contribution to the U.S. defined benefit pension plan in 2016.

CONSOLIDATED STATEMENTS OF CAS7

CONSOLIDATED STATEMENTS OF CASH FLOWS CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) $ in Millions	1 Months Ended
	Jul. 31, 2016USD ($)
Statement of Cash Flows [Abstract]
Defined benefit plan contributions made	$ (115)

STATEMENTS OF CHANGES IN CONSOL

STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY - USD ($) $ in Millions	Total	[CommonStockMember]	[AdditionalPaidInCapitalMember]	[RetainedEarningsMember]	[TreasuryStockMember]	[AccumulatedOtherComprehensiveIncomeMember]	[NoncontrollingInterestMember]
Total Stockholders' Equity at Dec. 31, 2014	$ 2,709.3	$ 11	$ 1,164.2	$ 2,398.9	$ (44.3)	$ (931.4)	$ 110.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(142.6)			(151)			8.4
Other comprehensive income (loss)	2.2					6	(3.8)
Cash dividends on common stock	(57.9)			(57.9)
Dividends to noncontrolling interests	(16)						(16)
Redeemable noncontrolling interest	0			(0.3)			0.3
Employee stock plans	10.5		(5.4)	(8)	23.9
Total Stockholders' Equity at Sep. 30, 2015	2,505.5	11	1,158.8	2,181.7	(20.4)	(925.4)	99.8
Total Stockholders' Equity at Dec. 31, 2015	2,184.4	11	1,161.7	1,945.9	(21.3)	(1,014.5)	101.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(640.8)			(650.8)			10
Other comprehensive income (loss)	48.2					52.8	(4.6)
Cash dividends on common stock	(25.8)			(25.8)
Purchase of subsidiary shares from noncontrolling interest	(0.1)						(0.1)
Dividends to noncontrolling interests	(16)						(16)
Employee stock plans	12.8		21.6	(2.2)	(6.6)
Total Stockholders' Equity at Sep. 30, 2016	$ 1,562.7	$ 11	$ 1,183.3	$ 1,267.1	$ (27.9)	$ (961.7)	$ 90.9

STATEMENTS OF CHANGES IN CONSO9

STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY (PARENTHETICAL) - $ / shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Cash dividends on common stock per share	$ 0.24	$ 0.54

Accounting Policies

Accounting Policies	9 Months Ended
	Sep. 30, 2016
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 2015 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, 2015 financial information has been derived from the Company’s audited consolidated financial statements. Pending Accounting Pronouncements In March 2016, the FASB issued new guidance to simplify employee share-based payment accounting. The areas for simplification in this guidance involve several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This new guidance is effective for the Company’s 2017 fiscal year with early adoption permitted. The Company is currently evaluating the possible impact of this new guidance, but does not anticipate that it will have a material impact on its consolidated financial statements. In February 2016, the FASB issued new guidance on the accounting for leases. This new guidance will require that a lessee recognize assets and liabilities on the balance sheet for all leases with a lease term of more than twelve months, with the result being the recognition of a right of use asset and a lease liability. The new lease accounting requirements are effective for the Company’s 2019 fiscal year with a modified retrospective transition approach required, with early adoption permitted. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements. In July 2015, the FASB issued changes to simplify the measurement of inventory valuation at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The new inventory measurement requirements are effective for the Company’s 2017 fiscal year, and will replace the current inventory valuation guidance that requires the use of a lower of cost or market framework. This change in the measurement of inventory does not apply to inventory valued on a LIFO basis, which is the accounting basis used for most of the Company’s inventory. The adoption of these changes is not expected to have a material impact on the Company’s consolidated financial statements. In May 2014, the FASB issued changes to revenue recognition with customers, which is required to be adopted by the Company in fiscal year 2018. This update provides a five-step analysis of transactions to determine when and how revenue is recognized, along with expanded disclosure requirements. 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. The Company plans to adopt this accounting standard update using the modified retrospective method, with the cumulative effect of initially applying this update recognized in the first reporting period of 2018. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2016
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories at September 30, 2016 and December 31, 2015 were as follows (in millions): September 30, December 31, Raw materials and supplies $ 157.0 $ 216.0 Work-in-process 865.7 990.3 Finished goods 169.4 184.1 Total inventories at current cost 1,192.1 1,390.4 Adjustment from current cost to LIFO cost basis 113.3 136.4 Inventory valuation reserves (187.5 ) (206.3 ) Progress payments (39.0 ) (48.9 ) Total inventories, net $ 1,078.9 $ 1,271.6 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. Due to deflationary impacts primarily related to raw materials, the carrying value of the Company’s inventory as valued on LIFO exceeds current replacement cost, and based on a lower of cost or market value analysis, a net realizable value (NRV) inventory reserve is required. Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV inventory reserves were as follows (in millions): Nine months ended September 30, 2016 2015 LIFO benefit (charge) $ (23.1 ) $ 80.3 NRV benefit (charge) 23.5 (80.3 ) Net cost of sales impact $ 0.4 $ — The first nine months of 2016 and 2015 results included $17.7 million and $16.6 million , respectively, in inventory valuation charges related to the market-based valuation of titanium products. Additionally, in the third quarter of 2016, in conjunction with the indefinite idling of the Company’s Rowley, UT titanium sponge facility (see Note 10 for further explanation), an additional $11.3 million charge was taken to revalue titanium sponge inventory based on revised assessments of industrial grade titanium market conditions and expected utilization of this inventory.

Property Plant And Equipment

Property Plant And Equipment	9 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Property Plant and Equipment	Property, Plant and Equipment Property, plant and equipment at September 30, 2016 and December 31, 2015 was as follows (in millions): September 30, December 31, Land $ 31.7 $ 31.0 Buildings 847.3 1,048.2 Equipment and leasehold improvements 3,646.8 3,858.1 4,525.8 4,937.3 Accumulated depreciation and amortization (2,011.4 ) (2,009.1 ) Total property, plant and equipment, net $ 2,514.4 $ 2,928.2 The construction in progress portion of property, plant and equipment at September 30, 2016 was $130.9 million .

Debt

Debt	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Debt	Debt Debt at September 30, 2016 and December 31, 2015 was as follows (in millions): September 30, December 31, Allegheny Technologies 5.875% Notes due 2023 (a) $ 500.0 $ 500.0 Allegheny Technologies 5.95% Notes due 2021 500.0 500.0 Allegheny Technologies 9.375% Notes due 2019 350.0 350.0 Allegheny Technologies 4.75% Convertible Senior Notes due 2022 287.5 — Allegheny Ludlum 6.95% debentures due 2025 150.0 150.0 Term Loan due 2017 100.0 — U.S. revolving credit facility — — Foreign credit facilities 3.8 1.4 Industrial revenue bonds, due through 2020, and other 2.5 3.8 Debt issuance costs (18.0 ) (9.5 ) Total debt 1,875.8 1,495.7 Short-term debt and current portion of long-term debt 5.4 3.9 Total long-term debt $ 1,870.4 $ 1,491.8 (a) Bearing interest at 7.875% effective February 15, 2016. The stated interest rate payable on the Senior Notes due 2023 (2023 Notes) is subject to adjustment in the event of changes in the credit ratings on the 2023 Notes by either Moody’s or Standard & Poor’s (S&P). During the first quarter of 2016, S&P downgraded the Company’s credit rating one notch to B+ from BB-. This downgrade resulted in an increase of the interest rate on the 2023 Notes from 7.625% as of December 31, 2015 to 7.875% effective with the interest period beginning February 15, 2016 and represents an additional $1.3 million of interest expense measured on an annual basis. Any further credit rating downgrades will not affect the interest rate of the 2023 Notes. Revolving Credit Facility The Company has an Asset Based Lending (ABL) Revolving Credit Facility, which matures in September 2020 and is collateralized by the accounts receivable and inventory of the Company’s domestic operations. The revolving credit portion of the ABL facility is $400 million , which includes a letter of credit sub-facility of up to $200 million . In May 2016, the ABL facility was amended to add an eighteen month term loan (Term Loan) in the amount of $100.0 million , to support the Company’s restructuring actions and operational needs, and to amend certain of the ABL covenants and related defined terms. The interest rate on this Term Loan is 3.5% plus a LIBOR spread. Costs associated with amending the ABL facility were $0.9 million , and are being amortized to interest expense over the term of the facility. Proceeds of the Term Loan were used to pay down outstanding borrowings under the revolving credit portion of the ABL facility. The Term Loan is due on November 13, 2017 and can be prepaid in its entirety on a one-time basis on or after May 13, 2017 if certain minimum liquidity conditions are satisfied. The underwriting fees and other third-party expenses for the issuance of the Term Loan were $1.0 million and are being amortized to interest expense over the eighteen month term of the loan. As amended, the applicable interest rate for borrowings under the ABL facility includes interest rate spreads based on available borrowing capacity that range between 2.0% and 2.5% for LIBOR-based borrowings and between 1.0% and 1.5% for base rate borrowings. As amended, the ABL facility contains a financial covenant whereby the Company must maintain a fixed charge coverage ratio of not less than 1.00 : 1.00 after an event of default has occurred and is continuing or if the undrawn availability under the ABL facility is less than the greater of (i) 12.5% of the then applicable maximum borrowing amount or (ii) $40.0 million . The Company does not meet this required fixed charge coverage ratio at September 30, 2016 . As a result, the Company is not able to access this remaining 12.5% or $62.5 million of the ABL facility until it meets the required ratio. Additionally, the Company must demonstrate liquidity, as calculated in accordance with the terms of the agreement, of at least $500 million on the date that is 91 days prior to June 1, 2019, the maturity date of the 9.375% Senior Notes due 2019, and that such liquidity is available at all times thereafter until the 9.375% Senior Notes due 2019 are paid in full or refinanced. There were no outstanding revolving credit borrowings under the ABL facility as of September 30, 2016 , and $10.8 million was utilized to support the issuance of letters of credit. Average revolving credit borrowings under the ABL facility for the first nine months of 2016 were $109 million , bearing an average annual interest rate of 1.757% . The Company has an additional separate credit facility for the issuance of letters of credit. As of September 30, 2016 , $32 million in letters of credit were outstanding under this facility. Convertible Notes In May 2016, the Company issued and sold $250 million aggregate principal amount of 4.75% Convertible Senior Notes due 2022 (the Convertible Notes). The Company granted the underwriters a 30-day option to purchase up to an additional $37.5 million aggregate principal amount of Convertible Notes on the same terms and conditions to cover over-allotments, if any. On June 1, 2016, the Company announced that the underwriters exercised this option in full and on June 2, 2016, the Company completed the offering and sale of the additional $37.5 million aggregate principal amount of Convertible Notes. Interest on the Convertible Notes is payable in cash semi-annually in arrears on each January 1 and July 1, commencing January 1, 2017. The Company used a portion of the proceeds from the Convertible Notes to make a $115 million contribution in July 2016 to the Company’s U.S. defined benefit pension plan, and expects to use additional Convertible Note proceeds to meet future pension funding requirements. The underwriting fees and other third-party expense for the issuance of the Convertible Notes were $9.4 million and are being amortized to interest expense over the 6 -year term of the Convertible Notes. The Company does not have the right to redeem the Convertible Notes prior to their stated maturity date. Holders of the Convertible Notes have the option to convert their notes into shares of the Company’s common stock, at any time prior to the close of business on the business day immediately preceding the stated maturity date (July 1, 2022). The initial conversion rate for the Convertible Notes is 69.2042 shares of ATI common stock per $1,000 (in whole dollars) principal amount of Notes ( 19.9 million shares), equivalent to conversion price of $14.45 per share, subject to adjustment in certain events. Other than receiving cash in lieu of fractional shares, holders do not have the option to receive cash instead of shares of common stock upon conversion. Accrued and unpaid interest that exists upon conversion of a note will be deemed paid by the delivery of shares of ATI common stock and no cash payment or additional shares will be given to the holders. If the Company undergoes a fundamental change, holders of the Convertible Notes may require the Company to repurchase the notes in whole or in part for cash at a price equal to 100% of the principal amount of the notes to be purchased plus any accrued and unpaid interest to, but excluding, the repurchase date.

Derivative Financial Instrument

Derivative Financial Instruments and Hedging	9 Months Ended
	Sep. 30, 2016
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 September 30, 2016 , 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 29 million pounds of nickel with hedge dates through 2020. The aggregate notional amount hedged is approximately 30% of a single year’s estimated nickel raw material purchase requirements. At September 30, 2016 , the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas cost hedges. In the first nine months of 2016, due to changes in expected operating levels, the Company concluded that additional portions of these natural gas hedges for 2016 and the first quarter of 2017 were ineffective based on forecast changes in underlying natural gas usage. The Company recognized a $0.4 million and $1.7 million pre-tax loss for the three and nine months ended September 30, 2016 , respectively, for natural gas cash flow hedge ineffectiveness, which is reported in selling and administrative expenses on the consolidated statement of operations. Approximately 90% of the Company’s annual forecasted domestic requirements for natural gas for 2017 and approximately 25% for 2018 are hedged. 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. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions. In 2015, the Company net settled substantially all of its foreign currency forward contracts designated as cash flow hedges with 2016 and 2017 maturity dates. The portion of the deferred gains on these settled cash flow hedges determined to be effective is currently recognized in accumulated other comprehensive income and is reclassified to earnings when the underlying transactions occur. As of September 30, 2016 , the Company held 67.2 million euro notional value of foreign currency forward contracts designated as fair value hedges with maturity dates through 2017. The Company recorded a $0.5 million and $3.0 million charge in the three and nine months ended September 30, 2016 , respectively, and a $1.8 million charge and a $5.6 million benefit in the three and nine months ended September 30, 2015 , respectively, in costs of sales on the consolidated statement of operations for maturities and 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) Asset derivatives Balance sheet location September 30, December 31, Derivatives designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets $ 0.2 $ 1.6 Nickel and other raw material contracts Prepaid expenses and other current assets 3.5 — Foreign exchange contracts Other assets 0.2 0.4 Nickel and other raw material contracts Other assets 5.8 — Total derivatives designated as hedging instruments 9.7 2.0 Derivatives not designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets 0.2 0.4 Total derivatives not designated as hedging instruments 0.2 0.4 Total asset derivatives $ 9.9 $ 2.4 Liability derivatives Balance sheet location Derivatives designated as hedging instruments: Natural gas contracts Accrued liabilities $ 8.5 $ 17.3 Nickel and other raw material contracts Accrued liabilities 8.8 22.2 Foreign exchange contracts Accrued liabilities 1.4 0.1 Natural gas contracts Other long-term liabilities 0.8 8.5 Nickel and other raw material contracts Other long-term liabilities 8.7 23.0 Foreign exchange contracts Other long-term liabilities 0.3 0.1 Total derivatives designated as hedging instruments 28.5 71.2 Derivatives not designated as hedging instruments: Foreign exchange contracts Accrued liabilities — 0.1 Total derivatives not designated as hedging instruments — 0.1 Total liability derivatives $ 28.5 $ 71.3 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. Assuming market prices remain constant with those at September 30, 2016 , a loss of $9.3 million is expected to be recognized over the next 12 months. Activity with regard to derivatives designated as cash flow hedges for the three and nine month periods ended September 30, 2016 and 2015 was as follows (in millions): Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (a) Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing) (b) Derivatives in Cash Flow Three months ended September 30, Three months ended September 30, Three months ended September 30, Hedging Relationships 2016 2015 2016 2015 2016 2015 Nickel and other raw material contracts $ 4.2 $ (13.5 ) $ (2.2 ) $ (2.4 ) $ — $ — Natural gas contracts (1.2 ) (3.7 ) (1.3 ) (1.6 ) (0.3 ) — Electricity contracts — — — — — — Foreign exchange contracts — 0.7 3.4 6.0 — — Total $ 3.0 $ (16.5 ) $ (0.1 ) $ 2.0 $ (0.3 ) $ — Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (a) Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing) (b) Derivatives in Cash Flow Nine months ended September 30, Nine months ended September 30, Nine months ended September 30, Hedging Relationships 2016 2015 2016 2015 2016 2015 Nickel and other raw material contracts $ 13.0 $ (26.6 ) $ (9.9 ) $ (7.0 ) $ — $ — Natural gas contracts 1.1 (9.5 ) (7.2 ) (6.4 ) (1.2 ) — Electricity contracts — — — (0.1 ) — — Foreign exchange contracts (0.5 ) 24.6 13.0 18.5 — — Total $ 13.6 $ (11.5 ) $ (4.1 ) $ 5.0 $ (1.2 ) $ — (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 amounts excluded from effectiveness testing are presented in selling and administrative expenses. 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. The Company has 10 million euro notional value outstanding as of September 30, 2016 of foreign currency forward contracts not designated as hedges, with maturity dates into the second quarter of 2017. These derivatives that are not designated as hedging instruments were as follows: (In millions) Amount of Gain (Loss) Recognized in Income on Derivatives Derivatives Not Designated Three months ended September 30, Nine months ended September 30, as Hedging Instruments 2016 2015 2016 2015 Foreign exchange contracts $ (0.2 ) $ — $ (0.1 ) $ 3.0 Changes in the fair value of foreign exchange contract derivatives not designated as hedging instruments are recorded in cost of sales.

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	Fair Value of Financial Instruments The estimated fair value of financial instruments at September 30, 2016 was as follows: Fair Value Measurements at Reporting Date Using (In millions) Total Carrying Amount Total Estimated Fair Value Quoted Prices in Active Markets for Identical Assets(Level 1) Significant Observable Inputs (Level 2) Cash and cash equivalents $ 188.4 $ 188.4 $ 188.4 $ — Derivative financial instruments: Assets 9.9 9.9 — 9.9 Liabilities 28.5 28.5 — 28.5 Debt (a) 1,893.8 1,980.9 1,874.6 106.3 The estimated fair value of financial instruments at December 31, 2015 was as follows: Fair Value Measurements at Reporting Date Using (In millions) Total Carrying Amount Total Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Cash and cash equivalents $ 149.8 $ 149.8 $ 149.8 $ — Derivative financial instruments: Assets 2.4 2.4 — 2.4 Liabilities 71.3 71.3 — 71.3 Debt (a) 1,505.2 969.7 964.5 5.2 (a) The total carrying amount for debt excludes debt issuance costs related to the recognized debt liability which is presented in the consolidated balance sheet as a direct reduction from the carrying amount of the debt liability. 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 2016 or 2015 . 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 Postret

Pension Plans and Other Postretirement Benefits	9 Months Ended
	Sep. 30, 2016
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 retirement 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 retiree health care plans, Company contributions towards premiums are capped based on the cost as of a certain date, thereby creating a defined contribution. For the non-collectively bargained plans, the Company maintains the right to amend or terminate the plans at its discretion. For the three month periods ended September 30, 2016 and 2015 , the components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions): Pension Benefits Other Postretirement Benefits Three months ended September 30, Three months ended September 30, 2016 2015 2016 2015 Service cost - benefits earned during the year $ 5.2 $ 5.7 $ 0.6 $ 0.7 Interest cost on benefits earned in prior years 31.4 30.3 4.0 4.4 Expected return on plan assets (37.2 ) (42.1 ) — — Amortization of prior service cost (credit) 0.3 0.3 (0.7 ) 1.2 Amortization of net actuarial loss 16.3 15.1 2.4 3.7 Total retirement benefit expense $ 16.0 $ 9.3 $ 6.3 $ 10.0 For the nine month periods ended September 30, 2016 and 2015 , the components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions): Pension Benefits Other Postretirement Benefits Nine months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Service cost - benefits earned during the year $ 15.5 $ 17.1 $ 1.9 $ 2.1 Interest cost on benefits earned in prior years 94.1 90.8 12.0 13.4 Expected return on plan assets (111.5 ) (126.2 ) — — Amortization of prior service cost (credit) 0.9 0.9 (0.9 ) 3.6 Amortization of net actuarial loss 49.0 45.3 7.2 10.9 Total retirement benefit expense $ 48.0 $ 27.9 $ 20.2 $ 30.0 On March 4, 2016, the Company announced that it had reached a four-year labor agreement with the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union (USW) covering USW-represented employees of its ATI Flat Rolled Products business unit and at two locations in the High Performance Materials & Components business segment. The new labor agreement included changes to several retirement benefit programs, including a freeze to new entrants to ATI’s defined benefit pension plan, the elimination of defined benefit retiree healthcare for new employees, and changes in the levels of profit-based contributions for retiree medical benefits. The Company remeasured its other postretirement benefit obligation as of the March 1, 2016 contract effective date using a 4.05% discount rate, compared to a 4.50% discount rate as of December 31, 2015. Based on the remeasurement, other postretirement benefit liabilities decreased $22.5 million , and other postretirement benefit expense will decrease by $7.5 million in the March through December 2016 period. In July 2016, the Company made a $115 million contribution to its U.S. defined benefit pension plan and expects to use additional proceeds from its recent convertible debt issuance to meet future pension funding requirements.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Third quarter 2016 results included a benefit for income taxes of $4.3 million , or 0.8% of the loss before income taxes, which includes a $173.1 million income tax valuation allowance charge on U.S. federal deferred tax assets, and $4.1 million of discrete charges. The third quarter 2016 effective tax rate was 34.1% excluding these charges. Beginning in the third quarter of 2015, the Company’s results reflected a three year cumulative loss for U.S. operations; prior thereto, the Company’s historical results reflected a three year cumulative profit. The three year cumulative loss condition, which continues in 2016, limits the ability to consider other positive subjective evidence, such as projections of future results, to assess the realizability of deferred tax assets. The third quarter 2016 actions to indefinitely idle the Rowley, UT titanium sponge production facility (see Note 10 for further information) resulted in a reassessment of the realizability of U.S. federal deferred tax assets. The third quarter 2015 provision for income taxes was $23.4 million , which included a $63.9 million deferred tax valuation allowance. The 2015 valuation allowance included $56.6 million for certain state and federal tax benefits recognized in prior years, and $7.3 million valuation allowance recorded as part of the 2015 effective tax rate, representing approximately a 6% tax rate impact. For the first nine months of 2016 , the benefit for income taxes was $64.4 million , or 9.1% of the loss before income taxes, compared to a provision for income taxes of $23.7 million for the 2015 comparable period. The income tax rates for both year-to-date periods were impacted by the valuation allowance charges discussed above. The first nine months of 2016 included discrete tax expense of $0.5 million and income taxes in the first nine months of 2015 included discrete tax expense of $57.9 million , primarily due to the valuation allowance discussed above.

Business Segments

Business Segments	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Business Segments	Business Segments The Company operates in two business segments: High Performance Materials & Components (HPMC) and Flat Rolled Products (FRP). The measure of segment operating profit, which is used to analyze the performance and results of the business segments, excludes all effects of LIFO inventory accounting and any related changes in net realizable value inventory reserves which offset the Company’s aggregate net debit LIFO valuation balance, income taxes, corporate expenses, net interest expense, closed operations expenses and restructuring costs, if any. 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 September 30, Nine months ended September 30, 2016 2015 2016 2015 Total sales: High Performance Materials & Components $ 474.7 $ 490.1 $ 1,493.7 $ 1,588.5 Flat Rolled Products 321.7 377.8 927.2 1,516.0 796.4 867.9 2,420.9 3,104.5 Intersegment sales: High Performance Materials & Components 12.9 15.4 40.5 59.9 Flat Rolled Products 13.0 19.8 41.9 63.9 25.9 35.2 82.4 123.8 Sales to external customers: High Performance Materials & Components 461.8 474.7 1,453.2 1,528.6 Flat Rolled Products 308.7 358.0 885.3 1,452.1 $ 770.5 $ 832.7 $ 2,338.5 $ 2,980.7 Operating profit (loss): High Performance Materials & Components $ 47.0 $ 18.8 $ 114.9 $ 136.1 Flat Rolled Products (20.8 ) (91.8 ) (162.2 ) (121.8 ) Total operating profit (loss) 26.2 (73.0 ) (47.3 ) 14.3 LIFO and net realizable value reserves — (0.2 ) 0.4 — Corporate expenses (9.8 ) (10.7 ) (32.6 ) (33.6 ) Closed operations and other expenses (15.4 ) (6.5 ) (24.6 ) (18.6 ) Restructuring and other charges (499.9 ) — (509.9 ) — Interest expense, net (32.6 ) (27.5 ) (91.2 ) (81.0 ) Loss before income taxes $ (531.5 ) $ (117.9 ) $ (705.2 ) $ (118.9 ) Restructuring and other charges for the third quarter ended September 30, 2016 primarily relate to the indefinite idling of the Company’s Rowley, UT titanium sponge facility and include $471.3 million of long-lived asset impairment charges, $11.3 million of inventory valuation charges for titanium sponge that are classified in cost of sales (see Note 2 for additional information), and $17.3 million of facility shutdown, idling and employee benefit costs. The nine months ended September 30, 2016 also include a $9.0 million charge for severance obligations in the FRP operations, and a $1.0 million charge for severance obligations in the HPMC segment. See Note 10 for additional information on restructuring charges. Results for the HPMC segment exclude the Rowley, UT titanium sponge operations beginning with the third quarter of 2016, with such operations being reported in closed operations and other expenses, and identifiable assets for the HPMC segment decreased by $521 million from December 31, 2015 as a result of this reporting change and the above asset impairment charge for Rowley.

Restructuring Charges

Restructuring Charges	9 Months Ended
	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Restructuring Charges	Restructuring Charges For the three and nine months ended September 30, 2016 , the Company recorded restructuring charges of $488.6 million and $498.6 million , respectively, which are presented as restructuring charges in the consolidated statement of operations. These charges for the three months ended September 30, 2016 were comprised of $471.3 million in long-lived impairment charges, $16.3 million of facility shutdown and idling costs and $1.0 million of employee benefit costs. On August 24, 2016, the Company announced the indefinite idling of the Rowley, UT titanium sponge production facility and the consolidation of certain titanium manufacturing operations. Over the last several years, significant global capacity has been added to produce titanium sponge, which is a key raw material used to produce ATI’s titanium products. In addition, demand for industrial-grade titanium products from global markets continues to be weak. As a result of these factors, titanium sponge, including aerospace quality sponge, can now be purchased from qualified global producers under long-term supply agreements at prices lower than the production costs at ATI’s titanium sponge facility in Rowley, UT. ATI has entered into long-term cost competitive supply agreements with several producers of premium-grade and standard-grade titanium sponge. The lower cost titanium sponge purchased under these supply agreements will replace the titanium sponge produced at the Rowley facility. As a result of these actions, the Company recorded a non-cash impairment charge of $470.8 million during the third quarter ended September 30, 2016 to reduce the carrying value of the Rowley, UT facility to an estimated fair value of $15.0 million . The long-lived asset impairment charges were based on analysis of the estimated fair values, including asset appraisals using cost, income and market approaches, which represent Level 3 unobservable information in the fair value hierarchy. In addition, during the third quarter ended September 30, 2016 , the Company recognized $16.3 million of facility shutdown and idling costs, including contract termination costs, and $1.0 million of employee benefit costs including severance obligations. Additional closure costs for the Rowley facility, including additional severance costs for the elimination of approximately 150 positions, are expected to be recorded in the fourth quarter of 2016 with the orderly wind-down of operations through December 2016. The Rowley facility is being idled in a manner that allows the facility to be restarted in the future if supported by market conditions. During the first quarter of 2016, a $9.0 million charge was recorded for severance obligations in the Flat Rolled Products (FRP) operations, with the reduction of approximately one-third of FRP’s salaried workforce through the elimination of over 250 positions, which is expected to be completed by the end of 2016. During the second quarter of 2016, an additional $1.0 million charge was recorded for severance obligations for approximately 20 employees in the High Performance Materials & Components segment. Reserves for restructuring charges at September 30, 2016 consist of severance and employee benefit costs and closure costs incurred in both 2015 and 2016, the majority of which are expected to be paid over the next twelve months. Restructuring reserves are as follows: Severance and Employee Benefit Costs Closure Costs Total Restructuring Reserves Balance at December 31, 2015 $ 4.5 $ 3.6 $ 8.1 Additions 11.0 16.0 27.0 Payments (8.6 ) (3.3 ) (11.9 ) Balance at September 30, 2016 $ 6.9 $ 16.3 $ 23.2

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interest	9 Months Ended
	Sep. 30, 2016
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interest During the first nine months of 2016, the 15.0% redeemable noncontrolling interest in ATI Flowform Products was purchased by ATI at the $12.1 million acquisition date carrying value, resulting in no remaining redeemable noncontrolling interest held in ATI Flowform Products as of September 30, 2016 .

Per Share Information

Per Share Information	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Per Share Information	Per Share Information The following table sets forth the computation of basic and diluted loss per common share: Three months ended Nine months ended (In millions, except per share amounts) September 30, September 30, 2016 2015 2016 2015 Numerator: Numerator for basic loss per common share – Loss attributable to ATI $ (530.8 ) $ (144.6 ) $ (650.8 ) $ (151.0 ) Redeemable noncontrolling interest (Note 11) — (0.2 ) — (0.3 ) Effect of dilutive securities: 4.75% Convertible Senior Notes due 2022 — — — — Numerator for diluted loss per common share – Loss attributable to ATI after assumed conversions $ (530.8 ) $ (144.8 ) $ (650.8 ) $ (151.3 ) Denominator: Denominator for basic net loss per common share – weighted average shares 107.3 107.3 107.3 107.3 Effect of dilutive securities: Share-based compensation — — — — 4.75% Convertible Senior Notes due 2022 — — — — Denominator for diluted net loss per common share – adjusted weighted average shares and assumed conversions 107.3 107.3 107.3 107.3 Basic loss attributable to ATI per common share $ (4.95 ) $ (1.35 ) $ (6.07 ) $ (1.41 ) Diluted loss attributable to ATI per common share $ (4.95 ) $ (1.35 ) $ (6.07 ) $ (1.41 ) Common stock that would be issuable upon the assumed conversion of the 2022 Convertible Notes and other option equivalents and contingently issuable shares are excluded from the computation of contingently issuable shares, and therefore, from the denominator for diluted earnings per share, if the effect of inclusion is anti-dilutive. There were 21.0 million and 10.3 million anti-dilutive shares for the three and nine month periods ended September 30, 2016 , respectively. There were 0.8 million and 0.9 million anti-dilutive shares for the three and nine month periods ended September 30, 2015 , respectively.

Financial Information for Subsi

Financial Information for Subsidiary and Guarantor Parent	9 Months Ended
	Sep. 30, 2016
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 September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.3 $ 4.3 $ 181.8 $ — $ 188.4 Accounts receivable, net 0.1 115.7 338.2 — 454.0 Intercompany notes receivable — — 2,955.8 (2,955.8 ) — Inventories, net — 137.6 941.3 — 1,078.9 Prepaid expenses and other current assets 3.3 4.9 32.6 — 40.8 Total current assets 5.7 262.5 4,449.7 (2,955.8 ) 1,762.1 Property, plant and equipment, net 1.5 1,587.7 925.2 — 2,514.4 Goodwill — — 644.4 — 644.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,363.3 37.7 — (5,401.0 ) — Other assets 22.1 26.1 223.2 — 271.4 Total assets $ 5,392.6 $ 1,914.0 $ 6,442.5 $ (8,556.8 ) $ 5,192.3 Liabilities and stockholders’ equity: Accounts payable $ 3.5 $ 123.9 $ 157.8 $ — $ 285.2 Accrued liabilities 35.6 91.0 184.3 — 310.9 Intercompany notes payable 1,442.1 1,513.7 — (2,955.8 ) — Short-term debt and current portion of long-term debt 0.7 0.3 4.4 — 5.4 Total current liabilities 1,481.9 1,728.9 346.5 (2,955.8 ) 601.5 Long-term debt 1,620.9 149.9 99.6 — 1,870.4 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 245.1 66.5 — 311.6 Pension liabilities 658.9 4.7 45.0 — 708.6 Deferred income taxes 51.3 — — — 51.3 Other long-term liabilities 16.9 18.8 50.5 — 86.2 Total liabilities 3,829.9 2,347.4 608.1 (3,155.8 ) 3,629.6 Total stockholders’ equity (deficit) 1,562.7 (433.4 ) 5,834.4 (5,401.0 ) 1,562.7 Total liabilities and stockholders’ equity $ 5,392.6 $ 1,914.0 $ 6,442.5 $ (8,556.8 ) $ 5,192.3 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the three months ended September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 253.0 $ 517.5 $ — $ 770.5 Cost of sales 14.0 266.6 439.7 — 720.3 Gross profit (loss) (14.0 ) (13.6 ) 77.8 — 50.2 Selling and administrative expenses 23.8 4.2 32.5 — 60.5 Restructuring charges — 0.5 488.1 — 488.6 Operating loss (37.8 ) (18.3 ) (442.8 ) — (498.9 ) Interest income (expense), net (36.5 ) (19.3 ) 23.2 — (32.6 ) Other income (loss) including equity in income of unconsolidated subsidiaries (457.2 ) 0.2 (0.2 ) 457.2 — Income (loss) before income tax provision (benefit) (531.5 ) (37.4 ) (419.8 ) 457.2 (531.5 ) Income tax provision (benefit) (4.3 ) (9.1 ) (165.8 ) 174.9 (4.3 ) Net income (loss) (527.2 ) (28.3 ) (254.0 ) 282.3 (527.2 ) Less: Net income attributable to noncontrolling interests — — 3.6 — 3.6 Net income (loss) attributable to ATI $ (527.2 ) $ (28.3 ) $ (257.6 ) $ 282.3 $ (530.8 ) Comprehensive income (loss) attributable to ATI $ (516.8 ) $ (27.0 ) $ (260.0 ) $ 285.0 $ (518.8 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the nine months ended September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 727.7 $ 1,610.8 $ — $ 2,338.5 Cost of sales 43.0 852.0 1,378.3 — 2,273.3 Gross profit (loss) (43.0 ) (124.3 ) 232.5 — 65.2 Selling and administrative expenses 66.3 18.8 97.3 — 182.4 Restructuring charges — 9.5 489.1 — 498.6 Operating loss (109.3 ) (152.6 ) (353.9 ) — (615.8 ) Interest income (expense), net (101.4 ) (51.0 ) 61.2 — (91.2 ) Other income (loss) including equity in income of unconsolidated subsidiaries (494.5 ) 0.6 1.5 494.2 1.8 Income (loss) before income tax provision (benefit) (705.2 ) (203.0 ) (291.2 ) 494.2 (705.2 ) Income tax provision (benefit) (64.4 ) (70.1 ) (116.3 ) 186.4 (64.4 ) Net income (loss) (640.8 ) (132.9 ) (174.9 ) 307.8 (640.8 ) Less: Net income attributable to noncontrolling interests — — 10.0 — 10.0 Net income (loss) attributable to ATI $ (640.8 ) $ (132.9 ) $ (184.9 ) $ 307.8 $ (650.8 ) Comprehensive income (loss) attributable to ATI $ (592.6 ) $ (114.2 ) $ (199.0 ) $ 307.8 $ (598.0 ) Condensed Statements of Cash Flows For the nine months ended September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (73.0 ) $ (183.7 ) $ 169.0 $ (24.0 ) $ (111.7 ) Investing Activities: Purchases of property, plant and equipment (0.5 ) (93.0 ) (81.4 ) — (174.9 ) Net receipts/(payments) on intercompany activity — — (102.0 ) 102.0 — Asset disposals and other — — 2.1 — 2.1 Cash flows provided by (used in) investing activities (0.5 ) (93.0 ) (181.3 ) 102.0 (172.8 ) Financing Activities: Borrowings on long-term debt 287.5 — 100.0 — 387.5 Payments on long-term debt and capital leases (0.5 ) (0.2 ) (1.7 ) — (2.4 ) Net borrowings under credit facilities — — 2.4 — 2.4 Debt issuance costs (9.4 ) — (1.0 ) — (10.4 ) Net receipts/(payments) on intercompany activity (176.4 ) 278.4 — (102.0 ) — Dividends paid to stockholders (25.8 ) — (24.0 ) 24.0 (25.8 ) Dividends paid to noncontrolling interests — — (16.0 ) — (16.0 ) Acquisition of noncontrolling interests — — (12.2 ) — (12.2 ) Cash flows provided by (used in) financing activities 75.4 278.2 47.5 (78.0 ) 323.1 Increase in cash and cash equivalents $ 1.9 $ 1.5 $ 35.2 $ — $ 38.6 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Balance Sheets December 31, 2015 Guarantor Non-guarantor (In millions) Parent Subsidiary Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 0.4 $ 2.8 $ 146.6 $ — $ 149.8 Accounts receivable, net 0.1 100.3 299.9 — 400.3 Intercompany notes receivable — — 2,601.5 (2,601.5 ) — Inventories, net — 239.9 1,031.7 — 1,271.6 Prepaid expenses and other current assets 9.3 3.8 32.8 — 45.9 Total current assets 9.8 346.8 4,112.5 (2,601.5 ) 1,867.6 Property, plant and equipment, net 2.2 1,559.9 1,366.1 — 2,928.2 Goodwill — — 651.4 — 651.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,742.5 37.7 — (5,780.2 ) — Other assets 13.4 23.0 268.1 — 304.5 Total assets $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7 Liabilities and stockholders’ equity: Accounts payable $ 4.8 $ 171.1 $ 204.9 $ — $ 380.8 Accrued liabilities 42.1 74.0 185.7 — 301.8 Intercompany notes payable 1,325.4 1,276.1 — (2,601.5 ) — Short-term debt and current portion of long-term debt 0.7 0.1 3.1 — 3.9 Total current liabilities 1,373.0 1,521.3 393.7 (2,601.5 ) 686.5 Long-term debt 1,341.7 149.7 0.4 — 1,491.8 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 280.0 79.2 — 359.2 Pension liabilities 778.0 5.2 50.6 — 833.8 Deferred income taxes 75.6 — — — 75.6 Other long-term liabilities 15.2 20.7 72.4 — 108.3 Total liabilities 3,583.5 2,176.9 596.3 (2,801.5 ) 3,555.2 Redeemable noncontrolling interest — — 12.1 — 12.1 Total stockholders’ equity (deficit) 2,184.4 (209.5 ) 5,989.7 (5,780.2 ) 2,184.4 Total liabilities and stockholders’ equity $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the three months ended September 30, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 286.3 $ 546.4 $ — $ 832.7 Cost of sales 9.2 363.5 488.7 — 861.4 Gross profit (loss) (9.2 ) (77.2 ) 57.7 — (28.7 ) Selling and administrative expenses 22.9 9.3 30.3 — 62.5 Operating income (loss) (32.1 ) (86.5 ) 27.4 — (91.2 ) Interest income (expense), net (29.5 ) (12.6 ) 14.6 — (27.5 ) Other income (loss) including equity in income of unconsolidated subsidiaries (56.3 ) 0.2 0.7 56.2 0.8 Income (loss) before income tax provision (benefit) (117.9 ) (98.9 ) 42.7 56.2 (117.9 ) Income tax provision (benefit) 23.4 (35.1 ) 11.0 24.1 23.4 Net income (loss) (141.3 ) (63.8 ) 31.7 32.1 (141.3 ) Less: Net income attributable to noncontrolling interests — — 3.3 — 3.3 Net income (loss) attributable to ATI $ (141.3 ) $ (63.8 ) $ 28.4 $ 32.1 $ (144.6 ) Comprehensive income (loss) attributable to ATI $ (163.5 ) $ (60.5 ) $ 16.7 $ 44.6 $ (162.7 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the nine months ended September 30, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,231.5 $ 1,749.2 $ — $ 2,980.7 Cost of sales 22.0 1,296.5 1,504.4 — 2,822.9 Gross profit (loss) (22.0 ) (65.0 ) 244.8 — 157.8 Selling and administrative expenses 70.1 30.4 97.5 — 198.0 Operating income (loss) (92.1 ) (95.4 ) 147.3 — (40.2 ) Interest income (expense), net (86.1 ) (37.3 ) 42.4 — (81.0 ) Other income (loss) including equity in income of unconsolidated subsidiaries 59.3 0.8 1.8 (59.6 ) 2.3 Income (loss) before income tax provision (benefit) (118.9 ) (131.9 ) 191.5 (59.6 ) (118.9 ) Income tax provision (benefit) 23.7 (46.3 ) 67.4 (21.1 ) 23.7 Net income (loss) (142.6 ) (85.6 ) 124.1 (38.5 ) (142.6 ) Less: Net income attributable to noncontrolling interests — — 8.4 — 8.4 Net income (loss) attributable to ATI $ (142.6 ) $ (85.6 ) $ 115.7 $ (38.5 ) $ (151.0 ) Comprehensive income (loss) attributable to ATI $ (140.4 ) $ (76.0 ) $ 101.9 $ (30.5 ) $ (145.0 ) Condensed Statements of Cash Flows For the nine months ended September 30, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (61.3 ) $ (171.1 ) $ 341.3 $ — $ 108.9 Investing Activities: Purchases of property, plant and equipment (0.1 ) (45.0 ) (54.4 ) — (99.5 ) Purchases of businesses, net of cash acquired — — (0.5 ) — (0.5 ) Net receipts/(payments) on intercompany activity — — (333.3 ) 333.3 — Asset disposals and other — 0.2 (0.2 ) — — Cash flows provided by (used in) investing activities (0.1 ) (44.8 ) (388.4 ) 333.3 (100.0 ) Financing Activities: Payments on long-term debt and capital leases (0.4 ) (0.1 ) (22.8 ) — (23.3 ) Net receipts/(payments) on intercompany activity 124.2 209.1 — (333.3 ) — Dividends paid to stockholders (57.9 ) — — — (57.9 ) Other (1.3 ) — 1.6 — 0.3 Cash flows provided by (used in) financing activities 64.6 209.0 (21.2 ) (333.3 ) (80.9 ) Increase (decrease) in cash and cash equivalents $ 3.2 $ (6.9 ) $ (68.3 ) $ — $ (72.0 )

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2016
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 September 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, June 30, 2016 $ (913.7 ) $ (59.8 ) $ — $ (0.2 ) $ (973.7 ) OCI before reclassifications — (2.8 ) — 3.0 0.2 Amounts reclassified from AOCI (a) 11.4 (b) — (b) — (c) 0.4 11.8 Net current-period OCI 11.4 (2.8 ) — 3.4 12.0 Balance, September 30, 2016 $ (902.3 ) $ (62.6 ) $ — $ 3.2 $ (961.7 ) Attributable to noncontrolling interests: Balance, June 30, 2016 $ — $ 16.4 $ — $ — $ 16.4 OCI before reclassifications — (1.6 ) — — (1.6 ) Amounts reclassified from AOCI — (b) — — — — Net current-period OCI — (1.6 ) — — (1.6 ) Balance, September 30, 2016 $ — $ 14.8 $ — $ — $ 14.8 The changes in AOCI by component, net of tax, for the nine month period ended September 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, December 31, 2015 $ (951.2 ) $ (47.6 ) $ — $ (15.7 ) $ (1,014.5 ) OCI before reclassifications 13.9 (15.0 ) — 13.6 12.5 Amounts reclassified from AOCI (a) 35.0 (b) — (b) — (c) 5.3 40.3 Net current-period OCI 48.9 (15.0 ) — 18.9 52.8 Balance, September 30, 2016 $ (902.3 ) $ (62.6 ) $ — $ 3.2 $ (961.7 ) Attributable to noncontrolling interests: Balance, December 31, 2015 $ — $ 19.4 $ — $ — $ 19.4 OCI before reclassifications — (4.6 ) — — (4.6 ) Amounts reclassified from AOCI — (b) — — — — Net current-period OCI — (4.6 ) — — (4.6 ) Balance, September 30, 2016 $ — $ 14.8 $ — $ — $ 14.8 (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 related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (see Note 5). The changes in AOCI by component, net of tax, for the three month period ended September 30, 2015 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, June 30, 2015 $ (906.5 ) $ (19.0 ) $ (0.1 ) $ 18.3 $ (907.3 ) OCI before reclassifications — (12.1 ) — (16.5 ) (28.6 ) Amounts reclassified from AOCI (a) 12.5 (b) — (b) — (c) (2.0 ) 10.5 Net current-period OCI 12.5 (12.1 ) — (18.5 ) (18.1 ) Balance, September 30, 2015 $ (894.0 ) $ (31.1 ) $ (0.1 ) $ (0.2 ) $ (925.4 ) Attributable to noncontrolling interests: Balance, June 30, 2015 $ — $ 25.3 $ — $ — $ 25.3 OCI before reclassifications — (4.1 ) — — (4.1 ) Amounts reclassified from AOCI — — — — — Net current-period OCI — (4.1 ) — — $ (4.1 ) Balance, September 30, 2015 $ — $ 21.2 $ — $ — $ 21.2 The changes in AOCI by component, net of tax, for the nine month period ended September 30, 2015 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, December 31, 2014 $ (931.5 ) $ (16.2 ) $ — $ 16.3 $ (931.4 ) OCI before reclassifications — (14.9 ) (0.1 ) (11.5 ) (26.5 ) Amounts reclassified from AOCI (a) 37.5 (b) — (b) — (c) (5.0 ) 32.5 Net current-period OCI 37.5 (14.9 ) (0.1 ) (16.5 ) 6.0 Balance, September 30, 2015 $ (894.0 ) $ (31.1 ) $ (0.1 ) $ (0.2 ) $ (925.4 ) Attributable to noncontrolling interests: Balance, December 31, 2014 $ — $ 25.0 $ — $ — $ 25.0 OCI before reclassifications — (3.8 ) — — (3.8 ) Amounts reclassified from AOCI — (b) — — — — Net current-period OCI — (3.8 ) — — $ (3.8 ) Balance, September 30, 2015 $ — $ 21.2 $ — $ — $ 21.2 (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 related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (see Note 5). Reclassifications out of AOCI for the three and nine month periods ended September 30, 2016 and 2015 were as follows: Amount reclassified from AOCI Details about AOCI Components (In millions) Three months ended September 30, 2016 Three months ended September 30, 2015 Nine months ended September 30, 2016 Nine months ended September 30, 2015 Affected line item in the statements of operations Postretirement benefit plans Prior service (cost) credit $ 0.4 $ (1.5 ) (a) $ — $ (4.5 ) (a) Actuarial losses (18.7 ) (18.8 ) (a) (56.2 ) (56.2 ) (a) (18.3 ) (20.3 ) (c) (56.2 ) (60.7 ) (c) Total before tax (6.9 ) (7.8 ) (21.2 ) (23.2 ) Tax benefit $ (11.4 ) $ (12.5 ) $ (35.0 ) $ (37.5 ) Net of tax Derivatives Nickel and other raw material contracts $ (3.5 ) $ (3.9 ) (b) $ (15.9 ) $ (11.4 ) (b) Natural gas contracts (2.5 ) (2.6 ) (b) (13.5 ) (10.4 ) (b) Electricity contracts — — (b) — (0.2 ) (b) Foreign exchange contracts 5.4 9.8 (b) 20.9 30.1 (b) (0.6 ) 3.3 (c) (8.5 ) 8.1 (c) Total before tax (0.2 ) 1.3 (3.2 ) 3.1 Tax provision (benefit) $ (0.4 ) $ 2.0 $ (5.3 ) $ 5.0 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 related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (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	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company is subject to various domestic and international environmental laws and regulations that govern the discharge of pollutants and disposal of wastes, and which may require that it investigate and remediate the effects of the release or disposal of materials at sites associated with past and present operations. The Company could incur substantial cleanup costs, fines, and civil or criminal sanctions, third party property damage or personal injury claims as a result of violations or liabilities under these laws or noncompliance with environmental permits required at its facilities. The Company is currently involved in the investigation and remediation of a number of its current and former sites, as well as third party sites. Environmental liabilities are recorded when the Company’s liability is probable and the costs are reasonably estimable. In many cases, however, the Company is not able to determine whether it is liable or, if liability is probable, to reasonably estimate the loss or range of loss. Estimates of the Company’s liability remain subject to additional uncertainties, including the nature and extent of site contamination, available remediation alternatives, the extent of corrective actions that may be required, and the number, participation, and financial condition of other potentially responsible parties (PRPs). The Company adjusts its accruals to reflect new information as appropriate. Future adjustments could have a material adverse effect on the Company’s consolidated results of operations in a given period, but the Company cannot reliably predict the amounts of such future adjustments. At September 30, 2016 , the Company’s reserves for environmental remediation obligations totaled approximately $14 million , of which $8 million was included in other current liabilities. The reserve includes estimated probable future costs of $2 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 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. 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 $17 million . 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. 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, 2015 and subsequently filed Quarterly Reports on Form 10-Q 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.

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On October 25, 2016, ATI announced the permanent closure of the Midland, PA commodity stainless steel sheet melt and finishing facility and the Bagdad, PA grain-oriented electrical steel finishing facility. These facilities were indefinitely idled earlier in 2016, and management has concluded that the facilities cannot be operated at an acceptable rate of return. As a result of these actions, fourth quarter 2016 results are expected to include a range of $4 million to $14 million for contract termination costs, approximately $3 million of termination benefits for pension and other postretirement benefit obligations, and approximately $2 million for supplemental unemployment benefits. Cash expenditures for the contract termination and supplemental unemployment benefit costs are expected to be incurred through the first quarter of 2018.

Accounting Policies (Policies)

Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
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 2015 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, 2015 financial information has been derived from the Company’s audited consolidated financial statements.
New Accounting Pronouncements	Pending Accounting Pronouncements In March 2016, the FASB issued new guidance to simplify employee share-based payment accounting. The areas for simplification in this guidance involve several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This new guidance is effective for the Company’s 2017 fiscal year with early adoption permitted. The Company is currently evaluating the possible impact of this new guidance, but does not anticipate that it will have a material impact on its consolidated financial statements. In February 2016, the FASB issued new guidance on the accounting for leases. This new guidance will require that a lessee recognize assets and liabilities on the balance sheet for all leases with a lease term of more than twelve months, with the result being the recognition of a right of use asset and a lease liability. The new lease accounting requirements are effective for the Company’s 2019 fiscal year with a modified retrospective transition approach required, with early adoption permitted. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements. In July 2015, the FASB issued changes to simplify the measurement of inventory valuation at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The new inventory measurement requirements are effective for the Company’s 2017 fiscal year, and will replace the current inventory valuation guidance that requires the use of a lower of cost or market framework. This change in the measurement of inventory does not apply to inventory valued on a LIFO basis, which is the accounting basis used for most of the Company’s inventory. The adoption of these changes is not expected to have a material impact on the Company’s consolidated financial statements. In May 2014, the FASB issued changes to revenue recognition with customers, which is required to be adopted by the Company in fiscal year 2018. This update provides a five-step analysis of transactions to determine when and how revenue is recognized, along with expanded disclosure requirements. 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. The Company plans to adopt this accounting standard update using the modified retrospective method, with the cumulative effect of initially applying this update recognized in the first reporting period of 2018. 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. Due to deflationary impacts primarily related to raw materials, the carrying value of the Company’s inventory as valued on LIFO exceeds current replacement cost, and based on a lower of cost or market value analysis, a net realizable value (NRV) inventory reserve is required.
Derivatives	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. 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 September 30, 2016 , 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 29 million pounds of nickel with hedge dates through 2020. The aggregate notional amount hedged is approximately 30% of a single year’s estimated nickel raw material purchase requirements. At September 30, 2016 , the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas cost hedges. In the first nine months of 2016, due to changes in expected operating levels, the Company concluded that additional portions of these natural gas hedges for 2016 and the first quarter of 2017 were ineffective based on forecast changes in underlying natural gas usage. The Company recognized a $0.4 million and $1.7 million pre-tax loss for the three and nine months ended September 30, 2016 , respectively, for natural gas cash flow hedge ineffectiveness, which is reported in selling and administrative expenses on the consolidated statement of operations. Approximately 90% of the Company’s annual forecasted domestic requirements for natural gas for 2017 and approximately 25% for 2018 are hedged. 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. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions. In 2015, the Company net settled substantially all of its foreign currency forward contracts designated as cash flow hedges with 2016 and 2017 maturity dates. The portion of the deferred gains on these settled cash flow hedges determined to be effective is currently recognized in accumulated other comprehensive income and is reclassified to earnings when the underlying transactions occur. As of September 30, 2016 , the Company held 67.2 million euro notional value of foreign currency forward contracts designated as fair value hedges with maturity dates through 2017. The Company recorded a $0.5 million and $3.0 million charge in the three and nine months ended September 30, 2016 , respectively, and a $1.8 million charge and a $5.6 million benefit in the three and nine months ended September 30, 2015 , respectively, in costs of sales on the consolidated statement of operations for maturities and 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.
Pension And Other Postretirement Plans	The Company has defined benefit pension plans or defined contribution retirement 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 retiree health care 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)	9 Months Ended
	Sep. 30, 2016
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories at September 30, 2016 and December 31, 2015 were as follows (in millions): September 30, December 31, Raw materials and supplies $ 157.0 $ 216.0 Work-in-process 865.7 990.3 Finished goods 169.4 184.1 Total inventories at current cost 1,192.1 1,390.4 Adjustment from current cost to LIFO cost basis 113.3 136.4 Inventory valuation reserves (187.5 ) (206.3 ) Progress payments (39.0 ) (48.9 ) Total inventories, net $ 1,078.9 $ 1,271.6
Schedule of Inventory Valuation Impact on Income	Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV inventory reserves were as follows (in millions): Nine months ended September 30, 2016 2015 LIFO benefit (charge) $ (23.1 ) $ 80.3 NRV benefit (charge) 23.5 (80.3 ) Net cost of sales impact $ 0.4 $ —

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Property Plant And Equipment	Property, plant and equipment at September 30, 2016 and December 31, 2015 was as follows (in millions): September 30, December 31, Land $ 31.7 $ 31.0 Buildings 847.3 1,048.2 Equipment and leasehold improvements 3,646.8 3,858.1 4,525.8 4,937.3 Accumulated depreciation and amortization (2,011.4 ) (2,009.1 ) Total property, plant and equipment, net $ 2,514.4 $ 2,928.2

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of Debt Instruments	Debt at September 30, 2016 and December 31, 2015 was as follows (in millions): September 30, December 31, Allegheny Technologies 5.875% Notes due 2023 (a) $ 500.0 $ 500.0 Allegheny Technologies 5.95% Notes due 2021 500.0 500.0 Allegheny Technologies 9.375% Notes due 2019 350.0 350.0 Allegheny Technologies 4.75% Convertible Senior Notes due 2022 287.5 — Allegheny Ludlum 6.95% debentures due 2025 150.0 150.0 Term Loan due 2017 100.0 — U.S. revolving credit facility — — Foreign credit facilities 3.8 1.4 Industrial revenue bonds, due through 2020, and other 2.5 3.8 Debt issuance costs (18.0 ) (9.5 ) Total debt 1,875.8 1,495.7 Short-term debt and current portion of long-term debt 5.4 3.9 Total long-term debt $ 1,870.4 $ 1,491.8 (a) Bearing interest at 7.875% effective February 15, 2016.

Derivative Financial Instrume30

Derivative Financial Instruments and Hedging (Tables)	9 Months Ended
	Sep. 30, 2016
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) Asset derivatives Balance sheet location September 30, December 31, Derivatives designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets $ 0.2 $ 1.6 Nickel and other raw material contracts Prepaid expenses and other current assets 3.5 — Foreign exchange contracts Other assets 0.2 0.4 Nickel and other raw material contracts Other assets 5.8 — Total derivatives designated as hedging instruments 9.7 2.0 Derivatives not designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets 0.2 0.4 Total derivatives not designated as hedging instruments 0.2 0.4 Total asset derivatives $ 9.9 $ 2.4 Liability derivatives Balance sheet location Derivatives designated as hedging instruments: Natural gas contracts Accrued liabilities $ 8.5 $ 17.3 Nickel and other raw material contracts Accrued liabilities 8.8 22.2 Foreign exchange contracts Accrued liabilities 1.4 0.1 Natural gas contracts Other long-term liabilities 0.8 8.5 Nickel and other raw material contracts Other long-term liabilities 8.7 23.0 Foreign exchange contracts Other long-term liabilities 0.3 0.1 Total derivatives designated as hedging instruments 28.5 71.2 Derivatives not designated as hedging instruments: Foreign exchange contracts Accrued liabilities — 0.1 Total derivatives not designated as hedging instruments — 0.1 Total liability derivatives $ 28.5 $ 71.3
Schedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance	Activity with regard to derivatives designated as cash flow hedges for the three and nine month periods ended September 30, 2016 and 2015 was as follows (in millions): Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (a) Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing) (b) Derivatives in Cash Flow Three months ended September 30, Three months ended September 30, Three months ended September 30, Hedging Relationships 2016 2015 2016 2015 2016 2015 Nickel and other raw material contracts $ 4.2 $ (13.5 ) $ (2.2 ) $ (2.4 ) $ — $ — Natural gas contracts (1.2 ) (3.7 ) (1.3 ) (1.6 ) (0.3 ) — Electricity contracts — — — — — — Foreign exchange contracts — 0.7 3.4 6.0 — — Total $ 3.0 $ (16.5 ) $ (0.1 ) $ 2.0 $ (0.3 ) $ — Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (a) Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing) (b) Derivatives in Cash Flow Nine months ended September 30, Nine months ended September 30, Nine months ended September 30, Hedging Relationships 2016 2015 2016 2015 2016 2015 Nickel and other raw material contracts $ 13.0 $ (26.6 ) $ (9.9 ) $ (7.0 ) $ — $ — Natural gas contracts 1.1 (9.5 ) (7.2 ) (6.4 ) (1.2 ) — Electricity contracts — — — (0.1 ) — — Foreign exchange contracts (0.5 ) 24.6 13.0 18.5 — — Total $ 13.6 $ (11.5 ) $ (4.1 ) $ 5.0 $ (1.2 ) $ — (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 amounts excluded from effectiveness testing are presented in selling and administrative expenses.
Schedule Of Derivative Instruments Not Designated as Hedging Instruments	These derivatives that are not designated as hedging instruments were as follows: (In millions) Amount of Gain (Loss) Recognized in Income on Derivatives Derivatives Not Designated Three months ended September 30, Nine months ended September 30, as Hedging Instruments 2016 2015 2016 2015 Foreign exchange contracts $ (0.2 ) $ — $ (0.1 ) $ 3.0

Fair Value of Financial Instr31

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value By Balance Sheet Grouping	The estimated fair value of financial instruments at September 30, 2016 was as follows: Fair Value Measurements at Reporting Date Using (In millions) Total Carrying Amount Total Estimated Fair Value Quoted Prices in Active Markets for Identical Assets(Level 1) Significant Observable Inputs (Level 2) Cash and cash equivalents $ 188.4 $ 188.4 $ 188.4 $ — Derivative financial instruments: Assets 9.9 9.9 — 9.9 Liabilities 28.5 28.5 — 28.5 Debt (a) 1,893.8 1,980.9 1,874.6 106.3 The estimated fair value of financial instruments at December 31, 2015 was as follows: Fair Value Measurements at Reporting Date Using (In millions) Total Carrying Amount Total Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Cash and cash equivalents $ 149.8 $ 149.8 $ 149.8 $ — Derivative financial instruments: Assets 2.4 2.4 — 2.4 Liabilities 71.3 71.3 — 71.3 Debt (a) 1,505.2 969.7 964.5 5.2

Pension Plans and Other Postr32

Pension Plans and Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Schedule Of Defined Benefit Plans Disclosures [Table Text Block]	For the three month periods ended September 30, 2016 and 2015 , the components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions): Pension Benefits Other Postretirement Benefits Three months ended September 30, Three months ended September 30, 2016 2015 2016 2015 Service cost - benefits earned during the year $ 5.2 $ 5.7 $ 0.6 $ 0.7 Interest cost on benefits earned in prior years 31.4 30.3 4.0 4.4 Expected return on plan assets (37.2 ) (42.1 ) — — Amortization of prior service cost (credit) 0.3 0.3 (0.7 ) 1.2 Amortization of net actuarial loss 16.3 15.1 2.4 3.7 Total retirement benefit expense $ 16.0 $ 9.3 $ 6.3 $ 10.0 For the nine month periods ended September 30, 2016 and 2015 , the components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions): Pension Benefits Other Postretirement Benefits Nine months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Service cost - benefits earned during the year $ 15.5 $ 17.1 $ 1.9 $ 2.1 Interest cost on benefits earned in prior years 94.1 90.8 12.0 13.4 Expected return on plan assets (111.5 ) (126.2 ) — — Amortization of prior service cost (credit) 0.9 0.9 (0.9 ) 3.6 Amortization of net actuarial loss 49.0 45.3 7.2 10.9 Total retirement benefit expense $ 48.0 $ 27.9 $ 20.2 $ 30.0

Business Segments (Tables)

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2016
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 September 30, Nine months ended September 30, 2016 2015 2016 2015 Total sales: High Performance Materials & Components $ 474.7 $ 490.1 $ 1,493.7 $ 1,588.5 Flat Rolled Products 321.7 377.8 927.2 1,516.0 796.4 867.9 2,420.9 3,104.5 Intersegment sales: High Performance Materials & Components 12.9 15.4 40.5 59.9 Flat Rolled Products 13.0 19.8 41.9 63.9 25.9 35.2 82.4 123.8 Sales to external customers: High Performance Materials & Components 461.8 474.7 1,453.2 1,528.6 Flat Rolled Products 308.7 358.0 885.3 1,452.1 $ 770.5 $ 832.7 $ 2,338.5 $ 2,980.7 Operating profit (loss): High Performance Materials & Components $ 47.0 $ 18.8 $ 114.9 $ 136.1 Flat Rolled Products (20.8 ) (91.8 ) (162.2 ) (121.8 ) Total operating profit (loss) 26.2 (73.0 ) (47.3 ) 14.3 LIFO and net realizable value reserves — (0.2 ) 0.4 — Corporate expenses (9.8 ) (10.7 ) (32.6 ) (33.6 ) Closed operations and other expenses (15.4 ) (6.5 ) (24.6 ) (18.6 ) Restructuring and other charges (499.9 ) — (509.9 ) — Interest expense, net (32.6 ) (27.5 ) (91.2 ) (81.0 ) Loss before income taxes $ (531.5 ) $ (117.9 ) $ (705.2 ) $ (118.9 )

Restructuring Charges (Tables)

Restructuring Charges (Tables)	9 Months Ended
	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Reserve by Type of Cost	Reserves for restructuring charges at September 30, 2016 consist of severance and employee benefit costs and closure costs incurred in both 2015 and 2016, the majority of which are expected to be paid over the next twelve months. Restructuring reserves are as follows: Severance and Employee Benefit Costs Closure Costs Total Restructuring Reserves Balance at December 31, 2015 $ 4.5 $ 3.6 $ 8.1 Additions 11.0 16.0 27.0 Payments (8.6 ) (3.3 ) (11.9 ) Balance at September 30, 2016 $ 6.9 $ 16.3 $ 23.2

Per Share Information (Tables)

Per Share Information (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share Diluted By Common Class	The following table sets forth the computation of basic and diluted loss per common share: Three months ended Nine months ended (In millions, except per share amounts) September 30, September 30, 2016 2015 2016 2015 Numerator: Numerator for basic loss per common share – Loss attributable to ATI $ (530.8 ) $ (144.6 ) $ (650.8 ) $ (151.0 ) Redeemable noncontrolling interest (Note 11) — (0.2 ) — (0.3 ) Effect of dilutive securities: 4.75% Convertible Senior Notes due 2022 — — — — Numerator for diluted loss per common share – Loss attributable to ATI after assumed conversions $ (530.8 ) $ (144.8 ) $ (650.8 ) $ (151.3 ) Denominator: Denominator for basic net loss per common share – weighted average shares 107.3 107.3 107.3 107.3 Effect of dilutive securities: Share-based compensation — — — — 4.75% Convertible Senior Notes due 2022 — — — — Denominator for diluted net loss per common share – adjusted weighted average shares and assumed conversions 107.3 107.3 107.3 107.3 Basic loss attributable to ATI per common share $ (4.95 ) $ (1.35 ) $ (6.07 ) $ (1.41 ) Diluted loss attributable to ATI per common share $ (4.95 ) $ (1.35 ) $ (6.07 ) $ (1.41 )

Financial Information for Sub36

Financial Information for Subsidiary and Guarantor Parent (Tables)	9 Months Ended
	Sep. 30, 2016
Condensed Statement of Income Captions [Line Items]
Balance Sheets	Balance Sheets December 31, 2015 Guarantor Non-guarantor (In millions) Parent Subsidiary Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 0.4 $ 2.8 $ 146.6 $ — $ 149.8 Accounts receivable, net 0.1 100.3 299.9 — 400.3 Intercompany notes receivable — — 2,601.5 (2,601.5 ) — Inventories, net — 239.9 1,031.7 — 1,271.6 Prepaid expenses and other current assets 9.3 3.8 32.8 — 45.9 Total current assets 9.8 346.8 4,112.5 (2,601.5 ) 1,867.6 Property, plant and equipment, net 2.2 1,559.9 1,366.1 — 2,928.2 Goodwill — — 651.4 — 651.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,742.5 37.7 — (5,780.2 ) — Other assets 13.4 23.0 268.1 — 304.5 Total assets $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7 Liabilities and stockholders’ equity: Accounts payable $ 4.8 $ 171.1 $ 204.9 $ — $ 380.8 Accrued liabilities 42.1 74.0 185.7 — 301.8 Intercompany notes payable 1,325.4 1,276.1 — (2,601.5 ) — Short-term debt and current portion of long-term debt 0.7 0.1 3.1 — 3.9 Total current liabilities 1,373.0 1,521.3 393.7 (2,601.5 ) 686.5 Long-term debt 1,341.7 149.7 0.4 — 1,491.8 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 280.0 79.2 — 359.2 Pension liabilities 778.0 5.2 50.6 — 833.8 Deferred income taxes 75.6 — — — 75.6 Other long-term liabilities 15.2 20.7 72.4 — 108.3 Total liabilities 3,583.5 2,176.9 596.3 (2,801.5 ) 3,555.2 Redeemable noncontrolling interest — — 12.1 — 12.1 Total stockholders’ equity (deficit) 2,184.4 (209.5 ) 5,989.7 (5,780.2 ) 2,184.4 Total liabilities and stockholders’ equity $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7 Balance Sheets September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.3 $ 4.3 $ 181.8 $ — $ 188.4 Accounts receivable, net 0.1 115.7 338.2 — 454.0 Intercompany notes receivable — — 2,955.8 (2,955.8 ) — Inventories, net — 137.6 941.3 — 1,078.9 Prepaid expenses and other current assets 3.3 4.9 32.6 — 40.8 Total current assets 5.7 262.5 4,449.7 (2,955.8 ) 1,762.1 Property, plant and equipment, net 1.5 1,587.7 925.2 — 2,514.4 Goodwill — — 644.4 — 644.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,363.3 37.7 — (5,401.0 ) — Other assets 22.1 26.1 223.2 — 271.4 Total assets $ 5,392.6 $ 1,914.0 $ 6,442.5 $ (8,556.8 ) $ 5,192.3 Liabilities and stockholders’ equity: Accounts payable $ 3.5 $ 123.9 $ 157.8 $ — $ 285.2 Accrued liabilities 35.6 91.0 184.3 — 310.9 Intercompany notes payable 1,442.1 1,513.7 — (2,955.8 ) — Short-term debt and current portion of long-term debt 0.7 0.3 4.4 — 5.4 Total current liabilities 1,481.9 1,728.9 346.5 (2,955.8 ) 601.5 Long-term debt 1,620.9 149.9 99.6 — 1,870.4 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 245.1 66.5 — 311.6 Pension liabilities 658.9 4.7 45.0 — 708.6 Deferred income taxes 51.3 — — — 51.3 Other long-term liabilities 16.9 18.8 50.5 — 86.2 Total liabilities 3,829.9 2,347.4 608.1 (3,155.8 ) 3,629.6 Total stockholders’ equity (deficit) 1,562.7 (433.4 ) 5,834.4 (5,401.0 ) 1,562.7 Total liabilities and stockholders’ equity $ 5,392.6 $ 1,914.0 $ 6,442.5 $ (8,556.8 ) $ 5,192.3
Statements of Operations and Comprehensive Income	Statements of Operations and Comprehensive Income For the three months ended September 30, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 286.3 $ 546.4 $ — $ 832.7 Cost of sales 9.2 363.5 488.7 — 861.4 Gross profit (loss) (9.2 ) (77.2 ) 57.7 — (28.7 ) Selling and administrative expenses 22.9 9.3 30.3 — 62.5 Operating income (loss) (32.1 ) (86.5 ) 27.4 — (91.2 ) Interest income (expense), net (29.5 ) (12.6 ) 14.6 — (27.5 ) Other income (loss) including equity in income of unconsolidated subsidiaries (56.3 ) 0.2 0.7 56.2 0.8 Income (loss) before income tax provision (benefit) (117.9 ) (98.9 ) 42.7 56.2 (117.9 ) Income tax provision (benefit) 23.4 (35.1 ) 11.0 24.1 23.4 Net income (loss) (141.3 ) (63.8 ) 31.7 32.1 (141.3 ) Less: Net income attributable to noncontrolling interests — — 3.3 — 3.3 Net income (loss) attributable to ATI $ (141.3 ) $ (63.8 ) $ 28.4 $ 32.1 $ (144.6 ) Comprehensive income (loss) attributable to ATI $ (163.5 ) $ (60.5 ) $ 16.7 $ 44.6 $ (162.7 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the nine months ended September 30, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,231.5 $ 1,749.2 $ — $ 2,980.7 Cost of sales 22.0 1,296.5 1,504.4 — 2,822.9 Gross profit (loss) (22.0 ) (65.0 ) 244.8 — 157.8 Selling and administrative expenses 70.1 30.4 97.5 — 198.0 Operating income (loss) (92.1 ) (95.4 ) 147.3 — (40.2 ) Interest income (expense), net (86.1 ) (37.3 ) 42.4 — (81.0 ) Other income (loss) including equity in income of unconsolidated subsidiaries 59.3 0.8 1.8 (59.6 ) 2.3 Income (loss) before income tax provision (benefit) (118.9 ) (131.9 ) 191.5 (59.6 ) (118.9 ) Income tax provision (benefit) 23.7 (46.3 ) 67.4 (21.1 ) 23.7 Net income (loss) (142.6 ) (85.6 ) 124.1 (38.5 ) (142.6 ) Less: Net income attributable to noncontrolling interests — — 8.4 — 8.4 Net income (loss) attributable to ATI $ (142.6 ) $ (85.6 ) $ 115.7 $ (38.5 ) $ (151.0 ) Comprehensive income (loss) attributable to ATI $ (140.4 ) $ (76.0 ) $ 101.9 $ (30.5 ) $ (145.0 ) Statements of Operations and Comprehensive Income For the three months ended September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 253.0 $ 517.5 $ — $ 770.5 Cost of sales 14.0 266.6 439.7 — 720.3 Gross profit (loss) (14.0 ) (13.6 ) 77.8 — 50.2 Selling and administrative expenses 23.8 4.2 32.5 — 60.5 Restructuring charges — 0.5 488.1 — 488.6 Operating loss (37.8 ) (18.3 ) (442.8 ) — (498.9 ) Interest income (expense), net (36.5 ) (19.3 ) 23.2 — (32.6 ) Other income (loss) including equity in income of unconsolidated subsidiaries (457.2 ) 0.2 (0.2 ) 457.2 — Income (loss) before income tax provision (benefit) (531.5 ) (37.4 ) (419.8 ) 457.2 (531.5 ) Income tax provision (benefit) (4.3 ) (9.1 ) (165.8 ) 174.9 (4.3 ) Net income (loss) (527.2 ) (28.3 ) (254.0 ) 282.3 (527.2 ) Less: Net income attributable to noncontrolling interests — — 3.6 — 3.6 Net income (loss) attributable to ATI $ (527.2 ) $ (28.3 ) $ (257.6 ) $ 282.3 $ (530.8 ) Comprehensive income (loss) attributable to ATI $ (516.8 ) $ (27.0 ) $ (260.0 ) $ 285.0 $ (518.8 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the nine months ended September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 727.7 $ 1,610.8 $ — $ 2,338.5 Cost of sales 43.0 852.0 1,378.3 — 2,273.3 Gross profit (loss) (43.0 ) (124.3 ) 232.5 — 65.2 Selling and administrative expenses 66.3 18.8 97.3 — 182.4 Restructuring charges — 9.5 489.1 — 498.6 Operating loss (109.3 ) (152.6 ) (353.9 ) — (615.8 ) Interest income (expense), net (101.4 ) (51.0 ) 61.2 — (91.2 ) Other income (loss) including equity in income of unconsolidated subsidiaries (494.5 ) 0.6 1.5 494.2 1.8 Income (loss) before income tax provision (benefit) (705.2 ) (203.0 ) (291.2 ) 494.2 (705.2 ) Income tax provision (benefit) (64.4 ) (70.1 ) (116.3 ) 186.4 (64.4 ) Net income (loss) (640.8 ) (132.9 ) (174.9 ) 307.8 (640.8 ) Less: Net income attributable to noncontrolling interests — — 10.0 — 10.0 Net income (loss) attributable to ATI $ (640.8 ) $ (132.9 ) $ (184.9 ) $ 307.8 $ (650.8 ) Comprehensive income (loss) attributable to ATI $ (592.6 ) $ (114.2 ) $ (199.0 ) $ 307.8 $ (598.0 )
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows For the nine months ended September 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (73.0 ) $ (183.7 ) $ 169.0 $ (24.0 ) $ (111.7 ) Investing Activities: Purchases of property, plant and equipment (0.5 ) (93.0 ) (81.4 ) — (174.9 ) Net receipts/(payments) on intercompany activity — — (102.0 ) 102.0 — Asset disposals and other — — 2.1 — 2.1 Cash flows provided by (used in) investing activities (0.5 ) (93.0 ) (181.3 ) 102.0 (172.8 ) Financing Activities: Borrowings on long-term debt 287.5 — 100.0 — 387.5 Payments on long-term debt and capital leases (0.5 ) (0.2 ) (1.7 ) — (2.4 ) Net borrowings under credit facilities — — 2.4 — 2.4 Debt issuance costs (9.4 ) — (1.0 ) — (10.4 ) Net receipts/(payments) on intercompany activity (176.4 ) 278.4 — (102.0 ) — Dividends paid to stockholders (25.8 ) — (24.0 ) 24.0 (25.8 ) Dividends paid to noncontrolling interests — — (16.0 ) — (16.0 ) Acquisition of noncontrolling interests — — (12.2 ) — (12.2 ) Cash flows provided by (used in) financing activities 75.4 278.2 47.5 (78.0 ) 323.1 Increase in cash and cash equivalents $ 1.9 $ 1.5 $ 35.2 $ — $ 38.6 Condensed Statements of Cash Flows For the nine months ended September 30, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (61.3 ) $ (171.1 ) $ 341.3 $ — $ 108.9 Investing Activities: Purchases of property, plant and equipment (0.1 ) (45.0 ) (54.4 ) — (99.5 ) Purchases of businesses, net of cash acquired — — (0.5 ) — (0.5 ) Net receipts/(payments) on intercompany activity — — (333.3 ) 333.3 — Asset disposals and other — 0.2 (0.2 ) — — Cash flows provided by (used in) investing activities (0.1 ) (44.8 ) (388.4 ) 333.3 (100.0 ) Financing Activities: Payments on long-term debt and capital leases (0.4 ) (0.1 ) (22.8 ) — (23.3 ) Net receipts/(payments) on intercompany activity 124.2 209.1 — (333.3 ) — Dividends paid to stockholders (57.9 ) — — — (57.9 ) Other (1.3 ) — 1.6 — 0.3 Cash flows provided by (used in) financing activities 64.6 209.0 (21.2 ) (333.3 ) (80.9 ) Increase (decrease) in cash and cash equivalents $ 3.2 $ (6.9 ) $ (68.3 ) $ — $ (72.0 )

Accumulated Other Comprehensi37

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
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 September 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, June 30, 2016 $ (913.7 ) $ (59.8 ) $ — $ (0.2 ) $ (973.7 ) OCI before reclassifications — (2.8 ) — 3.0 0.2 Amounts reclassified from AOCI (a) 11.4 (b) — (b) — (c) 0.4 11.8 Net current-period OCI 11.4 (2.8 ) — 3.4 12.0 Balance, September 30, 2016 $ (902.3 ) $ (62.6 ) $ — $ 3.2 $ (961.7 ) Attributable to noncontrolling interests: Balance, June 30, 2016 $ — $ 16.4 $ — $ — $ 16.4 OCI before reclassifications — (1.6 ) — — (1.6 ) Amounts reclassified from AOCI — (b) — — — — Net current-period OCI — (1.6 ) — — (1.6 ) Balance, September 30, 2016 $ — $ 14.8 $ — $ — $ 14.8 The changes in AOCI by component, net of tax, for the nine month period ended September 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, December 31, 2015 $ (951.2 ) $ (47.6 ) $ — $ (15.7 ) $ (1,014.5 ) OCI before reclassifications 13.9 (15.0 ) — 13.6 12.5 Amounts reclassified from AOCI (a) 35.0 (b) — (b) — (c) 5.3 40.3 Net current-period OCI 48.9 (15.0 ) — 18.9 52.8 Balance, September 30, 2016 $ (902.3 ) $ (62.6 ) $ — $ 3.2 $ (961.7 ) Attributable to noncontrolling interests: Balance, December 31, 2015 $ — $ 19.4 $ — $ — $ 19.4 OCI before reclassifications — (4.6 ) — — (4.6 ) Amounts reclassified from AOCI — (b) — — — — Net current-period OCI — (4.6 ) — — (4.6 ) Balance, September 30, 2016 $ — $ 14.8 $ — $ — $ 14.8 (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 related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (see Note 5). The changes in AOCI by component, net of tax, for the three month period ended September 30, 2015 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, June 30, 2015 $ (906.5 ) $ (19.0 ) $ (0.1 ) $ 18.3 $ (907.3 ) OCI before reclassifications — (12.1 ) — (16.5 ) (28.6 ) Amounts reclassified from AOCI (a) 12.5 (b) — (b) — (c) (2.0 ) 10.5 Net current-period OCI 12.5 (12.1 ) — (18.5 ) (18.1 ) Balance, September 30, 2015 $ (894.0 ) $ (31.1 ) $ (0.1 ) $ (0.2 ) $ (925.4 ) Attributable to noncontrolling interests: Balance, June 30, 2015 $ — $ 25.3 $ — $ — $ 25.3 OCI before reclassifications — (4.1 ) — — (4.1 ) Amounts reclassified from AOCI — — — — — Net current-period OCI — (4.1 ) — — $ (4.1 ) Balance, September 30, 2015 $ — $ 21.2 $ — $ — $ 21.2 The changes in AOCI by component, net of tax, for the nine month period ended September 30, 2015 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, December 31, 2014 $ (931.5 ) $ (16.2 ) $ — $ 16.3 $ (931.4 ) OCI before reclassifications — (14.9 ) (0.1 ) (11.5 ) (26.5 ) Amounts reclassified from AOCI (a) 37.5 (b) — (b) — (c) (5.0 ) 32.5 Net current-period OCI 37.5 (14.9 ) (0.1 ) (16.5 ) 6.0 Balance, September 30, 2015 $ (894.0 ) $ (31.1 ) $ (0.1 ) $ (0.2 ) $ (925.4 ) Attributable to noncontrolling interests: Balance, December 31, 2014 $ — $ 25.0 $ — $ — $ 25.0 OCI before reclassifications — (3.8 ) — — (3.8 ) Amounts reclassified from AOCI — (b) — — — — Net current-period OCI — (3.8 ) — — $ (3.8 ) Balance, September 30, 2015 $ — $ 21.2 $ — $ — $ 21.2 (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 related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (see Note 5).
Reclassification out of Accumulated Other Comprehensive Income	Reclassifications out of AOCI for the three and nine month periods ended September 30, 2016 and 2015 were as follows: Amount reclassified from AOCI Details about AOCI Components (In millions) Three months ended September 30, 2016 Three months ended September 30, 2015 Nine months ended September 30, 2016 Nine months ended September 30, 2015 Affected line item in the statements of operations Postretirement benefit plans Prior service (cost) credit $ 0.4 $ (1.5 ) (a) $ — $ (4.5 ) (a) Actuarial losses (18.7 ) (18.8 ) (a) (56.2 ) (56.2 ) (a) (18.3 ) (20.3 ) (c) (56.2 ) (60.7 ) (c) Total before tax (6.9 ) (7.8 ) (21.2 ) (23.2 ) Tax benefit $ (11.4 ) $ (12.5 ) $ (35.0 ) $ (37.5 ) Net of tax Derivatives Nickel and other raw material contracts $ (3.5 ) $ (3.9 ) (b) $ (15.9 ) $ (11.4 ) (b) Natural gas contracts (2.5 ) (2.6 ) (b) (13.5 ) (10.4 ) (b) Electricity contracts — — (b) — (0.2 ) (b) Foreign exchange contracts 5.4 9.8 (b) 20.9 30.1 (b) (0.6 ) 3.3 (c) (8.5 ) 8.1 (c) Total before tax (0.2 ) 1.3 (3.2 ) 3.1 Tax provision (benefit) $ (0.4 ) $ 2.0 $ (5.3 ) $ 5.0 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 related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (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.

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 157		$ 157		$ 216
Work-in-process	865.7		865.7		990.3
Finished goods	169.4		169.4		184.1
Total inventories at current cost	1,192.1		1,192.1		1,390.4
Adjustment from current cost to LIFO cost basis	113.3		113.3		136.4
Inventory valuation reserves	(187.5)		(187.5)		(206.3)
Progress payments	(39)		(39)		(48.9)
Total inventories, net	1,078.9		1,078.9		$ 1,271.6
Inventory [Line Items]
LIFO benefit (charge)			(23.1)	$ 80.3
NRV benefit (charge)			23.5	(80.3)
Net cost of sales impact	0	$ (0.2)	0.4	0
Inventory Valuation Reserve | Titanium products
Inventory [Line Items]
Inventory valuation charges			$ 17.7	$ 16.6
Inventory Valuation Reserve | Titanium Sponge Inventory
Inventory [Line Items]
Inventory valuation charges	$ 11.3

Property, Plant and Equipment39

Property, Plant and Equipment (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Land	$ 31.7	$ 31
Buildings	847.3	1,048.2
Equipment and leasehold improvements	3,646.8	3,858.1
Property Plant And Equipment, gross	4,525.8	4,937.3
Accumulated depreciation and amortization	(2,011.4)	(2,009.1)
Total property, plant and equipment, net	2,514.4	$ 2,928.2
Construction in progress	$ 130.9

Debt Schedule of Debt (Details)

Debt Schedule of Debt (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2016	Dec. 31, 2015	Feb. 15, 2016	Dec. 31, 2013
Debt Instrument [Line Items]
Deferred Finance Costs, Noncurrent, Net		$ (18)	$ (9.5)
Total Debt		1,875.8	1,495.7
Short-term debt and current portion of long-term debt		5.4	3.9
Long-term debt		1,870.4	1,491.8
Allegheny Technologies, Convertible Senior Notes, 4.75%, Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 287.5	0
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date		Jul. 1, 2022
Interest rate		4.75%
Allegheny Technologies 5.875% Notes due 2023 (a)
Debt Instrument [Line Items]
Long-term Debt, Gross	[1]	$ 500	$ 500
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date		Aug. 15, 2023	Aug. 15, 2023
Interest rate		7.875%	7.625%	7.875%	5.875%
Allegheny Technologies 5.95% Notes due 2021
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 500	$ 500
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date		Jan. 15, 2021	Jan. 15, 2021
Interest rate		5.95%	5.95%
Allegheny Technologies 9.375% Notes due 2019
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 350	$ 350
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date		Jun. 1, 2019	Jun. 1, 2019
Interest rate		9.375%	9.375%
Allegheny Ludlum 6.95% debentures due 2025
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 150	$ 150
Debt Instrument, Issuer		Allegheny Ludlum
Debt Instrument, Maturity Date		Dec. 15, 2025	Dec. 15, 2025
Interest rate		6.95%	6.95%
Domestic Bank Group $400 million asset-based credit facility
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 0	$ 0
2017 Term Loan
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 100	0
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date		Nov. 13, 2017
Foreign credit facilities
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 3.8	1.4
Industrial revenue bonds, due through 2020, and other
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 2.5	$ 3.8
Debt Instrument, Maturity Date Range, End		Jan. 1, 2020	Jan. 1, 2020
[1]	Bearing interest at 7.875% effective February 15, 2016.

Debt Narrative (Details)

Debt Narrative (Details)		Jun. 02, 2016USD ($)	Jul. 31, 2016USD ($)	May 31, 2016	Sep. 30, 2016USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	May 24, 2016USD ($)$ / shares	Feb. 15, 2016	Dec. 31, 2015USD ($)	Dec. 31, 2013
Debt Instrument [Line Items]
Debt issuance costs						$ 10,400,000	$ 0
Defined benefit plan contributions made			$ 115,000,000
Allegheny Technologies 5.875% Notes due 2023 (a)
Debt Instrument [Line Items]
Interest rate					7.875%	7.875%			7.875%	7.625%	5.875%
Additional annual interest expense to be incurred						$ 1,300,000
Outstanding borrowings	[1]				$ 500,000,000	500,000,000				$ 500,000,000
Domestic Bank Group $400 million asset-based credit facility
Debt Instrument [Line Items]
Debt issuance costs						900,000
Outstanding borrowings					0	0				0
Amount utilized to support the issuance of letters of credit					10,800,000	10,800,000
Average borrowings during period						$ 109,000,000
Interest rate during period						1.757%
Domestic Bank Group $400 million asset-based credit facility | Revolving credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 400,000,000	$ 400,000,000
Minimum fixed charge coverage ratio allowed in event of default					1	1
Minimum remaining borrowing capacity as a percent of maximum borrowing capacity					12.50%	12.50%
Line of Credit Facility, Remaining Borrowing Capacity					$ 62,500,000	$ 62,500,000
Minimum remaining borrowing capacity					40,000,000	40,000,000
Minimum required liquidity prior to maturity of 9.375% Senior Notes due 2019					500,000,000	$ 500,000,000
Minimum required liquidity number of days prior to maturity of 9.375% Senior Notes due 2019						91 days
Domestic Bank Group $400 million asset-based credit facility | Revolving credit facility | Minimum | LIBOR based borrowings
Debt Instrument [Line Items]
Variable interest rate (percentage)						2.00%
Domestic Bank Group $400 million asset-based credit facility | Revolving credit facility | Minimum | Base rate borrowings
Debt Instrument [Line Items]
Variable interest rate (percentage)						1.00%
Domestic Bank Group $400 million asset-based credit facility | Revolving credit facility | Maximum | LIBOR based borrowings
Debt Instrument [Line Items]
Variable interest rate (percentage)						2.50%
Domestic Bank Group $400 million asset-based credit facility | Revolving credit facility | Maximum | Base rate borrowings
Debt Instrument [Line Items]
Variable interest rate (percentage)						1.50%
Domestic Bank Group $400 million asset-based credit facility | Letter of credit sub-facility
Debt Instrument [Line Items]
Maximum borrowing capacity					200,000,000	$ 200,000,000
2017 Term Loan
Debt Instrument [Line Items]
Debt issuance costs						1,000,000
Outstanding borrowings					$ 100,000,000	100,000,000				0
2017 Term Loan | LIBOR based borrowings
Debt Instrument [Line Items]
Variable interest rate (percentage)					3.50%
Seperateletter of Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding					$ 32,000,000	$ 32,000,000
Allegheny Technologies, Convertible Senior Notes, 4.75%, Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate					4.75%	4.75%
Outstanding borrowings					$ 287,500,000	$ 287,500,000				$ 0
Convertible Debt | Allegheny Technologies, Convertible Senior Notes, 4.75%, Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate								4.75%
Long-term Debt		$ 37,500,000						$ 250,000,000
Debt issuance costs		$ 9,400,000
Term of debt instrument					6 years
Conversion ratio				0.0692042
Number of shares issuable				19,900,000
Conversion price (in USD per share) | $ / shares								$ 14.45
[1]	Bearing interest at 7.875% effective February 15, 2016.

Derivative Financial Instrume42

Derivative Financial Instruments and Hedging (Details) € in Millions, lb in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)lb	Sep. 30, 2015USD ($)	Sep. 30, 2016EUR (€)
Derivative Instruments Gain Loss [Line Items]
Percentage of estimated annual nickel requirements			30.00%
Percentage Of Forecasted Natural Gas Usage Hedged for 2017			90.00%
Percentage Of Forecasted Natural Gas Usage Hedged for 2018			25.00%
Reclassification of Cash Flow Hedge Gain (Loss) [Abstract]
Cash Flow Hedge Gain (Loss) To Be Reclassified Within Twelve Months			$ (9.3)
Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	$ 3	$ (16.5)	13.6	$ (11.5)
Cost Of Sales | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	(0.1)	2	(4.1)	5
Selling And Administrative Expenses | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	(0.3)	0	$ (1.2)	0
Nickel
Derivative Instruments Gain Loss [Line Items]
Notional amount of nickel hedge (in pounds of nickel) | lb			29
Nickel and other raw material contracts | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	4.2	(13.5)	$ 13	(26.6)
Nickel and other raw material contracts | Cost Of Sales | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	(2.2)	(2.4)	(9.9)	(7)
Nickel and other raw material contracts | Selling And Administrative Expenses | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
Natural gas contracts | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	(1.2)	(3.7)	1.1	(9.5)
Natural gas contracts | Cost Of Sales | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	(1.3)	(1.6)	(7.2)	(6.4)
Natural gas contracts | Selling And Administrative Expenses | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	(0.3)	0	(1.2)	0
Electricity contracts | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	0	0	0	0
Electricity contracts | Cost Of Sales | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	0	0	0	(0.1)
Electricity contracts | Selling And Administrative Expenses | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
Foreign exchange contracts | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	0	0.7	(0.5)	24.6
Foreign exchange contracts | Cost Of Sales | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	3.4	6	13	18.5
Foreign exchange contracts | Selling And Administrative Expenses | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
Designated as Hedging Instrument | Foreign exchange forward | Cost Of Sales | Fair Value Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Net	(0.5)	(1.8)	(3)	5.6
Designated as Hedging Instrument | Foreign exchange forward | Maturity Dates Through 2017 [Member] | Fair Value Hedging
Derivative Instruments Gain Loss [Line Items]
Notional amount of derivative | €					€ 67.2
Designated as Hedging Instrument | Natural gas contracts | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Loss on Cash Flow Hedge Ineffectiveness	0.4		1.7
Not Designated as Hedging Instrument | Foreign exchange forward | Maturity Dates Through 2017 [Member]
Derivative Instruments Gain Loss [Line Items]
Notional amount of derivative | €					€ 10
Not Designated as Hedging Instrument | Foreign exchange contracts | Cost Of Sales
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Net	$ (0.2)	$ 0	$ (0.1)	$ 3

Derivative Financial Instrume43

Derivative Financial Instruments and Hedging (Details2) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	$ 9.9	$ 2.4
Derivative Fair Value Of Derivative Liability	28.5	71.3
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	9.7	2
Derivative Fair Value Of Derivative Liability	28.5	71.2
Designated as Hedging Instrument | Nickel and other raw material contracts | Prepaid expenses and other current assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	3.5	0
Designated as Hedging Instrument | Nickel and other raw material contracts | Other assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	5.8	0
Designated as Hedging Instrument | Nickel and other raw material contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	8.8	22.2
Designated as Hedging Instrument | Nickel and other raw material contracts | Other long-term liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	8.7	23
Designated as Hedging Instrument | Natural gas contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	8.5	17.3
Designated as Hedging Instrument | Natural gas contracts | Other long-term liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.8	8.5
Designated as Hedging Instrument | Foreign exchange contracts | Prepaid expenses and other current assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	1.6
Designated as Hedging Instrument | Foreign exchange contracts | Other assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.4
Designated as Hedging Instrument | Foreign exchange contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	1.4	0.1
Designated as Hedging Instrument | Foreign exchange contracts | Other long-term liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.3	0.1
Not Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.4
Derivative Fair Value Of Derivative Liability	0	0.1
Not Designated as Hedging Instrument | Foreign exchange contracts | Prepaid expenses and other current assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.4
Not Designated as Hedging Instrument | Foreign exchange contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	$ 0	$ 0.1

Fair Value of Financial Instr44

Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Carrying Reported Amount Fair Value Disclosure
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 188.4	$ 149.8
Derivative financial instruments, Assets	9.9	2.4
Derivative Financial Instruments, liabilities	28.5	71.3
Debt	1,893.8	1,505.2
Estimate Of Fair Value Fair Value Disclosure
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	188.4	149.8
Derivative financial instruments, Assets	9.9	2.4
Derivative Financial Instruments, liabilities	28.5	71.3
Debt	1,980.9	969.7
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	188.4	149.8
Derivative financial instruments, Assets	0	0
Derivative Financial Instruments, liabilities	0	0
Debt	1,874.6	964.5
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	9.9	2.4
Derivative Financial Instruments, liabilities	28.5	71.3
Debt	$ 106.3	$ 5.2

Pension Plans and Other Postr45

Pension Plans and Other Postretirement Benefits (Details1) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Plans Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	$ 5.2	$ 5.7	$ 15.5	$ 17.1
Interest cost on benefits earned in prior years	31.4	30.3	94.1	90.8
Expected return on plan assets	(37.2)	(42.1)	(111.5)	(126.2)
Amortization of prior service cost (credit)	0.3	0.3	0.9	0.9
Amortization of net actuarial loss	16.3	15.1	49	45.3
Total retirement benefit expense	16	9.3	48	27.9
Other Postretirement Benefit Plan, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	0.6	0.7	1.9	2.1
Interest cost on benefits earned in prior years	4	4.4	12	13.4
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(0.7)	1.2	(0.9)	3.6
Amortization of net actuarial loss	2.4	3.7	7.2	10.9
Total retirement benefit expense	$ 6.3	$ 10	$ 20.2	$ 30

Pension Plans and Other Postr46

Pension Plans and Other Postretirement Benefits Narrative (Details) - USD ($) $ in Millions	Mar. 01, 2016	Jul. 31, 2016	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan contributions made		$ 115
Other Postretirement Benefit Plan, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used	4.05%		4.50%
Remeasurement decrease in plan liabilities	$ 22.5
Remeausrement decrease in benefit expense for remainder of 2016	$ 7.5

Income Taxes - Quarterly Disclo

Income Taxes - Quarterly Disclosure (Details9) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments, Owned, Federal Income Tax Note [Line Items]
Income tax (provision) benefit	$ 4.3	$ (23.4)	$ 64.4	$ (23.7)
Effective Income Tax Rate Reconciliation, Percent	0.80%		9.10%
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	$ 173.1	$ 63.9
Amount of valuation allowance in the effective tax rate		6.00%
Discrete tax benefits (expense)	$ (4.1)		$ (0.5)	$ (57.9)
Effective tax rate excluding valuation allowance	34.10%
Discrete Item [Member]
Investments, Owned, Federal Income Tax Note [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount		$ 56.6
Part of Effective Tax Rate [Member]
Investments, Owned, Federal Income Tax Note [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount		$ 7.3

Business Segments (Details)

Business Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)segment	Sep. 30, 2015USD ($)
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract]
Number of business segments | segment			2
Segment Reporting Information [Line Items]
Sales	$ 770.5	$ 832.7	$ 2,338.5	$ 2,980.7
Operating profit (loss):	26.2	(73)	(47.3)	14.3
LIFO and net realizable value reserves	0	(0.2)	0.4	0
Corporate expenses	(9.8)	(10.7)	(32.6)	(33.6)
Closed operations and other expenses	(15.4)	(6.5)	(24.6)	(18.6)
Restructuring and other charges	(499.9)	0	(509.9)	0
Interest expense, net	(32.6)	(27.5)	(91.2)	(81)
Income (loss) before income tax provision (benefit)	(531.5)	(117.9)	(705.2)	(118.9)
High Performance Materials & Components
Segment Reporting Information [Line Items]
Operating profit (loss):	47	18.8	114.9	136.1
Flat Rolled Products
Segment Reporting Information [Line Items]
Operating profit (loss):	(20.8)	(91.8)	(162.2)	(121.8)
Operating Segments
Segment Reporting Information [Line Items]
Sales	796.4	867.9	2,420.9	3,104.5
Operating Segments | High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	474.7	490.1	1,493.7	1,588.5
Operating Segments | Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	321.7	377.8	927.2	1,516
Internal Customers | Operating Segments
Segment Reporting Information [Line Items]
Sales	25.9	35.2	82.4	123.8
Internal Customers | Operating Segments | High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	12.9	15.4	40.5	59.9
Internal Customers | Operating Segments | Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	13	19.8	41.9	63.9
External Customers | Operating Segments
Segment Reporting Information [Line Items]
Sales	770.5	832.7	2,338.5	2,980.7
External Customers | Operating Segments | High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	461.8	474.7	1,453.2	1,528.6
External Customers | Operating Segments | Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	$ 308.7	$ 358	$ 885.3	$ 1,452.1

Business Segments - Additional

Business Segments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 488.6			$ 0	$ 498.6	$ 0
Long-lived impairment charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges	471.3
Facility shutdown, idling, and employee benefit costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	17.3
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 1	$ 9
Inventory Valuation Reserve | Titanium Sponge Inventory
Restructuring Cost and Reserve [Line Items]
Inventory valuation charges	$ 11.3
High Performance Materials & Components
Restructuring Cost and Reserve [Line Items]
Increase (Decrease) in Assets					$ (521)

Restructuring Charges (Details)

Restructuring Charges (Details) $ in Millions	3 Months Ended					9 Months Ended		12 Months Ended
	Dec. 31, 2016USD ($)employee	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)employee	Mar. 31, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2016USD ($)employee
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 488.6			$ 0	$ 498.6	$ 0
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning of period	$ 23.2			$ 8.1		8.1		$ 8.1
Restructuring Charges						27
Payments for Restructuring						(11.9)
Restructuring reserve, end of period		23.2				23.2
Long-lived impairment charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges		471.3
Facility shutdown and idling costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		16.3
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning of period	16.3			3.6		3.6		3.6
Restructuring Charges						16
Payments for Restructuring						(3.3)
Restructuring reserve, end of period		16.3				16.3
Employee benefit costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		1
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 1	9
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning of period	$ 6.9			$ 4.5		4.5		$ 4.5
Restructuring Charges						11
Payments for Restructuring						(8.6)
Restructuring reserve, end of period		6.9				6.9
Rowley, UT facility
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charge		470.8
Estimated fair value after impairment		$ 15				$ 15
Rowley, UT facility | Forecast
Restructuring Cost and Reserve [Line Items]
Number of positions expected to be eliminated | employee	150
Flat Rolled Products | Forecast
Restructuring Cost and Reserve [Line Items]
Number of positions expected to be eliminated | employee								250
High Performance Materials & Components | Employee severance
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | employee			20

Redeemable Noncontrolling Int51

Redeemable Noncontrolling Interest (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interest		$ 0
Redeemable noncontrolling interest	$ 0		$ 12.1
ATI Flowform Products [Member]
Redeemable Noncontrolling Interest [Line Items]
Payments to Noncontrolling Interests	$ 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		$ (0.3)

Per Share Information (Details)

Per Share Information (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share Reconciliation [Abstract]
Loss attributable to ATI	$ (530,800,000)	$ (144,600,000)	$ (650,800,000)	$ (151,000,000)
Redeemable noncontrolling interest	0	(200,000)	0	(300,000)
4.75% Convertible Senor Notes due 2022	0	0	0	0
Loss attributable to ATI after assumed conversions	$ (530,800,000)	$ (144,800,000)	$ (650,800,000)	$ (151,300,000)
Denominator for basic net loss per common share – weighted average shares	107.3	107.3	107.3	107.3
Share-based compensation	0	0	0	0
Effective of dilutive securities: 4.75% Convertible Senior Notes due 2022	0	0	0	0
Denominator for diluted net loss per common share – adjusted weighted average shares and assumed conversions	107.3	107.3	107.3	107.3
Basic loss attributable to ATI per common share (in dollars per share)	$ (4.95)	$ (1.35)	$ (6.07)	$ (1.41)
Diluted loss attributable to ATI per common share (in dollars per share)	$ (4.95)	$ (1.35)	$ (6.07)	$ (1.41)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount	21	0.8	10.3	0.9

Financial Information for Sub53

Financial Information for Subsidiary and Guarantor Parent (Narrative) (Details) - Allegheny Ludlum 6.95% debentures due 2025 - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 150	$ 150
Interest rate	6.95%	6.95%

Financial Information for Sub54

Financial Information for Subsidiary and Guarantor Parent (B.S.) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 188.4	$ 149.8	$ 197.5	$ 269.5
Accounts receivable, net	454	400.3
Intercompany notes receivable	0	0
Inventories, net	1,078.9	1,271.6
Prepaid expenses and other current assets	40.8	45.9
Total current assets	1,762.1	1,867.6
Property, plant and equipment, net	2,514.4	2,928.2
Goodwill	644.4	651.4
Intercompany notes receivable	0	0
Investment in subsidiaries	0	0
Other assets	271.4	304.5
Total assets	5,192.3	5,751.7
LIABILITIES AND EQUITY
Accounts payable	285.2	380.8
Accrued liabilities	310.9	301.8
Intercompany notes payable	0	0
Short-term debt and current portion of long-term debt	5.4	3.9
Total current liabilities	601.5	686.5
Long-term debt	1,870.4	1,491.8
Intercompany notes payable	0	0
Accrued postretirement benefits	311.6	359.2
Pension liabilities	708.6	833.8
Deferred income taxes	51.3	75.6
Other long-term liabilities	86.2	108.3
Total liabilities	3,629.6	3,555.2
Redeemable noncontrolling interest	0	12.1
Total stockholders’ equity	1,562.7	2,184.4	$ 2,505.5	$ 2,709.3
Total Liabilities and Equity	5,192.3	5,751.7
Reportable Legal Entities | Parent Company
ASSETS
Cash and cash equivalents	2.3	0.4
Accounts receivable, net	0.1	0.1
Intercompany notes receivable	0	0
Inventories, net	0	0
Prepaid expenses and other current assets	3.3	9.3
Total current assets	5.7	9.8
Property, plant and equipment, net	1.5	2.2
Goodwill	0	0
Intercompany notes receivable	0	0
Investment in subsidiaries	5,363.3	5,742.5
Other assets	22.1	13.4
Total assets	5,392.6	5,767.9
LIABILITIES AND EQUITY
Accounts payable	3.5	4.8
Accrued liabilities	35.6	42.1
Intercompany notes payable	1,442.1	1,325.4
Short-term debt and current portion of long-term debt	0.7	0.7
Total current liabilities	1,481.9	1,373
Long-term debt	1,620.9	1,341.7
Intercompany notes payable	0	0
Accrued postretirement benefits	0	0
Pension liabilities	658.9	778
Deferred income taxes	51.3	75.6
Other long-term liabilities	16.9	15.2
Total liabilities	3,829.9	3,583.5
Redeemable noncontrolling interest		0
Total stockholders’ equity	1,562.7	2,184.4
Total Liabilities and Equity	5,392.6	5,767.9
Reportable Legal Entities | Subsidiary
ASSETS
Cash and cash equivalents	4.3	2.8
Accounts receivable, net	115.7	100.3
Intercompany notes receivable	0	0
Inventories, net	137.6	239.9
Prepaid expenses and other current assets	4.9	3.8
Total current assets	262.5	346.8
Property, plant and equipment, net	1,587.7	1,559.9
Goodwill	0	0
Intercompany notes receivable	0	0
Investment in subsidiaries	37.7	37.7
Other assets	26.1	23
Total assets	1,914	1,967.4
LIABILITIES AND EQUITY
Accounts payable	123.9	171.1
Accrued liabilities	91	74
Intercompany notes payable	1,513.7	1,276.1
Short-term debt and current portion of long-term debt	0.3	0.1
Total current liabilities	1,728.9	1,521.3
Long-term debt	149.9	149.7
Intercompany notes payable	200	200
Accrued postretirement benefits	245.1	280
Pension liabilities	4.7	5.2
Deferred income taxes	0	0
Other long-term liabilities	18.8	20.7
Total liabilities	2,347.4	2,176.9
Redeemable noncontrolling interest		0
Total stockholders’ equity	(433.4)	(209.5)
Total Liabilities and Equity	1,914	1,967.4
Reportable Legal Entities | NonGuarantor Subsidiaries
ASSETS
Cash and cash equivalents	181.8	146.6
Accounts receivable, net	338.2	299.9
Intercompany notes receivable	2,955.8	2,601.5
Inventories, net	941.3	1,031.7
Prepaid expenses and other current assets	32.6	32.8
Total current assets	4,449.7	4,112.5
Property, plant and equipment, net	925.2	1,366.1
Goodwill	644.4	651.4
Intercompany notes receivable	200	200
Investment in subsidiaries	0	0
Other assets	223.2	268.1
Total assets	6,442.5	6,598.1
LIABILITIES AND EQUITY
Accounts payable	157.8	204.9
Accrued liabilities	184.3	185.7
Intercompany notes payable	0	0
Short-term debt and current portion of long-term debt	4.4	3.1
Total current liabilities	346.5	393.7
Long-term debt	99.6	0.4
Intercompany notes payable	0	0
Accrued postretirement benefits	66.5	79.2
Pension liabilities	45	50.6
Deferred income taxes	0	0
Other long-term liabilities	50.5	72.4
Total liabilities	608.1	596.3
Redeemable noncontrolling interest		12.1
Total stockholders’ equity	5,834.4	5,989.7
Total Liabilities and Equity	6,442.5	6,598.1
Eliminations
ASSETS
Cash and cash equivalents	0	0
Accounts receivable, net	0	0
Intercompany notes receivable	(2,955.8)	(2,601.5)
Inventories, net	0	0
Prepaid expenses and other current assets	0	0
Total current assets	(2,955.8)	(2,601.5)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intercompany notes receivable	(200)	(200)
Investment in subsidiaries	(5,401)	(5,780.2)
Other assets	0	0
Total assets	(8,556.8)	(8,581.7)
LIABILITIES AND EQUITY
Accounts payable	0	0
Accrued liabilities	0	0
Intercompany notes payable	(2,955.8)	(2,601.5)
Short-term debt and current portion of long-term debt	0	0
Total current liabilities	(2,955.8)	(2,601.5)
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	(3,155.8)	(2,801.5)
Redeemable noncontrolling interest		0
Total stockholders’ equity	(5,401)	(5,780.2)
Total Liabilities and Equity	$ (8,556.8)	$ (8,581.7)

Financial Information for Sub55

Financial Information for Subsidiary and Guarantor Parent (I.S.) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Sales	$ 770.5	$ 832.7	$ 2,338.5	$ 2,980.7
Cost of sales	720.3	861.4	2,273.3	2,822.9
Gross profit (loss)	50.2	(28.7)	65.2	157.8
Selling and administrative expenses	60.5	62.5	182.4	198
Restructuring charges	488.6	0	498.6	0
Operating income (loss)	(498.9)	(91.2)	(615.8)	(40.2)
Interest income (expense), net	(32.6)	(27.5)	(91.2)	(81)
Other income (loss) including equity in income of unconsolidated subsidiaries	0	0.8	1.8	2.3
Income (loss) before income tax provision (benefit)	(531.5)	(117.9)	(705.2)	(118.9)
Income tax provision (benefit)	(4.3)	23.4	(64.4)	23.7
Net income (loss)	(527.2)	(141.3)	(640.8)	(142.6)
Less: Net income attributable to noncontrolling interests	3.6	3.3	10	8.4
Net income (loss) attributable to ATI	(530.8)	(144.6)	(650.8)	(151)
Comprehensive income (loss) attributable to ATI	(518.8)	(162.7)	(598)	(145)
Reportable Legal Entities | Parent Company
Income Statement [Abstract]
Sales	0	0	0	0
Cost of sales	14	9.2	43	22
Gross profit (loss)	(14)	(9.2)	(43)	(22)
Selling and administrative expenses	23.8	22.9	66.3	70.1
Restructuring charges	0		0
Operating income (loss)	(37.8)	(32.1)	(109.3)	(92.1)
Interest income (expense), net	(36.5)	(29.5)	(101.4)	(86.1)
Other income (loss) including equity in income of unconsolidated subsidiaries	(457.2)	(56.3)	(494.5)	59.3
Income (loss) before income tax provision (benefit)	(531.5)	(117.9)	(705.2)	(118.9)
Income tax provision (benefit)	(4.3)	23.4	(64.4)	23.7
Net income (loss)	(527.2)	(141.3)	(640.8)	(142.6)
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	(527.2)	(141.3)	(640.8)	(142.6)
Comprehensive income (loss) attributable to ATI	(516.8)	(163.5)	(592.6)	(140.4)
Reportable Legal Entities | Subsidiary
Income Statement [Abstract]
Sales	253	286.3	727.7	1,231.5
Cost of sales	266.6	363.5	852	1,296.5
Gross profit (loss)	(13.6)	(77.2)	(124.3)	(65)
Selling and administrative expenses	4.2	9.3	18.8	30.4
Restructuring charges	0.5		9.5
Operating income (loss)	(18.3)	(86.5)	(152.6)	(95.4)
Interest income (expense), net	(19.3)	(12.6)	(51)	(37.3)
Other income (loss) including equity in income of unconsolidated subsidiaries	0.2	0.2	0.6	0.8
Income (loss) before income tax provision (benefit)	(37.4)	(98.9)	(203)	(131.9)
Income tax provision (benefit)	(9.1)	(35.1)	(70.1)	(46.3)
Net income (loss)	(28.3)	(63.8)	(132.9)	(85.6)
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	(28.3)	(63.8)	(132.9)	(85.6)
Comprehensive income (loss) attributable to ATI	(27)	(60.5)	(114.2)	(76)
Reportable Legal Entities | NonGuarantor Subsidiaries
Income Statement [Abstract]
Sales	517.5	546.4	1,610.8	1,749.2
Cost of sales	439.7	488.7	1,378.3	1,504.4
Gross profit (loss)	77.8	57.7	232.5	244.8
Selling and administrative expenses	32.5	30.3	97.3	97.5
Restructuring charges	488.1		489.1
Operating income (loss)	(442.8)	27.4	(353.9)	147.3
Interest income (expense), net	23.2	14.6	61.2	42.4
Other income (loss) including equity in income of unconsolidated subsidiaries	(0.2)	0.7	1.5	1.8
Income (loss) before income tax provision (benefit)	(419.8)	42.7	(291.2)	191.5
Income tax provision (benefit)	(165.8)	11	(116.3)	67.4
Net income (loss)	(254)	31.7	(174.9)	124.1
Less: Net income attributable to noncontrolling interests	3.6	3.3	10	8.4
Net income (loss) attributable to ATI	(257.6)	28.4	(184.9)	115.7
Comprehensive income (loss) attributable to ATI	(260)	16.7	(199)	101.9
Eliminations
Income Statement [Abstract]
Sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit (loss)	0	0	0	0
Selling and administrative expenses	0	0	0	0
Restructuring charges	0		0
Operating income (loss)	0	0	0	0
Interest income (expense), net	0	0	0	0
Other income (loss) including equity in income of unconsolidated subsidiaries	457.2	56.2	494.2	(59.6)
Income (loss) before income tax provision (benefit)	457.2	56.2	494.2	(59.6)
Income tax provision (benefit)	174.9	24.1	186.4	(21.1)
Net income (loss)	282.3	32.1	307.8	(38.5)
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	282.3	32.1	307.8	(38.5)
Comprehensive income (loss) attributable to ATI	$ 285	$ 44.6	$ 307.8	$ (30.5)

Financial Information for Sub56

Financial Information for Subsidiary and Guarantor Parent (Cash Flow) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Statement of Cash Flows
Cash flows provided by (used in) operating activities	$ (111.7)	$ 108.9
Investing Activities:
Purchases of property, plant and equipment	(174.9)	(99.5)
Purchases of businesses, net of cash acquired	0	(0.5)
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	2.1	0
Cash used in investing activities	(172.8)	(100)
Financing Activities:
Borrowings on long-term debt	387.5
Payments on long-term debt and capital leases	(2.4)	(23.3)
Net borrowings under credit facilities	2.4	1.7
Debt issuance costs	(10.4)	0
Net receipts/(payments) on intercompany activity	0	0
Dividends paid to stockholders	(25.8)	(57.9)
Dividends paid to noncontrolling interests	(16)	0
Acquisition of noncontrolling interests	12.2	0
Proceeds from (Payments for) Other Financing Activities		0.3
Cash provided by (used in) financing activities	323.1	(80.9)
Increase (decrease) in cash and cash equivalents	38.6	(72)
Reportable Legal Entities | Parent Company
Statement of Cash Flows
Cash flows provided by (used in) operating activities	(73)	(61.3)
Investing Activities:
Purchases of property, plant and equipment	(0.5)	(0.1)
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	(0.5)	(0.1)
Financing Activities:
Borrowings on long-term debt	287.5
Payments on long-term debt and capital leases	(0.5)	(0.4)
Net borrowings under credit facilities	0
Debt issuance costs	(9.4)
Net receipts/(payments) on intercompany activity	(176.4)	124.2
Dividends paid to stockholders	(25.8)	(57.9)
Dividends paid to noncontrolling interests	0
Acquisition of noncontrolling interests	0
Proceeds from (Payments for) Other Financing Activities		(1.3)
Cash provided by (used in) financing activities	75.4	64.6
Increase (decrease) in cash and cash equivalents	1.9	3.2
Reportable Legal Entities | Subsidiary
Statement of Cash Flows
Cash flows provided by (used in) operating activities	(183.7)	(171.1)
Investing Activities:
Purchases of property, plant and equipment	(93)	(45)
Purchases of businesses, net of cash acquired		0
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0	0.2
Cash used in investing activities	(93)	(44.8)
Financing Activities:
Borrowings on long-term debt	0
Payments on long-term debt and capital leases	(0.2)	(0.1)
Net borrowings under credit facilities	0
Debt issuance costs	0
Net receipts/(payments) on intercompany activity	278.4	209.1
Dividends paid to stockholders	0	0
Dividends paid to noncontrolling interests	0
Acquisition of noncontrolling interests	0
Proceeds from (Payments for) Other Financing Activities		0
Cash provided by (used in) financing activities	278.2	209
Increase (decrease) in cash and cash equivalents	1.5	(6.9)
Reportable Legal Entities | NonGuarantor Subsidiaries
Statement of Cash Flows
Cash flows provided by (used in) operating activities	169	341.3
Investing Activities:
Purchases of property, plant and equipment	(81.4)	(54.4)
Purchases of businesses, net of cash acquired		(0.5)
Net receipts/(payments) on intercompany activity	(102)	(333.3)
Asset disposals and other	2.1	(0.2)
Cash used in investing activities	(181.3)	(388.4)
Financing Activities:
Borrowings on long-term debt	100
Payments on long-term debt and capital leases	(1.7)	(22.8)
Net borrowings under credit facilities	2.4
Debt issuance costs	(1)
Net receipts/(payments) on intercompany activity	0	0
Dividends paid to stockholders	(24)	0
Dividends paid to noncontrolling interests	(16)
Acquisition of noncontrolling interests	12.2
Proceeds from (Payments for) Other Financing Activities		1.6
Cash provided by (used in) financing activities	47.5	(21.2)
Increase (decrease) in cash and cash equivalents	35.2	(68.3)
Eliminations
Statement of Cash Flows
Cash flows provided by (used in) operating activities	(24)	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	102	333.3
Asset disposals and other	0	0
Cash used in investing activities	102	333.3
Financing Activities:
Borrowings on long-term debt	0
Payments on long-term debt and capital leases	0	0
Net borrowings under credit facilities	0
Debt issuance costs	0
Net receipts/(payments) on intercompany activity	(102)	(333.3)
Dividends paid to stockholders	24	0
Dividends paid to noncontrolling interests	0
Acquisition of noncontrolling interests	0
Proceeds from (Payments for) Other Financing Activities		0
Cash provided by (used in) financing activities	(78)	(333.3)
Increase (decrease) in cash and cash equivalents	$ 0	$ 0

Financial Information for Sub57

Financial Information for Subsidiary and Guarantor Parent (Changes) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Current assets	$ 1,762.1		$ 1,867.6
Assets	5,192.3		5,751.7
Current liabilities	601.5		686.5
Liabilities	3,629.6		3,555.2
Stockholders' equity	1,562.7	$ 2,505.5	$ 2,184.4	$ 2,709.3
Cash flows provided by (used in) operating activities	(111.7)	108.9
Net Cash Provided by (Used in) Investing Activities	(172.8)	(100)
Cash provided by (used in) financing activities	$ 323.1	$ (80.9)

Accumulated Other Comprehensi58

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2016		Sep. 30, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (973.7)		$ (907.3)		$ (1,014.5)		$ (931.4)
OCI before reclassifications	0.2		(28.6)		12.5		(26.5)
Amounts reclassified from AOCI	11.8		10.5		40.3		32.5
Net current-period OCI	12		(18.1)		52.8		6
Ending balance	(961.7)		(925.4)		(961.7)		(925.4)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	16.4		25.3		19.4		25
OCI before reclassifications	(1.6)		(4.1)		(4.6)		(3.8)
Amounts reclassified from AOCI	0		0		0		0
Net current-period OCI	(1.6)		(4.1)		(4.6)		(3.8)
Ending balance	14.8		21.2		14.8		21.2
Post- retirement benefit plans [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(913.7)		(906.5)		(951.2)		(931.5)
OCI before reclassifications	0		0		13.9		0
Amounts reclassified from AOCI	11.4	[1]	12.5	[2]	35	[1]	37.5	[2]
Net current-period OCI	11.4		12.5		48.9		37.5
Ending balance	(902.3)		(894)		(902.3)		(894)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	0		0		0		0
OCI before reclassifications	0		0		0		0
Amounts reclassified from AOCI	0		0		0		0
Net current-period OCI	0		0		0		0
Ending balance	0		0		0		0
Currency translation adjustment [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(59.8)		(19)		(47.6)		(16.2)
OCI before reclassifications	(2.8)		(12.1)		(15)		(14.9)
Amounts reclassified from AOCI	0	[3]	0	[4]	0	[3]	0	[4]
Net current-period OCI	(2.8)		(12.1)		(15)		(14.9)
Ending balance	(62.6)		(31.1)		(62.6)		(31.1)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	16.4		25.3		19.4		25
OCI before reclassifications	(1.6)		(4.1)		(4.6)		(3.8)
Amounts reclassified from AOCI	0	[3]	0	[4]	0	[3]	0	[4]
Net current-period OCI	(1.6)		(4.1)		(4.6)		(3.8)
Ending balance	14.8		21.2		14.8		21.2
Unrealized holding gains on securities [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0		(0.1)		0		0
OCI before reclassifications	0		0		0		(0.1)
Amounts reclassified from AOCI	0	[3]	0	[4]	0	[3]	0	[4]
Net current-period OCI	0		0		0		(0.1)
Ending balance	0		(0.1)		0		(0.1)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	0		0		0		0
OCI before reclassifications	0		0		0		0
Amounts reclassified from AOCI	0		0		0		0
Net current-period OCI	0		0		0		0
Ending balance	0		0		0		0
Derivatives [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(0.2)		18.3		(15.7)		16.3
OCI before reclassifications	3		(16.5)		13.6		(11.5)
Amounts reclassified from AOCI	0.4	[5]	(2)	[6]	5.3	[5]	(5)	[6]
Net current-period OCI	3.4		(18.5)		18.9		(16.5)
Ending balance	3.2		(0.2)		3.2		(0.2)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	0		0		0		0
OCI before reclassifications	0		0		0		0
Amounts reclassified from AOCI	0		0		0		0
Net current-period OCI	0		0		0		0
Ending balance	$ 0		$ 0		$ 0		$ 0
[1]	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 7).
[2]	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 7).
[3]	No amounts were reclassified to earnings.
[4]	No amounts were reclassified to earnings.
[5]	Amounts related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (see Note 5).
[6]	Amounts related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (see Note 5).

Accumulated Other Comprehensi59

Accumulated Other Comprehensive Income (Loss) (Details 2) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization to net income (loss) of net prior service cost (credit)		$ (0.4)	$ 1.5	$ 0	$ 4.5
Amount reclassified from AOCI, Postretirement benefit plans, Actuarial losses		18.7	18.8	56.2	56.2
Income (loss) before income tax provision (benefit)		(531.5)	(117.9)	(705.2)	(118.9)
Income tax provision (benefit)		(4.3)	23.4	(64.4)	23.7
Cost of sales		(720.3)	(861.4)	(2,273.3)	(2,822.9)
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 (loss) of net prior service cost (credit)	[1]	0.4	(1.5)	0	(4.5)
Amount reclassified from AOCI, Postretirement benefit plans, Actuarial losses	[1]	(18.7)	(18.8)	(56.2)	(56.2)
Income (loss) before income tax provision (benefit)	[2]	(18.3)	(20.3)	(56.2)	(60.7)
Income tax provision (benefit)		(6.9)	(7.8)	(21.2)	(23.2)
Net income (loss)		(11.4)	(12.5)	(35)	(37.5)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income tax provision (benefit)	[2]	(0.6)	3.3	(8.5)	8.1
Income tax provision (benefit)		(0.2)	1.3	(3.2)	3.1
Net income (loss)		(0.4)	2	(5.3)	5
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]
Cost of sales	[3]	(3.5)	(3.9)	(15.9)	(11.4)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Natural gas contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	[3]		(2.6)		(10.4)
Cost of Sales and Selling and Administrative Expenses	[3]	(2.5)		(13.5)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Electricity contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	[3]	0	0	0	(0.2)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	[3]	$ 5.4	$ 9.8	$ 20.9	$ 30.1
[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 related to the effective portion of the derivatives are included in cost of goods sold in the period or periods the hedged item affects earnings. Amounts related to the ineffective portion of the derivatives are presented in selling and administrative expenses on the consolidated statement of operations (see Note 5).

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Sep. 30, 2016USD ($)
Components of Environmental Loss Accrual [Abstract]
Accrual For Environmental Loss Contingencies	$ 14
Accrued Environmental Loss Contingencies Current	8
Federal Superfund and comparable state-managed sites	2
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
Maximum
Loss Contingency, Estimate [Abstract]
Loss contingency maximum possible loss	$ 17

Subsequent Event (Details)

Subsequent Event (Details) - Subsequent Event $ in Millions	Oct. 25, 2016USD ($)
Contract Termination | Minimum
Subsequent Event [Line Items]
Restructuring charges expected	$ 4
Contract Termination | Maximum
Subsequent Event [Line Items]
Restructuring charges expected	14
Employee benefit costs
Subsequent Event [Line Items]
Restructuring charges expected	3
Unemployment Benefits
Subsequent Event [Line Items]
Restructuring charges expected	$ 2