ATI (ATI) 10-Q 2 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	6 Months Ended
	Jun. 30, 2017	Jul. 21, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
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		108,879,684
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Entity Public Float			$ 1,400,000,000

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 154.6	$ 229.6
Accounts receivable, net	538.6	452.1
Inventories, net	1,076.2	1,037
Prepaid expenses and other current assets	30.7	47.8
Total current assets	1,800.1	1,766.5
Property, plant and equipment, net	2,492.3	2,498.9
Goodwill	643.5	641.9
Other assets	250.4	262.7
Total assets	5,186.3	5,170
Current Liabilities:
Accounts payable	355.5	294.3
Accrued liabilities	278	309.3
Short term debt and current portion of long-term debt	67.5	105.1
Total current liabilities	701	708.7
Long-term debt	1,876.6	1,771.9
Accrued postretirement benefits	308	317.7
Pension liabilities	682.9	827.9
Deferred income taxes	20.1	15.6
Other long-term liabilities	83.3	83.4
Total liabilities	3,671.9	3,725.2
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 June 30, 2017 and December 31, 2016; outstanding-108,879,682 shares at June 30, 2017 and 108,925,254 shares at December 31, 2016	11	11
Additional paid-in capital	1,191.3	1,188.8
Retained earnings	1,303.8	1,277.1
Treasury stock: 815,489 shares at June 30, 2017 and 769,917 shares at December 31, 2016	(25.4)	(28)
Accumulated other comprehensive loss, net of tax	(1,067.2)	(1,093.7)
Total ATI stockholders’ equity	1,413.5	1,355.2
Noncontrolling interests
Noncontrolling interests	100.9	89.6
Total Equity	1,514.4	1,444.8
Total Liabilities and Equity	$ 5,186.3	$ 5,170

CONSOLIDATED BALANCE SHEETS (PA

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
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	108,879,682	108,925,254
Treasury stock	815,489	769,917

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Sales	$ 880.2	$ 810.5	$ 1,746.1	$ 1,568
Cost of sales	767.9	762.3	1,521	1,553
Gross profit	112.3	48.2	225.1	15
Selling and administrative expenses	66.7	59.3	126.2	121.9
Restructuring charges	0	1	0	10
Operating income (loss)	45.6	(12.1)	98.9	(116.9)
Interest expense, net	(34.5)	(30.3)	(68)	(58.6)
Other income, net	0.2	1	3.5	1.8
Income (loss) before income taxes	11.3	(41.4)	34.4	(173.7)
Income tax benefit	(2.1)	(25.9)	(0.1)	(60.1)
Net income (loss)	13.4	(15.5)	34.5	(113.6)
Less: Net income attributable to noncontrolling interests	3.3	3.3	6.9	6.4
Net income (loss) attributable to ATI	$ 10.1	$ (18.8)	$ 27.6	$ (120)
Basic net income (loss) attributable to ATI per common share (in dollars per share)	$ 0.09	$ (0.18)	$ 0.26	$ (1.12)
Diluted net income (loss) attributable to ATI per common share (in dollars per share)	0.09	(0.18)	0.25	(1.12)
Dividends declared per common share (in dollars per share)	$ 0	$ 0.08	$ 0	$ 0.16

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 13.4	$ (15.5)	$ 34.5	$ (113.6)
Currency translation adjustment
Unrealized net change arising during the period	4.4	(9.8)	14.8	(15.2)
Derivatives
Net derivatives gain (loss) on hedge transactions	(8.2)	26.3	(10.8)	17.1
Reclassification to net income (loss) of net realized loss (gain)	(1.4)	2.9	(2.3)	7.9
Income taxes on derivative transactions	(5)	11.1	(5)	9.5
Total	(4.6)	18.1	(8.1)	15.5
Postretirement benefit plans
Amortization of net actuarial loss	18	18.8	35.8	37.5
Net gain arising during period	0	0	0	22.5
Amortization to net income (loss) of net prior service cost (credits)	(0.4)	(0.5)	(0.8)	0.4
Income taxes on postretirement benefit plans	13	6.9	13	22.9
Total	4.6	11.4	22	37.5
Other comprehensive income, net of tax	4.4	19.7	28.7	37.8
Comprehensive income (loss)	17.8	4.2	63.2	(75.8)
Less: Comprehensive income attributable to noncontrolling interests	3.5	1.8	9.1	3.4
Comprehensive income (loss) attributable to ATI	$ 14.3	$ 2.4	$ 54.1	$ (79.2)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016
Operating Activities:
Net income (loss)		$ 34.5	$ (113.6)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization		80.6	87.8
Deferred taxes		7.6	(62.4)
Changes in operating assets and liabilities:
Inventories		(39.2)	177.3
Accounts receivable		(86.5)	(92.2)
Accounts payable		58.2	(37.3)
Retirement benefits (a)	[1]	(135)	10.3
Accrued income taxes		0.9	0.1
Accrued liabilities and other		(6.6)	(3.6)
Cash used in operating activities		(85.5)	(33.6)
Investing Activities:
Purchases of property, plant and equipment		(55.3)	(145.3)
Asset disposals and other		3.3	1.8
Cash used in investing activities		(52)	(143.5)
Financing Activities:
Borrowings on long-term debt		7.3	387.5
Payments on long-term debt and capital leases		(0.8)	(0.6)
Net borrowings under credit facilities		59.4	2.5
Debt issuance costs		(0.8)	(10.4)
Dividends paid to stockholders		0	(17.2)
Acquisition of noncontrolling interests		0	(12.2)
Sale to noncontrolling Interests		2.2	0
Shares repurchased for income tax withholding on share-based compensation		(4.8)	0
Cash provided by financing activities		62.5	349.6
Increase (decrease) in cash and cash equivalents
Increase (decrease) in cash and cash equivalents		(75)	172.5
Cash and cash equivalents at beginning of period		229.6	149.8
Cash and cash equivalents at end of period		$ 154.6	$ 322.3
[1]	Includes a $(135) million contribution to the U.S. defined benefit pension plan in 2017.

CONSOLIDATED STATEMENTS OF CAS7

CONSOLIDATED STATEMENTS OF CASH FLOWS CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) $ in Millions	1 Months Ended
	Mar. 31, 2017USD ($)
Statement of Cash Flows [Abstract]
Defined benefit plan contributions made	$ (135)

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, 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)	(113.6)			(120)			6.4
Other comprehensive income (loss)	37.8					40.8	(3)
Cash dividends on common stock	(17.2)			(17.2)
Purchase of subsidiary shares from noncontrolling interest	(0.1)						(0.1)
Employee stock plans	8		16.4	(2)	(6.4)
Total Stockholders' Equity at Jun. 30, 2016	2,099.3	11	1,178.1	1,806.7	(27.7)	(973.7)	104.9
Total Stockholders' Equity at Dec. 31, 2016	1,444.8	11	1,188.8	1,277.1	(28)	(1,093.7)	89.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	34.5			27.6			6.9
Other comprehensive income (loss)	28.7					26.5	2.2
Sales of subsidiary shares to noncontrolling interest	2.2						2.2
Employee stock plans	4.2		2.5	(0.9)	2.6
Total Stockholders' Equity at Jun. 30, 2017	$ 1,514.4	$ 11	$ 1,191.3	$ 1,303.8	$ (25.4)	$ (1,067.2)	$ 100.9

STATEMENTS OF CHANGES IN CONSO9

STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY (PARENTHETICAL)	6 Months Ended
	Jun. 30, 2016$ / shares
Statement of Stockholders' Equity [Abstract]
Cash dividends on common stock per share	$ 0.16

Accounting Policies

Accounting Policies	6 Months Ended
	Jun. 30, 2017
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 2016 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, 2016 financial information has been derived from the Company’s audited consolidated financial statements. New Accounting Pronouncements Adopted In January 2017, the Company early adopted changes issued by the Financial Accounting Standards Board (FASB) to simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill, which is currently required if a reporting unit with goodwill fails a Step 1 test comparing the fair value of the reporting unit to its carrying value including goodwill. Under this new guidance, an entity should perform its annual, or interim, goodwill impairment test using just the Step 1 test of comparing the fair value of a reporting unit with its carrying amount. Any goodwill impairment, representing the amount by which the carrying amount exceeds the reporting unit’s fair value, is determined using this Step 1 test. Any goodwill impairment loss recognized would not exceed the total carrying amount of goodwill allocated to that reporting unit. The adoption of these changes did not have a material impact on the Company’s financial statements. In January 2017, the Company adopted changes issued by the FASB 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, which will be prospectively adopted. The adoption of these changes did not have a material impact on the Company’s financial statements. In January 2017, the Company adopted changes issued by the FASB 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 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 did not have a material impact on the Company’s financial statements. Pending Accounting Pronouncement In March 2017, the FASB issued changes to the accounting for defined benefit pension and other postretirement benefit expenses. This new guidance requires the disaggregation of the service cost component from the other components of net benefit cost. The service cost component of net benefit cost is to be reported in the same line item on the consolidated statement of operations as other compensation costs arising from services rendered by the pertinent employees, while the other components of net benefit cost are to be presented in the consolidated statement of operations separately, outside a subtotal of operating income. The amendments also provide explicit guidance to allow only the service cost component of net benefit cost to be eligible for capitalization. This new guidance is effective for the Company’s 2018 fiscal year, with the adoption of the change in presentation of net benefit cost in the consolidated statement of operations to be applied retrospectively, and the change in capitalization for only service cost applied prospectively. The guidance allows a practical expedient that permits the use of the amounts disclosed in the retirement benefits footnote for the prior comparative periods as the estimation basis for applying the retrospective presentation requirements. The Company will adopt this new guidance in the first quarter of fiscal year 2018 using this practical expedient. The Company expects such adoption to have a material impact to reported operating income due to the change in presentation of non-service cost expense components. For example, applying the practical expedient to fiscal year 2016 results, operating income for 2016 would be $70.6 million higher, with the reclassification of this amount representing the other components of net benefit cost to a newly-created non-operating retirement benefit expense category, with no net impact to the reported 2016 loss before income taxes. The Company expects to have a one-time, unfavorable impact to pre-tax reported results in the first quarter of 2018 upon adoption due to the change limiting only the service cost component of net benefit cost to be capitalizable into inventory. Using expected fiscal year 2017 defined benefit retirement expense and current inventory levels, this impact in the first quarter of 2018 is projected to be approximately $5 million , pre-tax. 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 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. Although the Company is currently evaluating the impact of this standard on individual customer contracts, the Company has evaluated the impact of this standard on the broad categories of its customer contracts, and anticipates the adoption of this guidance will not have a material impact on the consolidated statement of operations but does expect an impact to the consolidated balance sheet for reclassifications to contract assets and liabilities, the magnitude of which is still being determined. The Company also expects an increase to financial statement footnote disclosures regarding revenues, contract assets and contract liabilities as a result of this accounting standard update.

Inventories

Inventories	6 Months Ended
	Jun. 30, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories at June 30, 2017 and December 31, 2016 were as follows (in millions): June 30, December 31, Raw materials and supplies $ 141.6 $ 149.6 Work-in-process 886.7 837.9 Finished goods 159.4 161.7 Total inventories at current cost 1,187.7 1,149.2 Adjustment from current cost to LIFO cost basis 79.1 97.3 Inventory valuation reserves (150.2 ) (169.0 ) Progress payments (40.4 ) (40.5 ) Total inventories, net $ 1,076.2 $ 1,037.0 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): Six months ended June 30, 2017 2016 LIFO benefit (charge) $ (18.2 ) $ (4.6 ) NRV benefit (charge) 18.1 5.0 Net cost of sales impact $ (0.1 ) $ 0.4 The first six months of 2016 results included $17.7 million in inventory valuation charges related to the market-based valuation of titanium products.

Property Plant And Equipment

Property Plant And Equipment	6 Months Ended
	Jun. 30, 2017
Property, Plant and Equipment [Abstract]
Property Plant and Equipment	Property, Plant and Equipment Property, plant and equipment at June 30, 2017 and December 31, 2016 was as follows (in millions): June 30, December 31, Land $ 31.5 $ 31.4 Buildings 840.3 829.6 Equipment and leasehold improvements 3,527.0 3,497.2 4,398.8 4,358.2 Accumulated depreciation and amortization (1,906.5 ) (1,859.3 ) Total property, plant and equipment, net $ 2,492.3 $ 2,498.9 The construction in progress portion of property, plant and equipment at June 30, 2017 was $77.1 million .

Debt

Debt	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Debt	Debt Debt at June 30, 2017 and December 31, 2016 was as follows (in millions): June 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 287.5 287.5 Allegheny Ludlum 6.95% debentures due 2025 150.0 150.0 Term Loan due 2022 100.0 100.0 U.S. revolving credit facility 60.0 — Foreign credit facilities 4.0 4.4 Other 8.6 2.2 Debt issuance costs (16.0 ) (17.1 ) Total debt 1,944.1 1,877.0 Short term debt and current portion of long-term debt 67.5 105.1 Total long-term debt $ 1,876.6 $ 1,771.9 (a) Bearing interest at 7.875% effective February 15, 2016. Revolving Credit Facility The Company has an Asset Based Lending (ABL) Credit Facility, which 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 . The ABL facility includes a term loan (Term Loan) in the amount of $100.0 million . In June 2017, the ABL facility was amended to, among other things, extend the duration of the facility from September 2020 to February 2022. As amended, the applicable interest rate for revolving credit borrowings under the ABL facility includes interest rate spreads based on available borrowing capacity that range between 1.75% and 2.25% for LIBOR-based borrowings and between 1.0% and 1.5% for base rate borrowings. 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 revolving credit portion of the facility is less than the greater of (i) 10% , as amended, of the then applicable maximum borrowing amount under the revolving credit portion of the ABL and any outstanding Term Loan balance, or (ii) $40.0 million . The Company does not meet this required fixed charge coverage ratio at June 30, 2017 . As a result, the Company is not able to access $50.0 million of the revolving credit portion 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 ABL facility, 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 at least $700 million on the date that is 91 days prior to January 15, 2021, the maturity date of the 5.95% Senior Notes due 2021, and that such liquidity is available at all times thereafter until the 9.375% Senior Notes due 2019 and the 5.95% Senior Notes due 2021 are paid in full or refinanced. Costs associated with entering into the ABL amendment were $1.0 million , and are being amortized, along with any previous unamortized deferred costs, to interest expense over the extended term of the facility ending February 2022. Also in June 2017, the $100.0 million Term Loan was amended to extend the maturity date from November 2017 to February 2022 and to reduce the interest rate to 3.0% plus a LIBOR spread. The amended Term Loan can be prepaid in minimum increments of $50.0 million on or after the earlier of December 2018 or upon refinancing or retirement of the 9.375% Senior Notes due 2019 if certain minimum liquidity conditions are satisfied. The underwriting costs associated with amending the Term Loan were $0.8 million , and are being amortized, along with any previous unamortized deferred costs, to interest expense over the extended term of the loan ending February 2022. As of June 30, 2017 , there were $60.0 million of outstanding borrowings under the ABL facility, and $45.1 million was utilized to support the issuance of letters of credit. Average revolving credit borrowings under the ABL facility for the first six months of 2017 and 2016 were $36 million and $164 million , respectively, bearing an average annual interest rate of 3.376% and 1.757% , respectively.

Derivative Financial Instrument

Derivative Financial Instruments and Hedging	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 , 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 27 million pounds of nickel with hedge dates through 2021. The aggregate notional amount hedged is approximately 35% of a single year’s estimated nickel raw material purchase requirements. At June 30, 2017 , the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas cost hedges. In the first six months of 2016, due to changes in expected operating levels within Flat Rolled Products segment operations, the Company concluded that additional portions of these natural gas cash flow hedges for 2016 and the first quarter of 2017 were ineffective based on forecast changes in underlying natural gas usage. The Company recognized $0.2 million and $1.3 million of pre-tax losses for the three and six months ended June 30, 2016 , respectively, for natural gas cash flow hedge ineffectiveness, which is reported in selling and administrative expenses on the consolidated statement of operations. At June 30, 2017 the Company hedged approximately 70% of the Company’s forecasted domestic requirements for natural gas for the remainder of 2017, approximately 35% for 2018, and approximately 25% for 2019. 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 June 30, 2017 , the Company held 21.6 million euro notional value of foreign currency forward contracts designated as fair value hedges with maturity dates through 2017. The Company recorded $1.9 million and $2.2 million of charges in the three and six months ended June 30, 2017 , respectively, and a $3.1 million benefit and a $2.5 million charge in the three and six months ended June 30, 2016 , 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 June 30, December 31, Derivatives designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets $ 0.2 $ 2.4 Natural gas contacts Prepaid expenses and other current assets 0.1 0.2 Nickel and other raw material contracts Prepaid expenses and other current assets 1.3 2.2 Foreign exchange contracts Other assets — 0.2 Natural gas contracts Other assets 0.2 0.2 Nickel and other raw material contracts Other assets 1.2 3.3 Total derivatives designated as hedging instruments 3.0 8.5 Derivatives not designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets — 0.6 Total derivatives not designated as hedging instruments — 0.6 Total asset derivatives $ 3.0 $ 9.1 Liability derivatives Balance sheet location Derivatives designated as hedging instruments: Natural gas contracts Accrued liabilities $ 1.9 $ 2.5 Nickel and other raw material contracts Accrued liabilities 8.1 6.7 Foreign exchange contracts Accrued liabilities 0.7 — Natural gas contracts Other long-term liabilities 0.2 — Nickel and other raw material contracts Other long-term liabilities 9.6 9.4 Foreign exchange contracts Other long-term liabilities — 0.1 Total derivatives designated as hedging instruments 20.5 18.7 Derivatives not designated as hedging instruments: Foreign exchange contracts Accrued Liabilities 0.3 — Total derivatives not designated as hedging instruments 0.3 — Total liability derivatives $ 20.8 $ 18.7 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 and are reported as changes within accrued liabilities and other on the consolidated statements of cash flows. 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, excluding any impacts of changes to income tax valuation allowances effecting results of operations or other comprehensive income, when applicable (see Note 12 for further explanation). Assuming market prices remain constant with those at June 30, 2017 , a loss of $5.7 million , net of tax and excluding income tax valuation allowance changes, is expected to be recognized over the next 12 months. Activity with regard to derivatives designated as cash flow hedges for the three and six month periods ended June 30, 2017 and 2016 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 June 30, Three months ended June 30, Three months ended June 30, Hedging Relationships 2017 2016 2017 2016 2017 2016 Nickel and other raw material contracts $ (4.6 ) $ 12.2 $ (1.0 ) $ (3.8 ) $ — $ — Natural gas contracts (0.5 ) 4.3 (0.7 ) (2.7 ) — (0.2 ) Foreign exchange contracts (0.1 ) (0.2 ) 2.5 4.9 — — Total $ (5.2 ) $ 16.3 $ 0.8 $ (1.6 ) $ — $ (0.2 ) 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 Six months ended June 30, Six months ended June 30, Six months ended June 30, Hedging Relationships 2017 2016 2017 2016 2017 2016 Nickel and other raw material contracts $ (4.4 ) $ 8.8 $ (1.6 ) $ (7.7 ) $ — $ — Natural gas contracts (2.1 ) 2.3 (2.1 ) (5.9 ) — (0.9 ) Foreign exchange contracts (0.2 ) (0.5 ) 5.1 9.6 — — Total $ (6.7 ) $ 10.6 $ 1.4 $ (4.0 ) $ — $ (0.9 ) (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 8 million euro notional value outstanding as of June 30, 2017 of foreign currency forward contracts not designated as hedges, with maturity dates into the fourth quarter of 2017. These derivatives that are not designated as hedging instruments were as follows: (In millions) Amount of Gain (Loss) Recognized on Derivatives Three months ended June 30, Six months ended June 30, Derivatives Not Designated as Hedging Instruments 2017 2016 2017 2016 Foreign exchange contracts $ (0.5 ) $ 0.7 $ (0.6 ) $ 0.1 Changes in the fair value of foreign exchange contract derivatives not designated as hedging instruments are recorded in cost of sales and are reported as changes within accrued liabilities and other on the consolidated statements of cash flows.

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	Fair Value of Financial Instruments The estimated fair value of financial instruments at June 30, 2017 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 $ 154.6 $ 154.6 $ 154.6 $ — Derivative financial instruments: Assets 3.0 3.0 — 3.0 Liabilities 20.8 20.8 — 20.8 Debt (a) 1,960.1 2,122.1 1,949.5 172.6 The estimated fair value of financial instruments at December 31, 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 $ 229.6 $ 229.6 $ 229.6 $ — Derivative financial instruments: Assets 9.1 9.1 — 9.1 Liabilities 18.7 18.7 — 18.7 Debt (a) 1,894.1 1,975.0 1,868.4 106.6 (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 2017 or 2016 . 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.

Retirement Benefits

Retirement Benefits	6 Months Ended
	Jun. 30, 2017
Retirement Benefits [Abstract]
Retirement Benefits	The Company has defined contribution retirement plans or defined benefit pension plans covering substantially all employees. Company contributions to defined contribution retirement plans are generally based on a percentage of eligible pay or based on hours worked. 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 collectively-bargained 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 three month periods ended June 30, 2017 and 2016 , 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 June 30, Three months ended June 30, 2017 2016 2017 2016 Service cost - benefits earned during the year $ 3.5 $ 5.1 $ 0.6 $ 0.7 Interest cost on benefits earned in prior years 29.2 31.3 3.6 3.9 Expected return on plan assets (36.7 ) (37.1 ) — — Amortization of prior service cost (credit) 0.3 0.3 (0.7 ) (0.8 ) Amortization of net actuarial loss 15.7 16.4 2.3 2.4 Total retirement benefit expense $ 12.0 $ 16.0 $ 5.8 $ 6.2 For the six month periods ended June 30, 2017 and 2016 , 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 Six months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Service cost - benefits earned during the year $ 7.0 $ 10.3 $ 1.2 $ 1.3 Interest cost on benefits earned in prior years 58.4 62.7 7.3 8.0 Expected return on plan assets (73.4 ) (74.3 ) — — Amortization of prior service cost (credit) 0.6 0.6 (1.4 ) (0.2 ) Amortization of net actuarial loss 31.3 32.7 4.5 4.8 Total retirement benefit expense $ 23.9 $ 32.0 $ 11.6 $ 13.9 Effective January 31, 2017, closure of the U.K. defined benefit pension plan to future accruals for service and pay (hard freeze) occurred. In March 2017, the Company made a $135 million cash contribution to the ATI Pension Plan, its U.S. qualified defined benefit pension plan, completing the Company’s funding requirements for 2017.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company maintains income tax valuation allowances on its U.S. Federal and state deferred tax assets due to a three year cumulative loss condition which limits the ability to consider other positive subjective evidence, such as projections of future results, to assess the realizability of deferred tax assets. Results in both 2017 and 2016 include impacts from income taxes which differ from a standard 35% tax rate, primarily related to income tax valuation allowance changes. Second quarter 2017 results included a benefit for income taxes of $2.1 million , which includes $5.4 million of discrete tax benefits recognized in the quarter largely for the effects of amending tax returns for prior periods in certain domestic jurisdictions. The second quarter 2016 benefit for income taxes was $25.9 million , which includes $2.8 million of discrete tax benefits. For the first six months of 2017 , the benefit for income taxes was $0.1 million , compared to a benefit for income taxes of $60.1 million , or 34.6% of the loss before income taxes, for the comparable 2016 period. The first six months of 2017 and 2016 included discrete tax benefits of $6.7 million and $3.6 million , respectively.

Business Segments

Business Segments	6 Months Ended
	Jun. 30, 2017
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 June 30, Six months ended June 30, 2017 2016 2017 2016 Total sales: High Performance Materials & Components $ 543.3 $ 511.1 $ 1,067.0 $ 1,019.0 Flat Rolled Products 373.2 324.3 746.2 605.5 916.5 835.4 1,813.2 1,624.5 Intersegment sales: High Performance Materials & Components 16.9 12.7 30.2 27.6 Flat Rolled Products 19.4 12.2 36.9 28.9 36.3 24.9 67.1 56.5 Sales to external customers: High Performance Materials & Components 526.4 498.4 1,036.8 991.4 Flat Rolled Products 353.8 312.1 709.3 576.6 $ 880.2 $ 810.5 $ 1,746.1 $ 1,568.0 Operating profit (loss): High Performance Materials & Components $ 68.0 $ 38.8 $ 118.9 $ 67.9 Flat Rolled Products 2.9 (31.8 ) 21.9 (141.4 ) Total operating profit (loss) 70.9 7.0 140.8 (73.5 ) LIFO and net realizable value reserves (0.1 ) 0.4 (0.1 ) 0.4 Corporate expenses (11.8 ) (11.8 ) (22.1 ) (22.8 ) Closed operations and other expenses (13.2 ) (5.7 ) (16.2 ) (9.2 ) Restructuring and other charges — (1.0 ) — (10.0 ) Interest expense, net (34.5 ) (30.3 ) (68.0 ) (58.6 ) Income (loss) before income taxes $ 11.3 $ (41.4 ) $ 34.4 $ (173.7 ) Closed operations and other expenses in 2017 reflect higher costs due to the additions of the Rowley, UT, Midland, PA and Bagdad, PA facilities as a result of closure actions in 2016. Closed operations and other expenses in 2017 also reflect more significant foreign currency impacts, primarily from the Company’s European Treasury Center operation. The first six months of 2016 include $10.0 million of restructuring charges for severance obligations. During the first quarter of 2016 , a $9.0 million charge was recorded for severance obligations in the FRP operations, with the reduction of approximately one-third of FRP’s salaried workforce, which was largely completed by the end of 2016 . During the second quarter of 2016 , an additional $1.0 million charge was recorded for severance obligations in the HPMC segment. These severance charges were excluded from segment operating results. Reserves for restructuring charges at June 30, 2017 were $13.4 million , of which $6.6 million relates to severance and employee benefit costs and $6.8 million to closure costs. The decline in these reserves compared to $33.1 million at December 31, 2016 is due to payments. These restructuring reserves are expected to be substantially paid in 2017.

Per Share Information

Per Share Information	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Per Share Information	Per Share Information The following table sets forth the computation of basic and diluted income (loss) per common share: Three Months Ended Six months ended (In millions, except per share amounts) June 30, June 30, 2017 2016 2017 2016 Numerator: Numerator for basic income (loss) per common share – Net income (loss) attributable to ATI $ 10.1 $ (18.8 ) $ 27.6 $ (120.0 ) Effect of dilutive securities: 4.75% Convertible Senior Notes due 2022 1.8 — 4.8 — Numerator for diluted income (loss) per common share – Net income (loss) attributable to ATI after assumed conversions $ 11.9 $ (18.8 ) $ 32.4 $ (120.0 ) Denominator: Denominator for basic net income (loss) per common share – weighted average shares 107.7 107.3 107.6 107.3 Effect of dilutive securities: Share-based compensation 0.7 — 0.8 — 4.75% Convertible Senior Notes due 2022 19.9 — 19.9 — Denominator for diluted net income (loss) per common share – adjusted weighted average shares and assumed conversions 128.3 107.3 128.3 107.3 Basic net income (loss) attributable to ATI per common share $ 0.09 $ (0.18 ) $ 0.26 $ (1.12 ) Diluted net income (loss) attributable to ATI per common share $ 0.09 $ (0.18 ) $ 0.25 $ (1.12 ) 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 no anti-dilutive shares for the three and six month period ended June 30, 2017 . There were 9.3 million and 5.0 million anti-dilutive shares for the three and six month period ended June 30, 2016 , respectively.

Financial Information for Subsi

Financial Information for Subsidiary and Guarantor Parent	6 Months Ended
	Jun. 30, 2017
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 ATI Pension Plan, the Company’s 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 and valuation allowances. 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 June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.5 $ 2.6 $ 149.5 $ — $ 154.6 Accounts receivable, net 0.1 136.8 401.7 — 538.6 Intercompany notes receivable — — 3,282.0 (3,282.0 ) — Inventories, net — 160.2 916.0 — 1,076.2 Prepaid expenses and other current assets 5.3 4.1 21.3 — 30.7 Total current assets 7.9 303.7 4,770.5 (3,282.0 ) 1,800.1 Property, plant and equipment, net 1.1 1,585.6 905.6 — 2,492.3 Goodwill — — 643.5 — 643.5 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,498.2 37.7 — (5,535.9 ) — Other assets 26.8 19.3 204.3 — 250.4 Total assets $ 5,534.0 $ 1,946.3 $ 6,723.9 $ (9,017.9 ) $ 5,186.3 Liabilities and stockholders’ equity: Accounts payable $ 3.1 $ 161.2 $ 191.2 $ — $ 355.5 Accrued liabilities 51.8 75.9 150.3 — 278.0 Intercompany notes payable 1,670.6 1,611.4 — (3,282.0 ) — Short term debt and current portion of long-term debt 0.3 0.3 66.9 — 67.5 Total current liabilities 1,725.8 1,848.8 408.4 (3,282.0 ) 701.0 Long-term debt 1,623.1 149.8 103.7 — 1,876.6 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 238.4 69.6 — 308.0 Pension liabilities 634.8 4.9 43.2 — 682.9 Deferred income taxes 20.1 — — — 20.1 Other long-term liabilities 15.8 18.6 48.9 — 83.3 Total liabilities 4,019.6 2,460.5 673.8 (3,482.0 ) 3,671.9 Total stockholders’ equity (deficit) 1,514.4 (514.2 ) 6,050.1 (5,535.9 ) 1,514.4 Total liabilities and stockholders’ equity $ 5,534.0 $ 1,946.3 $ 6,723.9 $ (9,017.9 ) $ 5,186.3 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the three months ended June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 291.2 $ 589.0 $ — $ 880.2 Cost of sales 12.0 278.6 477.3 — 767.9 Gross profit (loss) (12.0 ) 12.6 111.7 — 112.3 Selling and administrative expenses 23.1 8.7 34.9 — 66.7 Operating income (loss) (35.1 ) 3.9 76.8 — 45.6 Interest income (expense), net (39.7 ) (22.5 ) 27.7 — (34.5 ) Other income (loss) including equity in income of unconsolidated subsidiaries 86.1 0.3 (0.1 ) (86.1 ) 0.2 Income (loss) before income tax provision (benefit) 11.3 (18.3 ) 104.4 (86.1 ) 11.3 Income tax provision (benefit) (2.1 ) (6.6 ) 33.6 (27.0 ) (2.1 ) Net income (loss) 13.4 (11.7 ) 70.8 (59.1 ) 13.4 Less: Net income attributable to noncontrolling interests — — 3.3 — 3.3 Net income (loss) attributable to ATI $ 13.4 $ (11.7 ) $ 67.5 $ (59.1 ) $ 10.1 Comprehensive income (loss) attributable to ATI $ 17.8 $ (11.3 ) $ 92.5 $ (84.7 ) $ 14.3 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the six months ended June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 578.4 $ 1,167.7 $ — $ 1,746.1 Cost of sales 23.0 538.7 959.3 — 1,521.0 Gross profit (loss) (23.0 ) 39.7 208.4 — 225.1 Selling and administrative expenses 44.3 18.4 63.5 — 126.2 Operating income (loss) (67.3 ) 21.3 144.9 — 98.9 Interest income (expense), net (78.3 ) (43.7 ) 54.0 — (68.0 ) Other income (loss) including equity in income of unconsolidated subsidiaries 180.0 0.8 2.7 (180.0 ) 3.5 Income (loss) before income tax provision (benefit) 34.4 (21.6 ) 201.6 (180.0 ) 34.4 Income tax provision (benefit) (0.1 ) (7.7 ) 69.1 (61.4 ) (0.1 ) Net income (loss) 34.5 (13.9 ) 132.5 (118.6 ) 34.5 Less: Net income attributable to noncontrolling interests — — 6.9 — 6.9 Net income (loss) attributable to ATI $ 34.5 $ (13.9 ) $ 125.6 $ (118.6 ) $ 27.6 Comprehensive income (loss) attributable to ATI $ 63.2 $ (11.6 ) $ 138.4 $ (135.9 ) $ 54.1 Condensed Statements of Cash Flows For the six months ended June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (54.6 ) $ (55.4 ) $ 24.5 $ — $ (85.5 ) Investing Activities: Purchases of property, plant and equipment — (19.9 ) (35.4 ) — (55.3 ) Net receipts/(payments) on intercompany activity — — (135.3 ) 135.3 — Asset disposals and other — 0.1 3.2 — 3.3 Cash flows provided by (used in) investing activities — (19.8 ) (167.5 ) 135.3 (52.0 ) Financing Activities: Borrowings on long-term debt — — 7.3 — 7.3 Payments on long-term debt and capital leases (0.2 ) (0.2 ) (0.4 ) — (0.8 ) Net borrowings under credit facilities — — 59.4 — 59.4 Debt issuance costs — — (0.8 ) — (0.8 ) Net receipts/(payments) on intercompany activity 59.8 75.5 — (135.3 ) — Sale to noncontrolling interests — — 2.2 — 2.2 Shares repurchased for income tax withholding on share-based compensation (4.8 ) — — — (4.8 ) Cash flows provided by (used in) financing activities 54.8 75.3 67.7 (135.3 ) 62.5 Increase (decrease) in cash and cash equivalents $ 0.2 $ 0.1 $ (75.3 ) $ — $ (75.0 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Balance Sheets December 31, 2016 Guarantor Non-guarantor (In millions) Parent Subsidiary Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.3 $ 2.5 $ 224.8 $ — $ 229.6 Accounts receivable, net 0.1 107.8 344.2 — 452.1 Intercompany notes receivable — — 2,892.9 (2,892.9 ) — Inventories, net — 106.7 930.3 — 1,037.0 Prepaid expenses and other current assets 6.6 5.2 36.0 — 47.8 Total current assets 9.0 222.2 4,428.2 (2,892.9 ) 1,766.5 Property, plant and equipment, net 1.3 1,583.6 914.0 — 2,498.9 Goodwill — — 641.9 — 641.9 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,241.2 37.7 — (5,278.9 ) — Other assets 23.0 25.5 214.2 — 262.7 Total assets $ 5,274.5 $ 1,869.0 $ 6,398.3 $ (8,371.8 ) $ 5,170.0 Liabilities and stockholders’ equity: Accounts payable $ 3.1 $ 97.4 $ 193.8 $ — $ 294.3 Accrued liabilities 54.6 83.3 171.4 — 309.3 Intercompany notes payable 1,341.1 1,551.8 — (2,892.9 ) — Short term debt and current portion of long-term debt 0.4 0.3 104.4 — 105.1 Total current liabilities 1,399.2 1,732.8 469.6 (2,892.9 ) 708.7 Long-term debt 1,621.7 150.0 0.2 — 1,771.9 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 244.0 73.7 — 317.7 Pension liabilities 778.5 5.2 44.2 — 827.9 Deferred income taxes 15.6 — — — 15.6 Other long-term liabilities 14.7 18.1 50.6 — 83.4 Total liabilities 3,829.7 2,350.1 638.3 (3,092.9 ) 3,725.2 Total stockholders’ equity (deficit) 1,444.8 (481.1 ) 5,760.0 (5,278.9 ) 1,444.8 Total liabilities and stockholders’ equity $ 5,274.5 $ 1,869.0 $ 6,398.3 $ (8,371.8 ) $ 5,170.0 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the three months ended June 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 260.9 $ 549.6 $ — $ 810.5 Cost of sales 9.6 286.9 465.8 — 762.3 Gross profit (loss) (9.6 ) (26.0 ) 83.8 — 48.2 Selling and administrative expenses 20.6 4.9 33.8 — 59.3 Restructuring charges — — 1.0 — 1.0 Operating income (loss) (30.2 ) (30.9 ) 49.0 — (12.1 ) Interest income (expense), net (33.7 ) (17.6 ) 21.0 — (30.3 ) Other income (loss) including equity in income of unconsolidated subsidiaries 22.5 0.3 0.9 (22.7 ) 1.0 Income (loss) before income tax provision (benefit) (41.4 ) (48.2 ) 70.9 (22.7 ) (41.4 ) Income tax provision (benefit) (25.9 ) (17.6 ) 25.8 (8.2 ) (25.9 ) Net income (loss) (15.5 ) (30.6 ) 45.1 (14.5 ) (15.5 ) Less: Net income attributable to noncontrolling interests — — 3.3 — 3.3 Net income (loss) attributable to ATI $ (15.5 ) $ (30.6 ) $ 41.8 $ (14.5 ) $ (18.8 ) Comprehensive income (loss) attributable to ATI $ 4.2 $ (29.3 ) $ 33.7 $ (6.2 ) $ 2.4 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the six months ended June 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 474.7 $ 1,093.3 $ — $ 1,568.0 Cost of sales 29.0 585.4 938.6 — 1,553.0 Gross profit (loss) (29.0 ) (110.7 ) 154.7 — 15.0 Selling and administrative expenses 42.5 14.6 64.8 — 121.9 Restructuring charges — 9.0 1.0 — 10.0 Operating income (loss) (71.5 ) (134.3 ) 88.9 — (116.9 ) Interest income (expense), net (64.9 ) (31.7 ) 38.0 — (58.6 ) Other income (loss) including equity in income of unconsolidated subsidiaries (37.3 ) 0.4 1.7 37.0 1.8 Income (loss) before income tax provision (benefit) (173.7 ) (165.6 ) 128.6 37.0 (173.7 ) Income tax provision (benefit) (60.1 ) (61.0 ) 49.5 11.5 (60.1 ) Net income (loss) (113.6 ) (104.6 ) 79.1 25.5 (113.6 ) Less: Net income attributable to noncontrolling interests — — 6.4 — 6.4 Net income (loss) attributable to ATI $ (113.6 ) $ (104.6 ) $ 72.7 $ 25.5 $ (120.0 ) Comprehensive income (loss) attributable to ATI $ (75.8 ) $ (87.2 ) $ 61.0 $ 22.8 $ (79.2 ) Condensed Statements of Cash Flows For the six months ended June 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (50.5 ) $ (166.8 ) $ 183.7 $ — $ (33.6 ) Investing Activities: Purchases of property, plant and equipment (0.3 ) (85.3 ) (59.7 ) — (145.3 ) Net receipts/(payments) on intercompany activity — — (43.5 ) 43.5 — Asset disposals and other — — 1.8 — 1.8 Cash flows provided by (used in) investing activities (0.3 ) (85.3 ) (101.4 ) 43.5 (143.5 ) Financing Activities: Borrowings on long-term debt 287.5 — 100.0 — 387.5 Payments on long-term debt and capital leases (0.3 ) (0.1 ) (0.2 ) — (0.6 ) Net borrowings under credit facilities — — 2.5 — 2.5 Debt issuance costs (9.4 ) — (1.0 ) — (10.4 ) Net receipts/(payments) on intercompany activity (209.8 ) 253.3 — (43.5 ) — Dividends paid to stockholders (17.2 ) — — — (17.2 ) Acquisition of noncontrolling interests — — (12.2 ) — (12.2 ) Cash flows provided by (used in) financing activities 50.8 253.2 89.1 (43.5 ) 349.6 Increase (decrease) in cash and cash equivalents $ — $ 1.1 $ 171.4 $ — $ 172.5

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, March 31, 2017 $ (954.7 ) $ (76.6 ) $ — $ 0.3 $ (40.4 ) $ (1,071.4 ) OCI before reclassifications — 4.2 — (5.2 ) 1.1 0.1 Amounts reclassified from AOCI (a) 11.2 (b) — (b) — (c) (0.8 ) (6.3 ) 4.1 Net current-period OCI 11.2 4.2 — (6.0 ) (5.2 ) 4.2 Balance, June 30, 2017 $ (943.5 ) $ (72.4 ) $ — $ (5.7 ) $ (45.6 ) $ (1,067.2 ) Attributable to noncontrolling interests: Balance, March 31, 2017 $ — $ 11.7 $ — $ — $ — $ 11.7 OCI before reclassifications — 0.2 — — — 0.2 Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — 0.2 — — — 0.2 Balance, June 30, 2017 $ — $ 11.9 $ — $ — $ — $ 11.9 The changes in AOCI by component, net of tax, for the six month period ended June 30, 2017 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, December 31, 2016 $ (965.5 ) $ (85.0 ) $ — $ 2.4 $ (45.6 ) $ (1,093.7 ) OCI before reclassifications — 12.6 — (6.7 ) — 5.9 Amounts reclassified from AOCI (a) 22.0 (b) — (b) — (c) (1.4 ) — 20.6 Net current-period OCI 22.0 12.6 — (8.1 ) — 26.5 Balance, June 30, 2017 $ (943.5 ) $ (72.4 ) $ — $ (5.7 ) $ (45.6 ) $ (1,067.2 ) Attributable to noncontrolling interests: Balance, December 31, 2016 $ — $ 9.7 $ — $ — $ — $ 9.7 OCI before reclassifications — 2.2 — — — 2.2 Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — 2.2 — — — 2.2 Balance, June 30, 2017 $ — $ 11.9 $ — $ — $ — $ 11.9 (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 June 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, March 31, 2016 $ (925.1 ) $ (51.5 ) $ — $ (18.3 ) $ — $ (994.9 ) OCI before reclassifications — (8.3 ) — 16.3 — 8.0 Amounts reclassified from AOCI (a) 11.4 (b) — (b) — (c) 1.8 — 13.2 Net current-period OCI 11.4 (8.3 ) — 18.1 — 21.2 Balance, June 30, 2016 $ (913.7 ) $ (59.8 ) $ — $ (0.2 ) $ — $ (973.7 ) Attributable to noncontrolling interests: Balance, March 31, 2016 $ — $ 17.9 $ — $ — $ — $ 17.9 OCI before reclassifications — (1.5 ) — — — (1.5 ) Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — (1.5 ) — — — $ (1.5 ) Balance, June 30, 2016 $ — $ 16.4 $ — $ — $ — $ 16.4 The changes in AOCI by component, net of tax, for the six month period ended June 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, December 31, 2015 $ (951.2 ) $ (47.6 ) $ — $ (15.7 ) $ — $ (1,014.5 ) OCI before reclassifications 13.9 (12.2 ) — 10.6 — 12.3 Amounts reclassified from AOCI (a) 23.6 (b) — (b) — (c) 4.9 — 28.5 Net current-period OCI 37.5 (12.2 ) — 15.5 — 40.8 Balance, June 30, 2016 $ (913.7 ) $ (59.8 ) $ — $ (0.2 ) $ — $ (973.7 ) Attributable to noncontrolling interests: Balance, December 31, 2015 $ — $ 19.4 $ — $ — $ — $ 19.4 OCI before reclassifications — (3.0 ) — — — (3.0 ) Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — (3.0 ) — — — $ (3.0 ) Balance, June 30, 2016 $ — $ 16.4 $ — $ — $ — $ 16.4 (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). Other comprehensive income (loss) amounts (OCI) reported above by category are net of applicable income tax expense (benefit) for each year presented. Income tax expense (benefit) on OCI items is recorded as a change in a deferred tax asset or liability. Amounts recognized in OCI in 2017 include the impact of any deferred tax asset valuation allowances, when applicable, resulting from the Company’s three year cumulative loss position. Foreign currency translation adjustments, including those pertaining to noncontrolling interests, are generally not adjusted for income taxes as they relate to indefinite investments in non-U.S. subsidiaries. Reclassifications out of AOCI for the three and six month periods ended June 30, 2017 and 2016 were as follows: Amount reclassified from AOCI Details about AOCI Components (In millions) Three months ended June 30, 2017 Three months ended June 30, 2016 Six months ended June 30, 2017 Six months ended June 30, 2016 Affected line item in the statements of operations Postretirement benefit plans Prior service (cost) credit $ 0.4 $ 0.5 (a) $ 0.8 $ (0.4 ) (a) Actuarial losses (18.0 ) (18.8 ) (a) (35.8 ) (37.5 ) (a) (17.6 ) (18.3 ) (c) (35.0 ) (37.9 ) (c) Total before tax (6.4 ) (6.9 ) (13.0 ) (14.3 ) Tax provision (benefit) (d) $ (11.2 ) $ (11.4 ) $ (22.0 ) $ (23.6 ) Net of tax Derivatives Nickel and other raw material contracts $ (1.6 ) $ (6.1 ) (b) $ (2.5 ) $ (12.4 ) (b) Natural gas contracts (1.1 ) (4.7 ) (b) (3.4 ) (11.0 ) (b) Foreign exchange contracts 4.1 7.9 (b) 8.2 15.5 (b) 1.4 (2.9 ) (c) 2.3 (7.9 ) (c) Total before tax 0.6 (1.1 ) 0.9 (3.0 ) Tax provision (benefit) (d) $ 0.8 $ (1.8 ) $ 1.4 $ (4.9 ) 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. (d) These amounts exclude the impact of any deferred tax asset valuation allowance, when applicable.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 , the Company’s reserves for environmental remediation obligations totaled approximately $14 million , of which $7 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 $19 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 21. 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, 2016 for a discussion of legal proceedings affecting the Company. A number of other lawsuits, claims and proceedings have been or may be asserted against the Company relating to the conduct of its currently and formerly owned businesses, including those pertaining to product liability, patent infringement, commercial, government contracting, construction, employment, employee and retiree benefits, taxes, environmental, health and safety and occupational disease, and stockholder and corporate governance matters. While the outcome of litigation cannot be predicted with certainty, and some of these lawsuits, claims or proceedings may be determined adversely to the Company, management does not believe that the disposition of any such pending matters is likely to have a material adverse effect on the Company’s financial condition or liquidity, although the resolution in any reporting period of one or more of these matters could have a material adverse effect on the Company’s consolidated results of operations for that period.

Accounting Policies (Policies)

Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
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 2016 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, 2016 financial information has been derived from the Company’s audited consolidated financial statements.
New Accounting Pronouncements Adopted	New Accounting Pronouncements Adopted In January 2017, the Company early adopted changes issued by the Financial Accounting Standards Board (FASB) to simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill, which is currently required if a reporting unit with goodwill fails a Step 1 test comparing the fair value of the reporting unit to its carrying value including goodwill. Under this new guidance, an entity should perform its annual, or interim, goodwill impairment test using just the Step 1 test of comparing the fair value of a reporting unit with its carrying amount. Any goodwill impairment, representing the amount by which the carrying amount exceeds the reporting unit’s fair value, is determined using this Step 1 test. Any goodwill impairment loss recognized would not exceed the total carrying amount of goodwill allocated to that reporting unit. The adoption of these changes did not have a material impact on the Company’s financial statements. In January 2017, the Company adopted changes issued by the FASB 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, which will be prospectively adopted. The adoption of these changes did not have a material impact on the Company’s financial statements. In January 2017, the Company adopted changes issued by the FASB 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 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 did not have a material impact on the Company’s financial statements.
New Accounting Pronouncements Not Yet Adopted	Pending Accounting Pronouncement In March 2017, the FASB issued changes to the accounting for defined benefit pension and other postretirement benefit expenses. This new guidance requires the disaggregation of the service cost component from the other components of net benefit cost. The service cost component of net benefit cost is to be reported in the same line item on the consolidated statement of operations as other compensation costs arising from services rendered by the pertinent employees, while the other components of net benefit cost are to be presented in the consolidated statement of operations separately, outside a subtotal of operating income. The amendments also provide explicit guidance to allow only the service cost component of net benefit cost to be eligible for capitalization. This new guidance is effective for the Company’s 2018 fiscal year, with the adoption of the change in presentation of net benefit cost in the consolidated statement of operations to be applied retrospectively, and the change in capitalization for only service cost applied prospectively. The guidance allows a practical expedient that permits the use of the amounts disclosed in the retirement benefits footnote for the prior comparative periods as the estimation basis for applying the retrospective presentation requirements. The Company will adopt this new guidance in the first quarter of fiscal year 2018 using this practical expedient. The Company expects such adoption to have a material impact to reported operating income due to the change in presentation of non-service cost expense components. For example, applying the practical expedient to fiscal year 2016 results, operating income for 2016 would be $70.6 million higher, with the reclassification of this amount representing the other components of net benefit cost to a newly-created non-operating retirement benefit expense category, with no net impact to the reported 2016 loss before income taxes. The Company expects to have a one-time, unfavorable impact to pre-tax reported results in the first quarter of 2018 upon adoption due to the change limiting only the service cost component of net benefit cost to be capitalizable into inventory. Using expected fiscal year 2017 defined benefit retirement expense and current inventory levels, this impact in the first quarter of 2018 is projected to be approximately $5 million , pre-tax. 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 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. Although the Company is currently evaluating the impact of this standard on individual customer contracts, the Company has evaluated the impact of this standard on the broad categories of its customer contracts, and anticipates the adoption of this guidance will not have a material impact on the consolidated statement of operations but does expect an impact to the consolidated balance sheet for reclassifications to contract assets and liabilities, the magnitude of which is still being determined. The Company also expects an increase to financial statement footnote disclosures regarding revenues, contract assets and contract liabilities as a result of this accounting standard update.
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	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 June 30, 2017 , 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 27 million pounds of nickel with hedge dates through 2021. The aggregate notional amount hedged is approximately 35% of a single year’s estimated nickel raw material purchase requirements. At June 30, 2017 , the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas cost hedges. In the first six months of 2016, due to changes in expected operating levels within Flat Rolled Products segment operations, the Company concluded that additional portions of these natural gas cash flow hedges for 2016 and the first quarter of 2017 were ineffective based on forecast changes in underlying natural gas usage. The Company recognized $0.2 million and $1.3 million of pre-tax losses for the three and six months ended June 30, 2016 , respectively, for natural gas cash flow hedge ineffectiveness, which is reported in selling and administrative expenses on the consolidated statement of operations. At June 30, 2017 the Company hedged approximately 70% of the Company’s forecasted domestic requirements for natural gas for the remainder of 2017, approximately 35% for 2018, and approximately 25% for 2019. 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 June 30, 2017 , the Company held 21.6 million euro notional value of foreign currency forward contracts designated as fair value hedges with maturity dates through 2017. The Company recorded $1.9 million and $2.2 million of charges in the three and six months ended June 30, 2017 , respectively, and a $3.1 million benefit and a $2.5 million charge in the three and six months ended June 30, 2016 , 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. 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 and are reported as changes within accrued liabilities and other on the consolidated statements of cash flows. 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, excluding any impacts of changes to income tax valuation allowances effecting results of operations or other comprehensive income, when applicable (see Note 12 for further explanation).
Retirement Benefits	The Company has defined contribution retirement plans or defined benefit pension plans covering substantially all employees. Company contributions to defined contribution retirement plans are generally based on a percentage of eligible pay or based on hours worked. 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 collectively-bargained 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.
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)	6 Months Ended
	Jun. 30, 2017
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories at June 30, 2017 and December 31, 2016 were as follows (in millions): June 30, December 31, Raw materials and supplies $ 141.6 $ 149.6 Work-in-process 886.7 837.9 Finished goods 159.4 161.7 Total inventories at current cost 1,187.7 1,149.2 Adjustment from current cost to LIFO cost basis 79.1 97.3 Inventory valuation reserves (150.2 ) (169.0 ) Progress payments (40.4 ) (40.5 ) Total inventories, net $ 1,076.2 $ 1,037.0
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): Six months ended June 30, 2017 2016 LIFO benefit (charge) $ (18.2 ) $ (4.6 ) NRV benefit (charge) 18.1 5.0 Net cost of sales impact $ (0.1 ) $ 0.4

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Jun. 30, 2017
Property, Plant and Equipment [Abstract]
Property Plant And Equipment	Property, plant and equipment at June 30, 2017 and December 31, 2016 was as follows (in millions): June 30, December 31, Land $ 31.5 $ 31.4 Buildings 840.3 829.6 Equipment and leasehold improvements 3,527.0 3,497.2 4,398.8 4,358.2 Accumulated depreciation and amortization (1,906.5 ) (1,859.3 ) Total property, plant and equipment, net $ 2,492.3 $ 2,498.9

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Schedule of Debt Instruments	Debt at June 30, 2017 and December 31, 2016 was as follows (in millions): June 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 287.5 287.5 Allegheny Ludlum 6.95% debentures due 2025 150.0 150.0 Term Loan due 2022 100.0 100.0 U.S. revolving credit facility 60.0 — Foreign credit facilities 4.0 4.4 Other 8.6 2.2 Debt issuance costs (16.0 ) (17.1 ) Total debt 1,944.1 1,877.0 Short term debt and current portion of long-term debt 67.5 105.1 Total long-term debt $ 1,876.6 $ 1,771.9 (a) Bearing interest at 7.875% effective February 15, 2016.

Derivative Financial Instrume27

Derivative Financial Instruments and Hedging (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, December 31, Derivatives designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets $ 0.2 $ 2.4 Natural gas contacts Prepaid expenses and other current assets 0.1 0.2 Nickel and other raw material contracts Prepaid expenses and other current assets 1.3 2.2 Foreign exchange contracts Other assets — 0.2 Natural gas contracts Other assets 0.2 0.2 Nickel and other raw material contracts Other assets 1.2 3.3 Total derivatives designated as hedging instruments 3.0 8.5 Derivatives not designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets — 0.6 Total derivatives not designated as hedging instruments — 0.6 Total asset derivatives $ 3.0 $ 9.1 Liability derivatives Balance sheet location Derivatives designated as hedging instruments: Natural gas contracts Accrued liabilities $ 1.9 $ 2.5 Nickel and other raw material contracts Accrued liabilities 8.1 6.7 Foreign exchange contracts Accrued liabilities 0.7 — Natural gas contracts Other long-term liabilities 0.2 — Nickel and other raw material contracts Other long-term liabilities 9.6 9.4 Foreign exchange contracts Other long-term liabilities — 0.1 Total derivatives designated as hedging instruments 20.5 18.7 Derivatives not designated as hedging instruments: Foreign exchange contracts Accrued Liabilities 0.3 — Total derivatives not designated as hedging instruments 0.3 — Total liability derivatives $ 20.8 $ 18.7
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 six month periods ended June 30, 2017 and 2016 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 June 30, Three months ended June 30, Three months ended June 30, Hedging Relationships 2017 2016 2017 2016 2017 2016 Nickel and other raw material contracts $ (4.6 ) $ 12.2 $ (1.0 ) $ (3.8 ) $ — $ — Natural gas contracts (0.5 ) 4.3 (0.7 ) (2.7 ) — (0.2 ) Foreign exchange contracts (0.1 ) (0.2 ) 2.5 4.9 — — Total $ (5.2 ) $ 16.3 $ 0.8 $ (1.6 ) $ — $ (0.2 ) 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 Six months ended June 30, Six months ended June 30, Six months ended June 30, Hedging Relationships 2017 2016 2017 2016 2017 2016 Nickel and other raw material contracts $ (4.4 ) $ 8.8 $ (1.6 ) $ (7.7 ) $ — $ — Natural gas contracts (2.1 ) 2.3 (2.1 ) (5.9 ) — (0.9 ) Foreign exchange contracts (0.2 ) (0.5 ) 5.1 9.6 — — Total $ (6.7 ) $ 10.6 $ 1.4 $ (4.0 ) $ — $ (0.9 ) (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 on Derivatives Three months ended June 30, Six months ended June 30, Derivatives Not Designated as Hedging Instruments 2017 2016 2017 2016 Foreign exchange contracts $ (0.5 ) $ 0.7 $ (0.6 ) $ 0.1

Fair Value of Financial Instr28

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value By Balance Sheet Grouping	The estimated fair value of financial instruments at June 30, 2017 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 $ 154.6 $ 154.6 $ 154.6 $ — Derivative financial instruments: Assets 3.0 3.0 — 3.0 Liabilities 20.8 20.8 — 20.8 Debt (a) 1,960.1 2,122.1 1,949.5 172.6 The estimated fair value of financial instruments at December 31, 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 $ 229.6 $ 229.6 $ 229.6 $ — Derivative financial instruments: Assets 9.1 9.1 — 9.1 Liabilities 18.7 18.7 — 18.7 Debt (a) 1,894.1 1,975.0 1,868.4 106.6 (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.

Retirement Benefits (Tables)

Retirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2017
Retirement Benefits [Abstract]
Schedule Of Defined Benefit Plans Disclosures [Table Text Block]	For the three month periods ended June 30, 2017 and 2016 , 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 June 30, Three months ended June 30, 2017 2016 2017 2016 Service cost - benefits earned during the year $ 3.5 $ 5.1 $ 0.6 $ 0.7 Interest cost on benefits earned in prior years 29.2 31.3 3.6 3.9 Expected return on plan assets (36.7 ) (37.1 ) — — Amortization of prior service cost (credit) 0.3 0.3 (0.7 ) (0.8 ) Amortization of net actuarial loss 15.7 16.4 2.3 2.4 Total retirement benefit expense $ 12.0 $ 16.0 $ 5.8 $ 6.2 For the six month periods ended June 30, 2017 and 2016 , 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 Six months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Service cost - benefits earned during the year $ 7.0 $ 10.3 $ 1.2 $ 1.3 Interest cost on benefits earned in prior years 58.4 62.7 7.3 8.0 Expected return on plan assets (73.4 ) (74.3 ) — — Amortization of prior service cost (credit) 0.6 0.6 (1.4 ) (0.2 ) Amortization of net actuarial loss 31.3 32.7 4.5 4.8 Total retirement benefit expense $ 23.9 $ 32.0 $ 11.6 $ 13.9

Business Segments (Tables)

Business Segments (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, Six months ended June 30, 2017 2016 2017 2016 Total sales: High Performance Materials & Components $ 543.3 $ 511.1 $ 1,067.0 $ 1,019.0 Flat Rolled Products 373.2 324.3 746.2 605.5 916.5 835.4 1,813.2 1,624.5 Intersegment sales: High Performance Materials & Components 16.9 12.7 30.2 27.6 Flat Rolled Products 19.4 12.2 36.9 28.9 36.3 24.9 67.1 56.5 Sales to external customers: High Performance Materials & Components 526.4 498.4 1,036.8 991.4 Flat Rolled Products 353.8 312.1 709.3 576.6 $ 880.2 $ 810.5 $ 1,746.1 $ 1,568.0 Operating profit (loss): High Performance Materials & Components $ 68.0 $ 38.8 $ 118.9 $ 67.9 Flat Rolled Products 2.9 (31.8 ) 21.9 (141.4 ) Total operating profit (loss) 70.9 7.0 140.8 (73.5 ) LIFO and net realizable value reserves (0.1 ) 0.4 (0.1 ) 0.4 Corporate expenses (11.8 ) (11.8 ) (22.1 ) (22.8 ) Closed operations and other expenses (13.2 ) (5.7 ) (16.2 ) (9.2 ) Restructuring and other charges — (1.0 ) — (10.0 ) Interest expense, net (34.5 ) (30.3 ) (68.0 ) (58.6 ) Income (loss) before income taxes $ 11.3 $ (41.4 ) $ 34.4 $ (173.7 )

Per Share Information (Tables)

Per Share Information (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share Diluted By Common Class	The following table sets forth the computation of basic and diluted income (loss) per common share: Three Months Ended Six months ended (In millions, except per share amounts) June 30, June 30, 2017 2016 2017 2016 Numerator: Numerator for basic income (loss) per common share – Net income (loss) attributable to ATI $ 10.1 $ (18.8 ) $ 27.6 $ (120.0 ) Effect of dilutive securities: 4.75% Convertible Senior Notes due 2022 1.8 — 4.8 — Numerator for diluted income (loss) per common share – Net income (loss) attributable to ATI after assumed conversions $ 11.9 $ (18.8 ) $ 32.4 $ (120.0 ) Denominator: Denominator for basic net income (loss) per common share – weighted average shares 107.7 107.3 107.6 107.3 Effect of dilutive securities: Share-based compensation 0.7 — 0.8 — 4.75% Convertible Senior Notes due 2022 19.9 — 19.9 — Denominator for diluted net income (loss) per common share – adjusted weighted average shares and assumed conversions 128.3 107.3 128.3 107.3 Basic net income (loss) attributable to ATI per common share $ 0.09 $ (0.18 ) $ 0.26 $ (1.12 ) Diluted net income (loss) attributable to ATI per common share $ 0.09 $ (0.18 ) $ 0.25 $ (1.12 )

Financial Information for Sub32

Financial Information for Subsidiary and Guarantor Parent (Tables)	6 Months Ended
	Jun. 30, 2017
Condensed Statement of Income Captions [Line Items]
Balance Sheets	Balance Sheets December 31, 2016 Guarantor Non-guarantor (In millions) Parent Subsidiary Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.3 $ 2.5 $ 224.8 $ — $ 229.6 Accounts receivable, net 0.1 107.8 344.2 — 452.1 Intercompany notes receivable — — 2,892.9 (2,892.9 ) — Inventories, net — 106.7 930.3 — 1,037.0 Prepaid expenses and other current assets 6.6 5.2 36.0 — 47.8 Total current assets 9.0 222.2 4,428.2 (2,892.9 ) 1,766.5 Property, plant and equipment, net 1.3 1,583.6 914.0 — 2,498.9 Goodwill — — 641.9 — 641.9 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,241.2 37.7 — (5,278.9 ) — Other assets 23.0 25.5 214.2 — 262.7 Total assets $ 5,274.5 $ 1,869.0 $ 6,398.3 $ (8,371.8 ) $ 5,170.0 Liabilities and stockholders’ equity: Accounts payable $ 3.1 $ 97.4 $ 193.8 $ — $ 294.3 Accrued liabilities 54.6 83.3 171.4 — 309.3 Intercompany notes payable 1,341.1 1,551.8 — (2,892.9 ) — Short term debt and current portion of long-term debt 0.4 0.3 104.4 — 105.1 Total current liabilities 1,399.2 1,732.8 469.6 (2,892.9 ) 708.7 Long-term debt 1,621.7 150.0 0.2 — 1,771.9 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 244.0 73.7 — 317.7 Pension liabilities 778.5 5.2 44.2 — 827.9 Deferred income taxes 15.6 — — — 15.6 Other long-term liabilities 14.7 18.1 50.6 — 83.4 Total liabilities 3,829.7 2,350.1 638.3 (3,092.9 ) 3,725.2 Total stockholders’ equity (deficit) 1,444.8 (481.1 ) 5,760.0 (5,278.9 ) 1,444.8 Total liabilities and stockholders’ equity $ 5,274.5 $ 1,869.0 $ 6,398.3 $ (8,371.8 ) $ 5,170.0 Balance Sheets June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.5 $ 2.6 $ 149.5 $ — $ 154.6 Accounts receivable, net 0.1 136.8 401.7 — 538.6 Intercompany notes receivable — — 3,282.0 (3,282.0 ) — Inventories, net — 160.2 916.0 — 1,076.2 Prepaid expenses and other current assets 5.3 4.1 21.3 — 30.7 Total current assets 7.9 303.7 4,770.5 (3,282.0 ) 1,800.1 Property, plant and equipment, net 1.1 1,585.6 905.6 — 2,492.3 Goodwill — — 643.5 — 643.5 Intercompany notes receivable — — 200.0 (200.0 ) — Investment in subsidiaries 5,498.2 37.7 — (5,535.9 ) — Other assets 26.8 19.3 204.3 — 250.4 Total assets $ 5,534.0 $ 1,946.3 $ 6,723.9 $ (9,017.9 ) $ 5,186.3 Liabilities and stockholders’ equity: Accounts payable $ 3.1 $ 161.2 $ 191.2 $ — $ 355.5 Accrued liabilities 51.8 75.9 150.3 — 278.0 Intercompany notes payable 1,670.6 1,611.4 — (3,282.0 ) — Short term debt and current portion of long-term debt 0.3 0.3 66.9 — 67.5 Total current liabilities 1,725.8 1,848.8 408.4 (3,282.0 ) 701.0 Long-term debt 1,623.1 149.8 103.7 — 1,876.6 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 238.4 69.6 — 308.0 Pension liabilities 634.8 4.9 43.2 — 682.9 Deferred income taxes 20.1 — — — 20.1 Other long-term liabilities 15.8 18.6 48.9 — 83.3 Total liabilities 4,019.6 2,460.5 673.8 (3,482.0 ) 3,671.9 Total stockholders’ equity (deficit) 1,514.4 (514.2 ) 6,050.1 (5,535.9 ) 1,514.4 Total liabilities and stockholders’ equity $ 5,534.0 $ 1,946.3 $ 6,723.9 $ (9,017.9 ) $ 5,186.3
Statements of Operations and Comprehensive Income	Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the three months ended June 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 260.9 $ 549.6 $ — $ 810.5 Cost of sales 9.6 286.9 465.8 — 762.3 Gross profit (loss) (9.6 ) (26.0 ) 83.8 — 48.2 Selling and administrative expenses 20.6 4.9 33.8 — 59.3 Restructuring charges — — 1.0 — 1.0 Operating income (loss) (30.2 ) (30.9 ) 49.0 — (12.1 ) Interest income (expense), net (33.7 ) (17.6 ) 21.0 — (30.3 ) Other income (loss) including equity in income of unconsolidated subsidiaries 22.5 0.3 0.9 (22.7 ) 1.0 Income (loss) before income tax provision (benefit) (41.4 ) (48.2 ) 70.9 (22.7 ) (41.4 ) Income tax provision (benefit) (25.9 ) (17.6 ) 25.8 (8.2 ) (25.9 ) Net income (loss) (15.5 ) (30.6 ) 45.1 (14.5 ) (15.5 ) Less: Net income attributable to noncontrolling interests — — 3.3 — 3.3 Net income (loss) attributable to ATI $ (15.5 ) $ (30.6 ) $ 41.8 $ (14.5 ) $ (18.8 ) Comprehensive income (loss) attributable to ATI $ 4.2 $ (29.3 ) $ 33.7 $ (6.2 ) $ 2.4 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the six months ended June 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 474.7 $ 1,093.3 $ — $ 1,568.0 Cost of sales 29.0 585.4 938.6 — 1,553.0 Gross profit (loss) (29.0 ) (110.7 ) 154.7 — 15.0 Selling and administrative expenses 42.5 14.6 64.8 — 121.9 Restructuring charges — 9.0 1.0 — 10.0 Operating income (loss) (71.5 ) (134.3 ) 88.9 — (116.9 ) Interest income (expense), net (64.9 ) (31.7 ) 38.0 — (58.6 ) Other income (loss) including equity in income of unconsolidated subsidiaries (37.3 ) 0.4 1.7 37.0 1.8 Income (loss) before income tax provision (benefit) (173.7 ) (165.6 ) 128.6 37.0 (173.7 ) Income tax provision (benefit) (60.1 ) (61.0 ) 49.5 11.5 (60.1 ) Net income (loss) (113.6 ) (104.6 ) 79.1 25.5 (113.6 ) Less: Net income attributable to noncontrolling interests — — 6.4 — 6.4 Net income (loss) attributable to ATI $ (113.6 ) $ (104.6 ) $ 72.7 $ 25.5 $ (120.0 ) Comprehensive income (loss) attributable to ATI $ (75.8 ) $ (87.2 ) $ 61.0 $ 22.8 $ (79.2 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the three months ended June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 291.2 $ 589.0 $ — $ 880.2 Cost of sales 12.0 278.6 477.3 — 767.9 Gross profit (loss) (12.0 ) 12.6 111.7 — 112.3 Selling and administrative expenses 23.1 8.7 34.9 — 66.7 Operating income (loss) (35.1 ) 3.9 76.8 — 45.6 Interest income (expense), net (39.7 ) (22.5 ) 27.7 — (34.5 ) Other income (loss) including equity in income of unconsolidated subsidiaries 86.1 0.3 (0.1 ) (86.1 ) 0.2 Income (loss) before income tax provision (benefit) 11.3 (18.3 ) 104.4 (86.1 ) 11.3 Income tax provision (benefit) (2.1 ) (6.6 ) 33.6 (27.0 ) (2.1 ) Net income (loss) 13.4 (11.7 ) 70.8 (59.1 ) 13.4 Less: Net income attributable to noncontrolling interests — — 3.3 — 3.3 Net income (loss) attributable to ATI $ 13.4 $ (11.7 ) $ 67.5 $ (59.1 ) $ 10.1 Comprehensive income (loss) attributable to ATI $ 17.8 $ (11.3 ) $ 92.5 $ (84.7 ) $ 14.3 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations and Comprehensive Income For the six months ended June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 578.4 $ 1,167.7 $ — $ 1,746.1 Cost of sales 23.0 538.7 959.3 — 1,521.0 Gross profit (loss) (23.0 ) 39.7 208.4 — 225.1 Selling and administrative expenses 44.3 18.4 63.5 — 126.2 Operating income (loss) (67.3 ) 21.3 144.9 — 98.9 Interest income (expense), net (78.3 ) (43.7 ) 54.0 — (68.0 ) Other income (loss) including equity in income of unconsolidated subsidiaries 180.0 0.8 2.7 (180.0 ) 3.5 Income (loss) before income tax provision (benefit) 34.4 (21.6 ) 201.6 (180.0 ) 34.4 Income tax provision (benefit) (0.1 ) (7.7 ) 69.1 (61.4 ) (0.1 ) Net income (loss) 34.5 (13.9 ) 132.5 (118.6 ) 34.5 Less: Net income attributable to noncontrolling interests — — 6.9 — 6.9 Net income (loss) attributable to ATI $ 34.5 $ (13.9 ) $ 125.6 $ (118.6 ) $ 27.6 Comprehensive income (loss) attributable to ATI $ 63.2 $ (11.6 ) $ 138.4 $ (135.9 ) $ 54.1
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows For the six months ended June 30, 2016 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (50.5 ) $ (166.8 ) $ 183.7 $ — $ (33.6 ) Investing Activities: Purchases of property, plant and equipment (0.3 ) (85.3 ) (59.7 ) — (145.3 ) Net receipts/(payments) on intercompany activity — — (43.5 ) 43.5 — Asset disposals and other — — 1.8 — 1.8 Cash flows provided by (used in) investing activities (0.3 ) (85.3 ) (101.4 ) 43.5 (143.5 ) Financing Activities: Borrowings on long-term debt 287.5 — 100.0 — 387.5 Payments on long-term debt and capital leases (0.3 ) (0.1 ) (0.2 ) — (0.6 ) Net borrowings under credit facilities — — 2.5 — 2.5 Debt issuance costs (9.4 ) — (1.0 ) — (10.4 ) Net receipts/(payments) on intercompany activity (209.8 ) 253.3 — (43.5 ) — Dividends paid to stockholders (17.2 ) — — — (17.2 ) Acquisition of noncontrolling interests — — (12.2 ) — (12.2 ) Cash flows provided by (used in) financing activities 50.8 253.2 89.1 (43.5 ) 349.6 Increase (decrease) in cash and cash equivalents $ — $ 1.1 $ 171.4 $ — $ 172.5 Condensed Statements of Cash Flows For the six months ended June 30, 2017 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (54.6 ) $ (55.4 ) $ 24.5 $ — $ (85.5 ) Investing Activities: Purchases of property, plant and equipment — (19.9 ) (35.4 ) — (55.3 ) Net receipts/(payments) on intercompany activity — — (135.3 ) 135.3 — Asset disposals and other — 0.1 3.2 — 3.3 Cash flows provided by (used in) investing activities — (19.8 ) (167.5 ) 135.3 (52.0 ) Financing Activities: Borrowings on long-term debt — — 7.3 — 7.3 Payments on long-term debt and capital leases (0.2 ) (0.2 ) (0.4 ) — (0.8 ) Net borrowings under credit facilities — — 59.4 — 59.4 Debt issuance costs — — (0.8 ) — (0.8 ) Net receipts/(payments) on intercompany activity 59.8 75.5 — (135.3 ) — Sale to noncontrolling interests — — 2.2 — 2.2 Shares repurchased for income tax withholding on share-based compensation (4.8 ) — — — (4.8 ) Cash flows provided by (used in) financing activities 54.8 75.3 67.7 (135.3 ) 62.5 Increase (decrease) in cash and cash equivalents $ 0.2 $ 0.1 $ (75.3 ) $ — $ (75.0 )

Accumulated Other Comprehensi33

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, March 31, 2017 $ (954.7 ) $ (76.6 ) $ — $ 0.3 $ (40.4 ) $ (1,071.4 ) OCI before reclassifications — 4.2 — (5.2 ) 1.1 0.1 Amounts reclassified from AOCI (a) 11.2 (b) — (b) — (c) (0.8 ) (6.3 ) 4.1 Net current-period OCI 11.2 4.2 — (6.0 ) (5.2 ) 4.2 Balance, June 30, 2017 $ (943.5 ) $ (72.4 ) $ — $ (5.7 ) $ (45.6 ) $ (1,067.2 ) Attributable to noncontrolling interests: Balance, March 31, 2017 $ — $ 11.7 $ — $ — $ — $ 11.7 OCI before reclassifications — 0.2 — — — 0.2 Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — 0.2 — — — 0.2 Balance, June 30, 2017 $ — $ 11.9 $ — $ — $ — $ 11.9 The changes in AOCI by component, net of tax, for the six month period ended June 30, 2017 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, December 31, 2016 $ (965.5 ) $ (85.0 ) $ — $ 2.4 $ (45.6 ) $ (1,093.7 ) OCI before reclassifications — 12.6 — (6.7 ) — 5.9 Amounts reclassified from AOCI (a) 22.0 (b) — (b) — (c) (1.4 ) — 20.6 Net current-period OCI 22.0 12.6 — (8.1 ) — 26.5 Balance, June 30, 2017 $ (943.5 ) $ (72.4 ) $ — $ (5.7 ) $ (45.6 ) $ (1,067.2 ) Attributable to noncontrolling interests: Balance, December 31, 2016 $ — $ 9.7 $ — $ — $ — $ 9.7 OCI before reclassifications — 2.2 — — — 2.2 Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — 2.2 — — — 2.2 Balance, June 30, 2017 $ — $ 11.9 $ — $ — $ — $ 11.9 (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 June 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, March 31, 2016 $ (925.1 ) $ (51.5 ) $ — $ (18.3 ) $ — $ (994.9 ) OCI before reclassifications — (8.3 ) — 16.3 — 8.0 Amounts reclassified from AOCI (a) 11.4 (b) — (b) — (c) 1.8 — 13.2 Net current-period OCI 11.4 (8.3 ) — 18.1 — 21.2 Balance, June 30, 2016 $ (913.7 ) $ (59.8 ) $ — $ (0.2 ) $ — $ (973.7 ) Attributable to noncontrolling interests: Balance, March 31, 2016 $ — $ 17.9 $ — $ — $ — $ 17.9 OCI before reclassifications — (1.5 ) — — — (1.5 ) Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — (1.5 ) — — — $ (1.5 ) Balance, June 30, 2016 $ — $ 16.4 $ — $ — $ — $ 16.4 The changes in AOCI by component, net of tax, for the six month period ended June 30, 2016 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Deferred Tax Asset Valuation Allowance Total Attributable to ATI: Balance, December 31, 2015 $ (951.2 ) $ (47.6 ) $ — $ (15.7 ) $ — $ (1,014.5 ) OCI before reclassifications 13.9 (12.2 ) — 10.6 — 12.3 Amounts reclassified from AOCI (a) 23.6 (b) — (b) — (c) 4.9 — 28.5 Net current-period OCI 37.5 (12.2 ) — 15.5 — 40.8 Balance, June 30, 2016 $ (913.7 ) $ (59.8 ) $ — $ (0.2 ) $ — $ (973.7 ) Attributable to noncontrolling interests: Balance, December 31, 2015 $ — $ 19.4 $ — $ — $ — $ 19.4 OCI before reclassifications — (3.0 ) — — — (3.0 ) Amounts reclassified from AOCI — (b) — — — — — Net current-period OCI — (3.0 ) — — — $ (3.0 ) Balance, June 30, 2016 $ — $ 16.4 $ — $ — $ — $ 16.4 (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 six month periods ended June 30, 2017 and 2016 were as follows: Amount reclassified from AOCI Details about AOCI Components (In millions) Three months ended June 30, 2017 Three months ended June 30, 2016 Six months ended June 30, 2017 Six months ended June 30, 2016 Affected line item in the statements of operations Postretirement benefit plans Prior service (cost) credit $ 0.4 $ 0.5 (a) $ 0.8 $ (0.4 ) (a) Actuarial losses (18.0 ) (18.8 ) (a) (35.8 ) (37.5 ) (a) (17.6 ) (18.3 ) (c) (35.0 ) (37.9 ) (c) Total before tax (6.4 ) (6.9 ) (13.0 ) (14.3 ) Tax provision (benefit) (d) $ (11.2 ) $ (11.4 ) $ (22.0 ) $ (23.6 ) Net of tax Derivatives Nickel and other raw material contracts $ (1.6 ) $ (6.1 ) (b) $ (2.5 ) $ (12.4 ) (b) Natural gas contracts (1.1 ) (4.7 ) (b) (3.4 ) (11.0 ) (b) Foreign exchange contracts 4.1 7.9 (b) 8.2 15.5 (b) 1.4 (2.9 ) (c) 2.3 (7.9 ) (c) Total before tax 0.6 (1.1 ) 0.9 (3.0 ) Tax provision (benefit) (d) $ 0.8 $ (1.8 ) $ 1.4 $ (4.9 ) 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. (d) These amounts exclude the impact of any deferred tax asset valuation allowance, when applicable.

Accounting Policies (Accounting

Accounting Policies (Accounting Pronouncements) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Mar. 31, 2018	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unfavorable impact on pre-tax operating results		$ (11.3)	$ 41.4	$ (34.4)	$ 173.7
Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Projected impact of new accounting principle on prior period operating income						$ 70.6
Forecast | Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unfavorable impact on pre-tax operating results	$ 5

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 141.6		$ 141.6		$ 149.6
Work-in-process	886.7		886.7		837.9
Finished goods	159.4		159.4		161.7
Total inventories at current cost	1,187.7		1,187.7		1,149.2
Adjustment from current cost to LIFO cost basis	79.1		79.1		97.3
Inventory valuation reserves	(150.2)		(150.2)		(169)
Progress payments	(40.4)		(40.4)		(40.5)
Total inventories, net	1,076.2		1,076.2		$ 1,037
Inventory [Line Items]
LIFO benefit (charge)			(18.2)	$ (4.6)
NRV benefit (charge)			18.1	5
Net cost of sales impact	$ (0.1)	$ 0.4	$ (0.1)	0.4
Inventory Valuation Reserve | Titanium products
Inventory [Line Items]
Inventory valuation charges				$ 17.7

Property, Plant and Equipment36

Property, Plant and Equipment (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Land	$ 31.5	$ 31.4
Buildings	840.3	829.6
Equipment and leasehold improvements	3,527	3,497.2
Property Plant And Equipment, gross	4,398.8	4,358.2
Accumulated depreciation and amortization	(1,906.5)	(1,859.3)
Total property, plant and equipment, net	2,492.3	$ 2,498.9
Construction in progress	$ 77.1

Debt Schedule of Debt (Details)

Debt Schedule of Debt (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended	12 Months Ended
		Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Feb. 15, 2016	Dec. 31, 2013
Debt Instrument [Line Items]
Debt Issuance Costs, Net		$ 16	$ 16	$ 17.1
Total Debt		1,944.1	1,944.1	1,877
Short term debt and current portion of long-term debt		67.5	67.5	105.1
Long-term debt		1,876.6	1,876.6	1,771.9
Allegheny Technologies, Convertible Senior Notes, 4.75%, Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 287.5	$ 287.5	$ 287.5
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date			Jul. 1, 2022	Jul. 1, 2022
Interest rate		4.75%	4.75%	4.75%
Allegheny Technologies 5.875% Notes due 2023 (a)
Debt Instrument [Line Items]
Long-term Debt, Gross	[1]	$ 500	$ 500	$ 500
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date			Aug. 15, 2023	Aug. 15, 2023
Interest rate		7.875%	7.875%	7.875%	7.875%	5.875%
Allegheny Technologies 5.95% Notes due 2021
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 500	$ 500	$ 500
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date			Jan. 15, 2021	Jan. 15, 2021
Interest rate		5.95%	5.95%	5.95%
Allegheny Technologies 9.375% Notes due 2019
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 350	$ 350	$ 350
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date			Jun. 1, 2019	Jun. 1, 2019
Interest rate		9.375%	9.375%	9.375%
Allegheny Ludlum 6.95% debentures due 2025
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 150	$ 150	$ 150
Debt Instrument, Issuer		Allegheny Ludlum
Debt Instrument, Maturity Date			Dec. 15, 2025	Dec. 15, 2025
Interest rate		6.95%	6.95%	6.95%
2022 Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 100	$ 100	$ 100
Debt Instrument, Issuer		Allegheny Technologies
Debt Instrument, Maturity Date			Feb. 28, 2022	Nov. 13, 2017
Domestic Bank Group $400 million asset-based credit facility
Debt Instrument [Line Items]
Short-term Debt		$ 60	$ 60	$ 0
Foreign credit facilities
Debt Instrument [Line Items]
Short-term Debt		4	4	4.4
Other
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 8.6	$ 8.6	$ 2.2
[1]	Bearing interest at 7.875% effective February 15, 2016.

Debt Narrative (Details)

Debt Narrative (Details)		1 Months Ended	3 Months Ended	6 Months Ended
		Mar. 31, 2017USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)	Feb. 15, 2016	Dec. 31, 2013
Debt Instrument [Line Items]
Payments of Debt Issuance Costs				$ 800,000	$ 10,400,000
Defined benefit plan contributions made		$ 135,000,000
Allegheny Technologies 5.875% Notes due 2023 (a)
Debt Instrument [Line Items]
Interest rate			7.875%	7.875%		7.875%	7.875%	5.875%
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]
Short-term Debt			60,000,000	60,000,000		0
Amount utilized to support the issuance of letters of credit			45,100,000	45,100,000
Average borrowings during period				$ 36,000,000	$ 164,000,000
Interest rate during period				3.376%	1.757%
Domestic Bank Group $400 million asset-based credit facility | Revolving credit facility
Debt Instrument [Line Items]
Payments of Debt Issuance Costs			1,000,000
Maximum borrowing capacity			$ 400,000,000	$ 400,000,000
Minimum fixed charge coverage ratio allowed in event of default			1	1
Percentage of borrowing capacity unavailable due to fixed charge coverage ratio covenant			10.00%	10.00%
Borrowing capacity unavailable due to fixed charge coverage ratio covenant			$ 40,000,000	$ 40,000,000
Remaining borrowing capacity unavailable due to fixed charge coverage ratio covenant			$ 50,000,000	50,000,000
Minimum required liquidity number of days prior to maturity of Senior Notes			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)			1.75%
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)			2.25%
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
2022 Term Loan [Member]
Debt Instrument [Line Items]
Payments of Debt Issuance Costs			800,000
Minimum prepayment increments allowed			50,000,000
Outstanding borrowings			$ 100,000,000	$ 100,000,000		$ 100,000,000
2022 Term Loan [Member] | LIBOR based borrowings
Debt Instrument [Line Items]
Variable interest rate (percentage)			3.00%
Allegheny Technologies 9.375% Notes due 2019
Debt Instrument [Line Items]
Interest rate			9.375%	9.375%		9.375%
Outstanding borrowings			$ 350,000,000	$ 350,000,000		$ 350,000,000
Allegheny Technologies 9.375% Notes due 2019 | Revolving credit facility
Debt Instrument [Line Items]
Minimum required liquidity prior to maturity of Senior Notes			$ 500,000,000	$ 500,000,000
Allegheny Technologies, Convertible Senior Notes, 4.75%, Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate			4.75%	4.75%		4.75%
Outstanding borrowings			$ 287,500,000	$ 287,500,000		$ 287,500,000
Allegheny Technologies 5.95% Notes due 2021
Debt Instrument [Line Items]
Interest rate			5.95%	5.95%		5.95%
Outstanding borrowings			$ 500,000,000	$ 500,000,000		$ 500,000,000
Allegheny Technologies 5.95% Notes due 2021 | Revolving credit facility
Debt Instrument [Line Items]
Minimum required liquidity prior to maturity of Senior Notes			$ 700,000,000	$ 700,000,000
[1]	Bearing interest at 7.875% effective February 15, 2016.

Derivative Financial Instrume39

Derivative Financial Instruments and Hedging (Details) € in Millions, lb in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)lb	Jun. 30, 2016USD ($)	Jun. 30, 2017EUR (€)
Derivative Instruments Gain Loss [Line Items]
Percentage of estimated annual nickel requirements			35.00%
Percentage Of Forecasted Natural Gas Usage Hedged for 2017			70.00%
Percentage Of Forecasted Natural Gas Usage Hedged for 2018			35.00%
Percentage of Forecasted Natural Gas Usage Hedged for 2019			25.00%
Reclassification of Cash Flow Hedge Gain (Loss) [Abstract]
Cash Flow Hedge Gain (Loss) To Be Reclassified Within Twelve Months			$ (5.7)
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	$ (5.2)	$ 16.3	(6.7)	$ 10.6
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	0.8	(1.6)	1.4	(4)
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	(0.2)	$ 0	(0.9)
Nickel
Derivative Instruments Gain Loss [Line Items]
Notional amount of nickel hedge (in pounds of nickel) | lb			27
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	(4.6)	12.2	$ (4.4)	8.8
Nickel and other raw material contracts | Cost Of Sales | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	(1)	(3.8)	(1.6)	(7.7)
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	(0.5)	4.3	(2.1)	2.3
Natural gas contracts | Cost Of Sales | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	(0.7)	(2.7)	(2.1)	(5.9)
Natural gas contracts | Selling And Administrative Expenses | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	(0.2)	0	(0.9)
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	(0.1)	(0.2)	(0.2)	(0.5)
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	2.5	4.9	5.1	9.6
Foreign exchange contracts | Selling And Administrative Expenses | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net	0	0	0	0
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	(1.9)	3.1	(2.2)	(2.5)
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 | €					€ 21.6
Designated as Hedging Instrument | Natural gas contracts | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Loss on Cash Flow Hedge Ineffectiveness		0.2		1.3
Not Designated as Hedging Instrument | Foreign exchange forward | Maturity Dates Through 2017 [Member]
Derivative Instruments Gain Loss [Line Items]
Notional amount of derivative | €					€ 8
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	$ (0.5)	$ 0.7	$ (0.6)	$ 0.1

Derivative Financial Instrume40

Derivative Financial Instruments and Hedging (Details2) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	$ 3	$ 9.1
Derivative Fair Value Of Derivative Liability	20.8	18.7
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	3	8.5
Derivative Fair Value Of Derivative Liability	20.5	18.7
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	1.3	2.2
Designated as Hedging Instrument | Nickel and other raw material contracts | Other assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	1.2	3.3
Designated as Hedging Instrument | Nickel and other raw material contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	8.1	6.7
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	9.6	9.4
Designated as Hedging Instrument | Natural gas contracts | Prepaid expenses and other current assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.1	0.2
Designated as Hedging Instrument | Natural gas contracts | Other assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.2
Designated as Hedging Instrument | Natural gas contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	1.9	2.5
Designated as Hedging Instrument | Natural gas contracts | Other long-term liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.2	0
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	2.4
Designated as Hedging Instrument | Foreign exchange contracts | Other assets
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.2
Designated as Hedging Instrument | Foreign exchange contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.7	0
Designated as Hedging Instrument | Foreign exchange contracts | Other long-term liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0	0.1
Not Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.6
Not Designated as Hedging Instrument | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.3	0
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	0.6
Not Designated as Hedging Instrument | Foreign exchange contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	$ 0.3	$ 0

Fair Value of Financial Instr41

Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Carrying Reported Amount Fair Value Disclosure
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 154.6	$ 229.6
Derivative financial instruments, Assets	3	9.1
Derivative Financial Instruments, liabilities	20.8	18.7
Debt	1,960.1	1,894.1
Estimate Of Fair Value Fair Value Disclosure
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	154.6	229.6
Derivative financial instruments, Assets	3	9.1
Derivative Financial Instruments, liabilities	20.8	18.7
Debt	2,122.1	1,975
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	154.6	229.6
Derivative financial instruments, Assets	0	0
Derivative Financial Instruments, liabilities	0	0
Debt	1,949.5	1,868.4
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	3	9.1
Derivative Financial Instruments, liabilities	20.8	18.7
Debt	$ 172.6	$ 106.6

Retirement Benefits (Details1)

Retirement Benefits (Details1) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pension Plans Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	$ 3.5	$ 5.1	$ 7	$ 10.3
Interest cost on benefits earned in prior years	29.2	31.3	58.4	62.7
Expected return on plan assets	(36.7)	(37.1)	(73.4)	(74.3)
Amortization of prior service cost (credit)	0.3	0.3	0.6	0.6
Amortization of net actuarial loss	15.7	16.4	31.3	32.7
Total retirement benefit expense	12	16	23.9	32
Other Postretirement Benefit Plan, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	0.6	0.7	1.2	1.3
Interest cost on benefits earned in prior years	3.6	3.9	7.3	8
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(0.7)	(0.8)	(1.4)	(0.2)
Amortization of net actuarial loss	2.3	2.4	4.5	4.8
Total retirement benefit expense	$ 5.8	$ 6.2	$ 11.6	$ 13.9

Retirement Benefits Narrative (

Retirement Benefits Narrative (Details) $ in Millions	1 Months Ended
	Mar. 31, 2017USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan contributions made	$ 135

Income Taxes - Quarterly Disclo

Income Taxes - Quarterly Disclosure (Details9) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Investments, Owned, Federal Income Tax Note [Line Items]
Income tax (provision) benefit	$ 2.1	$ 25.9	$ 0.1	$ 60.1
Effective Income Tax Rate Reconciliation, Percent				34.60%
Discrete tax benefits (expense)	$ 5.4	$ 2.8	$ 6.7	$ 3.6

Business Segments (Details)

Business Segments (Details) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017USD ($)segment	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract]
Number of business segments | segment	2
Segment Reporting Information [Line Items]
Sales	$ 880.2	$ 810.5		$ 1,746.1	$ 1,568
Operating profit (loss):	70.9	7		140.8	(73.5)
LIFO and net realizable value reserves	(0.1)	0.4		(0.1)	0.4
Corporate expenses	(11.8)	(11.8)		(22.1)	(22.8)
Closed operations and other expenses	(13.2)	(5.7)		(16.2)	(9.2)
Restructuring charges	0	1	$ 9	0	10
Interest expense, net	(34.5)	(30.3)		(68)	(58.6)
Income (loss) before income tax provision (benefit)	11.3	(41.4)		34.4	(173.7)
High Performance Materials & Components
Segment Reporting Information [Line Items]
Operating profit (loss):	68	38.8		118.9	67.9
Flat Rolled Products
Segment Reporting Information [Line Items]
Operating profit (loss):	2.9	(31.8)		21.9	(141.4)
Operating Segments
Segment Reporting Information [Line Items]
Sales	916.5	835.4		1,813.2	1,624.5
Operating Segments | High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	543.3	511.1		1,067	1,019
Operating Segments | Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	373.2	324.3		746.2	605.5
Internal Customers | Operating Segments
Segment Reporting Information [Line Items]
Sales	36.3	24.9		67.1	56.5
Internal Customers | Operating Segments | High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	16.9	12.7		30.2	27.6
Internal Customers | Operating Segments | Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	19.4	12.2		36.9	28.9
External Customers | Operating Segments
Segment Reporting Information [Line Items]
Sales	880.2	810.5		1,746.1	1,568
External Customers | Operating Segments | High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	526.4	498.4		1,036.8	991.4
External Customers | Operating Segments | Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	$ 353.8	$ 312.1		$ 709.3	$ 576.6

Business Segments - Additional

Business Segments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 0	$ (1)	$ (9)	$ 0	$ (10)
Restructuring reserve	13.4			13.4		$ 33.1
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	6.8			6.8
Employee benefit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 6.6			$ 6.6

Per Share Information (Details)

Per Share Information (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share Reconciliation [Abstract]
Net income (loss) attributable to ATI	$ 10.1	$ (18.8)	$ 27.6	$ (120)
4.75% Convertible Senor Notes due 2022	1.8	0	4.8	0
Net income (loss) attributable to ATI after assumed conversions	$ 11.9	$ (18.8)	$ 32.4	$ (120)
Denominator for basic net income (loss) per common share – weighted average shares	107.7	107.3	107.6	107.3
Share-based compensation	0.7	0	0.8	0
Effective of dilutive securities: 4.75% Convertible Senior Notes due 2022	19.9	0	19.9	0
Denominator for diluted net income (loss) per common share – adjusted weighted average shares and assumed conversions	128.3	107.3	128.3	107.3
Basic net income (loss) attributable to ATI per common share (in dollars per share)	$ 0.09	$ (0.18)	$ 0.26	$ (1.12)
Diluted net income (loss) attributable to ATI per common share (in dollars per share)	$ 0.09	$ (0.18)	$ 0.25	$ (1.12)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount	0	9.3	0	5

Financial Information for Sub48

Financial Information for Subsidiary and Guarantor Parent (Narrative) (Details) - Allegheny Ludlum 6.95% debentures due 2025 - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 150	$ 150
Interest rate	6.95%	6.95%

Financial Information for Sub49

Financial Information for Subsidiary and Guarantor Parent (B.S.) (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
ASSETS
Cash and cash equivalents	$ 154.6	$ 229.6	$ 322.3	$ 149.8
Accounts receivable, net	538.6	452.1
Intercompany notes receivable	0	0
Inventories, net	1,076.2	1,037
Prepaid expenses and other current assets	30.7	47.8
Total current assets	1,800.1	1,766.5
Property, plant and equipment, net	2,492.3	2,498.9
Goodwill	643.5	641.9
Intercompany notes receivable	0	0
Investment in subsidiaries	0	0
Other assets	250.4	262.7
Total assets	5,186.3	5,170
LIABILITIES AND EQUITY
Accounts payable	355.5	294.3
Accrued liabilities	278	309.3
Intercompany notes payable	0	0
Short term debt and current portion of long-term debt	67.5	105.1
Total current liabilities	701	708.7
Long-term debt	1,876.6	1,771.9
Intercompany notes payable	0	0
Accrued postretirement benefits	308	317.7
Pension liabilities	682.9	827.9
Deferred income taxes	20.1	15.6
Other long-term liabilities	83.3	83.4
Total liabilities	3,671.9	3,725.2
Total stockholders’ equity	1,514.4	1,444.8	$ 2,099.3	$ 2,184.4
Total Liabilities and Equity	5,186.3	5,170
Reportable Legal Entities | Parent Company
ASSETS
Cash and cash equivalents	2.5	2.3
Accounts receivable, net	0.1	0.1
Intercompany notes receivable	0	0
Inventories, net	0	0
Prepaid expenses and other current assets	5.3	6.6
Total current assets	7.9	9
Property, plant and equipment, net	1.1	1.3
Goodwill	0	0
Intercompany notes receivable	0	0
Investment in subsidiaries	5,498.2	5,241.2
Other assets	26.8	23
Total assets	5,534	5,274.5
LIABILITIES AND EQUITY
Accounts payable	3.1	3.1
Accrued liabilities	51.8	54.6
Intercompany notes payable	1,670.6	1,341.1
Short term debt and current portion of long-term debt	0.3	0.4
Total current liabilities	1,725.8	1,399.2
Long-term debt	1,623.1	1,621.7
Intercompany notes payable	0	0
Accrued postretirement benefits	0	0
Pension liabilities	634.8	778.5
Deferred income taxes	20.1	15.6
Other long-term liabilities	15.8	14.7
Total liabilities	4,019.6	3,829.7
Total stockholders’ equity	1,514.4	1,444.8
Total Liabilities and Equity	5,534	5,274.5
Reportable Legal Entities | Subsidiary
ASSETS
Cash and cash equivalents	2.6	2.5
Accounts receivable, net	136.8	107.8
Intercompany notes receivable	0	0
Inventories, net	160.2	106.7
Prepaid expenses and other current assets	4.1	5.2
Total current assets	303.7	222.2
Property, plant and equipment, net	1,585.6	1,583.6
Goodwill	0	0
Intercompany notes receivable	0	0
Investment in subsidiaries	37.7	37.7
Other assets	19.3	25.5
Total assets	1,946.3	1,869
LIABILITIES AND EQUITY
Accounts payable	161.2	97.4
Accrued liabilities	75.9	83.3
Intercompany notes payable	1,611.4	1,551.8
Short term debt and current portion of long-term debt	0.3	0.3
Total current liabilities	1,848.8	1,732.8
Long-term debt	149.8	150
Intercompany notes payable	200	200
Accrued postretirement benefits	238.4	244
Pension liabilities	4.9	5.2
Deferred income taxes	0	0
Other long-term liabilities	18.6	18.1
Total liabilities	2,460.5	2,350.1
Total stockholders’ equity	(514.2)	(481.1)
Total Liabilities and Equity	1,946.3	1,869
Reportable Legal Entities | NonGuarantor Subsidiaries
ASSETS
Cash and cash equivalents	149.5	224.8
Accounts receivable, net	401.7	344.2
Intercompany notes receivable	3,282	2,892.9
Inventories, net	916	930.3
Prepaid expenses and other current assets	21.3	36
Total current assets	4,770.5	4,428.2
Property, plant and equipment, net	905.6	914
Goodwill	643.5	641.9
Intercompany notes receivable	200	200
Investment in subsidiaries	0	0
Other assets	204.3	214.2
Total assets	6,723.9	6,398.3
LIABILITIES AND EQUITY
Accounts payable	191.2	193.8
Accrued liabilities	150.3	171.4
Intercompany notes payable	0	0
Short term debt and current portion of long-term debt	66.9	104.4
Total current liabilities	408.4	469.6
Long-term debt	103.7	0.2
Intercompany notes payable	0	0
Accrued postretirement benefits	69.6	73.7
Pension liabilities	43.2	44.2
Deferred income taxes	0	0
Other long-term liabilities	48.9	50.6
Total liabilities	673.8	638.3
Total stockholders’ equity	6,050.1	5,760
Total Liabilities and Equity	6,723.9	6,398.3
Eliminations
ASSETS
Cash and cash equivalents	0	0
Accounts receivable, net	0	0
Intercompany notes receivable	(3,282)	(2,892.9)
Inventories, net	0	0
Prepaid expenses and other current assets	0	0
Total current assets	(3,282)	(2,892.9)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intercompany notes receivable	(200)	(200)
Investment in subsidiaries	(5,535.9)	(5,278.9)
Other assets	0	0
Total assets	(9,017.9)	(8,371.8)
LIABILITIES AND EQUITY
Accounts payable	0	0
Accrued liabilities	0	0
Intercompany notes payable	(3,282)	(2,892.9)
Short term debt and current portion of long-term debt	0	0
Total current liabilities	(3,282)	(2,892.9)
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	(3,482)	(3,092.9)
Total stockholders’ equity	(5,535.9)	(5,278.9)
Total Liabilities and Equity	$ (9,017.9)	$ (8,371.8)

Financial Information for Sub50

Financial Information for Subsidiary and Guarantor Parent (I.S.) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Sales	$ 880.2	$ 810.5		$ 1,746.1	$ 1,568
Cost of sales	767.9	762.3		1,521	1,553
Gross profit (loss)	112.3	48.2		225.1	15
Selling and administrative expenses	66.7	59.3		126.2	121.9
Restructuring charges	0	1	$ 9	0	10
Operating income (loss)	45.6	(12.1)		98.9	(116.9)
Interest income (expense), net	(34.5)	(30.3)		(68)	(58.6)
Other income (loss) including equity in income of unconsolidated subsidiaries	0.2	1		3.5	1.8
Income (loss) before income tax provision (benefit)	11.3	(41.4)		34.4	(173.7)
Income tax provision (benefit)	(2.1)	(25.9)		(0.1)	(60.1)
Net income (loss)	13.4	(15.5)		34.5	(113.6)
Less: Net income attributable to noncontrolling interests	3.3	3.3		6.9	6.4
Net income (loss) attributable to ATI	10.1	(18.8)		27.6	(120)
Comprehensive income (loss) attributable to ATI	14.3	2.4		54.1	(79.2)
Reportable Legal Entities | Parent Company
Income Statement [Abstract]
Sales	0	0		0	0
Cost of sales	12	9.6		23	29
Gross profit (loss)	(12)	(9.6)		(23)	(29)
Selling and administrative expenses	23.1	20.6		44.3	42.5
Restructuring charges		0			0
Operating income (loss)	(35.1)	(30.2)		(67.3)	(71.5)
Interest income (expense), net	(39.7)	(33.7)		(78.3)	(64.9)
Other income (loss) including equity in income of unconsolidated subsidiaries	86.1	22.5		180	(37.3)
Income (loss) before income tax provision (benefit)	11.3	(41.4)		34.4	(173.7)
Income tax provision (benefit)	(2.1)	(25.9)		(0.1)	(60.1)
Net income (loss)	13.4	(15.5)		34.5	(113.6)
Less: Net income attributable to noncontrolling interests	0	0		0	0
Net income (loss) attributable to ATI	13.4	(15.5)		34.5	(113.6)
Comprehensive income (loss) attributable to ATI	17.8	4.2		63.2	(75.8)
Reportable Legal Entities | Subsidiary
Income Statement [Abstract]
Sales	291.2	260.9		578.4	474.7
Cost of sales	278.6	286.9		538.7	585.4
Gross profit (loss)	12.6	(26)		39.7	(110.7)
Selling and administrative expenses	8.7	4.9		18.4	14.6
Restructuring charges		0			9
Operating income (loss)	3.9	(30.9)		21.3	(134.3)
Interest income (expense), net	(22.5)	(17.6)		(43.7)	(31.7)
Other income (loss) including equity in income of unconsolidated subsidiaries	0.3	0.3		0.8	0.4
Income (loss) before income tax provision (benefit)	(18.3)	(48.2)		(21.6)	(165.6)
Income tax provision (benefit)	(6.6)	(17.6)		(7.7)	(61)
Net income (loss)	(11.7)	(30.6)		(13.9)	(104.6)
Less: Net income attributable to noncontrolling interests	0	0		0	0
Net income (loss) attributable to ATI	(11.7)	(30.6)		(13.9)	(104.6)
Comprehensive income (loss) attributable to ATI	(11.3)	(29.3)		(11.6)	(87.2)
Reportable Legal Entities | NonGuarantor Subsidiaries
Income Statement [Abstract]
Sales	589	549.6		1,167.7	1,093.3
Cost of sales	477.3	465.8		959.3	938.6
Gross profit (loss)	111.7	83.8		208.4	154.7
Selling and administrative expenses	34.9	33.8		63.5	64.8
Restructuring charges		1			1
Operating income (loss)	76.8	49		144.9	88.9
Interest income (expense), net	27.7	21		54	38
Other income (loss) including equity in income of unconsolidated subsidiaries	(0.1)	0.9		2.7	1.7
Income (loss) before income tax provision (benefit)	104.4	70.9		201.6	128.6
Income tax provision (benefit)	33.6	25.8		69.1	49.5
Net income (loss)	70.8	45.1		132.5	79.1
Less: Net income attributable to noncontrolling interests	3.3	3.3		6.9	6.4
Net income (loss) attributable to ATI	67.5	41.8		125.6	72.7
Comprehensive income (loss) attributable to ATI	92.5	33.7		138.4	61
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	(86.1)	(22.7)		(180)	37
Income (loss) before income tax provision (benefit)	(86.1)	(22.7)		(180)	37
Income tax provision (benefit)	(27)	(8.2)		(61.4)	11.5
Net income (loss)	(59.1)	(14.5)		(118.6)	25.5
Less: Net income attributable to noncontrolling interests	0	0		0	0
Net income (loss) attributable to ATI	(59.1)	(14.5)		(118.6)	25.5
Comprehensive income (loss) attributable to ATI	$ (84.7)	$ (6.2)		$ (135.9)	$ 22.8

Financial Information for Sub51

Financial Information for Subsidiary and Guarantor Parent (Cash Flow) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Statement of Cash Flows
Cash flows provided by (used in) operating activities	$ (85.5)	$ (33.6)
Investing Activities:
Purchases of property, plant and equipment	(55.3)	(145.3)
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	3.3	1.8
Cash used in investing activities	(52)	(143.5)
Financing Activities:
Borrowings on long-term debt	7.3	387.5
Payments on long-term debt and capital leases	(0.8)	(0.6)
Net borrowings under credit facilities	59.4	2.5
Debt issuance costs	(0.8)	(10.4)
Net receipts/(payments) on intercompany activity	0	0
Sale to noncontrolling Interests	2.2	0
Dividends paid to stockholders	0	(17.2)
Acquisition of noncontrolling interests	0	(12.2)
Shares repurchased for income tax withholding on share-based compensation	(4.8)	0
Cash provided by financing activities	62.5	349.6
Increase (decrease) in cash and cash equivalents	(75)	172.5
Reportable Legal Entities | Parent Company
Statement of Cash Flows
Cash flows provided by (used in) operating activities	(54.6)	(50.5)
Investing Activities:
Purchases of property, plant and equipment	0	(0.3)
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0	0
Cash used in investing activities	0	(0.3)
Financing Activities:
Borrowings on long-term debt	0	287.5
Payments on long-term debt and capital leases	(0.2)	(0.3)
Net borrowings under credit facilities	0	0
Debt issuance costs	0	(9.4)
Net receipts/(payments) on intercompany activity	59.8	(209.8)
Sale to noncontrolling Interests	0
Dividends paid to stockholders		(17.2)
Acquisition of noncontrolling interests		0
Shares repurchased for income tax withholding on share-based compensation	(4.8)
Cash provided by financing activities	54.8	50.8
Increase (decrease) in cash and cash equivalents	0.2	0
Reportable Legal Entities | Subsidiary
Statement of Cash Flows
Cash flows provided by (used in) operating activities	(55.4)	(166.8)
Investing Activities:
Purchases of property, plant and equipment	(19.9)	(85.3)
Net receipts/(payments) on intercompany activity	0	0
Asset disposals and other	0.1	0
Cash used in investing activities	(19.8)	(85.3)
Financing Activities:
Borrowings on long-term debt	0	0
Payments on long-term debt and capital leases	(0.2)	(0.1)
Net borrowings under credit facilities	0	0
Debt issuance costs	0	0
Net receipts/(payments) on intercompany activity	75.5	253.3
Sale to noncontrolling Interests	0
Dividends paid to stockholders		0
Acquisition of noncontrolling interests		0
Shares repurchased for income tax withholding on share-based compensation	0
Cash provided by financing activities	75.3	253.2
Increase (decrease) in cash and cash equivalents	0.1	1.1
Reportable Legal Entities | NonGuarantor Subsidiaries
Statement of Cash Flows
Cash flows provided by (used in) operating activities	24.5	183.7
Investing Activities:
Purchases of property, plant and equipment	(35.4)	(59.7)
Net receipts/(payments) on intercompany activity	(135.3)	(43.5)
Asset disposals and other	3.2	1.8
Cash used in investing activities	(167.5)	(101.4)
Financing Activities:
Borrowings on long-term debt	7.3	100
Payments on long-term debt and capital leases	(0.4)	(0.2)
Net borrowings under credit facilities	59.4	2.5
Debt issuance costs	(0.8)	(1)
Net receipts/(payments) on intercompany activity	0	0
Sale to noncontrolling Interests	2.2
Dividends paid to stockholders		0
Acquisition of noncontrolling interests		(12.2)
Shares repurchased for income tax withholding on share-based compensation	0
Cash provided by financing activities	67.7	89.1
Increase (decrease) in cash and cash equivalents	(75.3)	171.4
Eliminations
Statement of Cash Flows
Cash flows provided by (used in) operating activities	0	0
Investing Activities:
Purchases of property, plant and equipment	0	0
Net receipts/(payments) on intercompany activity	135.3	43.5
Asset disposals and other	0	0
Cash used in investing activities	135.3	43.5
Financing Activities:
Borrowings on long-term debt	0	0
Payments on long-term debt and capital leases	0	0
Net borrowings under credit facilities	0	0
Debt issuance costs	0	0
Net receipts/(payments) on intercompany activity	(135.3)	(43.5)
Sale to noncontrolling Interests	0
Dividends paid to stockholders		0
Acquisition of noncontrolling interests		0
Shares repurchased for income tax withholding on share-based compensation	0
Cash provided by financing activities	(135.3)	(43.5)
Increase (decrease) in cash and cash equivalents	$ 0	$ 0

Financial Information for Sub52

Financial Information for Subsidiary and Guarantor Parent (Changes) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Current assets	$ 1,800.1		$ 1,766.5
Assets	5,186.3		5,170
Current liabilities	701		708.7
Liabilities	3,671.9		3,725.2
Stockholders' equity	1,514.4	$ 2,099.3	$ 1,444.8	$ 2,184.4
Cash flows provided by (used in) operating activities	(85.5)	(33.6)
Net Cash Provided by (Used in) Investing Activities	(52)	(143.5)
Cash provided by financing activities	$ 62.5	$ 349.6

Accumulated Other Comprehensi53

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016		Jun. 30, 2017		Jun. 30, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (1,071.4)		$ (994.9)		$ (1,093.7)		$ (1,014.5)
OCI before reclassifications	0.1		8		5.9		12.3
Amounts reclassified from AOCI	4.1		13.2		20.6		28.5
Net current-period OCI	4.2		21.2		26.5		40.8
Ending balance	(1,067.2)		(973.7)		(1,067.2)		(973.7)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	11.7		17.9		9.7		19.4
OCI before reclassifications	0.2		(1.5)		2.2		(3)
Amounts reclassified from AOCI	0		0		0		0
Net current-period OCI	0.2		(1.5)		2.2		(3)
Ending balance	11.9		16.4		11.9		16.4
Post- retirement benefit plans [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(954.7)		(925.1)		(965.5)		(951.2)
OCI before reclassifications	0		0		0		13.9
Amounts reclassified from AOCI	11.2	[1]	11.4	[2]	22	[1]	23.6	[2]
Net current-period OCI	11.2		11.4		22		37.5
Ending balance	(943.5)		(913.7)		(943.5)		(913.7)
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	(76.6)		(51.5)		(85)		(47.6)
OCI before reclassifications	4.2		(8.3)		12.6		(12.2)
Amounts reclassified from AOCI	0	[3]	0	[4]	0	[3]	0	[4]
Net current-period OCI	4.2		(8.3)		12.6		(12.2)
Ending balance	(72.4)		(59.8)		(72.4)		(59.8)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	11.7		17.9		9.7		19.4
OCI before reclassifications	0.2		(1.5)		2.2		(3)
Amounts reclassified from AOCI	0	[3]	0	[4]	0	[3]	0	[4]
Net current-period OCI	0.2		(1.5)		2.2		(3)
Ending balance	11.9		16.4		11.9		16.4
Unrealized holding gains on securities [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0		0		0		0
OCI before reclassifications	0		0		0		0
Amounts reclassified from AOCI	0	[3]	0	[4]	0	[3]	0	[4]
Net current-period OCI	0		0		0		0
Ending balance	0		0		0		0
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	0.3		(18.3)		2.4		(15.7)
OCI before reclassifications	(5.2)		16.3		(6.7)		10.6
Amounts reclassified from AOCI	(0.8)	[5]	1.8	[6]	(1.4)	[5]	4.9	[6]
Net current-period OCI	(6)		18.1		(8.1)		15.5
Ending balance	(5.7)		(0.2)		(5.7)		(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
Accumulated Deferred Tax Asset Valuation Allowance [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(40.4)		0		(45.6)		0
OCI before reclassifications	1.1		0		0		0
Amounts reclassified from AOCI	(6.3)		0		0		0
Net current-period OCI	(5.2)		0		0		0
Ending balance	(45.6)		0		(45.6)		0
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 Comprehensi54

Accumulated Other Comprehensive Income (Loss) (Details 2) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization to net income (loss) of net prior service cost (credits)		$ (0.4)	$ (0.5)	$ (0.8)	$ 0.4
Amount reclassified from AOCI, Postretirement benefit plans, Actuarial losses		18	18.8	35.8	37.5
Income (loss) before income tax provision (benefit)		11.3	(41.4)	34.4	(173.7)
Income tax benefit		(2.1)	(25.9)	(0.1)	(60.1)
Cost of sales		(767.9)	(762.3)	(1,521)	(1,553)
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 (credits)	[1]	0.4	0.5	0.8	(0.4)
Amount reclassified from AOCI, Postretirement benefit plans, Actuarial losses	[1]	(18)	(18.8)	(35.8)	(37.5)
Income (loss) before income tax provision (benefit)	[2]	(17.6)	(18.3)	(35)	(37.9)
Income tax benefit	[3]	(6.4)	(6.9)	(13)	(14.3)
Net income (loss)		(11.2)	(11.4)	(22)	(23.6)
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]	1.4	(2.9)	2.3	(7.9)
Income tax benefit	[3]	0.6	(1.1)	0.9	(3)
Net income (loss)		0.8	(1.8)	1.4	(4.9)
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	[4]	(1.6)	(6.1)	(2.5)	(12.4)
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	[4]	(1.1)		(3.4)
Cost of Sales and Selling and Administrative Expenses	[4]		(4.7)		(11)
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	[4]	$ 4.1	$ 7.9	$ 8.2	$ 15.5
[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]	These amounts exclude the impact of any deferred tax asset valuation allowance, when applicable.
[4]	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	Jun. 30, 2017USD ($)
Components of Environmental Loss Accrual [Abstract]
Accrual For Environmental Loss Contingencies	$ 14
Accrued Environmental Loss Contingencies Current	7
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	$ 19