ATI (ATI) 10-K 26 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Feb. 12, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Document Period End Date	Dec. 31, 2015
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		108,912,564
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Entity Public Float			$ 3.3

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Sales	$ 3,719.6	$ 4,223.4	$ 4,043.5
Costs and expenses:
Cost of sales	3,659.3	3,844.8	3,790.9
Selling and administrative expenses	238.8	272.5	276.4
Impairment of goodwill	126.6	0	0
Restructuring charges	64.3	0	67.5
Income (loss) before interest, other income and income taxes	(369.4)	106.1	(91.3)
Interest expense, net	(110.2)	(108.7)	(65.2)
Other income, net	1.6	4.1	1.7
Income (loss) from continuing operations before income taxes	(478)	1.5	(154.8)
Income tax benefit	(112.1)	(8.7)	(63.6)
Income (loss) from continuing operations	(365.9)	10.2	(91.2)
Income (loss) from discontinued operations, net of tax	0	(0.6)	252.8
Net income (loss)	(365.9)	9.6	161.6
Less: Net income attributable to noncontrolling interests	12	12.2	7.6
Net income (loss) attributable to ATI	$ (377.9)	$ (2.6)	$ 154
Basic net income (loss) per common share
Continuing operations attributable to ATI per common share (in dollars per share)	$ (3.53)	$ (0.02)	$ (0.93)
Discontinued operations attributable to ATI per common share (in dollars per share)	0	(0.01)	2.37
Basic net income attributable to ATI per common share (in dollars per share)	(3.53)	(0.03)	1.44
Diluted net income (loss) per common share
Continuing operations attributable to ATI per common share (in dollars per share)	(3.53)	(0.02)	(0.93)
Discontinued operations attributable to ATI per common share (in dollars per share)	0	(0.01)	2.37
Diluted net income attributable to ATI per common share (in dollars per share)	$ (3.53)	$ (0.03)	$ 1.44
Loss from continuing operations, net of tax	$ (377.9)	$ (2)	$ (98.8)
Income (loss) from discontinued operations, net of tax	$ 0	$ (0.6)	$ 252.8

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (365.9)	$ 9.6	$ 161.6
Currency translation adjustment
Unrealized net change arising during the period	(37)	(34.1)	13.8
Reclassification adjustment included in net income (loss)	0	0.5	1.5
Total	(37)	(33.6)	15.3
Unrealized holding gain (loss) on securities
Net gain arising during the period	0	0	0.1
Derivatives
Net derivatives gain (loss) on hedge transactions	(33.3)	45.7	(25.2)
Reclassification to net income of net realized loss (gain)	(18.2)	(3.6)	14
Income taxes on derivative transactions	(19.5)	16.2	(4.3)
Total	(32)	25.9	(6.9)
Postretirement benefit plans- Actuarial loss
Amortization of net actuarial loss	75	88.1	129
Net gain (loss) arising during the period	(95.8)	(424.5)	384.9
Postretirement benefit plans- Prior Service Cost
Amortization to net income (loss) of net prior service cost (credits)	6.2	(0.7)	(15.2)
Income taxes on postretirement benefit plans	5.1	(124.5)	187.6
Total	(19.7)	(212.6)	311.1
Other comprehensive income (loss), net of tax	(88.7)	(220.3)	319.6
Comprehensive income (loss)	(454.6)	(210.7)	481.2
Less: Comprehensive income attributable to noncontrolling interests	6.4	10.1	11
Comprehensive income (loss) attributable to ATI	$ (461)	$ (220.8)	$ 470.2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 149.8	$ 269.5
Accounts receivable, net	400.3	603.6
Inventories, net	1,271.6	1,472.8
Prepaid expenses and other current assets	45.9	136.2
Total Current Assets	1,867.6	2,482.1
Property, plant and equipment, net	2,928.2	2,961.8
Goodwill	651.4	780.4
Other assets	304.5	347.4
Total Assets	5,751.7	6,571.7
Liabilities and Stockholders’ Equity
Accounts payable	380.8	556.7
Accrued liabilities	301.8	323.2
Short-term debt and current portion of long-term debt	3.9	17.8
Total Current Liabilities	686.5	897.7
Long-term debt	1,491.8	1,498.2
Accrued postretirement benefits	359.2	415.8
Pension liabilities	833.8	739.3
Deferred income taxes	75.6	143.1
Other long-term liabilities	108.3	156.2
Total Liabilities	3,555.2	3,850.3
Redeemable noncontrolling interest	12.1	12.1
ATI Stockholders’ Equity:
Preferred stock, par value $0.10: authorized-50,000,000 shares; issued-none	0	0
Common stock, par value $0.10: authorized-500,000,000 shares; issued- 109,695,171 shares at December 31, 2015 and 2014; outstanding-109,174,882 shares at December 31, 2015 and 108,710,914 shares at December 31, 2014	11	11
Additional paid-in capital	1,161.7	1,164.2
Retained earnings	1,945.9	2,398.9
Treasury stock: 520,289 shares at December 31, 2015 and 984,257 shares at December 31, 2014	(21.3)	(44.3)
Accumulated other comprehensive loss, net of tax	(1,014.5)	(931.4)
Total ATI Stockholders’ Equity	2,082.8	2,598.4
Noncontrolling interests
Noncontrolling Interests	101.6	110.9
Total Stockholders’ Equity	2,184.4	2,709.3
Total Liabilities and Stockholders’ Equity	$ 5,751.7	$ 6,571.7

Consolidated Balance Sheets (PA

Consolidated Balance Sheets (PARENTHETICAL) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.10	$ 0.1
Preferred stock, authorized	50,000,000	50,000,000
Preferred stock, issued	0	0
Common stock, par value	$ 0.10	$ 0.1
Common stock, authorized	500,000,000	500,000,000
Common stock, issued	109,695,171	109,695,171
Common stock, oustanding	109,174,882	108,710,914
Treasury Stock	520,289	984,257

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities:
Net income (loss)	$ (365.9)	$ 9.6	$ 161.6
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	189.9	176.8	189.9
Deferred taxes	(118)	31.7	70.1
Impairment of goodwill	126.6	0	0
Non-cash restructuring charges	54.5	0	72.7
Gain on sale of business	0	0	(428.3)
Change in operating assets and liabilities:
Retirement benefits	14.3	3.1	70.6
Accounts receivable	203.3	(70.3)	41.1
Inventories	201.2	(143.7)	146.6
Accounts payable	(211.3)	82.1	(7.8)
Accrued income taxes	55.8	(37.5)	(25.5)
Accrued liabilities and other	(19)	4.1	77.4
Cash provided by operating activities	131.4	55.9	368.4
Investing Activities:
Purchases of property, plant and equipment	(144.5)	(225.7)	(612.7)
Proceeds from sale of business, net of transaction costs	0	0	600.9
Purchases of businesses, net of cash acquired	(0.5)	(92.9)	0
Asset disposals and other	(0.1)	2.4	0.8
Cash flows provided by (used in) investing activities	(145.1)	(316.2)	(11)
Financing Activities:
Issuances of long-term debt	0	0	500
Payments on long-term debt and capital leases	(23.6)	(414.9)	(17.1)
Net borrowings (repayments) under credit facilities	1.5	0	(14.4)
Debt issuance costs	0	(1.2)	(5.2)
Dividends paid to shareholders	(66.5)	(77.1)	(76.9)
Dividends paid to noncontrolling interests	(16)	0	(18)
Shares repurchased for income tax withholding on share-based compensation	(1.4)	(3.9)	(6.6)
Taxes on share-based compensation	0	0	2.6
Exercises of stock options and other	0	0.1	0.4
Cash provided by (used in) financing activities	(106)	(497)	364.8
Increase (decrease) in cash and cash equivalents	(119.7)	(757.3)	722.2
Cash and cash equivalents at beginning of year	269.5	1,026.8	304.6
Cash and cash equivalents at end of year	$ 149.8	$ 269.5	$ 1,026.8

Statements of Changes in Consol

Statements of Changes in Consolidated Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balance at Dec. 31, 2012	$ 2,587.1	$ 11	$ 1,181.7	$ 2,427.6	$ (111.3)	$ (1,029.4)	$ 107.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	161.6			154			7.6
Other comprehensive income (loss)	319.6					316.2	3.4
Cash dividends on common stock	(76.9)			(76.9)
Dividends paid to noncontrolling interest	(18)						(18)
Employee Stock Plans	21.3		4.2	(14.6)	31.7
Ending balance at Dec. 31, 2013	2,994.7	11	1,185.9	2,490.1	(79.6)	(713.2)	100.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	9.6			(2.6)			12.2
Other comprehensive income (loss)	(220.3)					(218.2)	(2.1)
Cash dividends on common stock	(77.1)			(77.1)
Conversion of convertible notes	5			(0.5)	5.5
Redeemable noncontrolling interest	0			(0.3)			0.3
Employee Stock Plans	(2.6)		(21.7)	(10.7)	29.8
Ending balance at Dec. 31, 2014	2,709.3	11	1,164.2	2,398.9	(44.3)	(931.4)	110.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(365.9)			(377.9)			12
Other comprehensive income (loss)	(88.7)					(83.1)	(5.6)
Cash dividends on common stock	(66.5)			(66.5)
Dividends paid to noncontrolling interest	(16)						(16)
Redeemable noncontrolling interest	0			(0.3)			0.3
Employee Stock Plans	12.2		(2.5)	(8.3)	23
Ending balance at Dec. 31, 2015	$ 2,184.4	$ 11	$ 1,161.7	$ 1,945.9	$ (21.3)	$ (1,014.5)	$ 101.6

Statements of Changes in Conso8

Statements of Changes in Consolidated Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Cash dividends on common stock per share	$ 0.62	$ 0.72	$ 0.72

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Principles of Consolidation The consolidated financial statements include the accounts of Allegheny Technologies Incorporated and its subsidiaries, including the Chinese joint venture known as Shanghai STAL Precision Stainless Steel Company Limited (“STAL”), in which the Company has a 60% interest. The remaining 40% interest in STAL is owned by Baosteel Group, a state authorized investment company whose equity securities are publicly traded in the People’s Republic of China. The financial results of STAL are consolidated into the Company’s operating results and financial position, with the 40% interest of our minority partner recognized in the consolidated statement of operations as net income attributable to noncontrolling interests and as equity attributable to the noncontrolling interest within total stockholders’ equity. Investments in which the Company exercises significant influence, but which it does not control (generally a 20% to 50% ownership interest), including ATI’s 50% interest in the industrial titanium joint venture known as Uniti LLC (“Uniti”), are accounted for under the equity method of accounting. Accounts receivable from Uniti were $0.5 million and $4.3 million at December 31, 2015 and 2014 , respectively. Significant intercompany accounts and transactions have been eliminated. Unless the context requires otherwise, “Allegheny Technologies,” “ATI” and the “Company” refer to Allegheny Technologies Incorporated and its subsidiaries. Risks and Uncertainties and Use of Estimates The preparation of consolidated financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect reported amounts of assets and liabilities at the date of the financial statements, as well as the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Management believes that the estimates are reasonable. Certain prior year amounts have been reclassified in order to conform with the 2015 presentation. The Company markets its products to a diverse customer base, principally throughout the United States. No single customer accounted for more than 10% of sales for any year presented. The principal end markets for the ATI’s products are customers in the aerospace and defense, oil & gas/chemical & hydrocarbon processing industry, electrical energy, automotive, construction and mining, food equipment and appliances, and medical markets. At December 31, 2015, ATI has approximately 9,200 full-time employees, of which approximately 15% are located outside the United States. Approximately 50% of ATI’s workforce is covered by various collective bargaining agreements (“CBAs”), predominantly with the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied & Industrial Service Workers International Union, AFL-CIO, CLC (“USW”). Certain of these CBAs with the USW expired on June 30, 2015, including CBAs for approximately 2,000 USW-represented employees located primarily within Flat Rolled Products segment operations, and at two facilities in the High Performance Materials & Components segment. Due to the lack of progress in contract negotiations, the Company issued a lockout notice involving these workers which took effect August 15, 2015. The Company continues to operate the affected facilities with salaried employees and temporary workers. On February 22, 2016, the Company reached a tentative agreement with the bargaining committee of the USW on a new labor contract, which would end the lockout. The contract is subject to ratification by USW members. Cash Equivalents and Investments Cash equivalents are highly liquid investments valued at cost, which approximates fair value, acquired with an original maturity of three months or less. Accounts Receivable Accounts receivable are presented net of a reserve for doubtful accounts of $4.5 million and $4.8 million at December 31, 2015 and 2014 , respectively. Trade credit is extended based upon evaluations of each customer’s ability to perform its obligations, which are updated periodically. Accounts receivable reserves are determined based upon an aging of accounts and a review for collectability of specific accounts. Inventories 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. Costs include direct material, direct labor and applicable manufacturing and engineering overhead, and other direct costs. Most of the Company’s inventory is valued utilizing the LIFO costing methodology. Inventory of the Company’s non-U.S. operations is valued using average cost or FIFO methods. The Company evaluates product lines on a quarterly basis to identify inventory carrying values that exceed estimated net realizable value. In applying the lower of cost or market principle, market means current replacement cost, subject to a ceiling (market value shall not exceed net realizable value) and a floor (market shall not be less than net realizable value reduced by an allowance for a normal profit margin). The calculation of a resulting reserve, if any, is recognized as an expense in the period that the need for the reserve is identified. However, in cases where inventory at FIFO cost is lower than the LIFO carrying value, a write-down of the inventory to market may be required, subject to the ceiling and floor. It is the Company’s general policy to write-down to scrap value any inventory that is identified as obsolete and any inventory that has aged or has not moved in more than twelve months. In some instances this criterion is up to twenty-four months. Long-Lived Assets Property, plant and equipment are recorded at cost, including capitalized interest, and includes long-lived assets acquired under capital leases. The principal method of depreciation adopted for all property placed into service after July 1, 1996 is the straight-line method. For buildings and equipment acquired prior to July 1, 1996, depreciation is computed using a combination of accelerated and straight-line methods. Property, plant and equipment associated with the Company’s Rowley titanium sponge facility in the High Performance Materials & Components segment, and the Hot-Rolling and Processing Facility (HRPF) in the Flat Rolled Products segment, are being depreciated utilizing the units of production method of depreciation, which the Company believes provides a better matching of costs and revenues. The Company periodically reviews estimates of useful life and production capacity assigned to new and in service assets. Significant enhancements, including major maintenance activities that extend the lives of property and equipment, are capitalized. Costs related to repairs and maintenance are charged to expense in the period incurred. The cost and related accumulated depreciation of property and equipment retired or disposed of are removed from the accounts and any related gains or losses are included in income. The Company monitors the recoverability of the carrying value of its long-lived assets. An impairment charge is recognized when an indicator of impairment occurs and the expected net undiscounted future cash flows from an asset’s use (including any proceeds from disposition) are less than the asset’s carrying value and the asset’s carrying value exceeds its fair value. Assets to be disposed of by sale are stated at the lower of their fair values or carrying amounts and depreciation is no longer recognized. Goodwill Goodwill is reviewed annually for impairment or more frequently if impairment indicators arise. The review for goodwill impairment requires a comparison of the fair value of each reporting unit that has goodwill associated with its operations with its carrying amount, including goodwill. If this comparison reflects impairment, then the loss would be measured as the excess of recorded goodwill over its implied fair value. Implied fair value is the excess of the fair value of a reporting unit over the amounts assigned to its assets and liabilities. Generally accepted accounting standards provide the option to qualitatively assess goodwill for impairment before completing a quantitative assessment. Under the qualitative approach, if, after assessing the totality of events or circumstances, including both macroeconomic, industry and market factors, and entity-specific factors, the Company determines it is likely (more likely than not) that the fair value of a reporting unit is greater than its carrying amount, then the quantitative impairment analysis is not required. The quantitative assessment may be performed each year for a reporting unit at the Company’s option without first performing a qualitative assessment. The Company’s quantitative assessment of goodwill for possible impairment includes estimating the fair market value of a reporting unit which has goodwill associated with its operations using discounted cash flow and multiples of cash earnings valuation techniques, plus valuation comparisons to recent public sale transactions of similar businesses, if any. These impairment assessments and valuation methods require the Company to make estimates and assumptions regarding future operating results, cash flows, changes in working capital and capital expenditures, selling prices, profitability, and the cost of capital. Many of these assumptions are determined by reference to market participants identified by the Company. Although management believes that the estimates and assumptions used were reasonable, actual results could differ from those estimates and assumptions. Other events and changes in circumstances may also require goodwill to be tested for impairment between annual measurement dates. While a decline in stock price and market capitalization is not specifically cited as a goodwill impairment indicator, a company’s stock price and market capitalization should be considered in determining whether it is more likely than not that the fair value of a reporting unit is less that its carrying value. Additionally, a significant decline in a company’s stock price may suggest that an adverse change in the business climate may have caused the fair value of one or more reporting units to fall below carrying value. A sustained decline in market capitalization below book value may be determined to require an interim goodwill impairment review. Environmental Costs that mitigate or prevent future environmental contamination or extend the life, increase the capacity or improve the safety or efficiency of property utilized in current operations are capitalized. Other costs that relate to current operations or an existing condition caused by past operations are expensed. Environmental liabilities are recorded when the Company’s liability is probable and the costs are reasonably estimable, but generally not later than the completion of the feasibility study or the Company’s recommendation of a remedy or commitment to an appropriate plan of action. The accruals are reviewed periodically and, as investigations and remediations proceed, adjustments of the accruals are made to reflect new information as appropriate. Accruals for losses from environmental remediation obligations do not take into account the effects of inflation, and anticipated expenditures are not discounted to their present value. The accruals are not reduced by possible recoveries from insurance carriers or other third parties, but do reflect allocations among potentially responsible parties (“PRPs”) at Federal Superfund sites or similar state-managed sites after an assessment is made of the likelihood that such parties will fulfill their obligations at such sites and after appropriate cost-sharing or other agreements are entered. The measurement of environmental liabilities by the Company is based on currently available facts, present laws and regulations, and current technology. Such estimates take into consideration the Company’s prior experience in site investigation and remediation, the data concerning cleanup costs available from other companies and regulatory authorities, and the professional judgment of the Company’s environmental experts in consultation with outside environmental specialists, when necessary. Foreign Currency Translation Assets and liabilities of international operations are translated into U.S. dollars using year-end exchange rates, while revenues and expenses are translated at average exchange rates during the period. The resulting net translation adjustments are recorded as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Sales Recognition Sales are recognized when title passes or as services are rendered. Research and Development Company funded research and development costs from continuing operations were $14.2 million in 2015 , $17.4 million in 2014 , and $16.1 million in 2013 and were expensed as incurred. Customer funded research and development costs were $1.5 million in 2015 , $2.7 million in 2014 , and $2.7 million in 2013 . Stock-based Compensation The Company accounts for stock-based compensation transactions, such as nonvested stock and performance equity awards, using fair value. Compensation expense for an award is estimated at the date of grant and is recognized over the requisite service period. Compensation expense is adjusted for equity awards that do not vest because service or performance conditions are not satisfied. However, compensation expense already recognized is not adjusted if market conditions are not met, such as the Company’s total shareholder return performance relative to a peer group under the Company’s performance equity awards. Income Taxes The provision for, or benefit from, income taxes includes deferred taxes resulting from temporary differences in income for financial and tax purposes using the liability method. Such temporary differences result primarily from differences in the carrying value of assets and liabilities. Future realization of deferred income tax assets requires sufficient taxable income within the carryback and/or carryforward period available under tax law. The Company evaluates on a quarterly basis whether, based on all available evidence, it is probable that the deferred income tax assets are realizable. Valuation allowances are established when it is estimated that it is more likely than not that the tax benefit of the deferred tax asset will not be realized. The evaluation includes the consideration of all available evidence, both positive and negative, regarding historical operating results including recent years with reported losses, the estimated timing of future reversals of existing taxable temporary differences, estimated future taxable income exclusive of reversing temporary differences and carryforwards, and potential tax planning strategies which may be employed to prevent an operating loss or tax credit carryforward from expiring unused. It is the Company’s policy to classify interest and penalties recognized on underpayment of income taxes as income tax expense. Net Income Per Common Share Basic and diluted net income per share are calculated by dividing the net income available to common stockholders by the weighted average number of common shares outstanding during the year. Diluted amounts assume the issuance of common stock for all potentially dilutive share equivalents outstanding. The calculations of all diluted income/loss per share figures for a period exclude the potentially dilutive effect of dilutive share equivalents if there is a net loss from continuing operations since the inclusion in the calculation of additional shares in the net loss from continuing operations per share would result in a lower per share loss and therefore be anti-dilutive. New Accounting Pronouncements Adopted In November 2015, the Financial Accounting Standards Board (FASB) issued new guidance on the balance sheet classification of deferred taxes. To simplify the presentation of deferred income taxes, the amendments in this update require that deferred tax liabilities and assets be classified as noncurrent rather than separating deferred income tax liabilities and assets into current and noncurrent amounts in the statement of financial position as required by current generally accepted accounting principles. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015. Therefore, the $62.2 million of current deferred tax liabilities reported on the December 31, 2014 consolidated balance sheet were reclassified to non-current. In April 2015, the FASB issued new guidance on the presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this guidance. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015. Therefore, the $10.9 million of debt issuance costs reported as other assets on the December 31, 2014 consolidated balance sheet were reclassified to a reduction of the carrying amount of long-term debt. In August 2015, the FASB issued additional guidance on presentation of debt issuance costs specifically related to line-of-credit arrangements. This guidance indicated no objection to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. As such, the Company continued to present such costs, as it does today, within other assets on the consolidated balance sheets. In January 2015, the Company adopted changes issued by the FASB to the criteria for reporting discontinued operations. Under the new criteria, a disposal of a component of an entity is required to be reported as discontinued operations only if the disposal represents a strategic shift that has, or will have, a major effect on an entity’s operations and financial results. The criteria that there be no significant continuing involvement in the operations of the component after the disposal transaction has been removed under the new guidance. The new guidance also requires the presentation of the assets and liabilities of a disposal group that includes a discontinued operation for each comparative period and requires additional disclosures about discontinued operations, including the major line items constituting the pretax profit or loss of the discontinued operation, certain cash flow information for the discontinued operation, expanded disclosures about an entity’s significant continuing involvement in a discontinued operation, and disclosures about a disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation. The provisions of the new guidance are effective for all disposals that occur for the Company beginning in fiscal year 2015. The adoption of these changes had no impact on the consolidated financial statements. Pending Accounting Pronouncements In February 2016, the FASB issued new guidance on the accounting for leases. This new guidance will require that a lessee recognize assets and liabilities on the balance sheet for all leases with a lease term of more than twelve months, with the result being the recognition of a right of use asset and a lease liability. The new lease accounting requirements are effective for the Company’s 2019 fiscal year with a modified retrospective transition approach required, with early adoption permitted. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements. In July 2015, the FASB issued changes to simplify the measurement of inventory valuation at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The new inventory measurement requirements are effective for the Company’s 2017 fiscal year, and will replace the current inventory valuation guidance that requires the use of a lower of cost or market framework. This change in the measurement of inventory does not apply to inventory valued on a LIFO basis, which is the accounting basis used for most of the Company’s inventory. The adoption of these changes is not expected to have a material impact on the Company’s consolidated financial statements. In May 2014, the FASB issued changes to revenue recognition with customers. This update provides a five-step analysis of transactions to determine when and how revenue is recognized. An entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB approved a one-year deferral of the effective date of this new guidance resulting in it now being effective for the Company beginning in fiscal year 2018. This update may be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying this update recognized at the date of initial application. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Acquisitions	Acquisitions On February 7, 2014, the Company acquired 85% of Dynamic Flowform Corp. (“Dynamic Flowform”) for $72.9 million of cash consideration, net of cash acquired. The Dynamic Flowform acquisition was treated as an asset purchase for tax purposes. The holders of the 15% noncontrolling interest have a put option requiring the Company to purchase their equity interest (see Note 18 for additional explanation). The Company also incurred $0.7 million of pre-tax costs related to the acquisition, consisting primarily of professional fees, which were recorded in selling and administrative expenses in the 2014 consolidated statement of operations. Based in Billerica, MA, Dynamic Flowform, which has been renamed ATI Flowform Products, uses precision flowforming process technologies to produce thin-walled components in net or near-net shapes across multiple alloy systems, including nickel-based alloys and superalloys, titanium and titanium alloys, zirconium alloys, and specialty and stainless alloys. Management expects this acquisition to expand the Company’s capabilities to produce specialty materials parts and components, primarily in the aerospace and defense, and oil & gas/chemical & hydrocarbon processing industry markets. ATI Flowform Products results are included in the High Performance Materials & Components segment from the date of the acquisition. The purchase price allocation included technology, trademarks and customer intangible assets of $21.4 million , which are being amortized over a 23 year weighted average life, and goodwill of $46.8 million , which is deductible for tax purposes. The final allocation of the purchase price was completed in the second quarter of 2014. In addition, on June 12, 2014, the Company acquired Hanard Machine, Inc. (“Hanard”) for $20.5 million of cash consideration, net of cash acquired, including $20.0 million paid in 2014 and $0.5 million paid in 2015. Located in Salem, OR, Hanard performs precision machining on parts and components made from titanium alloys, nickel-based alloys and superalloys, aluminum, specialty steel, and other ferrous and non-ferrous metals. The business operates as ATI Cast Products Salem Operations, and is reported as a part of the High Performance Materials & Components segment from the date of the acquisition. Management expects this acquisition to expand the Company’s capabilities to produce finished specialty materials parts and components and reinforces the Company’s important aerospace supply chain role. The purchase price allocation included technology and customer intangible assets of $4.3 million , which are being amortized over a 20 year life, and goodwill of $8.4 million , which is deductible for tax purposes. The final allocation of the purchase price was completed in the second quarter of 2015. Pro forma financial information has not been included because these acquisitions did not meet certain significance thresholds individually or in the aggregate.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations On November 4, 2013, the Company sold its tungsten materials business, which produces tungsten powder, tungsten heavy alloys, tungsten carbide materials, and carbide cutting tools. In 2013, the Company received cash proceeds, net of transaction costs, of $600.9 million on the sale of this business and recognized a $428.3 million pre-tax ( $261.4 million after tax) gain which has been recorded in discontinued operations. Also, during 2013, the Company completed a strategic review of its iron castings and fabricated components businesses. These businesses were not projected to meet the Company’s long-term profitable growth and return on capital employed expectations, resulting in the closure of the fabricated components business and planned divestiture of the iron casting business in 2013. In April 2014, the Company announced the closure of the iron castings business, as the divestiture of this business through a sale process on commercially acceptable terms was unlikely to be successful. The orderly wind-down of operations was completed by the end of the third quarter 2014. The closure of the iron castings business resulted in $1.8 million of cash exit costs in 2014, primarily related to severance benefits, of which $1.0 million was paid in 2014 and $0.8 million was paid in 2015. The operating results of the tungsten materials, iron castings and fabricated components businesses have been included in discontinued operations in the Company’s consolidated statements of operations for all periods presented. Results of discontinued operations for 2014 include $1.8 million pre-tax of charges associated with the iron castings closure. Results of discontinued operations for 2013 include $19.5 million pre-tax ( $11.9 million after-tax) of charges associated with the iron castings and fabricated components divestitures, including $18.6 million of pre-tax asset impairment charges. The following table presents summarized results for these discontinued operations (in millions): 2014 2013 Sales $ 14.9 $ 268.2 Income (loss) before income taxes $ (0.9 ) $ 414.2

Inventories

Inventories	12 Months Ended
	Dec. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories at December 31, 2015 and 2014 were as follows (in millions): 2015 2014 Raw materials and supplies $ 216.0 $ 249.3 Work-in-process 990.3 1,184.1 Finished goods 184.1 172.2 Total inventories at current cost 1,390.4 1,605.6 Adjustment from current cost to LIFO cost basis 136.4 4.8 Inventory valuation reserves (206.3 ) (68.8 ) Progress payments (48.9 ) (68.8 ) Total inventories, net $ 1,271.6 $ 1,472.8 Inventories, before progress payments, determined on the LIFO method were $992.0 million at December 31, 2015 , and $1,102.4 million at December 31, 2014 . The remainder of the inventory was determined using the FIFO and average cost methods, and these inventory values do not differ materially from current cost. Due to deflationary impacts primarily related to raw materials, the carrying value of the Company’s inventory as valued on the LIFO inventory accounting method exceeded current replacement cost initially as of December 31, 2013, and based on a lower of cost or market value analysis, a net realizable value (NRV) inventory reserve was recorded. In applying the lower of cost or market principle, market means current replacement cost, subject to a ceiling (market value shall not exceed net realizable value) and a floor (market shall not exceed net realizable value reduced by an allowance for a normal profit margin). Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV reserves were as follows (in millions): Fiscal year ended December 31, 2015 2014 2013 LIFO benefit (charge) $ 131.6 $ (24.7 ) $ 80.9 NRV benefit (charge) $ (131.5 ) $ 25.0 $ (35.0 ) Net cost of sales impact $ 0.1 $ 0.3 $ 45.9 During 2015 and 2013 , inventory usage resulted in liquidations of LIFO inventory quantities, increasing cost of sales by $9.6 million and $3.8 million in 2015 and 2013 , respectively. These inventories were carried at differing costs prevailing in prior years as compared with the cost of current manufacturing cost and purchases. There were no LIFO liquidations in 2014 . The Company also recorded lower of cost or market charges primarily related to non-premium quality (PQ) grade products during the ramp-up and qualification of the Rowley, UT titanium sponge production facility and continued sluggish demand for industrial titanium products from global markets. These lower of cost or market charges were $24.5 million in 2015 , $23.2 million in 2014 and $20.5 million in 2013 . Additionally, in December 2015, based on current market prices for non-PQ grades of titanium sponge, the Company recorded a $25.4 million charge to revalue this inventory. This charge includes revised assessments of the non-PQ titanium market conditions and expected utilization of this inventory.

Property Plant And Equipment

Property Plant And Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property Plant and Equipment	Property, Plant and Equipment Property, plant and equipment at December 31, 2015 and 2014 was as follows: (In millions) 2015 2014 Land $ 31.0 $ 30.2 Buildings 1,048.2 1,048.9 Equipment and leasehold improvements 3,858.1 3,702.5 4,937.3 4,781.6 Accumulated depreciation and amortization (2,009.1 ) (1,819.8 ) Total property, plant and equipment, net $ 2,928.2 $ 2,961.8 Construction in progress at December 31, 2015 and 2014 was $119.6 million and $71.1 million , respectively. Capital expenditures on the consolidated statement of cash flows for the year ended December 31, 2015 exclude $35.4 million of completion payments that were included in property, plant and equipment and accrued at December 31, 2015 . Depreciation and amortization from continuing operations for the years ended December 31, 2015 , 2014 and 2013 was as follows: (In millions) 2015 2014 2013 Depreciation of property, plant and equipment $ 159.6 $ 146.7 $ 156.8 Software and other amortization 30.3 29.9 23.8 Total depreciation and amortization $ 189.9 $ 176.6 $ 180.6

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets At December 31, 2015 , the Company had $651.4 million of goodwill on its consolidated balance sheet, all of which relates to the High Performance Materials & Components segment. Goodwill decreased $129.0 million in 2015 , resulting from a $126.6 million impairment charge in the Flat Rolled Products segment and $2.6 million from the impact of foreign currency translation on goodwill denominated in functional currencies other than the U.S. dollar, partially offset by $0.2 million for final purchase accounting adjustments for the Hanard acquisition. The Company performs its annual goodwill impairment evaluations in the fourth quarter of each year. Quantitative goodwill assessments were performed for all reporting units in 2015. As a result of these assessments, the Company determined that the fair value of the Flat Rolled Products business was below carrying value, including goodwill. During the fourth quarter of 2015, the Company recorded a $126.6 million pre-tax impairment charge to write-off all the goodwill in the Flat Rolled Products segment. This was due to challenging market conditions in 2015 in this business, primarily impacting commodity stainless flat-rolled products. Fourth quarter 2015 market conditions continued to deteriorate in this business due in large part to a surge of imports into the U.S. market, and excess North American and global capacities for commodity stainless steel sheet. Base-selling prices for commodity stainless steel sheet products fell throughout 2015 and reached historic lows in December. In addition, weakness continued in the oil & gas/chemical & hydrocarbon processing industry market, which has been the largest end market for the Flat Rolled Products business. Restructuring actions were initiated in December 2015 in the Flat Rolled Products business in response to these market conditions and outlook, including announced idling of various operations (see Note 17). This goodwill impairment charge was excluded from the Flat Rolled Products business segment results. No goodwill impairments were determined to exist for the year ended December 31, 2015 for all other reporting units with goodwill. In order to validate the reasonableness of the estimated fair values of the reporting units as of the valuation date, a reconciliation of the aggregate fair values of all reporting units to market capitalization was performed using a reasonable control premium. No goodwill impairments were determined to exist for the years ended December 31, 2014 and 2013. Accumulated impairment losses as of December 31, 2015 were $126.6 million . Other intangible assets, which are included in Other assets on the accompanying consolidated balance sheets as of December 31, 2015 and 2014 were as follows: December 31, 2015 December 31, 2014 (in millions) Weighted Average Useful life (years) Gross carrying amount Accumulated amortization Gross carrying amount Accumulated amortization Technology 21 $ 91.4 $ (18.6 ) $ 91.4 $ (14.2 ) Customer relationships 24 35.7 (6.2 ) 35.7 (4.7 ) Trademarks 15 64.6 (8.6 ) 64.6 (4.3 ) Total amortizable intangible assets 191.7 (33.4 ) 191.7 (23.2 ) Amortization expense from continuing operations related to intangible assets was approximately $10.0 million for the years ended December 31, 2015 and 2014 . For each of the years ending December 31, 2016 through 2020, annual amortization expense is expected to be approximately $10.0 million .

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation	Asset Retirement Obligations The Company maintains reserves where a legal obligation exists to perform an asset retirement activity and the fair value of the liability can be reasonably estimated. These asset retirement obligations (“AROs”) include liabilities where the timing and (or) method of settlement may be conditional on a future event, that may or may not be within the control of the entity. At December 31, 2015 , the Company had recognized AROs of $25.0 million related to landfill closures, decommissioning costs, facility leases and conditional AROs associated with manufacturing activities using what may be characterized as potentially hazardous materials. The 2013 sale of the tungsten materials business included an indemnification to the buyer for conditional ARO costs of up to $13 million for a five year period. The Company recorded a $9.4 million charge in 2013 to increase recorded reserves to $13 million for these retained liabilities, which was reported as part of the gain on sale of the tungsten materials business. In addition, as part of facility closures in 2013, $4.2 million in decommissioning AROs were reported in continuing operations (see Note 17) on the 2013 consolidated statement of operations. Estimates of AROs are evaluated annually in the fourth quarter, or more frequently if material new information becomes known. Accounting for asset retirement obligations requires significant estimation and in certain cases, the Company has determined that an ARO exists, but the amount of the obligation is not reasonably estimable. The Company may determine that additional AROs are required to be recognized as new information becomes available. Changes in asset retirement obligations for the years ended December 31, 2015 and 2014 were as follows: (In millions) 2015 2014 Balance at beginning of year $ 25.4 $ 27.7 Accretion expense 0.6 0.9 Payments (0.8 ) (2.2 ) Revision of estimates (0.2 ) (1.0 ) Balance at end of year $ 25.0 $ 25.4

Supplemental Financial Statemen

Supplemental Financial Statement Information	12 Months Ended
	Dec. 31, 2015
Additional Financial Information Disclosure [Abstract]
Supplemental Financial Statement Information	Supplemental Financial Statement Information Cash and cash equivalents at December 31, 2015 and 2014 were as follows: (In millions) 2015 2014 Cash $ 149.3 $ 267.7 Other short-term investments 0.5 1.8 Total cash and cash equivalents $ 149.8 $ 269.5 Accounts receivable are presented net of a reserve for doubtful accounts of $4.5 million at December 31, 2015 , and $4.8 million at December 31, 2014 . During 2015 , the Company recognized expense of $1.1 million to increase the reserve for doubtful accounts and wrote off $1.4 million of uncollectible accounts, which decreased the reserve. During 2014 , the Company recognized expense of $0.5 million to increase the reserve for doubtful accounts and wrote off $1.0 million of uncollectible accounts, which decreased the reserve. During 2013 , the Company recognized expense of $1.1 million to increase the reserve for doubtful accounts and wrote off $0.8 million of uncollectible accounts, which decreased the reserve. Additionally, the reserve for doubtful accounts in 2013 decreased $0.5 million as a result of the sale of the tungsten materials business. Accrued liabilities included salaries, wages and other payroll-related liabilities of $50.9 million and $77.3 million at December 31, 2015 and 2014 , respectively. Other income (expense) from continuing operations for the years ended December 31, 2015 , 2014 , and 2013 was as follows: (In millions) 2015 2014 2013 Rent and royalty income $ 2.0 $ 4.0 $ 0.9 Net gains (losses) on property and investments — 0.1 0.7 Other (0.4 ) — 0.1 Total other income, net $ 1.6 $ 4.1 $ 1.7

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt	Debt Debt at December 31, 2015 and 2014 was as follows: (In millions) 2015 2014 Allegheny Technologies $500 million 5.875% Senior Notes due 2023 (a) $ 500.0 $ 500.0 Allegheny Technologies $500 million 5.95% Senior Notes due 2021 500.0 500.0 Allegheny Technologies $350 million 9.375% Senior Notes due 2019 350.0 350.0 Allegheny Ludlum 6.95% Debentures due 2025 150.0 150.0 Ladish Series B 6.14% Notes due 2016 (b) — 11.9 Ladish Series C 6.41% Notes due 2015 (c) — 10.3 U.S. revolving credit facilities — — Foreign credit agreements 1.4 — Industrial revenue bonds, due through 2020, and other 3.8 4.7 Debt issuance costs (d) (9.5 ) (10.9 ) Total short-term and long-term debt 1,495.7 1,516.0 Short-term debt and current portion of long-term debt 3.9 17.8 Total long-term debt $ 1,491.8 $ 1,498.2 (a) Bearing interest at 7.625% effective August 15, 2015. (b) Includes fair value adjustment of $0.4 million at December 31, 2014 . (c) Includes fair value adjustment of $0.3 million at December 31, 2014 . (d) In April 2015, the FASB issued new guidance on the presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015. Interest expense was $111.4 million in 2015 , $109.8 million in 2014 , and $66.0 million in 2013 . Interest expense was reduced by $2.2 million , $5.3 million , and $45.7 million , in 2015 , 2014 , and 2013 , respectively, from interest capitalization on capital projects. Interest and commitment fees paid were $113.4 million in 2015 , $113.2 million in 2014 , and $110.6 million in 2013 . Net interest expense includes interest income of $1.2 million in 2015 , $1.1 million in 2014 , and $0.8 million in 2013 . Scheduled principal payments during the next five years are $3.9 million in 2016, $0.9 million in 2017, $0.2 million in 2018, $350.2 million in 2019, and no payments in 2020. 2023 Notes On July 12, 2013, ATI issued $500 million aggregate principal amount of 5.875% Senior Notes due 2023 (the “2023 Notes”). Interest on the 2023 Notes is payable semi-annually in arrears, and the 2023 Notes will mature on August 15, 2023 , unless redeemed or repurchased earlier. Underwriting fees, discount, and other third-party expenses for the issuance of the 2023 Notes were $5.2 million in 2013, and are being amortized to interest expense over the 10 -year term of the 2023 Notes. The 2023 Notes are unsecured and unsubordinated obligations of the Company and equally ranked with all of its existing and future senior unsecured debt. The stated interest rate payable on the 2023 Notes is subject to adjustment in the event of changes in the credit ratings on the 2023 Notes by either Moody’s or Standard & Poor’s (“S&P”). Each notch of credit rating downgrade increases interest expense by 0.25% on the 2023 Notes, up to a maximum 4 notches by each of the two credit rating agencies, or a total 2.0% potential interest rate change up to 7.875% , of which 1.75% interest rate change has occurred as of December 31, 2015. During 2014, a one notch downgrade of the Company’s credit rating resulted in an increase of the interest rate on the 2023 Notes from 5.875% to 6.125% effective with the interest period beginning August 15, 2014. During 2015, additional downgrades of the Company’s credit rating resulted in increases to the interest rate on the 2023 Notes to 7.625% , effective for the interest period beginning August 15, 2015. These downgrades resulted in $4.1 million of additional interest expense for 2015. Therefore, one future downgrade of the Company’s credit rating by S&P could result in an additional increase to the interest cost with respect to the 2023 Notes by 0.25% . Any further credit rating downgrades have no effect on the interest rate of the 2023 Notes, and increases in the Company’s credit ratings from these rating agencies would reduce interest expense on the 2023 Notes to the original 5.875% interest rate in a similar manner. Credit Agreements On September 23, 2015, the Company entered into a $400 million Asset Based Lending (“ABL”) Revolving Credit Facility, which includes a letter of credit sub-facility of up to $200 million . The ABL facility replaced a $400 million revolving credit facility originally entered into on July 31, 2007 (as amended, the “Prior Credit Facility”). Costs associated with entering into the ABL facility were $1.5 million , and are being amortized to interest expense over the 5 -year term of the facility. The ABL facility matures in September 2020 and is collateralized by the accounts receivable and inventory of the Company’s domestic operations. The applicable interest rate for borrowings under the ABL facility includes interest rate spreads based on available borrowing capacity that range between 1.25% and 1.75% for LIBOR-based borrowings and between 0.25% and 0.75% for base rate borrowings. Compared to the Prior Credit Facility, the ABL facility contains no leverage or interest coverage ratios but does contain a financial covenant whereby the Company must maintain a fixed charge coverage ratio, measured over the prior four fiscal quarters, of not less than 1.00 : 1.00 after an event of default has occurred or if the undrawn availability under ABL facility is less than the greater of (i) 10% of the then applicable maximum borrowing amount or (ii) $40.0 million . The Company does not meet this required fixed charge coverage ratio at December 31, 2015. As a result, the Company is not able to access this remaining 10% or $40.0 million of the ABL facility until it meets the required ratio. Additionally, the Company must demonstrate liquidity, as calculated in accordance with the terms of the agreement, of at least $500 million on the date that is 91 days prior to June 1, 2019, the maturity date of the 9.375% Senior Notes due 2019, and such liquidity is available until the notes are paid in full or refinanced. There was no impact on the Company’s outstanding debt as a result of the ABL facility. There were no outstanding borrowings made under the ABL facility as of December 31, 2015, although approximately $4.6 million has been utilized to support the issuance of letters of credit. Average borrowings under the ABL and the Prior Credit Facility for the fiscal year ended December 31, 2015 were $61.0 million , bearing an average annual interest rate of 2.0% . Convertible Notes In June 2009, ATI issued $402.5 million in aggregate principal amount of 4.25% Convertible Senior Notes due 2014 (the “Convertible Notes”). Interest was payable semi-annually on June 1 and December 1 of each year. The Convertible Notes were unsecured and unsubordinated obligations of the Company and ranked equally with all of its existing and future senior unsecured debt. On June 2, 2014, the Company repaid the remaining $397.5 million outstanding of the Convertible Notes. Holders of the Convertible Notes had the option to convert their notes into shares of ATI common stock at any time prior to the close of business on the second scheduled trading day immediately preceding the June 1, 2014 maturity date. Prior to the maturity date, $5.0 million of the Convertible Notes were converted into 120,476 shares of ATI common stock. The conversion rate for the Convertible Notes was 23.9263 shares of ATI common stock per $1,000 principal amount of Convertible Notes, equivalent to a conversion price of approximately $41.795 per share. Other than receiving cash in lieu of fractional shares, holders did not have the option to receive cash instead of shares of common stock upon conversion. Ladish Notes In conjunction with the acquisition of Ladish Co., Inc. (“Ladish”, now ATI Ladish LLC) in May 2011, the Company assumed the Series B and Series C Notes previously issued by Ladish. During 2015, the Company prepaid $5.7 million in aggregate principal amount of its 6.14% ATI Ladish Series B senior notes due May 16, 2016, representing all of the remaining outstanding Series B Notes. Also during 2015, the Company repaid the $10.0 million aggregate principal amount of its outstanding 6.41% ATI Ladish Series C senior notes, due September 2, 2015. Foreign and Other Credit Facilities The Company has an additional separate credit facility for the issuance of letters of credit. As of December 31, 2015 , $32 million in letters of credit were outstanding under this facility. STAL, the Company’s Chinese joint venture company in which ATI has a 60% interest, has a separate $20 million revolving credit facility entered into in April 2015. Borrowings under the STAL revolving credit facility are in U.S. dollars based on U.S. interbank offered rates. The credit facility is supported solely by STAL’s financial capability without any guarantees from the joint venture partners. The credit facility requires STAL to maintain a minimum level of shareholders’ equity, and certain financial ratios. The Company has no off-balance sheet financing relationships as defined in Item 303(a)(4) of SEC Regulation S-K, with variable interest entities, structured finance entities, or any other unconsolidated entities. At December 31, 2015 , the Company had not guaranteed any third-party indebtedness.

Derivative Financial Instrument

Derivative Financial Instruments and Hedging	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments and Hedging	Derivative Financial Instruments and Hedging As part of its risk management strategy, the Company, from time-to-time, utilizes derivative financial instruments to manage its exposure to changes in raw material prices, energy costs, foreign currencies, and interest rates. In accordance with applicable accounting standards, the Company accounts for most of these contracts as hedges. In general, hedge effectiveness is determined by examining the relationship between offsetting changes in fair value or cash flows attributable to the item being hedged, and the financial instrument being used for the hedge. Effectiveness is measured utilizing regression analysis and other techniques to determine whether the change in the fair market value or cash flows of the derivative exceeds the change in fair value or cash flow of the hedged item. Calculated ineffectiveness, if any, is immediately recognized on the statement 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. Generally under these contracts, which are 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 December 31, 2015 , the Company had entered into financial hedging arrangements primarily at the request of its customers, related to firm orders, for an aggregate notional amount of approximately 26 million pounds of nickel with hedge dates through 2020 . The aggregate notional amount hedged is approximately 28% of a single year’s estimated nickel raw material purchase requirements. At December 31, 2015 , the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas hedges. In the fourth quarter 2015, due to changes in expected operating levels within Flat Rolled Products segment operations, the Company concluded that a portion of these natural gas cash hedges for 2016 were ineffective based on forecast changes in underlying natural gas usage. The Company recognized a $3.3 million pre-tax loss for the ineffective portion of these cash flow hedges, which is reported in selling and administrative expenses on the consolidated statement of operations for the year ended December 31, 2015 . Approximately 55% of the Company’s annual forecasted domestic requirements for natural gas for 2017 and approximately 15% for 2018 are hedged. While the majority of the Company’s direct export sales are transacted in U.S. dollars, foreign currency exchange contracts are used, from time-to-time, to limit transactional exposure to changes in currency exchange rates for those transactions denominated in a non-U.S. currency. The Company sometimes purchases foreign currency forward contracts that permit it to sell specified amounts of foreign currencies expected to be received from its export sales for pre-established U.S. dollar amounts at specified dates. The forward contracts are denominated in the same foreign currencies in which export sales are denominated. These contracts are designated as hedges of the variability in cash flows of a portion of the forecasted future export sales transactions which otherwise would expose the Company to foreign currency risk, primarily the euro. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions. During the fiscal year ended December 31, 2015 , the Company net settled 211.9 million euro notional value of foreign currency forward contracts designated as cash flow hedges with 2016 and 2017 maturity dates, receiving cash proceeds of $56.5 million which is reported in cash provided by operating activities on the consolidated cash flow statement. In the fourth quarter 2015, due to management actions in the Flat Rolled Products segment to de-emphasize commodity stainless steel sheet products in 2016, the Company concluded that a portion of these settled euro cash flow hedges for 2016 were ineffective based on forecast changes for euro-denominated sales. The Company recognized a $14.3 million pre-tax gain for the ineffective portion of these cash flow hedges, which is reported in selling and administrative expenses on the consolidated statement of operations for the year ended December 31, 2015 . 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 will be reclassified to earnings when the underlying transactions occur. In 2015, the Company entered into 244.7 million euro notional value of foreign currency forward contracts designated as fair value hedges with 2015, 2016 and 2017 maturity dates to replace a portion of the settled euro cash flow hedges, of which 139.2 million euro notional value was outstanding as of December 31, 2015 . The Company recorded a $9.0 million benefit in costs of sales on the consolidated statement of operations in the fiscal year ended December 31, 2015 , 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 were 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 counterpart 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) December 31, December 31, Asset derivatives Balance sheet location Derivatives designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets $ 1.6 $ 23.6 Nickel and other raw material contracts Prepaid expenses and other current assets — 1.1 Foreign exchange contracts Other assets 0.4 28.3 Nickel and other raw material contracts Other assets — 0.5 Total derivatives designated as hedging instruments: $ 2.0 $ 53.5 Derivatives not designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets 0.4 6.4 Total derivatives not designated as hedging instruments: 0.4 6.4 Total asset derivatives $ 2.4 $ 59.9 Liability derivatives Balance sheet location Derivatives designated as hedging instruments: Natural gas contracts Accrued liabilities $ 17.3 $ 10.2 Foreign exchange contracts Accrued liabilities 0.1 — Nickel and other raw material contracts Accrued liabilities 22.2 5.8 Electricity contracts Accrued liabilities — 0.1 Foreign exchange contracts Other long-term liabilities 0.1 — Natural gas contracts Other long-term liabilities 8.5 7.9 Nickel and other raw material contracts Other long-term liabilities 23.0 3.0 Total liability derivatives $ 71.2 $ 27.0 Derivatives not designated as hedging instruments: Foreign exchange contracts Accrued liabilities 0.1 — Total derivatives not designated as hedging instruments: 0.1 — Total liability derivatives $ 71.3 $ 27.0 For derivative financial instruments that are designated as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (OCI) and reclassified into earnings in the same period or periods during which the hedged item affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current period results. For derivative financial instruments that are designated as fair value hedges, changes in the fair value of these derivatives are recognized in current period results. The Company did not use net investment hedges for the periods presented. The effects of derivative instruments in the tables below are presented net of related income taxes. Assuming market prices remain constant with those at December 31, 2015 , a loss of $23.6 million , net of tax, is expected to be recognized over the next 12 months. Activity with regard to derivatives designated as cash flow hedges for the year ended December 31, 2015 were as follows (in millions): Derivatives in Cash Flow Hedging Relationships 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) 2015 2014 2015 2014 2015 2014 Nickel and other raw material contracts $ (34.2 ) $ (1.6 ) $ (10.5 ) $ (0.6 ) $ — $ — Natural gas contracts (14.1 ) (10.9 ) (9.2 ) 2.1 (2.1 ) — Electricity contracts — 0.5 (0.1 ) 0.4 — — Foreign exchange contracts 27.6 40.1 24.3 0.3 8.9 — Total $ (20.7 ) $ 28.1 $ 4.5 $ 2.2 $ 6.8 $ — (a) The gains (losses) reclassified from accumulated OCI into income related to the effective portion of the derivatives are presented in cost of sales in the same period or periods in which the hedged item affects earnings. (b) The gains (losses) recognized in income on derivatives related to the ineffective portion and the amount excluded from effectiveness testing are presented in selling and administrative expenses. 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 25 million euro notional value outstanding as of December 31, 2015 of foreign currency forward contracts not designated as hedges, with maturity dates into the third quarter of 2016. These derivatives that are not designated as hedging instruments were as follows: (In millions) Amount of Gain (Loss) Recognized in Income on Derivatives Derivatives Not Designated as Hedging Instruments 2015 2014 Foreign exchange contracts $ 3.9 $ 5.2 Changes in the fair value of foreign exchange contract derivatives not designated as hedging instruments are recorded in cost of sales.

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	Fair Value of Financial Instruments The estimated fair value of financial instruments at December 31, 2015 was as follows: Fair Value Measurements at Reporting Date Using (In millions) Total Carrying Amount Total Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Cash and cash equivalents $ 149.8 $ 149.8 $ 149.8 $ — Derivative financial instruments: Assets 2.4 2.4 — 2.4 Liabilities 71.3 71.3 — 71.3 Debt (a) 1,495.7 969.7 964.5 5.2 The estimated fair value of financial instruments at December 31, 2014 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 $ 269.5 $ 269.5 $ 269.5 $ — Derivative financial instruments: Assets 59.9 59.9 — 59.9 Liabilities 27.0 27.0 — 27.0 Debt (a) 1,516.0 1,616.0 1,589.1 26.9 (a) The total carrying amount for debt has been restated to reflect the adoption on a retrospective basis in the fourth quarter of fiscal year 2015 of new accounting guidance on the presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the consolidated balance sheet as a direct deduction from the carrying amount of that 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 2015 or 2014 . The following methods and assumptions were used by the Company in estimating the fair value of its financial instruments: Cash and cash equivalents: Fair values were 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 Allegheny Technologies 9.375% Senior Notes due 2019, the Allegheny Technologies 5.95% Senior Notes due 2021, the Allegheny Technologies 5.875% Senior Notes due 2023 and the Allegheny Ludlum 6.95% Debentures due 2025 were determined using Level 1 information. The fair values of the other short-term and long-term debt were determined using Level 2 information.

Pension Plans and Other Postret

Pension Plans and Other Postretirement Benefits	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Pension Plans and Other Postretirement Benefits	Pension Plans and Other Postretirement Benefits The Company has defined benefit pension plans or defined contribution retirement plans covering substantially all employees. Benefits under the defined benefit pension plans are generally based on years of service and/or final average pay. The Company funds the U.S. pension plans in accordance with the Employee Retirement Income Security Act of 1974, as amended, and the Internal Revenue Code (“Code”). The Company also sponsors several postretirement plans covering certain salaried and hourly employees. The plans provide health care and life insurance benefits for eligible retirees. In most retiree health care plans, Company contributions towards premiums are capped based on the cost as of a certain date, thereby creating a defined contribution. For the non-collectively bargained plans, the Company maintains the right to amend or terminate the plans at its discretion. In December 2014, the Company announced several significant changes to its retirement benefit programs. These changes are part of the Company’s ongoing initiatives to create an integrated and aligned business with a market competitive, cost competitive, and consistent health, welfare and retirement benefit structure across its operations. These changes included: • Freezing all future benefit accruals to its U.S. qualified defined benefit pension plan (U.S. Plan), and to the Company’s non-qualified defined benefit pension plans, including the executive Supplemental Pension Plan, effective December 31, 2014. • Implementing a consistent defined contribution retirement plan with a base 6.5% company contribution and up to 3% in Company matching contributions across all U.S. operations effective January 1, 2015. • Ending Company-provided salaried retiree life insurance benefits effective January 1, 2015. • Ending all remaining Company-provided salaried retiree medical benefits on January 1, 2016. The salaried retiree medical benefit plan being ended was assumed as part of the 2011 Ladish acquisition. Certain participants in the retiree medical plan will have transition provisions through the end of 2016. • These changes to pension, retiree life insurance and medical benefits do not affect benefits for those employees or retirees covered by collective bargaining contracts or other contractual employment agreements. The components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2013 2015 2014 2013 Service cost—benefits earned during the year $ 22.8 $ 29.4 $ 39.0 $ 2.7 $ 2.9 $ 3.2 Interest cost on benefits earned in prior years 121.0 133.6 122.8 17.9 24.0 22.4 Expected return on plan assets (168.3 ) (184.2 ) (176.0 ) (0.1 ) (0.3 ) (0.5 ) Amortization of prior service cost (credit) 1.3 2.3 3.0 4.9 (3.0 ) (18.2 ) Amortization of net actuarial loss 60.4 74.0 111.8 14.6 14.1 17.2 Curtailment (gain) loss — 0.5 — — (25.5 ) — Termination benefits — 0.3 4.8 — — 1.3 Total retirement benefit expense $ 37.2 $ 55.9 $ 105.4 $ 40.0 $ 12.2 $ 25.4 Other postretirement benefit costs for a defined contribution plan were $2.6 million and $4.6 million for the fiscal years ended December 31, 2014 and 2013, respectively. The curtailment loss for pension benefits recorded in 2014 relates to unamortized prior service cost recognized as a result of the freezing of pension benefit accruals in the fourth quarter of 2014, as discussed above. The curtailment gain for other postretirement benefits recorded in 2014 relates to the changes to salaried retiree life insurance and medical benefits in the fourth quarter of 2014 as discussed above. Special termination benefits recorded in 2014 relate to the acceptance of an early retirement benefit in the Forged Products business. Special termination benefits recorded in 2013 relate largely to the closure of the Flat Rolled Product segment’s Wallingford, CT finishing facility, and these costs were reported in restructuring costs for segment reporting (see Notes 16 and 17). Actuarial assumptions used to develop the components of defined benefit pension expense and other postretirement benefit expense were as follows: Pension Benefits Other Postretirement Benefits 2015 2014 2013 2015 2014 2013 Discount rate (a) 4.25 % 5.15 % 4.25 - 4.95% 4.10 % 5.15 % 4.25 % Rate of increase in future compensation levels 3.0 - 3.50% 3.0 - 3.50% 3.0 - 3.50% — — — Expected long-term rate of return on assets 8.00 % 8.25 % 8.25 % 4.0 % 8.3 % 8.3 % (a) Pension expense for 2013 was initially measured at a 4.25% discount rate. The U.S. Plan was remeasured using a 4.95% discount rate as of October 31, 2013, following the sale of the tungsten materials business. Actuarial assumptions used for the valuation of defined benefit pension and other postretirement benefit obligations at the end of the respective periods were as follows: Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 Discount rate 4.65 % 4.25 % 4.50 % 4.10 % Rate of increase in future compensation levels 3.0 - 3.5% 3.0 - 3.5% — — A reconciliation of the funded status for the Company’s defined benefit pension and other postretirement benefit plans at December 31, 2015 and 2014 was as follows: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Change in benefit obligations: Benefit obligation at beginning of year $ 2,953.9 $ 2,698.2 $ 466.1 $ 506.7 Service cost 22.8 29.4 2.7 2.9 Interest cost 121.0 133.6 17.9 24.0 Benefits paid (207.4 ) (269.9 ) (53.4 ) (54.3 ) Subsidy paid — — 0.7 1.0 Participant contributions 0.3 0.3 — — Effect of currency rates (4.8 ) (4.9 ) — — Net actuarial (gains) losses – discount rate change (124.4 ) 288.5 (14.1 ) 39.5 – other 44.5 78.4 (19.1 ) (19.5 ) Plan curtailments — — — (7.2 ) Plan settlements — — — (27.0 ) Special termination benefits — 0.3 — — Benefit obligation at end of year $ 2,805.9 $ 2,953.9 $ 400.8 $ 466.1 Pension benefit payments in 2014 include approximately $52 million associated with a one-time, voluntary lump sum cash out offer to terminated vested participants in the U.S. Plan. Changes in the pension benefit obligation for 2014 include the effects of updated estimates of participant life expectancy, including consideration of the impacts of the updated 2014 U.S. Society of Actuaries projections and Company-specific experience. These mortality assumption changes increased the pension benefit obligation at December 31, 2014 by approximately $90 million . Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Change in plan assets: Fair value of plan assets at beginning of year $ 2,204.4 $ 2,329.8 $ 2.9 $ 4.0 Actual returns on plan assets and plan expenses (41.1 ) 136.8 (1.0 ) (0.9 ) Employer contributions 10.3 11.5 — — Participant contributions 0.3 0.3 — — Effect of currency rates (4.2 ) (4.1 ) — — Benefits paid (207.4 ) (269.9 ) (0.1 ) (0.2 ) Fair value of plan assets at end of year $ 1,962.3 $ 2,204.4 $ 1.8 $ 2.9 Amounts recognized in the consolidated balance sheet: Current liabilities (9.8 ) (10.2 ) (39.8 ) (47.3 ) Noncurrent liabilities (833.8 ) (739.3 ) (359.2 ) (415.8 ) Total amount recognized $ (843.6 ) $ (749.5 ) $ (399.0 ) $ (463.1 ) Changes to accumulated other comprehensive loss related to pension and other postretirement benefit plans in 2015 and 2014 were as follows: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Beginning of year accumulated other comprehensive loss $ (1,352.1 ) $ (1,016.4 ) $ (152.9 ) $ (151.5 ) Amortization of net actuarial loss 60.4 74.0 14.6 14.1 Amortization of prior service cost (credit) 1.3 2.3 4.9 (3.0 ) Remeasurements (127.8 ) (412.0 ) 32.0 (12.5 ) End of year accumulated other comprehensive loss $ (1,418.2 ) $ (1,352.1 ) $ (101.4 ) $ (152.9 ) Net change in accumulated other comprehensive loss $ (66.1 ) $ (335.7 ) $ 51.5 $ (1.4 ) Amounts included in accumulated other comprehensive loss at December 31, 2015 and 2014 were as follows: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Prior service cost $ (3.6 ) $ (4.9 ) $ (6.9 ) $ (11.8 ) Net actuarial loss (1,414.6 ) (1,347.2 ) (94.5 ) (141.1 ) Accumulated other comprehensive loss (1,418.2 ) (1,352.1 ) (101.4 ) (152.9 ) Deferred tax effect 529.9 514.7 38.5 58.8 Accumulated other comprehensive loss, net of tax $ (888.3 ) $ (837.4 ) $ (62.9 ) $ (94.1 ) Retirement benefit expense for 2016 for defined benefit plans is estimated to be approximately $98 million , comprised of $64 million for pension expense and $34 million of expense for other postretirement benefits. As a result of the pension freeze effective December 31, 2014 and the resultant determination of inactive status, beginning in 2015, the U.S. Plan and the non-qualified U.S. pension plans changed the amortization period for accumulated other comprehensive loss recognition to the average remaining life expectancy, which is approximately 18 years on a weighted average basis, rather than the average remaining service period of 10 years, which was used in 2014 and prior periods. Amounts in accumulated other comprehensive loss that are expected to be recognized as components of net periodic benefit cost in 2016 are: (In millions) Pension Benefits Other Postretirement Benefits Total Amortization of prior service cost $ 1.3 $ 4.9 $ 6.2 Amortization of net actuarial loss 65.4 9.5 74.9 Amortization of accumulated other comprehensive loss $ 66.7 $ 14.4 $ 81.1 The accumulated benefit obligation for all defined benefit pension plans was $2,767.0 million and $2,917.3 million at December 31, 2015 and 2014 , respectively. Additional information for pension plans with accumulated benefit obligations in excess of plan assets: Pension Benefits (In millions) 2015 2014 Projected benefit obligation $ 2,805.9 $ 2,953.9 Accumulated benefit obligation $ 2,767.0 $ 2,917.3 Fair value of plan assets $ 1,962.3 $ 2,204.4 Based upon current regulations and actuarial studies, the Company does not expect to be required to make significant cash contributions to its U.S. Plan for 2016 . However, the Company may elect, depending upon the investment performance of the pension plan assets and other factors, to make voluntary cash contributions to this pension plan in the future. For 2016 , the Company expects to fund benefits of approximately $10 million for its U.S. nonqualified benefit pension plans and its U.K. defined benefit plan. The following table summarizes expected benefit payments from the Company’s various pension and other postretirement benefit defined benefit plans through 2025, and also includes estimated Medicare Part D subsidies projected to be received during this period based on currently available information. (In millions) Pension Benefits Other Postretirement Benefits Medicare Part D Subsidy 2016 $ 200.2 $ 42.6 $ 1.1 2017 195.0 35.7 1.0 2018 194.4 34.5 1.0 2019 191.7 34.2 1.0 2020 190.5 34.3 0.9 2021 - 2025 917.8 144.6 3.9 The annual assumed rate of increase in the per capita cost of covered benefits (the health care cost trend rate) for health care plans was 8.0% in 2016 and is assumed to gradually decrease to 4.5% in the year 2038 and remain at that level thereafter. Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plans. A one percentage point change in assumed health care cost trend rates would have the following effects: (In millions) One Percentage Point Increase One Percentage Point Decrease Effect on total of service and interest cost components for the year ended December 31, 2015 $ 0.5 $ (0.4 ) Effect on other postretirement benefit obligation at December 31, 2015 $ 7.6 $ (6.8 ) The plan assets for the U.S. Plan represent approximately 96% of total pension plan assets at December 31, 2015 . The U.S. Plan invests in a diversified portfolio consisting of an array of asset classes that attempts to maximize returns while minimizing volatility. These asset classes include U.S. domestic equities, developed market equities, emerging market equities, private equity, global high quality and high yield fixed income, floating rate debt and real estate. The Company continually monitors the investment results of these asset classes and its fund managers, and explores other potential asset classes for possible future investment. U.S. Plan assets at December 31, 2015 and 2014 included 3.0 million shares of ATI common stock with a fair value of $33.2 million and $102.7 million , respectively. Dividends of $1.8 million and $2.1 million were received by the U.S. Plan in 2015 and 2014 , respectively, on the ATI common stock held by this plan. The fair values of the Company’s pension plan assets at December 31, 2015 by asset category and by the level of inputs used to determine fair value, were as follows: (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Asset category Total (Level 1) (Level 2) (Level 3) Equity securities: ATI common stock $ 33.2 $ 33.2 $ — $ — Other U.S. equities (a) 522.0 254.1 267.9 — International equities (b) 239.8 — 239.8 — Global debt securities and cash: (c) Fixed income and cash equivalents 369.7 0.2 361.0 8.5 Floating rate 358.0 — — 358.0 Private equity 201.2 — — 201.2 Hedge funds 51.9 — — 51.9 Real estate and other 186.5 — 5.9 180.6 Total assets $ 1,962.3 $ 287.5 $ 874.6 $ 800.2 (a) Includes investments in commingled funds that invest in U.S. equity securities, comprised of approximately 90% large-cap U.S. companies and 10% small-cap U.S. companies. (b) Includes investments in commingled funds that invest in non-U.S. equity securities, comprised of approximately 90% developed countries and 10% emerging market economies. (c) Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments. The fair values of the Company’s pension plan assets at December 31, 2014 by asset category and by the level of inputs used to determine fair value, were as follows: (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Asset category Total (Level 1) (Level 2) (Level 3) Equity securities: ATI common stock $ 102.7 $ 102.7 $ — $ — Other U.S. equities (a) 673.8 306.1 367.7 — International equities (b) 238.2 — 238.2 — Global debt securities and cash: (c) Fixed income and cash equivalents 383.5 0.7 373.9 8.9 Floating rate 392.3 — — 392.3 Private equity 172.6 — — 172.6 Hedge funds 84.7 — — 84.7 Real estate and other 156.6 — 5.4 151.2 Total assets $ 2,204.4 $ 409.5 $ 985.2 $ 809.7 (a) Includes investments in commingled funds that invest in U.S. equity securities, comprised of approximately 90% large-cap U.S. companies and 10% small-cap U.S. companies. (b) Includes investments in commingled funds that invest in non-U.S. equity securities, comprised of approximately 80% developed countries and 20% emerging market economies. (c) Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments. Changes in the fair value of Level 3 pension plan assets for the year ended December 31, 2015 were as follows: (In millions) January 1, 2015 Balance Net Realized and Unrealized Gains (Losses) Net Purchases, Issuances and Settlements Net Transfers Into (Out Of) Level 3 December 31, 2015 Balance Global debt securities and cash: Fixed income and cash equivalents $ 8.9 $ — $ (0.4 ) $ — $ 8.5 Floating rate debt 392.3 6.8 (41.1 ) — 358.0 Private equity 172.6 11.7 16.9 — 201.2 Hedge funds 84.7 2.5 (35.3 ) — 51.9 Real estate and other 151.2 22.5 6.9 — 180.6 Total $ 809.7 $ 43.5 $ (53.0 ) $ — $ 800.2 Changes in the fair value of Level 3 pension plan assets for the year ended December 31, 2014 were as follows: (In millions) January 1, 2014 Balance Net Realized and Unrealized Gains (Losses) Net Purchases, Issuances and Settlements Net Transfers Into (Out Of) Level 3 December 31, 2014 Balance Global debt securities and cash: Fixed income and cash equivalents $ 0.8 $ 0.1 $ 8.0 $ — $ 8.9 Floating rate debt 294.5 4.6 93.2 — 392.3 Private equity 123.0 20.5 29.1 — 172.6 Hedge funds 111.2 4.5 (31.0 ) — 84.7 Real estate and other 125.8 13.7 11.7 — 151.2 Total $ 655.3 $ 43.4 $ 111.0 $ — $ 809.7 A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Investments in U.S. and International equities, and Fixed Income are predominantly held in common/collective trust funds and registered investment companies. These investments are public investment vehicles valued using the net asset value (NAV) provided by the administrator of the fund. The NAV is based on the value of the underlying assets owned by the fund, minus its liabilities, and then divided by the number of shares outstanding. In certain cases NAV is a quoted price in a market that is not active, and valuation is based on quoted prices for similar assets and liabilities in active markets, and these investments are classified within Level 2 of the valuation hierarchy. Investments that are not actively traded, such as non-publicly traded real estate funds, are classified within Level 3 of the valuation hierarchy, as the NAV is based on significant unobservable information. Hedge fund investments are made either (1) as a limited partner in a portfolio of underlying hedge funds managed by a general partner or (2) through commingled institutional funds (CIFs) that in-turn invest in various portfolios of hedge funds whereby the allocation of the Plan’s investments to each CIF is managed by a third party Investment Manager. All hedge fund investments are classified within Level 3 of the valuation hierarchy, as the valuations are substantially based on unobservable information. Private equity investments include both Direct Funds and Fund-of-Funds. All private equity investments are classified as Level 3 in the valuation hierarchy, as the valuations are substantially based upon unobservable information. Direct Funds are investments in Limited Partnership (LP) interests. Fund-of-Funds are investments in private equity funds that invest in other private equity funds or LPs. Real estate investments are made either (1) as a limited partner in a portfolio of properties managed by a general partner or (2) through a CIF that invests in a portfolio of real estate funds. For certain investments classified as Level 3 which have formal financial valuations reported on a one-quarter lag, fair value is determined utilizing net asset values adjusted for subsequent cash flows, estimated financial performance and other significant events. For 2016 , the expected long-term rate of returns on defined benefit pension assets will be 8.0% . In developing the expected long-term rate of return assumptions, the Company evaluated input from its third party pension plan asset managers and actuaries, including reviews of their asset class return expectations and long-term inflation assumptions. The expected long-term rate of return is based on expected asset allocations within ranges for each investment category, and includes consideration of both historical and projected annual compound returns, weighted on a 65%/35% basis, respectively. The Company’s actual returns on pension assets for the last five years have been (1.2)% for 2015 , 6.5% for 2014 , 14.3% for 2013 , 8.0% for 2012 , and 0.3% for 2011 . The target asset allocations for pension plans for 2016 , by major investment category, are: Asset category Target asset allocation range Equity securities: U. S. equities 18% - 40% International equities 7% - 17% Global debt securities and cash 35% - 55% Private equity* 0% - 10% Hedge funds* 0% - 10% Real estate and other* 0% - 10% * Have a combined target allocation of 18% and a 20% limit. At December 31, 2015 , other postretirement benefit plan assets of $1.8 million are primarily invested in private equity investments, which are classified as Level 3 in the valuation hierarchy, as the valuations are substantially based upon unobservable information. For 2016 , the expected long-term rate of returns on these other postretirement benefit assets will be 4.0% . Costs for defined contribution plans were $41.2 million in 2015 , $21.9 million in 2014 , and $24.3 million in 2013 . Company contributions to these defined contribution plans are funded with cash. Higher contributions in 2015 were the result of the implementation of the Company’s defined contribution retirement plan accross all U.S. operations in 2015 in conjunction with the freeze of the U.S. qualified defined benefit pension plan. Labor agreements with USW-represented employees require the Company to make contributions to VEBA trusts based upon the attainment of a certain level of profitability. The Company expects to make approximately $7 million of contributions, tied to profitability levels, to these VEBA trusts in 2016 . The Company contributes to several multiemployer defined benefit pension plans under collective bargaining agreements that cover certain of its union-represented employees. The risks of participating in such plans are different from the risks of single-employer plans, in the following respects: a. Assets contributed to a multiemployer plan by one employer may be used to provide benefits to employees of other participating employers. b. If a participating employer ceases to contribute to the plan, the unfunded obligations of the plan may be borne by the remaining participating employers. c. If the Company ceases to have an obligation to contribute to the multiemployer plan in which it had been a contributing employer, it may be required to pay to the plan an amount based on the underfunded status of the plan and on the history of the Company’s participation in the plan prior to the cessation of its obligation to contribute. The amount that an employer that has ceased to have an obligation to contribute to a multiemployer plan is required to pay to the plan is referred to as a withdrawal liability. The Company’s participation in multiemployer plans for the years ended December 31, 2015 , 2014 and 2013 is reported in the following table. The Company’s contributions to the Steelworkers Western Independent Shops Pension Plan exceed 5% of this plan’s total contributions for the plan year ended September 30, 2014, which is the most recent information available from the Plan Administrator. Pension Protection Act Zone Status (1) FIP / RP Status Pending / Implemented (2) in millions Expiration Dates of Collective Bargaining Agreements EIN / Pension Plan Number Company Contributions Surcharge Imposed (3) Pension Fund 2015 2014 2015 2014 2013 Steelworkers Western Independent Shops Pension Plan 90-0169564 / 001 Green Green N/A $ 0.7 $ 1.1 $ 1.0 No 6/30/2015 Boilermakers-Blacksmiths National Pension Trust 48-6168020 / 001 Yellow Yellow Yes 1.8 2.0 2.2 No 9/30/2018 IAM National Pension Fund 51-6031295 / 002 Green Green N/A 1.5 1.6 1.8 No Various between 2018-2019 (4) Total contributions $ 4.0 $ 4.7 $ 5.0 (1) The most recent Pension Protection Act Zone Status available for ATI’s fiscal years 2015 and 2014 is for plan years ending in calendar years 2014 and 2013 , respectively. The zone status is based on information provided to ATI and other participating employers by each plan and is certified by the plan’s actuary. A plan in the “red” zone had been determined to be in “critical status”, based on criteria established by the Code, and is generally less than 65% funded. A plan in the “yellow” zone has been determined to be in “endangered status”, based on criteria established under the Code, and is generally less than 80% funded. A plan in the “green” zone has been determined to be neither in “critical status” nor in “endangered status”, and is generally at least 80% funded. (2) The “FIP / RP status Pending / Implemented” column indicates whether a Funding Improvement Plan, as required under the Code by plans in the “yellow” zone, or a Rehabilitation Plan, as required under the Code to be adopted by plans in the “red” zone, is pending or has been implemented as of the end of the plan year that ended in 2015 . (3) The “Surcharge Imposed” column indicates whether ATI’s contribution rate for 2015 included an amount in addition to the contribution rate specified in the applicable collective bargaining agreement, as imposed by a plan in “critical status”, in accordance with the requirements of the Code. (4) The Company is party to five separate bargaining agreements that require contributions to this plan. Expiration dates of these collective bargaining agreements range between February 25, 2018 and July 14, 2019.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the fiscal years ended December 31, 2015 , 2014 and 2013 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, December 31, 2012 $ (1,030.0 ) $ 3.4 $ (0.1 ) $ (2.7 ) $ (1,029.4 ) OCI before reclassifications 241.1 10.4 0.1 (15.5 ) 236.1 Amounts reclassified from AOCI (a) 70.0 (b) 1.5 (c) — (d) 8.6 80.1 Net current-period OCI 311.1 11.9 0.1 (6.9 ) 316.2 Balance, December 31, 2013 (718.9 ) 15.3 — (9.6 ) (713.2 ) OCI before reclassifications (266.4 ) (32.0 ) — 28.1 (270.3 ) Amounts reclassified from AOCI (a) 53.8 (b) 0.5 (c) — (d) (2.2 ) 52.1 Net current-period OCI (212.6 ) (31.5 ) — 25.9 (218.2 ) Balance, December 31, 2014 (931.5 ) (16.2 ) — 16.3 (931.4 ) OCI before reclassifications (69.6 ) (31.4 ) — (20.7 ) (121.7 ) Amounts reclassified from AOCI (a) 49.9 (c) — (c) — (d) (11.3 ) 38.6 Net current-period OCI (19.7 ) (31.4 ) — (32.0 ) (83.1 ) Balance, December 31, 2015 $ (951.2 ) $ (47.6 ) $ — $ (15.7 ) $ (1,014.5 ) Attributable to noncontrolling interests: Balance, December 31, 2012 $ — $ 23.7 $ — $ — $ 23.7 OCI before reclassifications — 3.4 — — 3.4 Amounts reclassified from AOCI — (c) — — — — Net current-period OCI — 3.4 — — 3.4 Balance, December 31, 2013 — 27.1 — — 27.1 OCI before reclassifications — (2.1 ) — — (2.1 ) Amounts reclassified from AOCI — (c) — — — — Net current-period OCI — (2.1 ) — — (2.1 ) Balance, December 31, 2014 — 25.0 — — 25.0 OCI before reclassifications — (5.6 ) — — (5.6 ) Amounts reclassified from AOCI — (c) — — — — Net current-period OCI — (5.6 ) — — (5.6 ) Balance, December 31, 2015 $ — $ 19.4 $ — $ — $ 19.4 (a) Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 12). (b) Amount in 2014 is included in other income, net, and amount in 2013 is included in discontinued operations as part of the gain on sale of the tungsten materials business (see Note 3). (c) No amounts were reclassified to earnings. (d) 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 statements of operations (see Note 10). Other comprehensive income (loss) amounts are net of applicable income tax expense (benefit) for each year presented. 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 fiscal years ended December 31, 2015 , 2014 and 2013 were as follows: Amount reclassified from AOCI (d) Fiscal year ended Details about AOCI Components (In millions) December 31, 2015 December 31, 2014 December 31, 2013 Affected line item in the consolidated statement of operations Postretirement benefit plans Prior service credit (cost) $ (6.2 ) (a) $ 0.7 (a) 15.2 (a) Actuarial losses (75.0 ) (a) (88.1 ) (a) (129.0 ) (a) (81.2 ) (d) (87.4 ) (d) (113.8 ) (d) Total before tax (31.3 ) (33.6 ) (43.8 ) Tax benefit $ (49.9 ) $ (53.8 ) $ (70.0 ) Net of tax Currency translation adjustment $ — (d) $ (0.5 ) (b) , (d) $ (1.5 ) (b) , (d) Derivatives Nickel and other raw material contracts $ (16.9 ) (c) $ (1.0 ) (c) $ (8.8 ) (c) Natural gas contracts (18.2 ) (c) 3.4 (c) (3.8 ) (c) Electricity contracts (0.2 ) (c) 0.7 (c) (0.3 ) (c) Foreign exchange contracts 53.5 (c) 0.5 (c) (1.1 ) (c) 18.2 (d) 3.6 (d) (14.0 ) (d) Total before tax 6.9 1.4 (5.4 ) Tax provision (benefit) $ 11.3 $ 2.2 $ (8.6 ) 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 12. (b) Amount in 2014 is included in other income, net, and amount in 2013 is included in discontinued operations as part of the gain on sale of the tungsten materials business (see Note 3). (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 statements of operations (see Note 10). (d) 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.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock Authorized preferred stock may be issued in one or more series, with designations, powers and preferences as shall be designated by the Board of Directors. At December 31, 2015 , there were no shares of preferred stock issued. Share-based Compensation During 2007, the Company adopted the Allegheny Technologies Incorporated 2007 Incentive Plan (the “2007 Incentive Plan”), which was amended and restated in 2010 and further amended in 2012. During 2015, the Company adopted the Allegheny Technologies Incorporated 2015 Incentive Plan (the “2015 Incentive Plan”). Upon adoption of the 2015 Incentive Plan, the 2007 Incentive Plan was terminated, although outstanding awards under the 2007 Incentive Plan remain in effect in accordance with their respective terms. Awards earned under the Company’s share-based incentive compensation programs are generally paid with shares held in treasury, if sufficient treasury shares are held, and any additional required share payments are made with newly issued shares. At December 31, 2015, 3.4 million shares of common stock were available for future awards under the 2015 Incentive Plan. The general terms of each arrangement granted under the 2007 Incentive Plan or the 2015 Incentive Plan, and predecessor plans, the method of estimating fair value for each arrangement, and award activity is reported below. The Company sponsors two principal share-based incentive compensation programs, the Performance/Restricted Stock Program (PRSP) of nonvested stock awards, and the Long-Term Performance Plan (LTPP), which was adopted in 2014 and may include performance shares under the Total Shareholder Return (TSR) portion and nonvested stock awards under the Long-Term Shareholder Value (LTSV) portion. Periods prior to 2014 include performance equity awards issued under the former Total Shareholder Return Program (TRSP), which has the same performance measurement criteria as the TSR. Nonvested stock awards: Awards of nonvested stock are granted to employees, with either performance and/or service conditions. Awards of nonvested stock are also granted to non-employee directors, with service conditions. For nonvested stock awards, dividend equivalents, whether in stock or cash form, accumulate but are not paid until the underlying award vests. In 2015, 461,215 shares of nonvested stock were granted to employees under the PRSP. In 2015, 126,421 shares of nonvested stock were granted under the LTSV portion of the LTPP plan. LTSV awards vest at the end of a three -year measurement period subject to the achievement, in whole or in part, of specified operational goals. As of December 31, 2015, 85% and 100% of these operational goals were expected to be attained for the 2015 and 2014 LTSV awards, respectively. The fair value of nonvested stock awards is measured based on the stock price at the grant date, adjusted for non-participating dividends, as applicable, based on the current dividend rate. For nonvested stock awards to employees in 2015 , 2014 , 2013 and 2012 under the Company’s PRSP, one-half of the nonvested stock (“performance shares”) vests only on the attainment of an income target, measured cumulatively over a three -year period. The remaining nonvested stock awarded to most employees under the 2015 PRSP vests over a service period of three years; for certain senior executives this service period is five years for the 2015 award. The remaining PRSP nonvested stock awarded to employees under the 2012, 2013 and 2014 vests over a service period of five years, with accelerated vesting to three years if the performance shares’ vesting criterion is attained. Expense for each of these awards is recognized based on estimates of attaining the performance criterion, including estimated forfeitures. As of December 31, 2015, the income target for the 2013 PRSP award was not met, and 244,899 shares were forfeited. As of December 31, 2014, the income target for the 2012 PRSP award was not met, and 171,083 shares were forfeited. Vesting of the remaining portion of both the 2013 and 2012 PRSP awards continues over the five -year service period through February 2018 and 2017, respectively. The income targets for both the 2014 and 2015 PRSP awards are not expected to be attained for the performance shares, therefore, no expense was recognized on the performance shares. Expense for the remaining nonvested stock under the 2015 and 2014 PRSP awards is recognized on a straight line basis over the applicable three or five -year service period. Compensation expense in continuing operations related to all nonvested stock awards was $5.5 million in 2015 , $2.4 million in 2014 , and $11.3 million in 2013 . Reduced compensation expense in 2015 and 2014 is primarily the result of changes in estimates that PRSP award performance shares would vest. Approximately $17.9 million of unrecognized fair value compensation expense relating to nonvested stock awards is expected to be recognized through 2020 based on estimates of attaining performance vesting criteria, including estimated forfeitures. Activity under the Company’s nonvested stock awards for the years ended December 31, 2015 , 2014 , and 2013 was as follows: (Shares in thousands, $ in millions) 2015 2014 2013 Number of shares Weighted Average Grant Date Fair Value Number of shares Weighted Average Grant Date Fair Value Number of shares Weighted Average Grant Date Fair Value Nonvested, beginning of year 1,376 $ 47.8 927 $ 36.9 727 $ 38.6 Granted 669 20.8 675 20.3 576 16.4 Vested (23 ) (0.8 ) (18 ) (1.0 ) (333 ) (16.4 ) Forfeited (370 ) (10.8 ) (208 ) (8.4 ) (43 ) (1.7 ) Nonvested, end of year 1,652 $ 57.0 1,376 $ 47.8 927 $ 36.9 Performance equity awards: Award opportunities under the TSR, and previously the TSRP, are determined at a target number of shares, and performance equity awards pay out based on the measured return of the Company’s stock price and dividend performance at the end of three -year periods as compared to the stock price and dividend performance of a group of industry peers. In 2015, the Company established a 2015-2017 TSR award, with 328,564 shares at the target award level. A maximum of 2.05 million shares have been reserved for issuance for award periods under the TSR and the TSRP. The actual number of shares awarded at the end of the performance measurement period may range from a minimum of zero to a maximum of two times target. Fair values for these performance awards were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three -year time horizons matching the total shareholder return performance measurement periods. Compensation expense from continuing operations was $10.6 million in 2015 , $9.8 million in 2014 , and $12.3 million in 2013 for the fair value of TSR and TSRP awards. The estimated fair value of each performance equity award, the projected shares to be awarded and future compensation expense to be recognized for these awards, including actual and estimated forfeitures, was as follows: (Shares in thousands, $ in millions) TSR / TSRP Award Performance Period Award Fair Value December 31, 2015 Unrecognized Compensation Expense Minimum Shares Target Shares Maximum Shares 2013 - 2015 $ 10.5 $ — — 296 592 2014 - 2016 $ 9.3 3.1 — 277 554 2015 - 2017 $ 13.4 8.9 — 296 592 Total $ 12.0 — 869 1,738 Based on the Company’s stock price and dividend performance for the three-year period ended December 31, 2015 relative to the peer group, no award for the 2013-2015 TSRP performance period was earned. Undistributed Earnings of Investees Stockholders’ equity includes undistributed earnings of investees accounted for under the equity method of accounting of approximately $12 million at December 31, 2015 .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The income tax provision (benefit) was as follows: (In millions) 2015 2014 2013 Continuing operations: Current: Federal $ (60.7 ) $ (47.9 ) $ (127.5 ) State (0.4 ) (4.0 ) (10.2 ) Foreign 9.4 9.8 7.9 Total (51.7 ) (42.1 ) (129.8 ) Deferred: Federal (90.9 ) 34.1 62.7 State 30.4 (0.2 ) 4.6 Foreign 0.1 (0.5 ) (1.1 ) Total (60.4 ) 33.4 66.2 Income tax benefit from continuing operations $ (112.1 ) $ (8.7 ) $ (63.6 ) Income tax provision (benefit) from discontinued operations $ — $ (0.3 ) $ 161.4 Total company income tax provision (benefit) $ (112.1 ) $ (9.0 ) $ 97.8 The following is a reconciliation of income taxes computed at the statutory U.S. Federal income tax rate to the actual effective income tax benefit from continuing operations: Income Tax Provision (Benefit) (In millions) 2015 2014 2013 Taxes computed at the federal rate $ (167.3 ) $ 0.5 $ (54.2 ) State and local income taxes, net of federal tax benefit (20.6 ) (2.0 ) (11.8 ) Tax reserve adjustments 3.9 (0.5 ) (10.2 ) Repatriation of foreign earnings 13.4 0.3 9.4 Valuation allowance 74.5 0.5 9.1 Adjustment to prior years’ taxes (5.4 ) 0.1 (5.3 ) Foreign earnings taxed at different rate (11.2 ) (6.6 ) (2.5 ) Other 0.6 (1.0 ) 1.9 Income tax benefit $ (112.1 ) $ (8.7 ) $ (63.6 ) In 2015, the Company’s results reflected a three year cumulative loss from U.S. operations; prior thereto, the Company’s historical results reflected a three year cumulative profit. The three year cumulative loss limits the ability to consider other positive subjective evidence, such as projections of future results, to assess the realizability of deferred tax assets. As a result of this assessment, the Company established a $68.4 million valuation allowance in 2015, including $49.3 million for certain state and federal tax benefits recognized in prior years, and a $19.1 million valuation allowance recorded as part of the current year’s effective tax rate, representing approximately a 4% tax rate impact. Other valuation allowances recognized in 2015 and prior years relate to uncertainties of realizing tax attributes unrelated to the U.S. operations cumulative loss impact. In general, the Company is responsible for filing consolidated U.S. Federal, foreign and combined, unitary or separate state income tax returns. The Company is responsible for paying the taxes relating to such returns, including any subsequent adjustments resulting from the redetermination of such tax liability by the applicable taxing authorities. No provision has been made for U.S. Federal, state or additional foreign taxes related to approximately $168 million of undistributed earnings of foreign subsidiaries which have been permanently re-invested. It is not practical to determine the deferred tax liability on these earnings. Income (loss) from continuing operations before income taxes for the Company’s U.S. and non-U.S. operations was as follows: (In millions) 2015 2014 2013 U.S. $ (534.6 ) $ (46.1 ) $ (180.0 ) Non-U.S. 56.6 47.6 25.2 Income (loss) from continuing operations before income taxes $ (478.0 ) $ 1.5 $ (154.8 ) Income taxes paid and amounts received as refunds were as follows: (In millions) 2015 2014 2013 Income taxes paid $ 10.8 $ 15.1 $ 21.4 Income tax refunds received (63.3 ) (20.2 ) (18.3 ) Income taxes paid (received), net $ (52.5 ) $ (5.1 ) $ 3.1 The Company’s income tax payments have benefited over the last several years from provisions under the U.S. tax code allowing companies to immediately deduct a significant portion of the cost of new capital investments placed into service. In 2015, the Company received a $59.9 million federal tax refund of prior years’ taxes paid. After this refund, the Company has approximately $166 million of tax-effected federal net operating loss carryforwards and $43 million of other federal tax credits to offset future federal tax liabilities. Deferred income taxes result from temporary differences in the recognition of income and expense for financial and income tax reporting purposes, and differences between the fair value of assets acquired in business combinations accounted for as purchases for financial reporting purposes and their corresponding tax bases. Deferred income taxes represent future tax benefits or costs to be recognized when those temporary differences reverse. The categories of assets and liabilities that have resulted in differences in the timing of the recognition of income and expense at December 31, 2015 and 2014 were as follows: (In millions) 2015 2014 Deferred income tax assets Pensions $ 281.0 $ 251.8 Postretirement benefits other than pensions 144.7 169.0 Federal and state net operating loss tax carryovers 228.1 122.7 Federal and state tax credits 52.2 53.6 Deferred compensation and other benefit plans 25.9 25.6 Self insurance reserves 10.8 10.1 Other items 85.2 79.1 Gross deferred income tax assets 827.9 711.9 Valuation allowance for deferred tax assets (105.1 ) (34.4 ) Total deferred income tax assets 722.8 677.5 Deferred income tax liabilities Bases of property, plant and equipment 664.1 579.5 Inventory valuation 62.2 111.7 Bases of amortizable intangible assets 25.4 75.5 Other items 46.7 53.9 Total deferred tax liabilities 798.4 820.6 Net deferred tax liability $ (75.6 ) $ (143.1 ) The Company had $105.1 million and $34.4 million in deferred tax asset valuation allowances at December 31, 2015 and 2014 , respectively. The valuation allowance at December 31, 2015 includes $24.8 million for federal foreign tax credits, $61.8 million for state net operating loss tax carryforwards, $1.4 million for foreign net operating losses and credits, $13.8 million for state tax credits and $3.3 million for state temporary differences, since the Company has concluded, based on current tax laws, that it is more likely than not that these tax benefits would not be realized. For the state net operating loss tax carryforwards, expiration will generally occur within 20 years of the year generated and some utilization of the tax benefit may be limited to $5 million per year or 30% of apportioned income, whichever is greater. The changes in the liability for unrecognized income tax benefits for the years ended December 31, 2015 , 2014 and 2013 were as follows: (In millions) 2015 2014 2013 Balance at beginning of year $ 73.4 $ 72.8 $ 29.2 Increases in prior period tax positions 4.2 2.0 0.1 Decreases in prior period tax positions (0.6 ) (0.6 ) (5.8 ) Increases in current period tax positions 1.3 0.7 60.4 Expiration of the statute of limitations (0.7 ) (0.5 ) (0.7 ) Settlements (62.1 ) (0.7 ) (8.6 ) Interest and penalties, net (0.5 ) (0.3 ) (1.8 ) Balance at end of year $ 15.0 $ 73.4 $ 72.8 At December 31, 2015 , interest and penalties included in the liability for unrecognized tax benefits were $3.9 million . For the year ended December 31, 2014, $60.9 million of the liability for unrecognized income tax benefits relates to temporary differences, which would not impact the effective tax rate upon resolution of the uncertainty. In 2015, the Company resolved these various uncertain tax position matters related to temporary differences which resulted in this $60.9 million long-term liability for uncertain tax positions to be reclassified to a deferred tax liability. Including tax positions for which the Company determined that the tax position would not meet the more-likely-than-not recognition threshold upon examination by the tax authorities based upon the technical merits of the position, the total estimated unrecognized tax benefit that, if recognized, would affect ATI’s effective tax rate was approximately $12 million . At this time, the Company believes that it is reasonably possible that approximately $4 million of the estimated unrecognized tax benefits as of December 31, 2015 will be recognized within the next twelve months based on the expiration of statutory review periods. The Company, and/or one of its subsidiaries, files income tax returns in the U.S. Federal jurisdiction and in various state and foreign jurisdictions. A summary of tax years that remain subject to examination, by major tax jurisdiction, is as follows: Jurisdiction Earliest Year Open to Examination U.S. Federal 2014 States: Alabama 2012 Illinois 2012 North Carolina 2010 Oregon 2012 Pennsylvania 2012 Foreign: China 2011 Germany 2014 Poland 2011 United Kingdom 2012

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Business Segments	Business Segments The Company operates in two business segments: High Performance Materials & Components and Flat Rolled Products. The High Performance Materials & Components business segment produces, converts and distributes a wide range of high performance materials, including titanium and titanium-based alloys, nickel- and cobalt-based alloys and superalloys, zirconium and related alloys including hafnium and niobium, advanced powder alloys and other specialty materials, in long product forms such as ingot, billet, bar, rod, wire, shapes and rectangles, and seamless tubes, plus precision forgings and castings, components and machined parts. These products are designed for the high performance requirements of such major end markets as aerospace and defense, oil and gas, chemical and hydrocarbon processing industry, electrical energy, and medical. The Flat Rolled Products business segment produces, converts and distributes stainless steel, nickel-based alloys, specialty alloys, and titanium and titanium-based alloys, in a variety of product forms including plate, sheet, engineered strip, and Precision Rolled Strip ® products, as well as grain-oriented electrical steel. The major end markets for our flat-rolled products are oil and gas, chemical and hydrocarbon processing industry, electrical energy, automotive, food processing equipment and appliances, construction and mining, electronics, communication equipment and computers, and aerospace and defense. The business units in this segment include ATI Flat Rolled Products and STAL, in which the Company has a 60% ownership interest. Segment results also include ATI’s 50% interest in Uniti, which is accounted for under the equity method. Sales to Uniti, which are included in ATI’s consolidated statements of operations, were $55.4 million in 2015 , $75.3 million in 2014 , and $95.9 million in 2013 . ATI’s share of Uniti’s loss was $0.1 million in 2015 , $8.9 million in 2014 , and $7.1 million in 2013 , which is included in the Flat Rolled Products segment’s operating profit, and within cost of sales in the consolidated statements of operations. The remaining 50% interest in Uniti is held by VSMPO, a Russian producer of titanium, aluminum, and specialty steel products. In December 2015, the Company announced the idling of the standard stainless melt shop and sheet finishing operations at the Midland, PA facility, and the grain-oriented electrical steel operations in Western PA, including the Bagdad, PA facility. See Note 17 for further explanation. These actions are intended to return the Flat Rolled Products business to profitability as quickly as possible and execute our strategy for sustainable long-term profitable growth. The future restart of the Midland and GOES operations, respectively, will depend on future business conditions and our ability to earn an acceptable return on invested capital on products produced at these operations. Effective with the third quarter 2015, the Company changed its method of determining business unit performance as internally reported to its senior management, CEO, and Board of Directors. Segment operating results are now reported excluding 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. Additionally, segment operating results are now measured including all retirement benefit expense attributable to the business unit, for both current and former employees. Previously, the Company excluded defined benefit pension expense and all defined benefit and defined contribution postretirement medical and life insurance expense from segment operating profit. This change better aligns comparative operating performance following the 2014 U.S. defined benefit pension freeze for all non-represented employees and the change in 2015 to a company-wide defined contribution retirement plan structure. Under the Company’s previous reporting methodology, defined contribution retirement plan expense remained in segment operating results whereas defined benefit plan costs were excluded. Operating results for business segments, corporate and closed company and other expenses now include all applicable retirement benefit plan costs for pension and other postretirement benefits. Management considers these changes to be a more useful method of measuring business unit financial performance based on changes to retirement benefit plans and the impact of the Company’s aggregate net debit LIFO position. The segment results below reflect these changes for all periods presented. The measure of segment operating profit also excludes income taxes, corporate expenses, net interest expense, closed company expenses, charges for goodwill impairment (see Note 6) and restructuring charges and other costs (see Note 17). Discontinued operations are also excluded. Management believes segment operating profit, as defined, provides an appropriate measure of controllable operating results at the business segment level. Intersegment sales are generally recorded at full cost or market. Common services are allocated on the basis of estimated utilization. (In millions) 2015 2014 2013 Total sales: High Performance Materials & Components $ 2,062.7 $ 2,084.6 $ 2,016.7 Flat Rolled Products 1,807.9 2,320.2 2,146.6 Total sales 3,870.6 4,404.8 4,163.3 Intersegment sales: High Performance Materials & Components 76.8 77.8 71.9 Flat Rolled Products 74.2 103.6 47.9 Total intersegment sales 151.0 181.4 119.8 Sales to external customers: High Performance Materials & Components 1,985.9 2,006.8 1,944.8 Flat Rolled Products 1,733.7 2,216.6 2,098.7 Total sales to external customers $ 3,719.6 $ 4,223.4 $ 4,043.5 Total direct international sales were $1,577.0 million in 2015 , $1,607.5 million in 2014 , and $1,585.1 million in 2013 . Of these amounts, sales by operations in the United States to customers in other countries were $1,215.8 million in 2015 , $1,201.8 million in 2014 , and $1,175.1 million in 2013 . (In millions) 2015 2014 2013 Operating profit (loss): High Performance Materials & Components $ 157.1 $ 234.8 $ 159.6 Flat Rolled Products (241.9 ) (47.0 ) (147.8 ) Total operating profit (loss) (84.8 ) 187.8 11.8 LIFO and net realizable value reserves (See Note 4) 0.1 0.3 45.9 Corporate expenses (44.7 ) (49.6 ) (48.9 ) Closed company and other expenses (22.1 ) (28.3 ) (30.9 ) Impairment of goodwill (See Note 6) (126.6 ) — — Restructuring and other charges (89.7 ) — (67.5 ) Interest expense, net (110.2 ) (108.7 ) (65.2 ) Income (loss) before income taxes $ (478.0 ) $ 1.5 $ (154.8 ) Closed company and other expenses, which were $22.1 million in 2015 , $28.3 million in 2014 and $30.9 million in 2013 , includes charges incurred in connection with closed operations, pre-tax gains and losses on the sale of surplus real estate, non-strategic investments, and other assets, and other non-operating income or expense. Other items are primarily presented in selling and administrative expenses in the consolidated statements of operations. In 2015 , these other items included $4.5 million for closed company environmental costs, $2.3 million for retirement benefit expense and $15.3 million for other expenses including legal matters and real estate costs at closed companies. In 2014 , the Company recorded $28.3 million in other charges primarily related to closed companies, including $8.0 million for environmental costs, $7.1 million for retirement benefit expense, $3.8 million for closed company insurance obligations and $9.4 million for other expenses including legal matters and real estate costs at closed companies. In 2013 , the Company recorded $30.9 million in other charges primarily related to closed companies, including $16.7 million for retirement benefit expense, $3.9 million for environmental costs, and $10.3 million for other expenses including real estate costs at closed companies. Restructuring and other charges include $54.5 million in long-lived asset impairment charges, $25.4 million of inventory valuation charges for non-PQ titanium sponge (see Note 4 for additional information) and charges for severance and facility idling costs. See Note 17 for additional information on restructuring charges. Certain additional information regarding the Company’s business segments is presented below: (In millions) 2015 2014 2013 Depreciation and amortization: High Performance Materials & Components $ 131.8 $ 124.4 $ 127.4 Flat Rolled Products 55.6 49.3 49.5 Corporate 2.5 2.9 3.7 Total depreciation and amortization 189.9 176.6 180.6 Capital expenditures: High Performance Materials & Components 75.8 51.9 39.5 Flat Rolled Products 68.0 172.1 568.1 Corporate 0.7 1.7 0.2 Total capital expenditures 144.5 225.7 607.8 Identifiable assets: 2015 2014 2013 High Performance Materials & Components 3,355.5 3,555.8 3,452.2 Flat Rolled Products 2,189.5 2,601.6 2,320.9 Discontinued Operations 0.9 1.8 9.8 Corporate: Prepaid pension cost — — 5.1 Cash and cash equivalents and other 205.8 412.5 1,097.0 Total assets $ 5,751.7 $ 6,571.7 $ 6,885.0 Geographic information for external sales based on country of destination, and assets, are as follows: ($ in millions) 2015 Percent of total 2014 Percent of total 2013 Percent of total External sales: United States $ 2,142.6 58 % $ 2,615.9 62 % $ 2,458.4 61 % China 246.9 7 % 249.6 6 % 237.7 6 % Japan 202.3 5 % 89.3 2 % 124.7 3 % United Kingdom 198.2 5 % 228.4 5 % 251.5 6 % Germany 193.3 5 % 207.7 5 % 215.4 5 % Canada 154.5 4 % 147.0 3 % 141.0 4 % France 153.3 4 % 168.1 4 % 152.8 4 % Mexico 78.4 2 % 76.5 2 % 54.9 1 % Italy 65.0 2 % 160.7 4 % 132.3 3 % Other 285.1 8 % 280.2 7 % 274.8 7 % Total External Sales $ 3,719.6 100 % $ 4,223.4 100 % $ 4,043.5 100 % ($ in millions) 2015 Percent of total 2014 Percent of total 2013 Percent of total Total assets: United States $ 5,073.1 88 % $ 5,868.7 90 % $ 6,131.9 89 % China 260.0 5 % 280.5 4 % 258.1 4 % United Kingdom 154.3 3 % 196.3 3 % 208.0 3 % Luxembourg (a) 124.4 2 % 81.8 1 % 145.9 2 % Other 139.9 2 % 144.4 2 % 141.1 2 % Total Assets $ 5,751.7 100 % $ 6,571.7 100 % $ 6,885.0 100 % (a) Comprises assets held by the Company’s European Treasury Center operation.

Restructuring Costs

Restructuring Costs	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
Restructuring Costs	Restructuring Charges 2015 For the year ended December 31, 2015 , the Company recorded restructuring charges of $64.3 million ( $41.6 million after-tax or $0.39 per share) which are presented as restructuring charges in the consolidated statement of operations. These charges were comprised of $54.5 million in long-lived asset impairment charges, $3.5 million in facility idling costs, and $6.3 million in employee severance charges. The long-lived asset impairment charges were based on analysis of the estimated fair values, including asset appraisals using income and market approaches, which represents Level 3 unobservable information in the fair value hierarchy. • In December 2015, the Company announced the following rightsizing actions to better align its Flat Rolled Products operations to the challenging market conditions for its commodity products: • Idling the standard stainless melt shop and sheet finishing operations at the Midland, PA facility, which was completed in January 2016. A $24.2 million impairment charge was recognized to reduce the carrying value of the Midland facility to estimated fair value. • Idling grain-oriented electrical steel (GOES) operations in Western PA, including the Bagdad, PA facility, which is expected to be completed by April 2016. A $30.3 million impairment charge was recognized to reduce the carrying value of GOES operations assets to estimated fair value. A $3.5 million charge for future idling costs of the Midland and GOES operations was also recognized. The future restart of the Midland and GOES operations, respectively, will depend on future business conditions and the Company’s ability to earn an acceptable return on invested capital on products produced at these operations. • As announced in October 2015, in the fourth quarter 2015 the Company implemented a salaried workforce reduction of approximately 100 employees, in response to business conditions, in both the High Performance Materials & Components segment and at ATI’s headquarters. Severance charges of $6.3 million were recorded in the fourth quarter for this action and these cash costs will be paid over a period of up to 12 months. Reserves for restructuring charges at December 31, 2015 were approximately $8 million for severance and idling costs, which are expected to be paid in 2016. 2013 For the year ended December 31, 2013, the Company recorded restructuring charges in continuing operations of $67.5 million ( $41.2 million after-tax or $0.39 per share) which are presented as restructuring charges in the consolidated statement of operations. These charges were comprised of $55.1 million in long-lived asset impairment charges, $4.2 million in facility closure costs and $8.2 million in employee severance and termination benefit charges. The long-lived asset impairment charges were based on analysis of the estimated fair values, which represents Level 3 unobservable information in the fair value hierarchy. • In the High Performance Materials & Components segment, the Company permanently closed the previously idled Albany, Oregon standard-grade titanium sponge facility, resulting in a $38.1 million asset impairment charge in 2013. In addition, a charge was recorded for $3.5 million of asset retirement obligations, which were substantially completed in 2014. • In the Flat Rolled Products segment, the Company permanently closed the previously idled New Castle, Indiana stainless finishing facility in 2013, and the Wallingford, Connecticut stainless finishing facility in 2014. The closure of New Castle and Wallingford resulted in $6.3 million and $2.7 million , respectively, of asset impairment charges in 2013. Facility closure costs in 2013 included $0.3 million and $0.4 million in asset retirement obligations for New Castle and Wallingford, respectively. Additionally, pension and other postretirement benefit termination charges of $5.0 million , and $1.0 million of employee termination costs were recognized in 2013 for approximately 65 employees affected by the Wallingford facility closure. In addition to the above facility closures, restructuring costs in 2013 included $8.0 million of other long-lived asset impairment charges in the High Performance Materials & Components segment. Other severance charges in 2013 included $1.1 million in pension benefit termination charges in the High Performance Materials & Components segment, and $1.1 million in severance costs, collectively affecting approximately 75 employees. Reserves for restructuring charges at December 31, 2013 were approximately $2 million for severance costs, which were paid in 2014.

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interest	12 Months Ended
	Dec. 31, 2015
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interest The holders of the 15% noncontrolling interest in ATI Flowform Products have a put option to require the Company to purchase their equity interest at a redemption value determinable from a specified formula based on a multiple of EBITDA (subject to a fixed minimum linked to the original acquisition date value). The put option is fully exercisable beginning in the second quarter of 2017, and is also exercisable under certain other circumstances. The put option cannot be separated from the noncontrolling interest, and the combination of a noncontrolling interest and the redemption feature requires classification as redeemable noncontrolling interest in the consolidated balance sheet, separate from Stockholders’ Equity. The carrying amount of the redeemable noncontrolling interest approximates its maximum redemption value. Any subsequent change in maximum redemption value is adjusted through retained earnings. The adjustment to the carrying amount for the years ended December 31, 2015 and 2014 reduced retained earnings by $0.3 million . The Company applied the two-class method of calculating earnings per share, and as such this adjustment to the carrying amount was reflected in earnings per share. The redeemable noncontrolling interest was $12.1 million as of December 31, 2015 and 2014 , which was unchanged from the acquisition date value. In January 2016, the redeemable noncontrolling interest held by one of the parties with a 7.5% stake in ATI Flowform Products was purchased by ATI at the $6.1 million acquisition date carrying value, which results in a 7.5% remaining redeemable noncontrolling interest held in ATI Flowform Products following this transaction.

Per Share Information

Per Share Information	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Per Share Information	Per Share Information The following table sets forth the computation of basic and diluted income (loss) from continuing operations per common share: (In millions, except per share amounts) For the Years Ended December 31, 2015 2014 2013 Numerator: Numerator for basic loss from continuing operations per common share - Loss from continuing operations attributable to ATI $ (377.9 ) $ (2.0 ) $ (98.8 ) Redeemable noncontrolling interest (Note 18) (0.3 ) (0.3 ) — Effect of dilutive securities: 4.25% Convertible Senior Notes due 2014 — — — Numerator for diluted net loss per common share - Loss from continuing operations attributable to ATI after assumed conversions $ (378.2 ) $ (2.3 ) $ (98.8 ) Denominator: Denominator for basic net loss per common share—weighted average shares 107.3 107.1 106.8 Effect of dilutive securities: Share-based compensation — — — 4.25% Convertible Senior Notes due 2014 — — — Denominator for diluted net loss per common share—adjusted weighted average shares and assumed conversions 107.3 107.1 106.8 Basic loss from continuing operations attributable to ATI per common share $ (3.53 ) $ (0.02 ) $ (0.93 ) Diluted loss from continuing operations attributable to ATI per common share $ (3.53 ) $ (0.02 ) $ (0.93 ) Common stock that would be issuable upon the assumed conversion of the 2014 Convertible Notes (prior to maturity on June 2, 2014) and other option equivalents and contingently issuable shares are excluded from the computation of contingently issuable shares, and therefore, from the denominator for diluted earnings per share, if the effect of inclusion would have been anti-dilutive. Excluded shares were 0.8 million for 2015 , 4.7 million for 2014 and 10.0 million for 2013 .

Financial Information for Subsi

Financial Information for Subsidiary and Guarantor Parent	12 Months Ended
	Dec. 31, 2015
Financial Information for Subsidiary and Guarantor Parent [Abstract]
Financial Information for Subsidiary and Guarantor Parent	Financial Information for Subsidiary and Guarantor Parent The payment obligations under the $150.0 million 6.95% Debentures due 2025 issued by Allegheny Ludlum, LLC (formerly known as Allegheny Ludlum Corporation) (the “Subsidiary”) are fully and unconditionally guaranteed by Allegheny Technologies Incorporated (the “Guarantor Parent”). In accordance with positions established by the U.S. Securities and Exchange Commission, the following financial information sets forth separately financial information with respect to the Subsidiary, the Non-guarantor Subsidiaries and the Guarantor Parent. The principal elimination entries eliminate investments in subsidiaries and certain intercompany balances and transactions. Allegheny Technologies is the plan sponsor for the U.S. qualified defined benefit pension plan (the “Plan”) which covers certain current and former employees of the Subsidiary and the Non-guarantor Subsidiaries. As a result, the balance sheets presented for the Subsidiary and the Non-guarantor Subsidiaries do not include any Plan assets or liabilities, or the related deferred taxes. The Plan assets, liabilities and related deferred taxes and pension income or expense are recognized by the Guarantor Parent. Management and royalty fees charged to the Subsidiary and to the Non-guarantor Subsidiaries by the Guarantor Parent have been excluded solely for purposes of this presentation. Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Balance Sheets December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 0.4 $ 2.8 $ 146.6 $ — $ 149.8 Accounts receivable, net 0.1 100.3 299.9 — 400.3 Intercompany notes receivable — — 2,601.5 (2,601.5 ) — Inventories, net — 239.9 1,031.7 — 1,271.6 Prepaid expenses and other current assets 9.3 3.8 32.8 — 45.9 Total current assets 9.8 346.8 4,112.5 (2,601.5 ) 1,867.6 Property, plant and equipment, net 2.2 1,559.9 1,366.1 — 2,928.2 Goodwill — — 651.4 — 651.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investments in subsidiaries 5,742.5 37.7 — (5,780.2 ) — Other assets 13.4 23.0 268.1 — 304.5 Total assets $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7 Liabilities and stockholders’ equity: Accounts payable $ 4.8 $ 171.1 $ 204.9 $ — $ 380.8 Accrued liabilities 42.1 74.0 185.7 — 301.8 Intercompany notes payable 1,325.4 1,276.1 — (2,601.5 ) — Short-term debt and current portion of long-term debt 0.7 0.1 3.1 — 3.9 Total current liabilities 1,373.0 1,521.3 393.7 (2,601.5 ) 686.5 Long-term debt 1,341.7 149.7 0.4 — 1,491.8 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 280.0 79.2 — 359.2 Pension liabilities 778.0 5.2 50.6 — 833.8 Deferred income taxes 75.6 — — — 75.6 Other long-term liabilities 15.2 20.7 72.4 — 108.3 Total liabilities 3,583.5 2,176.9 596.3 (2,801.5 ) 3,555.2 Redeemable noncontrolling interest — — 12.1 — 12.1 Total stockholders’ equity 2,184.4 (209.5 ) 5,989.7 (5,780.2 ) 2,184.4 Total liabilities and stockholders’ equity $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations For the year ended December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,453.2 $ 2,266.4 $ — $ 3,719.6 Cost of sales 27.3 1,643.2 1,988.8 — 3,659.3 Selling and administrative expenses 88.2 29.4 121.2 — 238.8 Impairment of goodwill — 126.6 — — 126.6 Restructuring charges 1.6 58.0 4.7 — 64.3 Income (loss) before interest, other income and income taxes (117.1 ) (404.0 ) 151.7 — (369.4 ) Interest income (expense), net (117.3 ) (50.9 ) 58.0 — (110.2 ) Other income (expense) including equity in income of unconsolidated subsidiaries (243.6 ) 1.1 0.8 243.3 1.6 Income (loss) from continuing operations before income taxes (478.0 ) (453.8 ) 210.5 243.3 (478.0 ) Income tax provision (benefit) (112.1 ) (165.7 ) 51.6 114.1 (112.1 ) Income (loss) from continuing operations (365.9 ) (288.1 ) 158.9 129.2 (365.9 ) Income (loss) from discontinued operations, net of tax — — — — — Net income (loss) (365.9 ) (288.1 ) 158.9 129.2 (365.9 ) Less: Net income attributable to noncontrolling interest — — 12.0 — 12.0 Net income (loss) attributable to ATI $ (365.9 ) $ (288.1 ) $ 146.9 $ 129.2 $ (377.9 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Comprehensive Income For the year ended December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Net income (loss) $ (365.9 ) $ (288.1 ) $ 158.9 $ 129.2 $ (365.9 ) Other comprehensive income (loss) Currency translation adjustment arising during the period (37.0 ) — (37.0 ) 37.0 (37.0 ) Net derivative loss on hedge transactions (32.0 ) — — — (32.0 ) Pension and postretirement benefits (19.7 ) 29.8 3.1 (32.9 ) (19.7 ) Other comprehensive income (loss), net of tax (88.7 ) 29.8 (33.9 ) 4.1 (88.7 ) Comprehensive income (loss) (454.6 ) (258.3 ) 125.0 133.3 (454.6 ) Less: Comprehensive income attributable to noncontrolling interest — — 6.4 — 6.4 Comprehensive income (loss) attributable to ATI $ (454.6 ) $ (258.3 ) $ 118.6 $ 133.3 $ (461.0 ) Condensed Statements of Cash Flows For the year ended December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (70.0 ) $ (134.8 ) $ 360.2 $ (24.0 ) $ 131.4 Investing Activities: Purchases of property, plant and equipment (0.6 ) (66.9 ) (77.0 ) — (144.5 ) Net receipts (payments) on intercompany activity — — (327.9 ) 327.9 — Purchases of businesses, net of cash acquired — — (0.5 ) — (0.5 ) Asset disposals and other — 0.2 (0.3 ) — (0.1 ) Cash flows provided by (used in) investing activities (0.6 ) (66.7 ) (405.7 ) 327.9 (145.1 ) Financing Activities: Payments on long-term debt and capital leases (0.6 ) (0.1 ) (22.9 ) — (23.6 ) Net receipts (payments) on intercompany activity 137.3 190.6 — (327.9 ) — Dividends paid to stockholders (66.5 ) — (24.0 ) 24.0 (66.5 ) Dividends paid to noncontrolling interests — — (16.0 ) — (16.0 ) Other (1.4 ) — 1.5 — 0.1 Cash flows provided by (used in) financing activities 68.8 190.5 (61.4 ) (303.9 ) (106.0 ) Decrease in cash and cash equivalents $ (1.8 ) $ (11.0 ) $ (106.9 ) $ — $ (119.7 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Balance Sheets December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.2 $ 13.8 $ 253.5 $ — $ 269.5 Accounts receivable, net 0.1 209.1 394.4 — 603.6 Intercompany notes receivable — — 2,390.8 (2,390.8 ) — Inventories, net — 387.7 1,085.1 — 1,472.8 Prepaid expenses and other current assets 63.7 13.2 59.3 — 136.2 Total current assets 66.0 623.8 4,183.1 (2,390.8 ) 2,482.1 Property, plant and equipment, net 2.2 1,545.1 1,414.5 — 2,961.8 Goodwill — 126.6 653.8 — 780.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investments in subsidiaries 6,149.4 37.7 — (6,187.1 ) — Other assets 13.3 27.5 306.6 — 347.4 Total assets $ 6,230.9 $ 2,360.7 $ 6,758.0 $ (8,777.9 ) $ 6,571.7 Liabilities and stockholders’ equity: Accounts payable $ 4.5 $ 302.0 $ 250.2 $ — $ 556.7 Accrued liabilities 47.5 72.0 203.7 — 323.2 Intercompany notes payable 1,232.6 1,158.2 — (2,390.8 ) — Short-term debt and current portion of long-term debt 0.5 0.1 17.2 — 17.8 Total current liabilities 1,285.1 1,532.3 471.1 (2,390.8 ) 897.7 Long-term debt 1,340.2 149.8 8.2 — 1,498.2 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 153.0 262.8 — 415.8 Pension liabilities 675.5 6.0 57.8 — 739.3 Deferred income taxes 143.1 — — — 143.1 Other long-term liabilities 77.7 22.5 56.0 — 156.2 Total liabilities 3,521.6 2,063.6 855.9 (2,590.8 ) 3,850.3 Redeemable noncontrolling interest — — 12.1 — 12.1 Total stockholders’ equity 2,709.3 297.1 5,890.0 (6,187.1 ) 2,709.3 Total liabilities and stockholders’ equity $ 6,230.9 $ 2,360.7 $ 6,758.0 $ (8,777.9 ) $ 6,571.7 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations For the year ended December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,878.0 $ 2,345.4 $ — $ 4,223.4 Cost of sales 45.3 1,874.8 1,924.7 — 3,844.8 Selling and administrative expenses 103.9 44.0 124.6 — 272.5 Income (loss) before interest, other income and income taxes (149.2 ) (40.8 ) 296.1 — 106.1 Interest income (expense), net (111.0 ) (44.9 ) 47.2 — (108.7 ) Other income (expense) including equity in income of unconsolidated subsidiaries 261.7 1.1 2.9 (261.6 ) 4.1 Income (loss) from continuing operations before income taxes 1.5 (84.6 ) 346.2 (261.6 ) 1.5 Income tax provision (benefit) (8.7 ) (29.3 ) 116.7 (87.4 ) (8.7 ) Income (loss) from continuing operations 10.2 (55.3 ) 229.5 (174.2 ) 10.2 Income (loss) from discontinued operations, net of tax (0.6 ) — (0.6 ) 0.6 (0.6 ) Net income (loss) 9.6 (55.3 ) 228.9 (173.6 ) 9.6 Less: Net income attributable to noncontrolling interest — — 12.2 — 12.2 Net income (loss) attributable to ATI $ 9.6 $ (55.3 ) $ 216.7 $ (173.6 ) $ (2.6 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Comprehensive Income For the year ended December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Net income (loss) $ 9.6 $ (55.3 ) $ 228.9 $ (173.6 ) $ 9.6 Other comprehensive income (loss) Currency translation adjustment arising during the period (33.6 ) — (33.6 ) 33.6 (33.6 ) Net derivative gain on hedge transactions 25.9 — — — 25.9 Pension and postretirement benefits (212.6 ) 1.8 (28.4 ) 26.6 (212.6 ) Other comprehensive income (loss), net of tax (220.3 ) 1.8 (62.0 ) 60.2 (220.3 ) Comprehensive income (loss) (210.7 ) (53.5 ) 166.9 (113.4 ) (210.7 ) Less: Comprehensive income attributable to noncontrolling interest — — 10.1 — 10.1 Comprehensive income (loss) attributable to ATI $ (210.7 ) $ (53.5 ) $ 156.8 $ (113.4 ) $ (220.8 ) Condensed Statements of Cash Flows For the year ended December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (66.9 ) $ (313.8 ) $ 436.6 $ — $ 55.9 Investing Activities: Purchases of property, plant and equipment (0.1 ) (170.8 ) (54.8 ) — (225.7 ) Net receipts (payments) on intercompany activity — — (1,027.7 ) 1,027.7 — Purchases of businesses, net of cash acquired — — (92.9 ) — (92.9 ) Asset disposals and other — 1.7 0.7 — 2.4 Cash flows provided by (used in) investing activities (0.1 ) (169.1 ) (1,174.7 ) 1,027.7 (316.2 ) Financing Activities: Payments on long-term debt and capital leases (397.9 ) (0.1 ) (16.9 ) — (414.9 ) Net receipts (payments) on intercompany acivity 544.4 483.3 — (1,027.7 ) — Dividends paid to stockholders (77.1 ) — — — (77.1 ) Other (3.8 ) — (1.2 ) — (5.0 ) Cash flows provided by (used in) financing activities 65.6 483.2 (18.1 ) (1,027.7 ) (497.0 ) Increase (decrease) in cash and cash equivalents $ (1.4 ) $ 0.3 $ (756.2 ) $ — $ (757.3 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations For the year ended December 31, 2013 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,769.4 $ 2,274.1 $ — $ 4,043.5 Cost of sales 75.2 1,748.8 1,966.9 — 3,790.9 Selling and administrative expenses 124.3 34.9 117.2 — 276.4 Restructuring charges 1.1 15.7 50.7 — 67.5 Income (loss) before interest, other income and income taxes (200.6 ) (30.0 ) 139.3 — (91.3 ) Interest income (expense), net (63.4 ) (37.2 ) 35.4 — (65.2 ) Other income (expense) including equity in income of unconsolidated subsidiaries 109.2 0.9 0.8 (109.2 ) 1.7 Income (loss) from continuing operations, before income taxes (154.8 ) (66.3 ) 175.5 (109.2 ) (154.8 ) Income tax provision (benefit) (63.6 ) (20.0 ) 40.4 (20.4 ) (63.6 ) Income (loss) from continuing operations (91.2 ) (46.3 ) 135.1 (88.8 ) (91.2 ) Income (loss) from discontinued operations, net of tax 252.8 — 252.8 (252.8 ) 252.8 Net income (loss) 161.6 (46.3 ) 387.9 (341.6 ) 161.6 Less: Net income attributable to noncontrolling interest — — 7.6 — 7.6 Net income (loss) attributable to ATI $ 161.6 $ (46.3 ) $ 380.3 $ (341.6 ) $ 154.0 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Comprehensive Income For the year ended December 31, 2013 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Net income (loss) $ 161.6 $ (46.3 ) $ 387.9 $ (341.6 ) $ 161.6 Other comprehensive income (loss) Currency translation adjustment arising during the period 15.3 — 15.3 (15.3 ) 15.3 Unrealized holding gain (loss) on securities 0.1 — 0.1 (0.1 ) 0.1 Net derivative loss on hedge transactions (6.9 ) — — — (6.9 ) Pension and postretirement benefits 311.1 22.0 27.6 (49.6 ) 311.1 Other comprehensive income (loss), net of tax 319.6 22.0 43.0 (65.0 ) 319.6 Comprehensive income (loss) 481.2 (24.3 ) 430.9 (406.6 ) 481.2 Less: Comprehensive income attributable to noncontrolling interest — — 11.0 — 11.0 Comprehensive income (loss) attributable to ATI $ 481.2 $ (24.3 ) $ 419.9 $ (406.6 ) $ 470.2 Condensed Statements of Cash Flows For the year ended December 31, 2013 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (41.1 ) $ (50.4 ) $ 484.2 $ (24.3 ) $ 368.4 Investing Activities: Purchases of property, plant and equipment (0.2 ) (564.8 ) (47.7 ) — (612.7 ) Net receipts (payments) on intercompany activity — — (248.8 ) 248.8 — Proceeds from sale of business, net of transaction costs (7.9 ) — 608.8 — 600.9 Asset disposals and other — 0.2 0.6 — 0.8 Cash flows provided by (used in) investing activities (8.1 ) (564.6 ) 312.9 248.8 (11.0 ) Financing Activities: Borrowings on long-term debt 500.0 — — — 500.0 Net receipts (payments) on intercompany activity (366.7 ) 615.5 — (248.8 ) — Dividends paid to stockholders (76.9 ) — (24.3 ) 24.3 (76.9 ) Other (9.1 ) (0.1 ) (49.1 ) — (58.3 ) Cash flows provided by (used in) financing activities 47.3 615.4 (73.4 ) (224.5 ) 364.8 Increase (decrease) in cash and cash equivalents $ (1.9 ) $ 0.4 $ 723.7 $ — $ 722.2

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Rental expense from continuing operations under operating leases was $23.1 million in 2015 , $22.4 million in 2014 , and $20.5 million in 2013 . Future minimum rental commitments under operating leases with non-cancelable terms of more than one year at December 31, 2015 , were as follows: $19.7 million in 2016 , $12.8 million in 2017 , $11.0 million in 2018 , $9.2 million in 2019 , $8.5 million in 2020 and $21.9 million thereafter. Commitments for expenditures on property, plant and equipment at December 31, 2015 were approximately $92.3 million . 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 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 December 31, 2015 , the Company’s reserves for environmental remediation obligations totaled approximately $15 million , of which $8 million was included in other current liabilities. The reserve includes estimated probable future costs of $4 million for federal Superfund and comparable state-managed sites; $9 million for formerly owned or operated sites for which the Company has remediation or indemnification obligations; $1 million for owned or controlled sites at which Company operations have been discontinued; and $1 million for sites utilized by the Company in its ongoing operations. The Company continues to evaluate whether it may be able to recover a portion of 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 the costs for active matters may exceed the Company’s recorded reserves by as much as $16 million . However, future investigation or remediation activities may result in the discovery of additional hazardous materials, potentially higher levels of contamination than discovered during prior investigation, and may impact costs of the success or lack thereof in remedial solutions. Therefore, future developments, administrative actions or liabilities relating to environmental matters could have a material adverse effect on the Company’s consolidated financial condition or results of operations. The timing of expenditures depends on a number of factors that vary by site. The Company expects that it will expend present accruals over many years and that remediation of all sites with which it has been identified will be completed within thirty years. A number of other lawsuits, claims and proceedings have been or may be asserted against the Company relating to the conduct of its currently and formerly owned businesses, including those pertaining to product liability, patent infringement, commercial, government contracting, employment, employee and retiree benefits, taxes, environmental, health and safety, 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 consolidated 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. On February 11, 2016, the National Labor Relations Board (NLRB) served a complaint on ATI that alleges that the Company violated the National Labor Relations Act in connection with its collective bargaining negotiations with the USW and by locking out its USW-represented employees effective August 15, 2015. On February 22, 2016, the Company and the USW bargaining committee reached a tentative agreement, which would end the lockout and which provides for withdrawal of the complaint by the NLRB. The contract is subject to ratification by USW members.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) Quarter Ended (In millions, except share and per share amounts) March 31 June 30 September 30 December 31 2015 - Sales $ 1,125.5 $ 1,022.5 $ 832.7 $ 738.9 Gross Profit (Loss) 109.5 77.0 (28.7 ) (97.5 ) Income (loss) from continuing operations attributable to ATI 10.0 (16.4 ) (144.6 ) (226.9 ) Net income (loss) 12.6 (13.9 ) (141.3 ) (223.3 ) Net income (loss) attributable to ATI 10.0 (16.4 ) (144.6 ) (226.9 ) Basic income (loss) from continuing operations attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Basic income (loss) attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Diluted income (loss) from continuing operations attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Diluted income (loss) attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Average shares outstanding 108,854,720 109,190,876 109,204,307 109,171,124 2014 - Sales $ 987.3 $ 1,119.0 $ 1,069.6 $ 1,047.5 Gross Profit 70.2 89.5 97.0 121.9 Income (loss) from continuing operations attributable to ATI (18.1 ) (3.8 ) — 19.9 Net income (loss) (17.9 ) (0.7 ) 2.9 25.3 Net income (loss) attributable to ATI (20.0 ) (4.0 ) (0.7 ) 22.1 Basic income (loss) from continuing operations attributable to ATI per common share $ (0.17 ) $ (0.03 ) $ — $ 0.18 Basic income (loss) attributable to ATI per common share $ (0.19 ) $ (0.03 ) $ (0.01 ) $ 0.20 Diluted income (loss) from continuing operations attributable to ATI per common share $ (0.17 ) $ (0.03 ) $ — $ 0.18 Diluted income (loss) attributable to ATI per common share $ (0.19 ) $ (0.03 ) $ (0.01 ) $ 0.20 Average shares outstanding 108,173,581 108,628,024 108,712,682 108,704,983 Third quarter 2015 results include a $76.0 million pre-tax ( $49.5 million , net of tax) non-cash charge for net realizable value (NRV) inventory reserves, which are required to offset ATI’s aggregate net debit LIFO inventory balance that exceeds current inventory replacement cost. Third quarter 2015 results also include a $63.9 million tax valuation allowance on a portion of ATI’s deferred tax assets as a result of a three year cumulative loss from U.S. operations. Fourth quarter 2015 results include non-cash charges for goodwill and asset impairments, restructuring, inventory and other items. These charges were comprised of a $126.6 million pre-tax ( $79.2 million , net of tax) non-cash goodwill impairment charge in the Flat Rolled Products segment, $54.5 million pre-tax ( $34.1 million , net of tax) in non-cash long-lived asset impairment charges, $3.5 million pre-tax ( $2.2 million , net of tax) in facility idling costs, $25.4 million pre-tax ( $15.9 million , net of tax) in a non-cash charge to revalue inventory, $51.2 million pre-tax ( $32.0 million , net of tax) in NRV inventory reserve charges and $6.3 million pre-tax ( $3.9 million , net of tax) in employee severance and termination benefit charges arising from a reduction in force among salaried employees within the High Performance Materials & Components segment and the ATI Corporate office. Fourth quarter 2014 results from continuing operations include postretirement benefit curtailment and settlement gains of $25.5 million pre-tax ( $18.4 million , net of tax). All net of tax amounts presented above use the effective tax rate for the applicable quarterly period which differs from the effective tax rate for the full year.

Summary of Significant Accoun31

Summary of Significant Accounting Policies - Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Allegheny Technologies Incorporated and its subsidiaries, including the Chinese joint venture known as Shanghai STAL Precision Stainless Steel Company Limited (“STAL”), in which the Company has a 60% interest. The remaining 40% interest in STAL is owned by Baosteel Group, a state authorized investment company whose equity securities are publicly traded in the People’s Republic of China. The financial results of STAL are consolidated into the Company’s operating results and financial position, with the 40% interest of our minority partner recognized in the consolidated statement of operations as net income attributable to noncontrolling interests and as equity attributable to the noncontrolling interest within total stockholders’ equity. Investments in which the Company exercises significant influence, but which it does not control (generally a 20% to 50% ownership interest), including ATI’s 50% interest in the industrial titanium joint venture known as Uniti LLC (“Uniti”), are accounted for under the equity method of accounting. Accounts receivable from Uniti were $0.5 million and $4.3 million at December 31, 2015 and 2014 , respectively. Significant intercompany accounts and transactions have been eliminated. Unless the context requires otherwise, “Allegheny Technologies,” “ATI” and the “Company” refer to Allegheny Technologies Incorporated and its subsidiaries.
Use of Estimates	Risks and Uncertainties and Use of Estimates The preparation of consolidated financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect reported amounts of assets and liabilities at the date of the financial statements, as well as the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Management believes that the estimates are reasonable. Certain prior year amounts have been reclassified in order to conform with the 2015 presentation.
Concentration Risks	The Company markets its products to a diverse customer base, principally throughout the United States. No single customer accounted for more than 10% of sales for any year presented. The principal end markets for the ATI’s products are customers in the aerospace and defense, oil & gas/chemical & hydrocarbon processing industry, electrical energy, automotive, construction and mining, food equipment and appliances, and medical markets.
Cash Equivalents and Investments	Cash Equivalents and Investments Cash equivalents are highly liquid investments valued at cost, which approximates fair value, acquired with an original maturity of three months or less.
Accounts Receivable	Accounts Receivable Accounts receivable are presented net of a reserve for doubtful accounts of $4.5 million and $4.8 million at December 31, 2015 and 2014 , respectively. Trade credit is extended based upon evaluations of each customer’s ability to perform its obligations, which are updated periodically. Accounts receivable reserves are determined based upon an aging of accounts and a review for collectability of specific accounts.
Inventories	Inventories 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. Costs include direct material, direct labor and applicable manufacturing and engineering overhead, and other direct costs. Most of the Company’s inventory is valued utilizing the LIFO costing methodology. Inventory of the Company’s non-U.S. operations is valued using average cost or FIFO methods. The Company evaluates product lines on a quarterly basis to identify inventory carrying values that exceed estimated net realizable value. In applying the lower of cost or market principle, market means current replacement cost, subject to a ceiling (market value shall not exceed net realizable value) and a floor (market shall not be less than net realizable value reduced by an allowance for a normal profit margin). The calculation of a resulting reserve, if any, is recognized as an expense in the period that the need for the reserve is identified. However, in cases where inventory at FIFO cost is lower than the LIFO carrying value, a write-down of the inventory to market may be required, subject to the ceiling and floor. It is the Company’s general policy to write-down to scrap value any inventory that is identified as obsolete and any inventory that has aged or has not moved in more than twelve months. In some instances this criterion is up to twenty-four months.
Long-Lived Assets	Long-Lived Assets Property, plant and equipment are recorded at cost, including capitalized interest, and includes long-lived assets acquired under capital leases. The principal method of depreciation adopted for all property placed into service after July 1, 1996 is the straight-line method. For buildings and equipment acquired prior to July 1, 1996, depreciation is computed using a combination of accelerated and straight-line methods. Property, plant and equipment associated with the Company’s Rowley titanium sponge facility in the High Performance Materials & Components segment, and the Hot-Rolling and Processing Facility (HRPF) in the Flat Rolled Products segment, are being depreciated utilizing the units of production method of depreciation, which the Company believes provides a better matching of costs and revenues. The Company periodically reviews estimates of useful life and production capacity assigned to new and in service assets. Significant enhancements, including major maintenance activities that extend the lives of property and equipment, are capitalized. Costs related to repairs and maintenance are charged to expense in the period incurred. The cost and related accumulated depreciation of property and equipment retired or disposed of are removed from the accounts and any related gains or losses are included in income. The Company monitors the recoverability of the carrying value of its long-lived assets. An impairment charge is recognized when an indicator of impairment occurs and the expected net undiscounted future cash flows from an asset’s use (including any proceeds from disposition) are less than the asset’s carrying value and the asset’s carrying value exceeds its fair value. Assets to be disposed of by sale are stated at the lower of their fair values or carrying amounts and depreciation is no longer recognized.
Goodwill	Goodwill Goodwill is reviewed annually for impairment or more frequently if impairment indicators arise. The review for goodwill impairment requires a comparison of the fair value of each reporting unit that has goodwill associated with its operations with its carrying amount, including goodwill. If this comparison reflects impairment, then the loss would be measured as the excess of recorded goodwill over its implied fair value. Implied fair value is the excess of the fair value of a reporting unit over the amounts assigned to its assets and liabilities. Generally accepted accounting standards provide the option to qualitatively assess goodwill for impairment before completing a quantitative assessment. Under the qualitative approach, if, after assessing the totality of events or circumstances, including both macroeconomic, industry and market factors, and entity-specific factors, the Company determines it is likely (more likely than not) that the fair value of a reporting unit is greater than its carrying amount, then the quantitative impairment analysis is not required. The quantitative assessment may be performed each year for a reporting unit at the Company’s option without first performing a qualitative assessment. The Company’s quantitative assessment of goodwill for possible impairment includes estimating the fair market value of a reporting unit which has goodwill associated with its operations using discounted cash flow and multiples of cash earnings valuation techniques, plus valuation comparisons to recent public sale transactions of similar businesses, if any. These impairment assessments and valuation methods require the Company to make estimates and assumptions regarding future operating results, cash flows, changes in working capital and capital expenditures, selling prices, profitability, and the cost of capital. Many of these assumptions are determined by reference to market participants identified by the Company. Although management believes that the estimates and assumptions used were reasonable, actual results could differ from those estimates and assumptions. Other events and changes in circumstances may also require goodwill to be tested for impairment between annual measurement dates. While a decline in stock price and market capitalization is not specifically cited as a goodwill impairment indicator, a company’s stock price and market capitalization should be considered in determining whether it is more likely than not that the fair value of a reporting unit is less that its carrying value. Additionally, a significant decline in a company’s stock price may suggest that an adverse change in the business climate may have caused the fair value of one or more reporting units to fall below carrying value. A sustained decline in market capitalization below book value may be determined to require an interim goodwill impairment review.
Environmental	Environmental Costs that mitigate or prevent future environmental contamination or extend the life, increase the capacity or improve the safety or efficiency of property utilized in current operations are capitalized. Other costs that relate to current operations or an existing condition caused by past operations are expensed. Environmental liabilities are recorded when the Company’s liability is probable and the costs are reasonably estimable, but generally not later than the completion of the feasibility study or the Company’s recommendation of a remedy or commitment to an appropriate plan of action. The accruals are reviewed periodically and, as investigations and remediations proceed, adjustments of the accruals are made to reflect new information as appropriate. Accruals for losses from environmental remediation obligations do not take into account the effects of inflation, and anticipated expenditures are not discounted to their present value. The accruals are not reduced by possible recoveries from insurance carriers or other third parties, but do reflect allocations among potentially responsible parties (“PRPs”) at Federal Superfund sites or similar state-managed sites after an assessment is made of the likelihood that such parties will fulfill their obligations at such sites and after appropriate cost-sharing or other agreements are entered. The measurement of environmental liabilities by the Company is based on currently available facts, present laws and regulations, and current technology. Such estimates take into consideration the Company’s prior experience in site investigation and remediation, the data concerning cleanup costs available from other companies and regulatory authorities, and the professional judgment of the Company’s environmental experts in consultation with outside environmental specialists, when necessary.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of international operations are translated into U.S. dollars using year-end exchange rates, while revenues and expenses are translated at average exchange rates during the period. The resulting net translation adjustments are recorded as a component of accumulated other comprehensive income (loss) in stockholders’ equity.
Sales Recognition	Sales Recognition Sales are recognized when title passes or as services are rendered.
Research and Development	Research and Development Company funded research and development costs from continuing operations were $14.2 million in 2015 , $17.4 million in 2014 , and $16.1 million in 2013 and were expensed as incurred. Customer funded research and development costs were $1.5 million in 2015 , $2.7 million in 2014 , and $2.7 million in 2013 .
Stock-based Compensation	Stock-based Compensation The Company accounts for stock-based compensation transactions, such as nonvested stock and performance equity awards, using fair value. Compensation expense for an award is estimated at the date of grant and is recognized over the requisite service period. Compensation expense is adjusted for equity awards that do not vest because service or performance conditions are not satisfied. However, compensation expense already recognized is not adjusted if market conditions are not met, such as the Company’s total shareholder return performance relative to a peer group under the Company’s performance equity awards.
Income Taxes	Income Taxes The provision for, or benefit from, income taxes includes deferred taxes resulting from temporary differences in income for financial and tax purposes using the liability method. Such temporary differences result primarily from differences in the carrying value of assets and liabilities. Future realization of deferred income tax assets requires sufficient taxable income within the carryback and/or carryforward period available under tax law. The Company evaluates on a quarterly basis whether, based on all available evidence, it is probable that the deferred income tax assets are realizable. Valuation allowances are established when it is estimated that it is more likely than not that the tax benefit of the deferred tax asset will not be realized. The evaluation includes the consideration of all available evidence, both positive and negative, regarding historical operating results including recent years with reported losses, the estimated timing of future reversals of existing taxable temporary differences, estimated future taxable income exclusive of reversing temporary differences and carryforwards, and potential tax planning strategies which may be employed to prevent an operating loss or tax credit carryforward from expiring unused. It is the Company’s policy to classify interest and penalties recognized on underpayment of income taxes as income tax expense.
Net Income Per Common Share	Net Income Per Common Share Basic and diluted net income per share are calculated by dividing the net income available to common stockholders by the weighted average number of common shares outstanding during the year. Diluted amounts assume the issuance of common stock for all potentially dilutive share equivalents outstanding. The calculations of all diluted income/loss per share figures for a period exclude the potentially dilutive effect of dilutive share equivalents if there is a net loss from continuing operations since the inclusion in the calculation of additional shares in the net loss from continuing operations per share would result in a lower per share loss and therefore be anti-dilutive.
New Accounting Pronouncements Adopted	New Accounting Pronouncements Adopted In November 2015, the Financial Accounting Standards Board (FASB) issued new guidance on the balance sheet classification of deferred taxes. To simplify the presentation of deferred income taxes, the amendments in this update require that deferred tax liabilities and assets be classified as noncurrent rather than separating deferred income tax liabilities and assets into current and noncurrent amounts in the statement of financial position as required by current generally accepted accounting principles. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015. Therefore, the $62.2 million of current deferred tax liabilities reported on the December 31, 2014 consolidated balance sheet were reclassified to non-current. In April 2015, the FASB issued new guidance on the presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this guidance. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015. Therefore, the $10.9 million of debt issuance costs reported as other assets on the December 31, 2014 consolidated balance sheet were reclassified to a reduction of the carrying amount of long-term debt. In August 2015, the FASB issued additional guidance on presentation of debt issuance costs specifically related to line-of-credit arrangements. This guidance indicated no objection to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. As such, the Company continued to present such costs, as it does today, within other assets on the consolidated balance sheets. In January 2015, the Company adopted changes issued by the FASB to the criteria for reporting discontinued operations. Under the new criteria, a disposal of a component of an entity is required to be reported as discontinued operations only if the disposal represents a strategic shift that has, or will have, a major effect on an entity’s operations and financial results. The criteria that there be no significant continuing involvement in the operations of the component after the disposal transaction has been removed under the new guidance. The new guidance also requires the presentation of the assets and liabilities of a disposal group that includes a discontinued operation for each comparative period and requires additional disclosures about discontinued operations, including the major line items constituting the pretax profit or loss of the discontinued operation, certain cash flow information for the discontinued operation, expanded disclosures about an entity’s significant continuing involvement in a discontinued operation, and disclosures about a disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation. The provisions of the new guidance are effective for all disposals that occur for the Company beginning in fiscal year 2015. The adoption of these changes had no impact on the consolidated financial statements.
New Accounting Pronouncements Not yet Adopted	Pending Accounting Pronouncements In February 2016, the FASB issued new guidance on the accounting for leases. This new guidance will require that a lessee recognize assets and liabilities on the balance sheet for all leases with a lease term of more than twelve months, with the result being the recognition of a right of use asset and a lease liability. The new lease accounting requirements are effective for the Company’s 2019 fiscal year with a modified retrospective transition approach required, with early adoption permitted. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements. In July 2015, the FASB issued changes to simplify the measurement of inventory valuation at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The new inventory measurement requirements are effective for the Company’s 2017 fiscal year, and will replace the current inventory valuation guidance that requires the use of a lower of cost or market framework. This change in the measurement of inventory does not apply to inventory valued on a LIFO basis, which is the accounting basis used for most of the Company’s inventory. The adoption of these changes is not expected to have a material impact on the Company’s consolidated financial statements. In May 2014, the FASB issued changes to revenue recognition with customers. This update provides a five-step analysis of transactions to determine when and how revenue is recognized. An entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB approved a one-year deferral of the effective date of this new guidance resulting in it now being effective for the Company beginning in fiscal year 2018. This update may be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying this update recognized at the date of initial application. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements.
Asset Retirement Obligations	Asset Retirement Obligations The Company maintains reserves where a legal obligation exists to perform an asset retirement activity and the fair value of the liability can be reasonably estimated. These asset retirement obligations (“AROs”) include liabilities where the timing and (or) method of settlement may be conditional on a future event, that may or may not be within the control of the entity. At December 31, 2015 , the Company had recognized AROs of $25.0 million related to landfill closures, decommissioning costs, facility leases and conditional AROs associated with manufacturing activities using what may be characterized as potentially hazardous materials. The 2013 sale of the tungsten materials business included an indemnification to the buyer for conditional ARO costs of up to $13 million for a five year period. The Company recorded a $9.4 million charge in 2013 to increase recorded reserves to $13 million for these retained liabilities, which was reported as part of the gain on sale of the tungsten materials business. In addition, as part of facility closures in 2013, $4.2 million in decommissioning AROs were reported in continuing operations (see Note 17) on the 2013 consolidated statement of operations. Estimates of AROs are evaluated annually in the fourth quarter, or more frequently if material new information becomes known. Accounting for asset retirement obligations requires significant estimation and in certain cases, the Company has determined that an ARO exists, but the amount of the obligation is not reasonably estimable. The Company may determine that additional AROs are required to be recognized as new information becomes available.
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 on the statement 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. Generally under these contracts, which are 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 December 31, 2015 , the Company had entered into financial hedging arrangements primarily at the request of its customers, related to firm orders, for an aggregate notional amount of approximately 26 million pounds of nickel with hedge dates through 2020 . The aggregate notional amount hedged is approximately 28% of a single year’s estimated nickel raw material purchase requirements. At December 31, 2015 , the outstanding financial derivatives used to hedge the Company’s exposure to energy cost volatility included natural gas hedges. In the fourth quarter 2015, due to changes in expected operating levels within Flat Rolled Products segment operations, the Company concluded that a portion of these natural gas cash hedges for 2016 were ineffective based on forecast changes in underlying natural gas usage. The Company recognized a $3.3 million pre-tax loss for the ineffective portion of these cash flow hedges, which is reported in selling and administrative expenses on the consolidated statement of operations for the year ended December 31, 2015 . Approximately 55% of the Company’s annual forecasted domestic requirements for natural gas for 2017 and approximately 15% for 2018 are hedged. While the majority of the Company’s direct export sales are transacted in U.S. dollars, foreign currency exchange contracts are used, from time-to-time, to limit transactional exposure to changes in currency exchange rates for those transactions denominated in a non-U.S. currency. The Company sometimes purchases foreign currency forward contracts that permit it to sell specified amounts of foreign currencies expected to be received from its export sales for pre-established U.S. dollar amounts at specified dates. The forward contracts are denominated in the same foreign currencies in which export sales are denominated. These contracts are designated as hedges of the variability in cash flows of a portion of the forecasted future export sales transactions which otherwise would expose the Company to foreign currency risk, primarily the euro. In addition, the Company may also designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions. During the fiscal year ended December 31, 2015 , the Company net settled 211.9 million euro notional value of foreign currency forward contracts designated as cash flow hedges with 2016 and 2017 maturity dates, receiving cash proceeds of $56.5 million which is reported in cash provided by operating activities on the consolidated cash flow statement. In the fourth quarter 2015, due to management actions in the Flat Rolled Products segment to de-emphasize commodity stainless steel sheet products in 2016, the Company concluded that a portion of these settled euro cash flow hedges for 2016 were ineffective based on forecast changes for euro-denominated sales. The Company recognized a $14.3 million pre-tax gain for the ineffective portion of these cash flow hedges, which is reported in selling and administrative expenses on the consolidated statement of operations for the year ended December 31, 2015 . 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 will be reclassified to earnings when the underlying transactions occur. In 2015, the Company entered into 244.7 million euro notional value of foreign currency forward contracts designated as fair value hedges with 2015, 2016 and 2017 maturity dates to replace a portion of the settled euro cash flow hedges, of which 139.2 million euro notional value was outstanding as of December 31, 2015 . The Company recorded a $9.0 million benefit in costs of sales on the consolidated statement of operations in the fiscal year ended December 31, 2015 , 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 were 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 counterpart 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.
Pension Plans and Other Postretirement Benefits	Pension Plans and Other Postretirement Benefits The Company has defined benefit pension plans or defined contribution retirement plans covering substantially all employees. Benefits under the defined benefit pension plans are generally based on years of service and/or final average pay. The Company funds the U.S. pension plans in accordance with the Employee Retirement Income Security Act of 1974, as amended, and the Internal Revenue Code (“Code”). The Company also sponsors several postretirement plans covering certain salaried and hourly employees. The plans provide health care and life insurance benefits for eligible retirees. In most retiree health care plans, Company contributions towards premiums are capped based on the cost as of a certain date, thereby creating a defined contribution. For the non-collectively bargained plans, the Company maintains the right to amend or terminate the plans at its discretion.

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Discontinued operations, income from operations	The following table presents summarized results for these discontinued operations (in millions): 2014 2013 Sales $ 14.9 $ 268.2 Income (loss) before income taxes $ (0.9 ) $ 414.2

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2015
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories at December 31, 2015 and 2014 were as follows (in millions): 2015 2014 Raw materials and supplies $ 216.0 $ 249.3 Work-in-process 990.3 1,184.1 Finished goods 184.1 172.2 Total inventories at current cost 1,390.4 1,605.6 Adjustment from current cost to LIFO cost basis 136.4 4.8 Inventory valuation reserves (206.3 ) (68.8 ) Progress payments (48.9 ) (68.8 ) Total inventories, net $ 1,271.6 $ 1,472.8
Schedule of Inventory Valuation Impact on Income	Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV reserves were as follows (in millions): Fiscal year ended December 31, 2015 2014 2013 LIFO benefit (charge) $ 131.6 $ (24.7 ) $ 80.9 NRV benefit (charge) $ (131.5 ) $ 25.0 $ (35.0 ) Net cost of sales impact $ 0.1 $ 0.3 $ 45.9

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Schedule of property plant and equipment, net	Property, plant and equipment at December 31, 2015 and 2014 was as follows: (In millions) 2015 2014 Land $ 31.0 $ 30.2 Buildings 1,048.2 1,048.9 Equipment and leasehold improvements 3,858.1 3,702.5 4,937.3 4,781.6 Accumulated depreciation and amortization (2,009.1 ) (1,819.8 ) Total property, plant and equipment, net $ 2,928.2 $ 2,961.8
Schedule depreciation and amortization	Depreciation and amortization from continuing operations for the years ended December 31, 2015 , 2014 and 2013 was as follows: (In millions) 2015 2014 2013 Depreciation of property, plant and equipment $ 159.6 $ 146.7 $ 156.8 Software and other amortization 30.3 29.9 23.8 Total depreciation and amortization $ 189.9 $ 176.6 $ 180.6

Goodwill and Other Intangible35

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Other intangible assets, which are included in Other assets on the accompanying consolidated balance sheets as of December 31, 2015 and 2014 were as follows: December 31, 2015 December 31, 2014 (in millions) Weighted Average Useful life (years) Gross carrying amount Accumulated amortization Gross carrying amount Accumulated amortization Technology 21 $ 91.4 $ (18.6 ) $ 91.4 $ (14.2 ) Customer relationships 24 35.7 (6.2 ) 35.7 (4.7 ) Trademarks 15 64.6 (8.6 ) 64.6 (4.3 ) Total amortizable intangible assets 191.7 (33.4 ) 191.7 (23.2 )

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Schedule of changes in asset retirement obligations	Changes in asset retirement obligations for the years ended December 31, 2015 and 2014 were as follows: (In millions) 2015 2014 Balance at beginning of year $ 25.4 $ 27.7 Accretion expense 0.6 0.9 Payments (0.8 ) (2.2 ) Revision of estimates (0.2 ) (1.0 ) Balance at end of year $ 25.0 $ 25.4

Supplemental Financial Statem37

Supplemental Financial Statement Information (Tables)	12 Months Ended
	Dec. 31, 2015
Additional Financial Information Disclosure [Abstract]
Schedule of cash and cash equivalents	Cash and cash equivalents at December 31, 2015 and 2014 were as follows: (In millions) 2015 2014 Cash $ 149.3 $ 267.7 Other short-term investments 0.5 1.8 Total cash and cash equivalents $ 149.8 $ 269.5
Schedule of other non-operating income (expense)	Other income (expense) from continuing operations for the years ended December 31, 2015 , 2014 , and 2013 was as follows: (In millions) 2015 2014 2013 Rent and royalty income $ 2.0 $ 4.0 $ 0.9 Net gains (losses) on property and investments — 0.1 0.7 Other (0.4 ) — 0.1 Total other income, net $ 1.6 $ 4.1 $ 1.7

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of debt	Debt at December 31, 2015 and 2014 was as follows: (In millions) 2015 2014 Allegheny Technologies $500 million 5.875% Senior Notes due 2023 (a) $ 500.0 $ 500.0 Allegheny Technologies $500 million 5.95% Senior Notes due 2021 500.0 500.0 Allegheny Technologies $350 million 9.375% Senior Notes due 2019 350.0 350.0 Allegheny Ludlum 6.95% Debentures due 2025 150.0 150.0 Ladish Series B 6.14% Notes due 2016 (b) — 11.9 Ladish Series C 6.41% Notes due 2015 (c) — 10.3 U.S. revolving credit facilities — — Foreign credit agreements 1.4 — Industrial revenue bonds, due through 2020, and other 3.8 4.7 Debt issuance costs (d) (9.5 ) (10.9 ) Total short-term and long-term debt 1,495.7 1,516.0 Short-term debt and current portion of long-term debt 3.9 17.8 Total long-term debt $ 1,491.8 $ 1,498.2 (a) Bearing interest at 7.625% effective August 15, 2015. (b) Includes fair value adjustment of $0.4 million at December 31, 2014 . (c) Includes fair value adjustment of $0.3 million at December 31, 2014 . (d) In April 2015, the FASB issued new guidance on the presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015.

Derivative Financial Instrume39

Derivative Financial Instruments and Hedging (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of derivative instruments	(In millions) December 31, December 31, Asset derivatives Balance sheet location Derivatives designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets $ 1.6 $ 23.6 Nickel and other raw material contracts Prepaid expenses and other current assets — 1.1 Foreign exchange contracts Other assets 0.4 28.3 Nickel and other raw material contracts Other assets — 0.5 Total derivatives designated as hedging instruments: $ 2.0 $ 53.5 Derivatives not designated as hedging instruments: Foreign exchange contracts Prepaid expenses and other current assets 0.4 6.4 Total derivatives not designated as hedging instruments: 0.4 6.4 Total asset derivatives $ 2.4 $ 59.9 Liability derivatives Balance sheet location Derivatives designated as hedging instruments: Natural gas contracts Accrued liabilities $ 17.3 $ 10.2 Foreign exchange contracts Accrued liabilities 0.1 — Nickel and other raw material contracts Accrued liabilities 22.2 5.8 Electricity contracts Accrued liabilities — 0.1 Foreign exchange contracts Other long-term liabilities 0.1 — Natural gas contracts Other long-term liabilities 8.5 7.9 Nickel and other raw material contracts Other long-term liabilities 23.0 3.0 Total liability derivatives $ 71.2 $ 27.0 Derivatives not designated as hedging instruments: Foreign exchange contracts Accrued liabilities 0.1 — Total derivatives not designated as hedging instruments: 0.1 — Total liability derivatives $ 71.3 $ 27.0
Schedule of derivative instruments gain (loss)	Activity with regard to derivatives designated as cash flow hedges for the year ended December 31, 2015 were as follows (in millions): Derivatives in Cash Flow Hedging Relationships 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) 2015 2014 2015 2014 2015 2014 Nickel and other raw material contracts $ (34.2 ) $ (1.6 ) $ (10.5 ) $ (0.6 ) $ — $ — Natural gas contracts (14.1 ) (10.9 ) (9.2 ) 2.1 (2.1 ) — Electricity contracts — 0.5 (0.1 ) 0.4 — — Foreign exchange contracts 27.6 40.1 24.3 0.3 8.9 — Total $ (20.7 ) $ 28.1 $ 4.5 $ 2.2 $ 6.8 $ — (a) The gains (losses) reclassified from accumulated OCI into income related to the effective portion of the derivatives are presented in cost of sales in the same period or periods in which the hedged item affects earnings. (b) The gains (losses) recognized in income on derivatives related to the ineffective portion and the amount excluded from effectiveness testing are presented in selling and administrative expenses.
Schedule of derivatives not designated as hedging instruments, gain (loss)	These derivatives that are not designated as hedging instruments were as follows: (In millions) Amount of Gain (Loss) Recognized in Income on Derivatives Derivatives Not Designated as Hedging Instruments 2015 2014 Foreign exchange contracts $ 3.9 $ 5.2

Fair Value of Financial Instr40

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of financial instrument fair value	The estimated fair value of financial instruments at December 31, 2015 was as follows: Fair Value Measurements at Reporting Date Using (In millions) Total Carrying Amount Total Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Cash and cash equivalents $ 149.8 $ 149.8 $ 149.8 $ — Derivative financial instruments: Assets 2.4 2.4 — 2.4 Liabilities 71.3 71.3 — 71.3 Debt (a) 1,495.7 969.7 964.5 5.2 The estimated fair value of financial instruments at December 31, 2014 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 $ 269.5 $ 269.5 $ 269.5 $ — Derivative financial instruments: Assets 59.9 59.9 — 59.9 Liabilities 27.0 27.0 — 27.0 Debt (a) 1,516.0 1,616.0 1,589.1 26.9

Pension Plans and Other Postr41

Pension Plans and Other Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2015
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Schedule of defined benefit plans	The components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2013 2015 2014 2013 Service cost—benefits earned during the year $ 22.8 $ 29.4 $ 39.0 $ 2.7 $ 2.9 $ 3.2 Interest cost on benefits earned in prior years 121.0 133.6 122.8 17.9 24.0 22.4 Expected return on plan assets (168.3 ) (184.2 ) (176.0 ) (0.1 ) (0.3 ) (0.5 ) Amortization of prior service cost (credit) 1.3 2.3 3.0 4.9 (3.0 ) (18.2 ) Amortization of net actuarial loss 60.4 74.0 111.8 14.6 14.1 17.2 Curtailment (gain) loss — 0.5 — — (25.5 ) — Termination benefits — 0.3 4.8 — — 1.3 Total retirement benefit expense $ 37.2 $ 55.9 $ 105.4 $ 40.0 $ 12.2 $ 25.4
Schedule of assumptions used	Actuarial assumptions used to develop the components of defined benefit pension expense and other postretirement benefit expense were as follows: Pension Benefits Other Postretirement Benefits 2015 2014 2013 2015 2014 2013 Discount rate (a) 4.25 % 5.15 % 4.25 - 4.95% 4.10 % 5.15 % 4.25 % Rate of increase in future compensation levels 3.0 - 3.50% 3.0 - 3.50% 3.0 - 3.50% — — — Expected long-term rate of return on assets 8.00 % 8.25 % 8.25 % 4.0 % 8.3 % 8.3 % (a) Pension expense for 2013 was initially measured at a 4.25% discount rate. The U.S. Plan was remeasured using a 4.95% discount rate as of October 31, 2013, following the sale of the tungsten materials business.
Schedule of assumptions used for year end valuation	Actuarial assumptions used for the valuation of defined benefit pension and other postretirement benefit obligations at the end of the respective periods were as follows: Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 Discount rate 4.65 % 4.25 % 4.50 % 4.10 % Rate of increase in future compensation levels 3.0 - 3.5% 3.0 - 3.5% — —
Schedule of changes in projected benefit obligations	A reconciliation of the funded status for the Company’s defined benefit pension and other postretirement benefit plans at December 31, 2015 and 2014 was as follows: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Change in benefit obligations: Benefit obligation at beginning of year $ 2,953.9 $ 2,698.2 $ 466.1 $ 506.7 Service cost 22.8 29.4 2.7 2.9 Interest cost 121.0 133.6 17.9 24.0 Benefits paid (207.4 ) (269.9 ) (53.4 ) (54.3 ) Subsidy paid — — 0.7 1.0 Participant contributions 0.3 0.3 — — Effect of currency rates (4.8 ) (4.9 ) — — Net actuarial (gains) losses – discount rate change (124.4 ) 288.5 (14.1 ) 39.5 – other 44.5 78.4 (19.1 ) (19.5 ) Plan curtailments — — — (7.2 ) Plan settlements — — — (27.0 ) Special termination benefits — 0.3 — — Benefit obligation at end of year $ 2,805.9 $ 2,953.9 $ 400.8 $ 466.1
Schedule of changes in fair value of plan assets	Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Change in plan assets: Fair value of plan assets at beginning of year $ 2,204.4 $ 2,329.8 $ 2.9 $ 4.0 Actual returns on plan assets and plan expenses (41.1 ) 136.8 (1.0 ) (0.9 ) Employer contributions 10.3 11.5 — — Participant contributions 0.3 0.3 — — Effect of currency rates (4.2 ) (4.1 ) — — Benefits paid (207.4 ) (269.9 ) (0.1 ) (0.2 ) Fair value of plan assets at end of year $ 1,962.3 $ 2,204.4 $ 1.8 $ 2.9
Schedule of amounts recognized in balance sheet	Amounts recognized in the consolidated balance sheet: Current liabilities (9.8 ) (10.2 ) (39.8 ) (47.3 ) Noncurrent liabilities (833.8 ) (739.3 ) (359.2 ) (415.8 ) Total amount recognized $ (843.6 ) $ (749.5 ) $ (399.0 ) $ (463.1 )
Schedule of amounts recognized in other comprehensive income	Changes to accumulated other comprehensive loss related to pension and other postretirement benefit plans in 2015 and 2014 were as follows: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Beginning of year accumulated other comprehensive loss $ (1,352.1 ) $ (1,016.4 ) $ (152.9 ) $ (151.5 ) Amortization of net actuarial loss 60.4 74.0 14.6 14.1 Amortization of prior service cost (credit) 1.3 2.3 4.9 (3.0 ) Remeasurements (127.8 ) (412.0 ) 32.0 (12.5 ) End of year accumulated other comprehensive loss $ (1,418.2 ) $ (1,352.1 ) $ (101.4 ) $ (152.9 ) Net change in accumulated other comprehensive loss $ (66.1 ) $ (335.7 ) $ 51.5 $ (1.4 )
Schedule of net periodic benefit cost not yet recognized	Amounts included in accumulated other comprehensive loss at December 31, 2015 and 2014 were as follows: Pension Benefits Other Postretirement Benefits (In millions) 2015 2014 2015 2014 Prior service cost $ (3.6 ) $ (4.9 ) $ (6.9 ) $ (11.8 ) Net actuarial loss (1,414.6 ) (1,347.2 ) (94.5 ) (141.1 ) Accumulated other comprehensive loss (1,418.2 ) (1,352.1 ) (101.4 ) (152.9 ) Deferred tax effect 529.9 514.7 38.5 58.8 Accumulated other comprehensive loss, net of tax $ (888.3 ) $ (837.4 ) $ (62.9 ) $ (94.1 )
Schedule of amounts in accumulated other comprehensive income to be recognized	Amounts in accumulated other comprehensive loss that are expected to be recognized as components of net periodic benefit cost in 2016 are: (In millions) Pension Benefits Other Postretirement Benefits Total Amortization of prior service cost $ 1.3 $ 4.9 $ 6.2 Amortization of net actuarial loss 65.4 9.5 74.9 Amortization of accumulated other comprehensive loss $ 66.7 $ 14.4 $ 81.1
Schedule of accumulated benefit obligations in excess of fair value of plan assets	Additional information for pension plans with accumulated benefit obligations in excess of plan assets: Pension Benefits (In millions) 2015 2014 Projected benefit obligation $ 2,805.9 $ 2,953.9 Accumulated benefit obligation $ 2,767.0 $ 2,917.3 Fair value of plan assets $ 1,962.3 $ 2,204.4
Schedule of expected benefit payments	The following table summarizes expected benefit payments from the Company’s various pension and other postretirement benefit defined benefit plans through 2025, and also includes estimated Medicare Part D subsidies projected to be received during this period based on currently available information. (In millions) Pension Benefits Other Postretirement Benefits Medicare Part D Subsidy 2016 $ 200.2 $ 42.6 $ 1.1 2017 195.0 35.7 1.0 2018 194.4 34.5 1.0 2019 191.7 34.2 1.0 2020 190.5 34.3 0.9 2021 - 2025 917.8 144.6 3.9
Schedule of effect of one-percentage-point change in assumed health care cost trend rates	A one percentage point change in assumed health care cost trend rates would have the following effects: (In millions) One Percentage Point Increase One Percentage Point Decrease Effect on total of service and interest cost components for the year ended December 31, 2015 $ 0.5 $ (0.4 ) Effect on other postretirement benefit obligation at December 31, 2015 $ 7.6 $ (6.8 )
Schedule of allocation of plan assets	The fair values of the Company’s pension plan assets at December 31, 2015 by asset category and by the level of inputs used to determine fair value, were as follows: (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Asset category Total (Level 1) (Level 2) (Level 3) Equity securities: ATI common stock $ 33.2 $ 33.2 $ — $ — Other U.S. equities (a) 522.0 254.1 267.9 — International equities (b) 239.8 — 239.8 — Global debt securities and cash: (c) Fixed income and cash equivalents 369.7 0.2 361.0 8.5 Floating rate 358.0 — — 358.0 Private equity 201.2 — — 201.2 Hedge funds 51.9 — — 51.9 Real estate and other 186.5 — 5.9 180.6 Total assets $ 1,962.3 $ 287.5 $ 874.6 $ 800.2 (a) Includes investments in commingled funds that invest in U.S. equity securities, comprised of approximately 90% large-cap U.S. companies and 10% small-cap U.S. companies. (b) Includes investments in commingled funds that invest in non-U.S. equity securities, comprised of approximately 90% developed countries and 10% emerging market economies. (c) Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments. The fair values of the Company’s pension plan assets at December 31, 2014 by asset category and by the level of inputs used to determine fair value, were as follows: (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Asset category Total (Level 1) (Level 2) (Level 3) Equity securities: ATI common stock $ 102.7 $ 102.7 $ — $ — Other U.S. equities (a) 673.8 306.1 367.7 — International equities (b) 238.2 — 238.2 — Global debt securities and cash: (c) Fixed income and cash equivalents 383.5 0.7 373.9 8.9 Floating rate 392.3 — — 392.3 Private equity 172.6 — — 172.6 Hedge funds 84.7 — — 84.7 Real estate and other 156.6 — 5.4 151.2 Total assets $ 2,204.4 $ 409.5 $ 985.2 $ 809.7 (a) Includes investments in commingled funds that invest in U.S. equity securities, comprised of approximately 90% large-cap U.S. companies and 10% small-cap U.S. companies. (b) Includes investments in commingled funds that invest in non-U.S. equity securities, comprised of approximately 80% developed countries and 20% emerging market economies. (c) Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments.
Changes in fair value of level 3 plan investments	Changes in the fair value of Level 3 pension plan assets for the year ended December 31, 2015 were as follows: (In millions) January 1, 2015 Balance Net Realized and Unrealized Gains (Losses) Net Purchases, Issuances and Settlements Net Transfers Into (Out Of) Level 3 December 31, 2015 Balance Global debt securities and cash: Fixed income and cash equivalents $ 8.9 $ — $ (0.4 ) $ — $ 8.5 Floating rate debt 392.3 6.8 (41.1 ) — 358.0 Private equity 172.6 11.7 16.9 — 201.2 Hedge funds 84.7 2.5 (35.3 ) — 51.9 Real estate and other 151.2 22.5 6.9 — 180.6 Total $ 809.7 $ 43.5 $ (53.0 ) $ — $ 800.2 Changes in the fair value of Level 3 pension plan assets for the year ended December 31, 2014 were as follows: (In millions) January 1, 2014 Balance Net Realized and Unrealized Gains (Losses) Net Purchases, Issuances and Settlements Net Transfers Into (Out Of) Level 3 December 31, 2014 Balance Global debt securities and cash: Fixed income and cash equivalents $ 0.8 $ 0.1 $ 8.0 $ — $ 8.9 Floating rate debt 294.5 4.6 93.2 — 392.3 Private equity 123.0 20.5 29.1 — 172.6 Hedge funds 111.2 4.5 (31.0 ) — 84.7 Real estate and other 125.8 13.7 11.7 — 151.2 Total $ 655.3 $ 43.4 $ 111.0 $ — $ 809.7
Schedule of target asset allocations for pension plans	The target asset allocations for pension plans for 2016 , by major investment category, are: Asset category Target asset allocation range Equity securities: U. S. equities 18% - 40% International equities 7% - 17% Global debt securities and cash 35% - 55% Private equity* 0% - 10% Hedge funds* 0% - 10% Real estate and other* 0% - 10% * Have a combined target allocation of 18% and a 20% limit.
Schedule of multiemployer plans	The Company’s participation in multiemployer plans for the years ended December 31, 2015 , 2014 and 2013 is reported in the following table. The Company’s contributions to the Steelworkers Western Independent Shops Pension Plan exceed 5% of this plan’s total contributions for the plan year ended September 30, 2014, which is the most recent information available from the Plan Administrator. Pension Protection Act Zone Status (1) FIP / RP Status Pending / Implemented (2) in millions Expiration Dates of Collective Bargaining Agreements EIN / Pension Plan Number Company Contributions Surcharge Imposed (3) Pension Fund 2015 2014 2015 2014 2013 Steelworkers Western Independent Shops Pension Plan 90-0169564 / 001 Green Green N/A $ 0.7 $ 1.1 $ 1.0 No 6/30/2015 Boilermakers-Blacksmiths National Pension Trust 48-6168020 / 001 Yellow Yellow Yes 1.8 2.0 2.2 No 9/30/2018 IAM National Pension Fund 51-6031295 / 002 Green Green N/A 1.5 1.6 1.8 No Various between 2018-2019 (4) Total contributions $ 4.0 $ 4.7 $ 5.0 (1) The most recent Pension Protection Act Zone Status available for ATI’s fiscal years 2015 and 2014 is for plan years ending in calendar years 2014 and 2013 , respectively. The zone status is based on information provided to ATI and other participating employers by each plan and is certified by the plan’s actuary. A plan in the “red” zone had been determined to be in “critical status”, based on criteria established by the Code, and is generally less than 65% funded. A plan in the “yellow” zone has been determined to be in “endangered status”, based on criteria established under the Code, and is generally less than 80% funded. A plan in the “green” zone has been determined to be neither in “critical status” nor in “endangered status”, and is generally at least 80% funded. (2) The “FIP / RP status Pending / Implemented” column indicates whether a Funding Improvement Plan, as required under the Code by plans in the “yellow” zone, or a Rehabilitation Plan, as required under the Code to be adopted by plans in the “red” zone, is pending or has been implemented as of the end of the plan year that ended in 2015 . (3) The “Surcharge Imposed” column indicates whether ATI’s contribution rate for 2015 included an amount in addition to the contribution rate specified in the applicable collective bargaining agreement, as imposed by a plan in “critical status”, in accordance with the requirements of the Code. (4) The Company is party to five separate bargaining agreements that require contributions to this plan. Expiration dates of these collective bargaining agreements range between February 25, 2018 and July 14, 2019.

Accumulated Other Comprehensi42

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of accumulated other comprehensive income (loss)	The changes in accumulated other comprehensive income (loss) (AOCI) by component, net of tax, for the fiscal years ended December 31, 2015 , 2014 and 2013 were as follows (in millions): Post- retirement benefit plans Currency translation adjustment Unrealized holding gains on securities Derivatives Total Attributable to ATI: Balance, December 31, 2012 $ (1,030.0 ) $ 3.4 $ (0.1 ) $ (2.7 ) $ (1,029.4 ) OCI before reclassifications 241.1 10.4 0.1 (15.5 ) 236.1 Amounts reclassified from AOCI (a) 70.0 (b) 1.5 (c) — (d) 8.6 80.1 Net current-period OCI 311.1 11.9 0.1 (6.9 ) 316.2 Balance, December 31, 2013 (718.9 ) 15.3 — (9.6 ) (713.2 ) OCI before reclassifications (266.4 ) (32.0 ) — 28.1 (270.3 ) Amounts reclassified from AOCI (a) 53.8 (b) 0.5 (c) — (d) (2.2 ) 52.1 Net current-period OCI (212.6 ) (31.5 ) — 25.9 (218.2 ) Balance, December 31, 2014 (931.5 ) (16.2 ) — 16.3 (931.4 ) OCI before reclassifications (69.6 ) (31.4 ) — (20.7 ) (121.7 ) Amounts reclassified from AOCI (a) 49.9 (c) — (c) — (d) (11.3 ) 38.6 Net current-period OCI (19.7 ) (31.4 ) — (32.0 ) (83.1 ) Balance, December 31, 2015 $ (951.2 ) $ (47.6 ) $ — $ (15.7 ) $ (1,014.5 ) Attributable to noncontrolling interests: Balance, December 31, 2012 $ — $ 23.7 $ — $ — $ 23.7 OCI before reclassifications — 3.4 — — 3.4 Amounts reclassified from AOCI — (c) — — — — Net current-period OCI — 3.4 — — 3.4 Balance, December 31, 2013 — 27.1 — — 27.1 OCI before reclassifications — (2.1 ) — — (2.1 ) Amounts reclassified from AOCI — (c) — — — — Net current-period OCI — (2.1 ) — — (2.1 ) Balance, December 31, 2014 — 25.0 — — 25.0 OCI before reclassifications — (5.6 ) — — (5.6 ) Amounts reclassified from AOCI — (c) — — — — Net current-period OCI — (5.6 ) — — (5.6 ) Balance, December 31, 2015 $ — $ 19.4 $ — $ — $ 19.4 (a) Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 12). (b) Amount in 2014 is included in other income, net, and amount in 2013 is included in discontinued operations as part of the gain on sale of the tungsten materials business (see Note 3). (c) No amounts were reclassified to earnings. (d) 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 statements of operations (see Note 10).
Reclassification out of accumulated other comprehensive income	Reclassifications out of AOCI for the fiscal years ended December 31, 2015 , 2014 and 2013 were as follows: Amount reclassified from AOCI (d) Fiscal year ended Details about AOCI Components (In millions) December 31, 2015 December 31, 2014 December 31, 2013 Affected line item in the consolidated statement of operations Postretirement benefit plans Prior service credit (cost) $ (6.2 ) (a) $ 0.7 (a) 15.2 (a) Actuarial losses (75.0 ) (a) (88.1 ) (a) (129.0 ) (a) (81.2 ) (d) (87.4 ) (d) (113.8 ) (d) Total before tax (31.3 ) (33.6 ) (43.8 ) Tax benefit $ (49.9 ) $ (53.8 ) $ (70.0 ) Net of tax Currency translation adjustment $ — (d) $ (0.5 ) (b) , (d) $ (1.5 ) (b) , (d) Derivatives Nickel and other raw material contracts $ (16.9 ) (c) $ (1.0 ) (c) $ (8.8 ) (c) Natural gas contracts (18.2 ) (c) 3.4 (c) (3.8 ) (c) Electricity contracts (0.2 ) (c) 0.7 (c) (0.3 ) (c) Foreign exchange contracts 53.5 (c) 0.5 (c) (1.1 ) (c) 18.2 (d) 3.6 (d) (14.0 ) (d) Total before tax 6.9 1.4 (5.4 ) Tax provision (benefit) $ 11.3 $ 2.2 $ (8.6 ) 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 12. (b) Amount in 2014 is included in other income, net, and amount in 2013 is included in discontinued operations as part of the gain on sale of the tungsten materials business (see Note 3). (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 statements of operations (see Note 10). (d) 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.

Stockholders' Equity Stockholde

Stockholders' Equity Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Nonvested stock rollforward	Activity under the Company’s nonvested stock awards for the years ended December 31, 2015 , 2014 , and 2013 was as follows: (Shares in thousands, $ in millions) 2015 2014 2013 Number of shares Weighted Average Grant Date Fair Value Number of shares Weighted Average Grant Date Fair Value Number of shares Weighted Average Grant Date Fair Value Nonvested, beginning of year 1,376 $ 47.8 927 $ 36.9 727 $ 38.6 Granted 669 20.8 675 20.3 576 16.4 Vested (23 ) (0.8 ) (18 ) (1.0 ) (333 ) (16.4 ) Forfeited (370 ) (10.8 ) (208 ) (8.4 ) (43 ) (1.7 ) Nonvested, end of year 1,652 $ 57.0 1,376 $ 47.8 927 $ 36.9
Tsr/Tsrp Award Performance	The estimated fair value of each performance equity award, the projected shares to be awarded and future compensation expense to be recognized for these awards, including actual and estimated forfeitures, was as follows: (Shares in thousands, $ in millions) TSR / TSRP Award Performance Period Award Fair Value December 31, 2015 Unrecognized Compensation Expense Minimum Shares Target Shares Maximum Shares 2013 - 2015 $ 10.5 $ — — 296 592 2014 - 2016 $ 9.3 3.1 — 277 554 2015 - 2017 $ 13.4 8.9 — 296 592 Total $ 12.0 — 869 1,738

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule income tax provision (benefit)	The income tax provision (benefit) was as follows: (In millions) 2015 2014 2013 Continuing operations: Current: Federal $ (60.7 ) $ (47.9 ) $ (127.5 ) State (0.4 ) (4.0 ) (10.2 ) Foreign 9.4 9.8 7.9 Total (51.7 ) (42.1 ) (129.8 ) Deferred: Federal (90.9 ) 34.1 62.7 State 30.4 (0.2 ) 4.6 Foreign 0.1 (0.5 ) (1.1 ) Total (60.4 ) 33.4 66.2 Income tax benefit from continuing operations $ (112.1 ) $ (8.7 ) $ (63.6 ) Income tax provision (benefit) from discontinued operations $ — $ (0.3 ) $ 161.4 Total company income tax provision (benefit) $ (112.1 ) $ (9.0 ) $ 97.8
Schedule of effective income tax rate reconciliation	The following is a reconciliation of income taxes computed at the statutory U.S. Federal income tax rate to the actual effective income tax benefit from continuing operations: Income Tax Provision (Benefit) (In millions) 2015 2014 2013 Taxes computed at the federal rate $ (167.3 ) $ 0.5 $ (54.2 ) State and local income taxes, net of federal tax benefit (20.6 ) (2.0 ) (11.8 ) Tax reserve adjustments 3.9 (0.5 ) (10.2 ) Repatriation of foreign earnings 13.4 0.3 9.4 Valuation allowance 74.5 0.5 9.1 Adjustment to prior years’ taxes (5.4 ) 0.1 (5.3 ) Foreign earnings taxed at different rate (11.2 ) (6.6 ) (2.5 ) Other 0.6 (1.0 ) 1.9 Income tax benefit $ (112.1 ) $ (8.7 ) $ (63.6 )
Schedule of income before income tax	Income (loss) from continuing operations before income taxes for the Company’s U.S. and non-U.S. operations was as follows: (In millions) 2015 2014 2013 U.S. $ (534.6 ) $ (46.1 ) $ (180.0 ) Non-U.S. 56.6 47.6 25.2 Income (loss) from continuing operations before income taxes $ (478.0 ) $ 1.5 $ (154.8 )
Schedule of income taxes paid	Income taxes paid and amounts received as refunds were as follows: (In millions) 2015 2014 2013 Income taxes paid $ 10.8 $ 15.1 $ 21.4 Income tax refunds received (63.3 ) (20.2 ) (18.3 ) Income taxes paid (received), net $ (52.5 ) $ (5.1 ) $ 3.1
Schedule of deferred tax assets and liabilities	The categories of assets and liabilities that have resulted in differences in the timing of the recognition of income and expense at December 31, 2015 and 2014 were as follows: (In millions) 2015 2014 Deferred income tax assets Pensions $ 281.0 $ 251.8 Postretirement benefits other than pensions 144.7 169.0 Federal and state net operating loss tax carryovers 228.1 122.7 Federal and state tax credits 52.2 53.6 Deferred compensation and other benefit plans 25.9 25.6 Self insurance reserves 10.8 10.1 Other items 85.2 79.1 Gross deferred income tax assets 827.9 711.9 Valuation allowance for deferred tax assets (105.1 ) (34.4 ) Total deferred income tax assets 722.8 677.5 Deferred income tax liabilities Bases of property, plant and equipment 664.1 579.5 Inventory valuation 62.2 111.7 Bases of amortizable intangible assets 25.4 75.5 Other items 46.7 53.9 Total deferred tax liabilities 798.4 820.6 Net deferred tax liability $ (75.6 ) $ (143.1 )
Schedule of changes in unrecognized income tax benefits	The changes in the liability for unrecognized income tax benefits for the years ended December 31, 2015 , 2014 and 2013 were as follows: (In millions) 2015 2014 2013 Balance at beginning of year $ 73.4 $ 72.8 $ 29.2 Increases in prior period tax positions 4.2 2.0 0.1 Decreases in prior period tax positions (0.6 ) (0.6 ) (5.8 ) Increases in current period tax positions 1.3 0.7 60.4 Expiration of the statute of limitations (0.7 ) (0.5 ) (0.7 ) Settlements (62.1 ) (0.7 ) (8.6 ) Interest and penalties, net (0.5 ) (0.3 ) (1.8 ) Balance at end of year $ 15.0 $ 73.4 $ 72.8
Summary of income tax examinations	A summary of tax years that remain subject to examination, by major tax jurisdiction, is as follows: Jurisdiction Earliest Year Open to Examination U.S. Federal 2014 States: Alabama 2012 Illinois 2012 North Carolina 2010 Oregon 2012 Pennsylvania 2012 Foreign: China 2011 Germany 2014 Poland 2011 United Kingdom 2012

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Schedule of sales by segment	(In millions) 2015 2014 2013 Total sales: High Performance Materials & Components $ 2,062.7 $ 2,084.6 $ 2,016.7 Flat Rolled Products 1,807.9 2,320.2 2,146.6 Total sales 3,870.6 4,404.8 4,163.3 Intersegment sales: High Performance Materials & Components 76.8 77.8 71.9 Flat Rolled Products 74.2 103.6 47.9 Total intersegment sales 151.0 181.4 119.8 Sales to external customers: High Performance Materials & Components 1,985.9 2,006.8 1,944.8 Flat Rolled Products 1,733.7 2,216.6 2,098.7 Total sales to external customers $ 3,719.6 $ 4,223.4 $ 4,043.5
Schedule of operating profit (loss) by segment	(In millions) 2015 2014 2013 Operating profit (loss): High Performance Materials & Components $ 157.1 $ 234.8 $ 159.6 Flat Rolled Products (241.9 ) (47.0 ) (147.8 ) Total operating profit (loss) (84.8 ) 187.8 11.8 LIFO and net realizable value reserves (See Note 4) 0.1 0.3 45.9 Corporate expenses (44.7 ) (49.6 ) (48.9 ) Closed company and other expenses (22.1 ) (28.3 ) (30.9 ) Impairment of goodwill (See Note 6) (126.6 ) — — Restructuring and other charges (89.7 ) — (67.5 ) Interest expense, net (110.2 ) (108.7 ) (65.2 ) Income (loss) before income taxes $ (478.0 ) $ 1.5 $ (154.8 )
Schedule of other financial information by segment	Certain additional information regarding the Company’s business segments is presented below: (In millions) 2015 2014 2013 Depreciation and amortization: High Performance Materials & Components $ 131.8 $ 124.4 $ 127.4 Flat Rolled Products 55.6 49.3 49.5 Corporate 2.5 2.9 3.7 Total depreciation and amortization 189.9 176.6 180.6 Capital expenditures: High Performance Materials & Components 75.8 51.9 39.5 Flat Rolled Products 68.0 172.1 568.1 Corporate 0.7 1.7 0.2 Total capital expenditures 144.5 225.7 607.8 Identifiable assets: 2015 2014 2013 High Performance Materials & Components 3,355.5 3,555.8 3,452.2 Flat Rolled Products 2,189.5 2,601.6 2,320.9 Discontinued Operations 0.9 1.8 9.8 Corporate: Prepaid pension cost — — 5.1 Cash and cash equivalents and other 205.8 412.5 1,097.0 Total assets $ 5,751.7 $ 6,571.7 $ 6,885.0
Schedule of revenue by country	Geographic information for external sales based on country of destination, and assets, are as follows: ($ in millions) 2015 Percent of total 2014 Percent of total 2013 Percent of total External sales: United States $ 2,142.6 58 % $ 2,615.9 62 % $ 2,458.4 61 % China 246.9 7 % 249.6 6 % 237.7 6 % Japan 202.3 5 % 89.3 2 % 124.7 3 % United Kingdom 198.2 5 % 228.4 5 % 251.5 6 % Germany 193.3 5 % 207.7 5 % 215.4 5 % Canada 154.5 4 % 147.0 3 % 141.0 4 % France 153.3 4 % 168.1 4 % 152.8 4 % Mexico 78.4 2 % 76.5 2 % 54.9 1 % Italy 65.0 2 % 160.7 4 % 132.3 3 % Other 285.1 8 % 280.2 7 % 274.8 7 % Total External Sales $ 3,719.6 100 % $ 4,223.4 100 % $ 4,043.5 100 %
Schedule of company assets by country	($ in millions) 2015 Percent of total 2014 Percent of total 2013 Percent of total Total assets: United States $ 5,073.1 88 % $ 5,868.7 90 % $ 6,131.9 89 % China 260.0 5 % 280.5 4 % 258.1 4 % United Kingdom 154.3 3 % 196.3 3 % 208.0 3 % Luxembourg (a) 124.4 2 % 81.8 1 % 145.9 2 % Other 139.9 2 % 144.4 2 % 141.1 2 % Total Assets $ 5,751.7 100 % $ 6,571.7 100 % $ 6,885.0 100 % (a) Comprises assets held by the Company’s European Treasury Center operation.

Per Share Information (Tables)

Per Share Information (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule earnings per share	The following table sets forth the computation of basic and diluted income (loss) from continuing operations per common share: (In millions, except per share amounts) For the Years Ended December 31, 2015 2014 2013 Numerator: Numerator for basic loss from continuing operations per common share - Loss from continuing operations attributable to ATI $ (377.9 ) $ (2.0 ) $ (98.8 ) Redeemable noncontrolling interest (Note 18) (0.3 ) (0.3 ) — Effect of dilutive securities: 4.25% Convertible Senior Notes due 2014 — — — Numerator for diluted net loss per common share - Loss from continuing operations attributable to ATI after assumed conversions $ (378.2 ) $ (2.3 ) $ (98.8 ) Denominator: Denominator for basic net loss per common share—weighted average shares 107.3 107.1 106.8 Effect of dilutive securities: Share-based compensation — — — 4.25% Convertible Senior Notes due 2014 — — — Denominator for diluted net loss per common share—adjusted weighted average shares and assumed conversions 107.3 107.1 106.8 Basic loss from continuing operations attributable to ATI per common share $ (3.53 ) $ (0.02 ) $ (0.93 ) Diluted loss from continuing operations attributable to ATI per common share $ (3.53 ) $ (0.02 ) $ (0.93 )

Financial Information for Sub47

Financial Information for Subsidiary and Guarantor Parent (Tables)	12 Months Ended
	Dec. 31, 2015
Financial Information for Subsidiary and Guarantor Parent [Abstract]
Schedule of condensed consolidating balance sheets	Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Balance Sheets December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 2.2 $ 13.8 $ 253.5 $ — $ 269.5 Accounts receivable, net 0.1 209.1 394.4 — 603.6 Intercompany notes receivable — — 2,390.8 (2,390.8 ) — Inventories, net — 387.7 1,085.1 — 1,472.8 Prepaid expenses and other current assets 63.7 13.2 59.3 — 136.2 Total current assets 66.0 623.8 4,183.1 (2,390.8 ) 2,482.1 Property, plant and equipment, net 2.2 1,545.1 1,414.5 — 2,961.8 Goodwill — 126.6 653.8 — 780.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investments in subsidiaries 6,149.4 37.7 — (6,187.1 ) — Other assets 13.3 27.5 306.6 — 347.4 Total assets $ 6,230.9 $ 2,360.7 $ 6,758.0 $ (8,777.9 ) $ 6,571.7 Liabilities and stockholders’ equity: Accounts payable $ 4.5 $ 302.0 $ 250.2 $ — $ 556.7 Accrued liabilities 47.5 72.0 203.7 — 323.2 Intercompany notes payable 1,232.6 1,158.2 — (2,390.8 ) — Short-term debt and current portion of long-term debt 0.5 0.1 17.2 — 17.8 Total current liabilities 1,285.1 1,532.3 471.1 (2,390.8 ) 897.7 Long-term debt 1,340.2 149.8 8.2 — 1,498.2 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 153.0 262.8 — 415.8 Pension liabilities 675.5 6.0 57.8 — 739.3 Deferred income taxes 143.1 — — — 143.1 Other long-term liabilities 77.7 22.5 56.0 — 156.2 Total liabilities 3,521.6 2,063.6 855.9 (2,590.8 ) 3,850.3 Redeemable noncontrolling interest — — 12.1 — 12.1 Total stockholders’ equity 2,709.3 297.1 5,890.0 (6,187.1 ) 2,709.3 Total liabilities and stockholders’ equity $ 6,230.9 $ 2,360.7 $ 6,758.0 $ (8,777.9 ) $ 6,571.7 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Balance Sheets December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Assets: Cash and cash equivalents $ 0.4 $ 2.8 $ 146.6 $ — $ 149.8 Accounts receivable, net 0.1 100.3 299.9 — 400.3 Intercompany notes receivable — — 2,601.5 (2,601.5 ) — Inventories, net — 239.9 1,031.7 — 1,271.6 Prepaid expenses and other current assets 9.3 3.8 32.8 — 45.9 Total current assets 9.8 346.8 4,112.5 (2,601.5 ) 1,867.6 Property, plant and equipment, net 2.2 1,559.9 1,366.1 — 2,928.2 Goodwill — — 651.4 — 651.4 Intercompany notes receivable — — 200.0 (200.0 ) — Investments in subsidiaries 5,742.5 37.7 — (5,780.2 ) — Other assets 13.4 23.0 268.1 — 304.5 Total assets $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7 Liabilities and stockholders’ equity: Accounts payable $ 4.8 $ 171.1 $ 204.9 $ — $ 380.8 Accrued liabilities 42.1 74.0 185.7 — 301.8 Intercompany notes payable 1,325.4 1,276.1 — (2,601.5 ) — Short-term debt and current portion of long-term debt 0.7 0.1 3.1 — 3.9 Total current liabilities 1,373.0 1,521.3 393.7 (2,601.5 ) 686.5 Long-term debt 1,341.7 149.7 0.4 — 1,491.8 Intercompany notes payable — 200.0 — (200.0 ) — Accrued postretirement benefits — 280.0 79.2 — 359.2 Pension liabilities 778.0 5.2 50.6 — 833.8 Deferred income taxes 75.6 — — — 75.6 Other long-term liabilities 15.2 20.7 72.4 — 108.3 Total liabilities 3,583.5 2,176.9 596.3 (2,801.5 ) 3,555.2 Redeemable noncontrolling interest — — 12.1 — 12.1 Total stockholders’ equity 2,184.4 (209.5 ) 5,989.7 (5,780.2 ) 2,184.4 Total liabilities and stockholders’ equity $ 5,767.9 $ 1,967.4 $ 6,598.1 $ (8,581.7 ) $ 5,751.7
Schedule of condensed consolidating statements of operations	Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations For the year ended December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,453.2 $ 2,266.4 $ — $ 3,719.6 Cost of sales 27.3 1,643.2 1,988.8 — 3,659.3 Selling and administrative expenses 88.2 29.4 121.2 — 238.8 Impairment of goodwill — 126.6 — — 126.6 Restructuring charges 1.6 58.0 4.7 — 64.3 Income (loss) before interest, other income and income taxes (117.1 ) (404.0 ) 151.7 — (369.4 ) Interest income (expense), net (117.3 ) (50.9 ) 58.0 — (110.2 ) Other income (expense) including equity in income of unconsolidated subsidiaries (243.6 ) 1.1 0.8 243.3 1.6 Income (loss) from continuing operations before income taxes (478.0 ) (453.8 ) 210.5 243.3 (478.0 ) Income tax provision (benefit) (112.1 ) (165.7 ) 51.6 114.1 (112.1 ) Income (loss) from continuing operations (365.9 ) (288.1 ) 158.9 129.2 (365.9 ) Income (loss) from discontinued operations, net of tax — — — — — Net income (loss) (365.9 ) (288.1 ) 158.9 129.2 (365.9 ) Less: Net income attributable to noncontrolling interest — — 12.0 — 12.0 Net income (loss) attributable to ATI $ (365.9 ) $ (288.1 ) $ 146.9 $ 129.2 $ (377.9 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations For the year ended December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,878.0 $ 2,345.4 $ — $ 4,223.4 Cost of sales 45.3 1,874.8 1,924.7 — 3,844.8 Selling and administrative expenses 103.9 44.0 124.6 — 272.5 Income (loss) before interest, other income and income taxes (149.2 ) (40.8 ) 296.1 — 106.1 Interest income (expense), net (111.0 ) (44.9 ) 47.2 — (108.7 ) Other income (expense) including equity in income of unconsolidated subsidiaries 261.7 1.1 2.9 (261.6 ) 4.1 Income (loss) from continuing operations before income taxes 1.5 (84.6 ) 346.2 (261.6 ) 1.5 Income tax provision (benefit) (8.7 ) (29.3 ) 116.7 (87.4 ) (8.7 ) Income (loss) from continuing operations 10.2 (55.3 ) 229.5 (174.2 ) 10.2 Income (loss) from discontinued operations, net of tax (0.6 ) — (0.6 ) 0.6 (0.6 ) Net income (loss) 9.6 (55.3 ) 228.9 (173.6 ) 9.6 Less: Net income attributable to noncontrolling interest — — 12.2 — 12.2 Net income (loss) attributable to ATI $ 9.6 $ (55.3 ) $ 216.7 $ (173.6 ) $ (2.6 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Operations For the year ended December 31, 2013 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Sales $ — $ 1,769.4 $ 2,274.1 $ — $ 4,043.5 Cost of sales 75.2 1,748.8 1,966.9 — 3,790.9 Selling and administrative expenses 124.3 34.9 117.2 — 276.4 Restructuring charges 1.1 15.7 50.7 — 67.5 Income (loss) before interest, other income and income taxes (200.6 ) (30.0 ) 139.3 — (91.3 ) Interest income (expense), net (63.4 ) (37.2 ) 35.4 — (65.2 ) Other income (expense) including equity in income of unconsolidated subsidiaries 109.2 0.9 0.8 (109.2 ) 1.7 Income (loss) from continuing operations, before income taxes (154.8 ) (66.3 ) 175.5 (109.2 ) (154.8 ) Income tax provision (benefit) (63.6 ) (20.0 ) 40.4 (20.4 ) (63.6 ) Income (loss) from continuing operations (91.2 ) (46.3 ) 135.1 (88.8 ) (91.2 ) Income (loss) from discontinued operations, net of tax 252.8 — 252.8 (252.8 ) 252.8 Net income (loss) 161.6 (46.3 ) 387.9 (341.6 ) 161.6 Less: Net income attributable to noncontrolling interest — — 7.6 — 7.6 Net income (loss) attributable to ATI $ 161.6 $ (46.3 ) $ 380.3 $ (341.6 ) $ 154.0
Schedule of condensed consolidating comprehensive income	Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Comprehensive Income For the year ended December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Net income (loss) $ 9.6 $ (55.3 ) $ 228.9 $ (173.6 ) $ 9.6 Other comprehensive income (loss) Currency translation adjustment arising during the period (33.6 ) — (33.6 ) 33.6 (33.6 ) Net derivative gain on hedge transactions 25.9 — — — 25.9 Pension and postretirement benefits (212.6 ) 1.8 (28.4 ) 26.6 (212.6 ) Other comprehensive income (loss), net of tax (220.3 ) 1.8 (62.0 ) 60.2 (220.3 ) Comprehensive income (loss) (210.7 ) (53.5 ) 166.9 (113.4 ) (210.7 ) Less: Comprehensive income attributable to noncontrolling interest — — 10.1 — 10.1 Comprehensive income (loss) attributable to ATI $ (210.7 ) $ (53.5 ) $ 156.8 $ (113.4 ) $ (220.8 ) Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Comprehensive Income For the year ended December 31, 2013 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Net income (loss) $ 161.6 $ (46.3 ) $ 387.9 $ (341.6 ) $ 161.6 Other comprehensive income (loss) Currency translation adjustment arising during the period 15.3 — 15.3 (15.3 ) 15.3 Unrealized holding gain (loss) on securities 0.1 — 0.1 (0.1 ) 0.1 Net derivative loss on hedge transactions (6.9 ) — — — (6.9 ) Pension and postretirement benefits 311.1 22.0 27.6 (49.6 ) 311.1 Other comprehensive income (loss), net of tax 319.6 22.0 43.0 (65.0 ) 319.6 Comprehensive income (loss) 481.2 (24.3 ) 430.9 (406.6 ) 481.2 Less: Comprehensive income attributable to noncontrolling interest — — 11.0 — 11.0 Comprehensive income (loss) attributable to ATI $ 481.2 $ (24.3 ) $ 419.9 $ (406.6 ) $ 470.2 Allegheny Technologies Incorporated Financial Information for Subsidiary and Guarantor Parent Statements of Comprehensive Income For the year ended December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Net income (loss) $ (365.9 ) $ (288.1 ) $ 158.9 $ 129.2 $ (365.9 ) Other comprehensive income (loss) Currency translation adjustment arising during the period (37.0 ) — (37.0 ) 37.0 (37.0 ) Net derivative loss on hedge transactions (32.0 ) — — — (32.0 ) Pension and postretirement benefits (19.7 ) 29.8 3.1 (32.9 ) (19.7 ) Other comprehensive income (loss), net of tax (88.7 ) 29.8 (33.9 ) 4.1 (88.7 ) Comprehensive income (loss) (454.6 ) (258.3 ) 125.0 133.3 (454.6 ) Less: Comprehensive income attributable to noncontrolling interest — — 6.4 — 6.4 Comprehensive income (loss) attributable to ATI $ (454.6 ) $ (258.3 ) $ 118.6 $ 133.3 $ (461.0 )
Schedule of condensed consolidating statements of cash flow	Condensed Statements of Cash Flows For the year ended December 31, 2015 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (70.0 ) $ (134.8 ) $ 360.2 $ (24.0 ) $ 131.4 Investing Activities: Purchases of property, plant and equipment (0.6 ) (66.9 ) (77.0 ) — (144.5 ) Net receipts (payments) on intercompany activity — — (327.9 ) 327.9 — Purchases of businesses, net of cash acquired — — (0.5 ) — (0.5 ) Asset disposals and other — 0.2 (0.3 ) — (0.1 ) Cash flows provided by (used in) investing activities (0.6 ) (66.7 ) (405.7 ) 327.9 (145.1 ) Financing Activities: Payments on long-term debt and capital leases (0.6 ) (0.1 ) (22.9 ) — (23.6 ) Net receipts (payments) on intercompany activity 137.3 190.6 — (327.9 ) — Dividends paid to stockholders (66.5 ) — (24.0 ) 24.0 (66.5 ) Dividends paid to noncontrolling interests — — (16.0 ) — (16.0 ) Other (1.4 ) — 1.5 — 0.1 Cash flows provided by (used in) financing activities 68.8 190.5 (61.4 ) (303.9 ) (106.0 ) Decrease in cash and cash equivalents $ (1.8 ) $ (11.0 ) $ (106.9 ) $ — $ (119.7 ) Condensed Statements of Cash Flows For the year ended December 31, 2013 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (41.1 ) $ (50.4 ) $ 484.2 $ (24.3 ) $ 368.4 Investing Activities: Purchases of property, plant and equipment (0.2 ) (564.8 ) (47.7 ) — (612.7 ) Net receipts (payments) on intercompany activity — — (248.8 ) 248.8 — Proceeds from sale of business, net of transaction costs (7.9 ) — 608.8 — 600.9 Asset disposals and other — 0.2 0.6 — 0.8 Cash flows provided by (used in) investing activities (8.1 ) (564.6 ) 312.9 248.8 (11.0 ) Financing Activities: Borrowings on long-term debt 500.0 — — — 500.0 Net receipts (payments) on intercompany activity (366.7 ) 615.5 — (248.8 ) — Dividends paid to stockholders (76.9 ) — (24.3 ) 24.3 (76.9 ) Other (9.1 ) (0.1 ) (49.1 ) — (58.3 ) Cash flows provided by (used in) financing activities 47.3 615.4 (73.4 ) (224.5 ) 364.8 Increase (decrease) in cash and cash equivalents $ (1.9 ) $ 0.4 $ 723.7 $ — $ 722.2 Condensed Statements of Cash Flows For the year ended December 31, 2014 (In millions) Guarantor Parent Subsidiary Non-guarantor Subsidiaries Eliminations Consolidated Cash flows provided by (used in) operating activities $ (66.9 ) $ (313.8 ) $ 436.6 $ — $ 55.9 Investing Activities: Purchases of property, plant and equipment (0.1 ) (170.8 ) (54.8 ) — (225.7 ) Net receipts (payments) on intercompany activity — — (1,027.7 ) 1,027.7 — Purchases of businesses, net of cash acquired — — (92.9 ) — (92.9 ) Asset disposals and other — 1.7 0.7 — 2.4 Cash flows provided by (used in) investing activities (0.1 ) (169.1 ) (1,174.7 ) 1,027.7 (316.2 ) Financing Activities: Payments on long-term debt and capital leases (397.9 ) (0.1 ) (16.9 ) — (414.9 ) Net receipts (payments) on intercompany acivity 544.4 483.3 — (1,027.7 ) — Dividends paid to stockholders (77.1 ) — — — (77.1 ) Other (3.8 ) — (1.2 ) — (5.0 ) Cash flows provided by (used in) financing activities 65.6 483.2 (18.1 ) (1,027.7 ) (497.0 ) Increase (decrease) in cash and cash equivalents $ (1.4 ) $ 0.3 $ (756.2 ) $ — $ (757.3 )

Selected Quarterly Financial 48

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly financial information	Quarter Ended (In millions, except share and per share amounts) March 31 June 30 September 30 December 31 2015 - Sales $ 1,125.5 $ 1,022.5 $ 832.7 $ 738.9 Gross Profit (Loss) 109.5 77.0 (28.7 ) (97.5 ) Income (loss) from continuing operations attributable to ATI 10.0 (16.4 ) (144.6 ) (226.9 ) Net income (loss) 12.6 (13.9 ) (141.3 ) (223.3 ) Net income (loss) attributable to ATI 10.0 (16.4 ) (144.6 ) (226.9 ) Basic income (loss) from continuing operations attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Basic income (loss) attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Diluted income (loss) from continuing operations attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Diluted income (loss) attributable to ATI per common share $ 0.09 $ (0.15 ) $ (1.35 ) $ (2.12 ) Average shares outstanding 108,854,720 109,190,876 109,204,307 109,171,124 2014 - Sales $ 987.3 $ 1,119.0 $ 1,069.6 $ 1,047.5 Gross Profit 70.2 89.5 97.0 121.9 Income (loss) from continuing operations attributable to ATI (18.1 ) (3.8 ) — 19.9 Net income (loss) (17.9 ) (0.7 ) 2.9 25.3 Net income (loss) attributable to ATI (20.0 ) (4.0 ) (0.7 ) 22.1 Basic income (loss) from continuing operations attributable to ATI per common share $ (0.17 ) $ (0.03 ) $ — $ 0.18 Basic income (loss) attributable to ATI per common share $ (0.19 ) $ (0.03 ) $ (0.01 ) $ 0.20 Diluted income (loss) from continuing operations attributable to ATI per common share $ (0.17 ) $ (0.03 ) $ — $ 0.18 Diluted income (loss) attributable to ATI per common share $ (0.19 ) $ (0.03 ) $ (0.01 ) $ 0.20 Average shares outstanding 108,173,581 108,628,024 108,712,682 108,704,983

Summary of Significant Accoun49

Summary of Significant Accounting Policies - Principles of Consolidation (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Related party accounts receivable	$ 0.5	$ 4.3
Shanghai STAL Precision Stainless Steel Co Ltd [Member]
Noncontrolling Interest [Line Items]
Joint venture ownership percentage	60.00%
Joint venture ownership percentage by unaffiliated entity	40.00%
Uniti [Member]
Noncontrolling Interest [Line Items]
Equity method investment ownership percentage	50.00%

Summary of Significant Accoun50

Summary of Significant Accounting Policies - Basis of Presentation (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disposal Group, Including Discontinued Operations [Line Items]
Sales	$ 738.9	$ 832.7	$ 1,022.5	$ 1,125.5	$ 1,047.5	$ 1,069.6	$ 1,119	$ 987.3	$ 3,719.6	$ 4,223.4	$ 4,043.5

Summary of Significant Accoun51

Summary of Significant Accounting Policies - Risks and Uncertainties and Use of Estimates (Details)	12 Months Ended
	Dec. 31, 2015employeecustomer	Dec. 31, 2014customer	Dec. 31, 2013customer
Segment Reporting Information [Line Items]
Number of employees	9,200
Percent of employees located outside of the U.S.	15.00%
Percent of employees covered by collective bargaining agreements	50.00%
Sales Revenue [Member]
Segment Reporting Information [Line Items]
Number of customers | customer	0	0	0
Workforce Subject to Collective Bargaining Arrangements [Member] | Flat Rolled Products and High Performance Materials & Components [Member]
Segment Reporting Information [Line Items]
Number of employees	2,000

Summary of Significant Accoun52

Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Allowances for Doubtful Accounts	$ 4.5	$ 4.8

Summary of Significant Accoun53

Summary of Significant Accounting Policies - Research and Development (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Research and Development Expense	$ 14.2	$ 17.4	$ 16.1
Customer funded research and development costs	$ 1.5	$ 2.7	$ 2.7

Summary of Significant Accoun54

Summary of Significant Accounting Policies - New Accounting Pronouncements Adopted (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
New Accounting Pronouncement, Early Adoption [Line Items]
Debt issuance costs	[1]	$ 9.5	$ 10.9
Accounting Standard Update 2015-17 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Current deferred tax liabilities			62.2
Accounting Standard Update 2015-03 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Debt issuance costs			$ 10.9
[1]	In April 2015, the FASB issued new guidance on the presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015.

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Millions	Jun. 12, 2014	Feb. 07, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Cash consideration, net of cash acquired			$ 0.5	$ 92.9	$ 0
Goodwill			651.4	780.4
ATI Flowform [Member]
Business Acquisition [Line Items]
Percentage of company acquired		85.00%
Cash consideration, net of cash acquired		$ 72.9
Noncontrolling interest held by others (percent)		15.00%
Acquisition costs		$ 0.7
Intangible assets acquired		$ 21.4
Weighted average life of acquired intangible assets		23 years
Goodwill		$ 46.8
Hanard Machine, Inc. [Member]
Business Acquisition [Line Items]
Cash consideration, net of cash acquired	$ 20.5		$ 0.5	$ 20
Intangible assets acquired	$ 4.3
Weighted average life of acquired intangible assets	20 years
Goodwill	$ 8.4

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business, net of transaction costs	$ 0	$ 0	$ 600.9
Restructuring costs net of tax	41.6		41.2
Tungsten Materials Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business, net of transaction costs			600.9
Gain on disposed operation, pre-tax			428.3
Gain on disposed operation net of tax			261.4
Iron Castings Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring Charge		1.8
Cash exit costs paid	$ 0.8	$ 1
Iron Castings and Fabricated Components Businesses [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring Charge			19.5
Restructuring costs net of tax			11.9
Asset impairment charges			$ 18.6

Discontinued Operations - Sched

Discontinued Operations - Schedule of Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]
Sales	$ 14.9	$ 268.2
Income (loss) before income taxes	$ (0.9)	$ 414.2

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Raw materials and supplies	$ 216		$ 216	$ 249.3
Work-in-process	990.3		990.3	1,184.1
Finished goods	184.1		184.1	172.2
Total inventories at current cost	1,390.4		1,390.4	1,605.6
Adjustment from current cost to LIFO cost basis	(136.4)		(136.4)	(4.8)
Inventory valuation reserves	206.3		206.3	68.8
Progress payments	(48.9)		(48.9)	(68.8)
Total inventories, net	1,271.6		1,271.6	1,472.8
LIFO Inventory Amount	992		992	1,102.4
Inventory, LIFO Reserve, Effect on Income, Net [Abstract]
LIFO benefit (charge)			131.6	(24.7)	$ 80.9
NRV benefit (charge)	(51.2)	$ (76)	(131.5)	25	(35)
Lifo Provision Benefit and Change in Debit LIFO NRV reserve, net			(0.1)	(0.3)	(45.9)
Effect of LIFO liquidation on income			(9.6)	0	(3.8)
Industrial titanium products [Member] | Inventory Valuation Reserve [Member]
Inventory, LIFO Reserve, Effect on Income, Net [Abstract]
Lower of cost or market charges			$ 24.5	$ 23.2	$ 20.5
Non-PQ grade titanium sponge [Member] | Inventory Valuation Reserve [Member]
Inventory, LIFO Reserve, Effect on Income, Net [Abstract]
Lower of cost or market charges	$ 25.4

Property, Plant and Equipment59

Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property Plant And Equipment Details [Abstract]
Land	$ 31	$ 30.2
Buildings	1,048.2	1,048.9
Equipment and leasehold improvements	3,858.1	3,702.5
Property plant and equipment, gross	4,937.3	4,781.6
Accumulated depreciation and amortization	(2,009.1)	(1,819.8)
Property, plant and equipment, net	2,928.2	2,961.8
Construction in progress	119.6	71.1
Property, Plant and Equipment [Line Items]
Capital Expenditures Incurred but Not yet Paid	35.4
Depreciation, Depletion and Amortization [Abstract]
Software and other amortization	10	10
Total depreciation and amortization	189.9	176.8	$ 189.9
Operating Segments [Member]
Depreciation, Depletion and Amortization [Abstract]
Depreciation of property, plant and equipment	159.6	146.7	156.8
Software and other amortization	30.3	29.9	23.8
Total depreciation and amortization	$ 189.9	$ 176.6	$ 180.6

Goodwill and Other Intangible60

Goodwill and Other Intangible Assets - Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jun. 12, 2014
Goodwill [Line Items]
Goodwill	$ 651.4	$ 651.4	$ 780.4
Period increase (decrease) in goodwill		(129)
Impairment of goodwill		(126.6)	$ 0	$ 0
Goodwill translation adjustments		(2.6)
Accumulated goodwill impairment	126.6	126.6
Hanard Machine, Inc. [Member]
Goodwill [Line Items]
Goodwill					$ 8.4
Goodwill purchase accounting adjustments		0.2
High Performance Materials & Components [Member]
Goodwill [Line Items]
Goodwill	651.4	$ 651.4
Flat Rolled Products [Member]
Goodwill [Line Items]
Impairment of goodwill	$ (126.6)

Goodwill and Other Intangible61

Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 10	$ 10
Gross carrying amount	191.7	191.7
Accumulated amortization	(33.4)	(23.2)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,016	10
2,017	10
2,018	10
2,019	10
2,020	$ 10
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful life (years)	21 years
Gross carrying amount	$ 91.4	91.4
Accumulated amortization	$ (18.6)	(14.2)
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful life (years)	24 years
Gross carrying amount	$ 35.7	35.7
Accumulated amortization	$ (6.2)	(4.7)
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful life (years)	15 years
Gross carrying amount	$ 64.6	64.6
Accumulated amortization	$ (8.6)	$ (4.3)

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loss Contingencies [Line Items]
Asset retirement obligation	$ 25	$ 25.4	$ 27.7
Revision of estimates	$ (0.2)	$ (1)	4.2
Tungsten Materials Business [Member]
Loss Contingencies [Line Items]
Asset retirement obligation			$ 13
Asset retirement obligation period (in years)			5 years
Revision of estimates			$ 9.4
Restructuring Charges [Member]
Loss Contingencies [Line Items]
Revision of estimates			$ 4.2

Asset Retirement Obligations -

Asset Retirement Obligations - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]
Balance at beginning of year	$ 25.4	$ 27.7
Accretion expense	0.6	0.9
Payments	(0.8)	(2.2)
Revision of estimates	(0.2)	(1)	$ 4.2
Balance at end of year	$ 25	$ 25.4	$ 27.7

Supplemental Financial Statem64

Supplemental Financial Statement Information - Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash and Cash Equivalents [Abstract]
Cash	$ 149.3	$ 267.7
Other short-term investments	0.5	1.8
Total cash and cash equivalents	$ 149.8	$ 269.5	$ 1,026.8	$ 304.6

Supplemental Financial Statem65

Supplemental Financial Statement Information - Allowance for Doubtful Accounts (Details) - Allowance for Doubtful Accounts [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Reserve for doubtful accounts	$ 4.5	$ 4.8
Reserve for doubtful accounts, increase	1.1	0.5	$ 1.1
Reserve for doubtful accounts, decrease	$ 1.4	$ 1	0.8
Tungsten Materials Business [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Reserve for doubtful accounts, decrease			$ 0.5

Supplemental Financial Statem66

Supplemental Financial Statement Information - Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Additional Financial Information Disclosure [Abstract]
Accrued salaries, wages and payroll liabilities	$ 50.9	$ 77.3

Supplemental Financial Statem67

Supplemental Financial Statement Information - Other Non-operating Income (Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Nonoperating Income (Expense) [Abstract]
Rent and royalty income	$ 2	$ 4	$ 0.9
Net gains (losses) on property and investments	0	0.1	0.7
Other	(0.4)	0	0.1
Other income, net	$ 1.6	$ 4.1	$ 1.7

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($)		Jul. 12, 2013	Dec. 31, 2015		Dec. 31, 2014		Aug. 15, 2015	[2]	Dec. 31, 2013
Debt Instrument [Line Items]
Debt issuance costs	[1]		$ (9,500,000)		$ (10,900,000)
Total short-term and long-term debt			1,495,700,000		1,516,000,000
Short-term debt and current portion of long-term debt			3,900,000		17,800,000
Total long-term debt			$ 1,491,800,000		1,498,200,000
Domestic Bank Group $400 million unsecured credit agreement [Member]
Debt Instrument [Line Items]
Debt instrument carrying amount					$ 0
Allegheny Technologies $500 million 5.875% Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Debt instrument issuer	[2]		Allegheny Technologies		Allegheny Technologies
Debt instrument maturity date		Aug. 15, 2023
Debt instrument interest rate stated percentage					6.125%		7.625%		5.875%
Debt instrument carrying amount		$ 500,000,000	$ 500,000,000	[2]	$ 500,000,000	[2]
Allegheny Technologies $500 million 5.95% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument issuer			Allegheny Technologies		Allegheny Technologies
Debt instrument interest rate stated percentage			5.95%		5.95%
Debt instrument carrying amount			$ 500,000,000		$ 500,000,000
Allegheny Technologies $402.5 million 4.25% Convertible Senior Notes due 2014 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage									4.25%
Debt instrument carrying amount									$ 402,500,000
Allegheny Technologies $350 million 9.375% Senior Notes due 2019 [Member]
Debt Instrument [Line Items]
Debt instrument issuer			Allegheny Technologies		Allegheny Technologies
Debt instrument interest rate stated percentage			9.375%		9.375%
Debt instrument carrying amount			$ 350,000,000		$ 350,000,000
Allegheny Ludlum 6.95% Debentures due 2025 [Member]
Debt Instrument [Line Items]
Debt instrument issuer			Allegheny Ludlum		Allegheny Ludlum
Debt instrument interest rate stated percentage			6.95%		6.95%
Debt instrument carrying amount			$ 150,000,000		$ 150,000,000
Ladish Series B 6.14% Notes due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument issuer	[3]		ATI Ladish, LLC		ATI Ladish, LLC
Debt instrument interest rate stated percentage	[3]		6.14%		6.14%
Debt instrument carrying amount	[3]		$ 0		$ 11,900,000
Business acquisition fair value adjustment of debt assumed					$ 400,000
Ladish Series C 6.41% Notes due 2015 [Member]
Debt Instrument [Line Items]
Debt instrument issuer	[4]		ATI Ladish, LLC		ATI Ladish, LLC
Debt instrument interest rate stated percentage	[4]		6.41%		6.41%
Debt instrument carrying amount	[4]		$ 0		$ 10,300,000
Business acquisition fair value adjustment of debt assumed					300,000
Foreign credit agreements [Member]
Debt Instrument [Line Items]
Debt instrument carrying amount			1,400,000		0
Industrial revenue bonds, due through 2020, and other [Member]
Debt Instrument [Line Items]
Debt instrument carrying amount			$ 3,800,000		4,700,000
Accounting Standard Update 2015-03 [Member]
Debt Instrument [Line Items]
Debt issuance costs					$ (10,900,000)
[1]	In April 2015, the FASB issued new guidance on the presentation of debt issuance costs. This guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The Company early adopted this new guidance on a retrospective basis in the fourth quarter of fiscal year 2015.
[2]	Bearing interest at 7.625% effective August 15, 2015.
[3]	Includes fair value adjustment of $0.4 million at December 31, 2014.
[4]	Includes fair value adjustment of $0.3 million at December 31, 2014.

Debt - Narrative (Details)

Debt - Narrative (Details)

Sep. 23, 2015USD ($)

Jun. 02, 2014USD ($)

Jun. 01, 2014USD ($)shares

Jul. 12, 2013USD ($)

Dec. 31, 2015USD ($)

Dec. 31, 2014USD ($)

Dec. 31, 2013USD ($)$ / shares

Aug. 15, 2015

[1]

Interest Costs Incurred [Abstract]

Interest expense

$ 111,400,000

$ 109,800,000

$ 66,000,000

Interest costs capitalized

2,200,000

5,300,000

45,700,000

Interest costs paid

113,400,000

113,200,000

110,600,000

Interest income

1,200,000

1,100,000

800,000

Long-term Debt, Fiscal Year Maturity [Abstract]

2,016

3,900,000

2,017

900,000

2,018

200,000

2,019

350,200,000

2,020

0

Debt Instrument [Line Items]

Payments of debt issuance costs

0

1,200,000

$ 5,200,000

Allegheny Technologies $500 million 5.875% Senior Notes due 2023 [Member]

Debt Instrument [Line Items]

Debt instrument carrying amount

$ 500,000,000

$ 500,000,000

[1]

$ 500,000,000

[1]

Debt instrument interest rate stated percentage

6.125%

5.875%

7.625%

Debt instrument maturity date

Aug. 15, 2023

Payments of debt issuance costs

$ 5,200,000

Amortization period of debt issuance costs

10 years

Allegheny Technologies $350 million 9.375% Senior Notes due 2019 [Member]

Debt Instrument [Line Items]

Debt instrument carrying amount

$ 350,000,000

$ 350,000,000

Debt instrument interest rate stated percentage

9.375%

9.375%

Allegheny Technologies $402.5 million 4.25% Convertible Senior Notes due 2014 [Member]

Debt Instrument [Line Items]

Debt instrument carrying amount

$ 402,500,000

Debt instrument interest rate stated percentage

4.25%

Repayments of Convertible Debt

$ 397,500,000

Convertible notes, Amount converted

$ 5,000,000

Convertible notes, Shares issued | shares

120,476

Convertible debt conversion rate in shares of stock

0.0239263

Conversion price of convertible notes | $ / shares

$ 41.795

Ladish Series B 6.14% Notes due 2016 [Member]

Debt Instrument [Line Items]

Debt instrument carrying amount

[2]

$ 0

$ 11,900,000

Debt instrument interest rate stated percentage

[2]

6.14%

6.14%

Repayments of Debt

$ 5,700,000

Ladish Series C 6.41% Notes due 2015 [Member]

Debt Instrument [Line Items]

Debt instrument carrying amount

[3]

$ 0

$ 10,300,000

Debt instrument interest rate stated percentage

[3]

6.41%

6.41%

Repayments of Debt

$ 10,000,000

Domestic Bank Group $400 million unsecured credit agreement [Member]

Debt Instrument [Line Items]

Debt instrument carrying amount

$ 0

Seperate Letter of Credit Facility [Member]

Debt Instrument [Line Items]

Line of credit facility amount outstanding

$ 32,000,000

STAL Revolving Credit Facility [Member]

Debt Instrument [Line Items]

Joint venture ownership percentage

60.00%

Maximum [Member] | Allegheny Technologies $500 million 5.875% Senior Notes due 2023 [Member]

Debt Instrument [Line Items]

Debt instrument interest rate stated percentage

7.875%

Domestic Bank Group $400 million credit agreement [Member]

Debt Instrument [Line Items]

Line of Credit Facility, Average Outstanding Amount

$ 61,000,000

Line of Credit Facility, Interest Rate During Period

2.00%

STAL Revolving Credit Facility [Member]

Debt Instrument [Line Items]

Line of credit maximum borrowing capacity

$ 20,000,000

Allegheny Technologies, Senior Notes, 5.875, Due 2023 [Member]

Debt Instrument [Line Items]

Increase in stated interest rate due to downgrade (percent)

1.75%

Additional Annual Interest Expense to be Incurred

$ 4,100,000

Credit Downgrade, Increase in Interest Expense per Downgrade Notch, Percent

0.25%

Credit Downgrade, Maximum Number of Downgrade Notches

4

Credit Downgrade, Maximum Increase in Interest Rate Expense, Percent

2.00%

Domestic Bank Group $400 million asset-based credit facility [Member]

Debt Instrument [Line Items]

Debt instrument carrying amount

$ 0

Line of credit facility amount outstanding

$ 4,600,000

Revolving Credit Facility [Member] | Domestic Bank Group $400 million credit agreement [Member]

Debt Instrument [Line Items]

Line of credit maximum borrowing capacity

$ 400,000,000

Revolving Credit Facility [Member] | Domestic Bank Group $400 million asset-based credit facility [Member]

Debt Instrument [Line Items]

Amortization period of debt issuance costs

5 years

Line of credit maximum borrowing capacity

$ 400,000,000

Debt Issuance Cost

1,500,000

Debt Instrument, Covenant, Remaining Borrowing Capacity

40,000,000

Debt Instrument, Covenant, Minimum Required Liquidity

$ 500,000,000

Debt Instrument, Covenant, Minimum Liquidity, Number of Days Prior

91 days

Debt Instrument, Covenant, Fixed Charge Coverage Ratio

1

Debt Instrument, Covenant, Remaining Borrowing Capacity, Percent Minimum Borrowing Capacity

10.00%

Revolving Credit Facility [Member] | Domestic Bank Group $400 million asset-based credit facility [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]

Debt Instrument [Line Items]

Variable rate spread

1.25%

Revolving Credit Facility [Member] | Domestic Bank Group $400 million asset-based credit facility [Member] | Minimum [Member] | Base Rate [Member]

Debt Instrument [Line Items]

Variable rate spread

0.25%

Revolving Credit Facility [Member] | Domestic Bank Group $400 million asset-based credit facility [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]

Debt Instrument [Line Items]

Variable rate spread

1.75%

Revolving Credit Facility [Member] | Domestic Bank Group $400 million asset-based credit facility [Member] | Maximum [Member] | Base Rate [Member]

Debt Instrument [Line Items]

Variable rate spread

0.75%

Letter of Credit [Member] | Domestic Bank Group $400 million asset-based credit facility [Member]

Debt Instrument [Line Items]

Line of credit maximum borrowing capacity

$ 200,000,000

[1]

Bearing interest at 7.625% effective August 15, 2015.

[2]

Includes fair value adjustment of $0.4 million at December 31, 2014.

[3]

Includes fair value adjustment of $0.3 million at December 31, 2014.

Derivative Financial Instrume70

Derivative Financial Instruments and Hedging - Narrative (Details) - 12 months ended Dec. 31, 2015 € in Millions, lb in Millions, $ in Millions	EUR (€)lb	USD ($)lb
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Maximum amount of time hedged for nickel requirements	2,020	2,020
Percentage of estimated annual nickel requirements	28.00%	28.00%
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months		$ (23.6)
Nickel [Member]
Derivative [Line Items]
Derivative notional amount (in pounds of nickel) | lb	26	26
Cash Flow Hedging [Member] | Natural gas contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Percentage of forecasted natural gas usage hedged for 2017	55.00%	55.00%
Percentage of forecasted natural gas usage hedged for 2018	15.00%	15.00%
Pre-tax loss on ineffective portion of hedge		$ 3.3
Cash Flow Hedging [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative notional amount settled | €	€ 211.9
Proceeds from hedge		56.5
Pre-tax gain on ineffective portion of hedge		14.3
Fair Value Hedging [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] | Maturity Dates Through 2017 [Member]
Derivative [Line Items]
Derivative notional amount | €	139.2
Notional amount of derivatives entered during period | €	€ 244.7
Cost of Sales [Member] | Fair Value Hedging [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) on derivatives		$ 9

Derivative Financial Instrume71

Derivative Financial Instruments and Hedging - Schedule of Derivative Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	$ 2.4	$ 59.9
Fair value of derivative liability	71.3	27
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	2	53.5
Fair value of derivative liability	71.2	27
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	0.4	6.4
Fair value of derivative liability	0.1	0
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Prepaid expenses and other current assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	1.6	23.6
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	0.4	28.3
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	0.1	0
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	0.1	0
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Prepaid expenses and other current assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	0.4	6.4
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	0.1	0
Nickel and other raw material contracts [Member] | Designated as Hedging Instrument [Member] | Prepaid expenses and other current assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	0	1.1
Nickel and other raw material contracts [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	0	0.5
Nickel and other raw material contracts [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	22.2	5.8
Nickel and other raw material contracts [Member] | Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	23	3
Electricity contracts [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	0	0.1
Natural gas contracts [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	17.3	10.2
Natural gas contracts [Member] | Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	$ 8.5	$ 7.9

Derivative Financial Instrume72

Derivative Financial Instruments and Hedging - Schedule of Derivative Instruments Gain (Loss) (Details) - Cash Flow Hedging [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)		$ (20.7)	$ 28.1
Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	[1]	4.5	2.2
Selling and administrative expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[2]	6.8	0
Nickel and other raw material contracts [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)		(34.2)	(1.6)
Nickel and other raw material contracts [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	[1]	(10.5)	(0.6)
Nickel and other raw material contracts [Member] | Selling and administrative expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[2]	0	0
Natural gas contracts [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)		(14.1)	(10.9)
Natural gas contracts [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	[1]	(9.2)	2.1
Natural gas contracts [Member] | Selling and administrative expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[2]	(2.1)	0
Electricity contracts [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)		0	0.5
Electricity contracts [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	[1]	(0.1)	0.4
Electricity contracts [Member] | Selling and administrative expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[2]	0	0
Foreign Exchange Contract [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)		27.6	40.1
Foreign Exchange Contract [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	[1]	24.3	0.3
Foreign Exchange Contract [Member] | Selling and administrative expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[2]	$ 8.9	$ 0
[1]	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.
[2]	The gains (losses) recognized in income on derivatives related to the ineffective portion and the amount excluded from effectiveness testing are presented in selling and administrative expenses.

Derivative Financial Instrume73

Derivative Financial Instruments and Hedging - Schedule of Derivatives Not Designated as Hedging Instruments Gain (Loss) (Details) - Not Designated as Hedging Instrument [Member] € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2015EUR (€)
Foreign Exchange Contract [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives | $	$ 3.9	$ 5.2
Maturity Dates Through 2016 [Member] | Foreign Exchange Forward [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount | €			€ 25

Fair Value of Financial Instr74

Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 149.8	$ 269.5
Derivative financial instruments: Assets	0	0
Derivative financial instruments: Liabilities	0	0
Debt	964.5	1,589.1
Fair Value Measurements at Reporting Date Using Significant Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Derivative financial instruments: Assets	2.4	59.9
Derivative financial instruments: Liabilities	71.3	27
Debt	5.2	26.9
Total Carrying Amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	149.8	269.5
Derivative financial instruments: Assets	2.4	59.9
Derivative financial instruments: Liabilities	71.3	27
Debt	1,495.7	1,516
Fair Value Measurements at Reporting Date Using Total Estimated Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	149.8	269.5
Derivative financial instruments: Assets	2.4	59.9
Derivative financial instruments: Liabilities	71.3	27
Debt	$ 969.7	$ 1,616

Fair Value Of Financial Instr75

Fair Value Of Financial Instruments - Narrative (Details)	Dec. 31, 2015	Aug. 15, 2015	[1]	Dec. 31, 2014	Dec. 31, 2013
Allegheny Technologies $402.5 million 4.25% Convertible Senior Notes due 2014 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage					4.25%
Allegheny Technologies $350 million 9.375% Senior Notes due 2019 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage	9.375%			9.375%
Allegheny Technologies $350 million 9.375% Senior Notes due 2019 [Member] | Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage	9.375%
Allegheny Technologies $500 million 5.95% Senior Notes due 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage	5.95%			5.95%
Allegheny Technologies $500 million 5.95% Senior Notes due 2021 [Member] | Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage	5.95%
Allegheny Technologies $500 million 5.875% Senior Notes due 2023 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage		7.625%		6.125%	5.875%
Allegheny Technologies $500 million 5.875% Senior Notes due 2023 [Member] | Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage					5.875%
Allegheny Ludlum 6.95% Debentures due 2025 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage	6.95%			6.95%
Allegheny Ludlum 6.95% Debentures due 2025 [Member] | Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument interest rate stated percentage	6.95%
[1]	Bearing interest at 7.625% effective August 15, 2015.

Pension Plans and Other Postr76

Pension Plans and Other Postretirement Benefits - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected Retirement Benefit Expense In Next 12 months			$ 98
Defined contribution plan- Company contribution (percent)			6.50%
Defined contribution plan- Company matching contribution (percent)			3.00%
Other postretirement benefit costs for a defined contribution plan			$ 41.2	$ 21.9	$ 24.3
Projected future contributions to VEBA trusts			$ 7
US Qualified Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of total assets			96.00%
Number of shares of equity securities issued by employer included in plan assets			3	3
Fair value of employer equity securities included in plan assets			$ 33.2	$ 102.7
Dividends on employer stock received by plan			1.8	2.1
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected Retirement Benefit Expense In Next 12 months			64
One-time, voluntary lump sum payments				52
Benefit obligation increase for changes in mortality assumptions				$ 90
Weighted average life expectancy				18 years
Average remaining service period				10 years
Accumulated benefit obligation			$ 2,767	$ 2,917.3
Expected long-term rate of return on assets			8.00%	8.25%	8.25%
Actual return on plan assets	0.30%		(1.20%)	6.50%	14.30%	8.00%
Fair value of plan assets			$ 1,962.3	$ 2,204.4	$ 2,329.8
Other Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated employer contributions in next 12 months			10
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected Retirement Benefit Expense In Next 12 months			$ 34
Assumed increase in per capita cost of covered benefits in next 12 months			8.00%
Assumed ultimate health care cost trend rate			4.50%
Year that ultimate trend rate is reached			2,038
Expected long-term rate of return on assets			4.00%	8.30%	8.30%
Fair value of plan assets			$ 1.8	$ 2.9	$ 4
Private equity [Member] | Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets			201.2	172.6
Fair Value, Inputs, Level 3 [Member] | Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets			800.2	809.7	655.3
Fair Value, Inputs, Level 3 [Member] | Private equity [Member] | Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets			201.2	172.6	123
Fair Value, Inputs, Level 3 [Member] | Private equity [Member] | Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets			$ 1.8
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other postretirement benefit costs for a defined contribution plan				$ 2.6	$ 4.6
Forecast [Member] | Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected long-term rate of return on assets		8.00%
Forecast [Member] | Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected long-term rate of return on assets		4.00%
MultiemployerPlan1 [Member] | Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percent of Current Year Contributions to Plan that Company Contributions Exceed				5.00%

Pension Plans and Other Postr77

Pension Plans and Other Postretirement Benefits (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 41.2	$ 21.9	$ 24.3
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	22.8	29.4	39
Interest cost on benefits earned in prior years	121	133.6	122.8
Expected return on plan assets	(168.3)	(184.2)	(176)
Amortization of prior service cost (credit)	1.3	2.3	3
Amortization of net actuarial loss	60.4	74	111.8
Curtailment (gain) loss	0	0.5	0
Termination benefits	0	0.3	4.8
Total retirement benefit expense	37.2	55.9	105.4
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	2.7	2.9	3.2
Interest cost on benefits earned in prior years	17.9	24	22.4
Expected return on plan assets	(0.1)	(0.3)	(0.5)
Amortization of prior service cost (credit)	4.9	(3)	(18.2)
Amortization of net actuarial loss	14.6	14.1	17.2
Curtailment (gain) loss	0	(25.5)	0
Termination benefits	0	0	1.3
Total retirement benefit expense	$ 40	12.2	25.4
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized		$ 2.6	$ 4.6

Pension Plans and Other Postr78

Pension Plans and Other Postretirement Benefits (Details 2)		Oct. 31, 2013	Oct. 29, 2013	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate		4.95%	4.25%	4.25%	[1]	5.15%	[1]
Expected long-term rate of return on assets				8.00%		8.25%		8.25%
Pension Benefits [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	[1]							4.25%
Rate of increase in future compensation levels				3.00%		3.00%		3.00%
Pension Benefits [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	[1]							4.95%
Rate of increase in future compensation levels				3.50%		3.50%		4.50%
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	[1]			4.10%		5.15%		4.25%
Rate of increase in future compensation levels				0.00%		0.00%		0.00%
Expected long-term rate of return on assets				4.00%		8.30%		8.30%
[1]	Pension expense for 2013 was initially measured at a 4.25% discount rate. The U.S. Plan was remeasured using a 4.95% discount rate as of October 31, 2013, following the sale of the tungsten materials business.

Pension Plans and Other Postr79

Pension Plans and Other Postretirement Benefits (Details 3)	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.65%	4.25%
Pension Benefits [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of increase in future compensation levels	3.00%	3.00%
Pension Benefits [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of increase in future compensation levels	3.50%	3.50%
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.50%	4.10%
Rate of increase in future compensation levels	0.00%	0.00%

Pension Plans and Other Postr80

Pension Plans and Other Postretirement Benefits (Details 4) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 2,953.9	$ 2,698.2
Service cost	22.8	29.4	$ 39
Interest cost	121	133.6	122.8
Benefits paid	(207.4)	(269.9)
Subsidy paid	0	0
Participant contributions	0.3	0.3
Effect of currency rates	(4.8)	(4.9)
Net actuarial (gains) losses - discount rate change	(124.4)	288.5
Net actuarial (gains) losses - other	44.5	78.4
Plan curtailments	0	0
Plan settlements	0	0
Special termination benefits	0	0.3
Benefit obligation at end of year	2,805.9	2,953.9	2,698.2
Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	466.1	506.7
Service cost	2.7	2.9	3.2
Interest cost	17.9	24	22.4
Benefits paid	(53.4)	(54.3)
Subsidy paid	0.7	1
Participant contributions	0	0
Effect of currency rates	0	0
Net actuarial (gains) losses - discount rate change	(14.1)	39.5
Net actuarial (gains) losses - other	(19.1)	(19.5)
Plan curtailments	0	(7.2)
Plan settlements	0	(27)
Special termination benefits	0	0
Benefit obligation at end of year	$ 400.8	$ 466.1	$ 506.7

Pension Plans and Other Postr81

Pension Plans and Other Postretirement Benefits (Details 5) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 2,204.4	$ 2,329.8
Actual returns on plan assets and plan expenses	(41.1)	136.8
Employer contributions	10.3	11.5
Participant contributions	0.3	0.3
Effect of currency rates	(4.2)	(4.1)
Benefits paid	(207.4)	(269.9)
Fair value of plan assets at end of year	1,962.3	2,204.4
Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	2.9	4
Actual returns on plan assets and plan expenses	(1)	(0.9)
Employer contributions	0	0
Participant contributions	0	0
Effect of currency rates	0	0
Benefits paid	(0.1)	(0.2)
Fair value of plan assets at end of year	$ 1.8	$ 2.9

Pension Plans and Other Postr82

Pension Plans and Other Postretirement Benefits (Details 6) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	$ (9.8)	$ (10.2)
Noncurrent liabilities	(833.8)	(739.3)
Total amount recognized	(843.6)	(749.5)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(39.8)	(47.3)
Noncurrent liabilities	(359.2)	(415.8)
Total amount recognized	$ (399)	$ (463.1)

Pension Plans and Other Postr83

Pension Plans and Other Postretirement Benefits (Details 7) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), before Tax [Roll Forward]
Amortization of net actuarial loss	$ (75)	$ (88.1)	$ (129)
Amortization to net income (loss) of net prior service cost (credits)	(6.2)	0.7	15.2
Remeasurements	95.8	424.5	(384.9)
Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss), before Tax [Roll Forward]
Beginning of year accumulated other comprehensive loss	(1,352.1)	(1,016.4)
Amortization of net actuarial loss	60.4	74
Amortization to net income (loss) of net prior service cost (credits)	1.3	2.3
Remeasurements	(127.8)	(412)
End of year accumulated other comprehensive loss	(1,418.2)	(1,352.1)	(1,016.4)
Net change in accumulated other comprehensive loss	(66.1)	(335.7)
Other Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss), before Tax [Roll Forward]
Beginning of year accumulated other comprehensive loss	(152.9)	(151.5)
Amortization of net actuarial loss	14.6	14.1
Amortization to net income (loss) of net prior service cost (credits)	4.9	(3)
Remeasurements	32	(12.5)
End of year accumulated other comprehensive loss	(101.4)	(152.9)	$ (151.5)
Net change in accumulated other comprehensive loss	$ 51.5	$ (1.4)

Pension Plans and Other Postr84

Pension Plans and Other Postretirement Benefits (Details 8) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost) credit	$ (3.6)	$ (4.9)
Net actuarial loss	(1,414.6)	(1,347.2)
Accumulated other comprehensive loss	(1,418.2)	(1,352.1)	$ (1,016.4)
Deferred tax effect	529.9	514.7
Accumulated other comprehensive loss, net of tax	(888.3)	(837.4)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost) credit	(6.9)	(11.8)
Net actuarial loss	(94.5)	(141.1)
Accumulated other comprehensive loss	(101.4)	(152.9)	$ (151.5)
Deferred tax effect	38.5	58.8
Accumulated other comprehensive loss, net of tax	$ (62.9)	$ (94.1)

Pension Plans and Other Postr85

Pension Plans and Other Postretirement Benefits (Details 9) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit)	$ 6.2
Amortization of net actuarial loss	74.9
Amortization of accumulated other comprehensive loss	81.1
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit)	1.3
Amortization of net actuarial loss	65.4
Amortization of accumulated other comprehensive loss	66.7
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit)	4.9
Amortization of net actuarial loss	9.5
Amortization of accumulated other comprehensive loss	$ 14.4

Pension Plans and Other Postr86

Pension Plans and Other Postretirement Benefits (Details 10) - Pension Benefits [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 2,805.9	$ 2,953.9
Accumulated benefit obligation	2,767	2,917.3
Fair value of plan assets	$ 1,962.3	$ 2,204.4

Pension Plans and Other Postr87

Pension Plans and Other Postretirement Benefits (Details 14) $ in Millions	Dec. 31, 2015USD ($)
Pension Benefits [Member]
Defined Benefit Plan Expected Future Benefit Payments [Abstract]
2,016	$ 200.2
2,017	195
2,018	194.4
2,019	191.7
2,020	190.5
2021-2025	917.8
Other Postretirement Benefits [Member]
Defined Benefit Plan Expected Future Benefit Payments [Abstract]
2,016	42.6
2,017	35.7
2,018	34.5
2,019	34.2
2,020	34.3
2021-2025	144.6
Medicare Part D Subsidy [Abstract]
2,016	1.1
2,017	1
2,018	1
2,019	1
2,020	0.9
2021-2025	$ 3.9

Pension Plans and Other Postr88

Pension Plans and Other Postretirement Benefits (Details 22) - Other Postretirement Benefits [Member] $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Defined Benefit Plan Disclosure [Line Items]
Effect on total of service and interest cost components, One Percentage Point Increase	$ 0.5
Effect on total of service and interest cost components, One Percentage Point Decrease	(0.4)
Effect on other postretirement benefit obligation, One Percentage Point Increase	7.6
Effect on other postretirement benefit obligation, One Percentage Point Decrease	$ (6.8)

Pension Plans and Other Postr89

Pension Plans and Other Postretirement Benefits (Details 11) - USD ($) $ in Millions	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	$ 1,962.3		$ 2,204.4		$ 2,329.8
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	287.5		409.5
Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	874.6		985.2
Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	800.2		809.7		655.3
Equity Securities: ATI common stock [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	33.2		102.7
Equity Securities: ATI common stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	33.2		102.7
Equity Securities: ATI common stock [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0		0
Equity Securities: ATI common stock [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	$ 0		$ 0
Equity Securities: Other U.S. equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of co-mingled funds comprised of large-cap investments	90.00%		90.00%
Percentage of co-mingled funds comprised of small-cap investments	10.00%		10.00%
Equity Securities: Other U.S. equities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	$ 522	[1]	$ 673.8	[2]
Equity Securities: Other U.S. equities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	254.1	[1]	306.1	[2]
Equity Securities: Other U.S. equities [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	267.9	[1]	367.7	[2]
Equity Securities: Other U.S. equities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	$ 0	[1]	$ 0	[2]
Equity Securities: International equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of co-mingled funds comprised of developed countries investments	90.00%		80.00%
Percentage of co-mingled funds comprised of emerging market investments	10.00%		20.00%
Equity Securities: International equities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	$ 239.8	[3]	$ 238.2	[4]
Equity Securities: International equities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0	[3]	0	[4]
Equity Securities: International equities [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	239.8	[3]	238.2	[4]
Equity Securities: International equities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0	[3]	0	[4]
Fixed income and cash equivalents [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	369.7	[5]	383.5	[6]
Fixed income and cash equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0.2	[5]	0.7	[6]
Fixed income and cash equivalents [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	361	[5]	373.9	[6]
Fixed income and cash equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	8.5	[5]	8.9	[6]	0.8
Floating rate [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	358	[5]	392.3	[6]
Floating rate [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0	[5]	0	[6]
Floating rate [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0	[5]	0	[6]
Floating rate [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	358	[5]	392.3	[6]	294.5
Private equity [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	201.2		172.6
Private equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0		0
Private equity [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0		0
Private equity [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	201.2		172.6		123
Hedge funds [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	51.9		84.7
Hedge funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0		0
Hedge funds [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0		0
Hedge funds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	51.9		84.7		111.2
Real estate and other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	186.5		156.6
Real estate and other [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	0		0
Real estate and other [Member] | Significant Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	5.9		5.4
Real estate and other [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Fair Value Of Plan Assets	$ 180.6		$ 151.2		$ 125.8
[1]	Includes investments in commingled funds that invest in U.S. equity securities, comprised of approximately 90% large-cap U.S. companies and 10% small-cap U.S. companies.
[2]	Includes investments in commingled funds that invest in U.S. equity securities, comprised of approximately 90% large-cap U.S. companies and 10% small-cap U.S. companies.
[3]	Includes investments in commingled funds that invest in non-U.S. equity securities, comprised of approximately 90% developed countries and 10% emerging market economies.
[4]	Includes investments in commingled funds that invest in non-U.S. equity securities, comprised of approximately 80% developed countries and 20% emerging market economies.
[5]	Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments.
[6]	Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments.

Pension Plans and Other Postr90

Pension Plans and Other Postretirement Benefits (Details 12) - Pension Benefits [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		$ 2,204.4		$ 2,329.8
Net Realized and Unrealized Gains (Losses)		(41.1)		136.8
Fair value of plan assets at end of year		1,962.3		2,204.4
Fixed income and cash equivalents [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	[1]	383.5
Fair value of plan assets at end of year		369.7	[2]	383.5	[1]
Floating rate [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	[1]	392.3
Fair value of plan assets at end of year		358	[2]	392.3	[1]
Private equity [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		172.6
Fair value of plan assets at end of year		201.2		172.6
Hedge funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		84.7
Fair value of plan assets at end of year		51.9		84.7
Real estate and other [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		156.6
Fair value of plan assets at end of year		186.5		156.6
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		809.7		655.3
Net Realized and Unrealized Gains (Losses)		43.5		43.4
Net Purchases, Issuances and Settlements		(53)		111
Net Transfers Into (Out Of) Level 3		0		0
Fair value of plan assets at end of year		800.2		809.7
Significant Unobservable Inputs (Level 3) [Member] | Fixed income and cash equivalents [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		8.9	[1]	0.8
Net Realized and Unrealized Gains (Losses)		0		0.1
Net Purchases, Issuances and Settlements		(0.4)		8
Net Transfers Into (Out Of) Level 3		0		0
Fair value of plan assets at end of year		8.5	[2]	8.9	[1]
Significant Unobservable Inputs (Level 3) [Member] | Floating rate [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		392.3	[1]	294.5
Net Realized and Unrealized Gains (Losses)		6.8		4.6
Net Purchases, Issuances and Settlements		(41.1)		93.2
Net Transfers Into (Out Of) Level 3		0		0
Fair value of plan assets at end of year		358	[2]	392.3	[1]
Significant Unobservable Inputs (Level 3) [Member] | Private equity [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		172.6		123
Net Realized and Unrealized Gains (Losses)		11.7		20.5
Net Purchases, Issuances and Settlements		16.9		29.1
Net Transfers Into (Out Of) Level 3		0		0
Fair value of plan assets at end of year		201.2		172.6
Significant Unobservable Inputs (Level 3) [Member] | Hedge funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		84.7		111.2
Net Realized and Unrealized Gains (Losses)		2.5		4.5
Net Purchases, Issuances and Settlements		(35.3)		(31)
Net Transfers Into (Out Of) Level 3		0		0
Fair value of plan assets at end of year		51.9		84.7
Significant Unobservable Inputs (Level 3) [Member] | Real estate and other [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		151.2		125.8
Net Realized and Unrealized Gains (Losses)		22.5		13.7
Net Purchases, Issuances and Settlements		6.9		11.7
Net Transfers Into (Out Of) Level 3		0		0
Fair value of plan assets at end of year		$ 180.6		$ 151.2
[1]	Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments.
[2]	Global debt securities include both fixed interest rate and floating interest rate instruments. These are comprised of actively managed investments which include U.S. government and U.S. government agency securities, foreign government securities, corporate bonds, mortgage-backed securities and other debt securities, and include both investment grade and non-investment grade debt, public and private debt, and secured and unsecured debt investments. To mitigate risk, investment managers have limitations regarding the amount of investment in particular securities and the credit quality of such investments.

Pension Plans and Other Postr91

Pension Plans and Other Postretirement Benefits (Details 13) - Pension Benefits [Member]	12 Months Ended
	Dec. 31, 2015
U.S. equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations range, Minimum	18.00%
Target asset allocations range, Maximum	40.00%
International equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations range, Minimum	7.00%
Target asset allocations range, Maximum	17.00%
Global debt securities and cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations range, Minimum	35.00%
Target asset allocations range, Maximum	55.00%
Private equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations range, Minimum	0.00%	[1]
Target asset allocations range, Maximum	10.00%	[1]
Hedge funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations range, Minimum	0.00%	[1]
Target asset allocations range, Maximum	10.00%	[1]
Real estate and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations range, Minimum	0.00%	[1]
Target asset allocations range, Maximum	10.00%	[1]
Private Equity, Hedge Funds, and Real Estate and Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations range, Minimum	18.00%
Target asset allocations range, Maximum	20.00%
[1]	Have a combined target allocation of 18% and a 20% limit.

Pension Plans and Other Postr92

Pension Plans and Other Postretirement Benefits (Details 17) - Pension Benefits [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Multiemployer Plan Disclosure [Line Items]
Company Contributions		$ 4	$ 4.7	$ 5
Steelworkers Western Independent Shops Pension Plan [Member]
Multiemployer Plan Disclosure [Line Items]
EIN		900,169,564
Pension Plan Number		1
Pension Protection Act Zone Status	[1]	Green	Green
FIP / RP Status Pending / Implemented	[2]	NA
Company Contributions		$ 0.7	$ 1.1	1
Surcharge Imposed	[3]	No
Expiration Dates of Collective Bargaining Agreements		Jun. 30, 2015
Boilermakers-Blacksmiths National Pension Trust [Member]
Multiemployer Plan Disclosure [Line Items]
EIN		486,168,020
Pension Plan Number		1
Pension Protection Act Zone Status	[1]	Yellow	Yellow
FIP / RP Status Pending / Implemented	[2]	Implemented
Company Contributions		$ 1.8	$ 2	2.2
Surcharge Imposed	[3]	No
Expiration Dates of Collective Bargaining Agreements		Sep. 30, 2018
IAM National Pension Fund [Member]
Multiemployer Plan Disclosure [Line Items]
EIN		516,031,295
Pension Plan Number		2
Pension Protection Act Zone Status	[1]	Green	Green
FIP / RP Status Pending / Implemented	[2]	NA
Company Contributions		$ 1.5	$ 1.6	$ 1.8
Surcharge Imposed	[3]	No
Expiration Dates of Collective Bargaining Agreements, First Date	[4]	Feb. 25, 2018
Expiration Dates of Collective-Bargaining Agreements, Last Date	[4]	Jul. 14, 2019
[1]	The most recent Pension Protection Act Zone Status available for ATI’s fiscal years 2015 and 2014 is for plan years ending in calendar years 2014 and 2013, respectively. The zone status is based on information provided to ATI and other participating employers by each plan and is certified by the plan’s actuary. A plan in the “red” zone had been determined to be in “critical status”, based on criteria established by the Code, and is generally less than 65% funded. A plan in the “yellow” zone has been determined to be in “endangered status”, based on criteria established under the Code, and is generally less than 80% funded. A plan in the “green” zone has been determined to be neither in “critical status” nor in “endangered status”, and is generally at least 80% funded.
[2]	The “FIP / RP status Pending / Implemented” column indicates whether a Funding Improvement Plan, as required under the Code by plans in the “yellow” zone, or a Rehabilitation Plan, as required under the Code to be adopted by plans in the “red” zone, is pending or has been implemented as of the end of the plan year that ended in 2015.
[3]	The “Surcharge Imposed” column indicates whether ATI’s contribution rate for 2015 included an amount in addition to the contribution rate specified in the applicable collective bargaining agreement, as imposed by a plan in “critical status”, in accordance with the requirements of the Code.
[4]	The Company is party to five separate bargaining agreements that require contributions to this plan. Expiration dates of these collective bargaining agreements range between February 25, 2018 and July 14, 2019.

Accumulated Other Comprehensi93

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		$ (931.4)	$ (713.2)		$ (1,029.4)
OCI before reclassifications		(121.7)	(270.3)		236.1
Amounts reclassified from AOCI		38.6	52.1		80.1
Net current-period OCI		(83.1)	(218.2)		316.2
Ending balance		(1,014.5)	(931.4)		(713.2)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		25	27.1		23.7
OCI before reclassifications		(5.6)	(2.1)		3.4
Amounts reclassified from AOCI		0	0		0
Net current-period OCI		(5.6)	(2.1)		3.4
Ending balance		19.4	25		27.1
Post- retirement benefit plans [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		(931.5)	(718.9)		(1,030)
OCI before reclassifications		(69.6)	(266.4)		241.1
Amounts reclassified from AOCI	[1]	49.9	53.8		70
Net current-period OCI		(19.7)	(212.6)		311.1
Ending balance		(951.2)	(931.5)		(718.9)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		0	0		0
OCI before reclassifications		0	0		0
Amounts reclassified from AOCI		0	0		0
Net current-period OCI		0	0		0
Ending balance		0	0		0
Currency translation adjustment [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		(16.2)	15.3		3.4
OCI before reclassifications		(31.4)	(32)		10.4
Amounts reclassified from AOCI		0	0.5	[2]	1.5	[2]
Net current-period OCI		(31.4)	(31.5)		11.9
Ending balance		(47.6)	(16.2)		15.3
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		25	27.1		23.7
OCI before reclassifications		(5.6)	(2.1)		3.4
Amounts reclassified from AOCI	[3]	0	0		0
Net current-period OCI		(5.6)	(2.1)		3.4
Ending balance		19.4	25		27.1
Unrealized holding gains on securities [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		0	0		(0.1)
OCI before reclassifications		0	0		0.1
Amounts reclassified from AOCI	[3]	0	0		0
Net current-period OCI		0	0		0.1
Ending balance		0	0		0
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		0	0		0
OCI before reclassifications		0	0		0
Amounts reclassified from AOCI		0	0		0
Net current-period OCI		0	0		0
Ending balance		0	0		0
Derivatives [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		16.3	(9.6)		(2.7)
OCI before reclassifications		(20.7)	28.1		(15.5)
Amounts reclassified from AOCI	[4]	(11.3)	(2.2)		8.6
Net current-period OCI		(32)	25.9		(6.9)
Ending balance		(15.7)	16.3		(9.6)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		0	0		0
OCI before reclassifications		0	0		0
Amounts reclassified from AOCI		0	0		0
Net current-period OCI		0	0		0
Ending balance		$ 0	$ 0		$ 0
[1]	Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 12).
[2]	Amount in 2014 is included in other income, net, and amount in 2013 is included in discontinued operations as part of the gain on sale of the tungsten materials business (see Note 3).
[3]	No amounts were reclassified to earnings.
[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 statements of operations (see Note 10).

Accumulated Other Comprehensi94

Accumulated Other Comprehensive Income (Loss) (Details2) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization to net income (loss) of net prior service cost (credits)		$ 6.2	$ (0.7)		$ (15.2)
Amortization of net actuarial loss		75	88.1		129
Cost of sales		(3,659.3)	(3,844.8)		(3,790.9)
Income (loss) from continuing operations before income taxes		(478)	1.5		(154.8)
Income tax benefit		(112.1)	(8.7)		(63.6)
Income (loss) from continuing operations		(365.9)	10.2		(91.2)
Income (loss) from discontinued operations, net of tax		0	(0.6)		252.8
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]	(6.2)	0.7		15.2
Amortization of net actuarial loss	[1]	(75)	(88.1)		(129)
Income (loss) from continuing operations before income taxes	[2]	(81.2)	(87.4)		(113.8)
Income tax benefit		(31.3)	(33.6)		(43.8)
Income (loss) from continuing operations		(49.9)	(53.8)		(70)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Currency translation adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations	[2]	0	(0.5)	[3]
Income (loss) from discontinued operations, net of tax	[2],[3]				(1.5)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before income taxes	[2]	18.2	3.6		(14)
Income tax benefit		6.9	1.4		(5.4)
Income (loss) from continuing operations		11.3	2.2		(8.6)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Nickel and other raw material contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	[4]	(16.9)	(1)		(8.8)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Natural gas contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	[4]		3.4		(3.8)
Cost of Goods Sold and Selling, General and Administrative Expenses	[4]	(18.2)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Electricity contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	[4]	(0.2)	0.7		(0.3)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Foreign Exchange Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	[4]		$ 0.5		$ (1.1)
Cost of Goods Sold and Selling, General and Administrative Expenses	[4]	$ 53.5
[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 12.
[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]	Amount in 2014 is included in other income, net, and amount in 2013 is included in discontinued operations as part of the gain on sale of the tungsten materials business (see Note 3).
[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 statements of operations (see Note 10).

Stockholders' Equity (Details)

Stockholders' Equity (Details) $ / shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)plan$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)$ / sharesshares
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock, issued	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Number of share-based compensation plans | plan	2
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (shares)	669,000	675,000	576,000
Common stock shares available for future awards	3,400,000
Shares vested	23,000	18,000	333,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested beginning of the year (shares)	1,376,000	927,000	727,000
Granted (shares)	669,000	675,000	576,000
Vested (shares)	(23,000)	(18,000)	(333,000)
Forfeited (shares)	(370,000)	(208,000)	(43,000)
Nonvested end of the year (shares)	1,652,000	1,376,000	927,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning balance (in dollars per share) | $ / shares	$ 47.8	$ 36.9	$ 38.6
Granted (in dollars per share) | $ / shares	20.8	20.3	16.4
Vested (in dollars per share) | $ / shares	(0.8)	(1)	(16.4)
Forfeited (in dollars per share) | $ / shares	(10.8)	(8.4)	(1.7)
Ending balance (in dollars per share) | $ / shares	$ 57	$ 47.8	$ 36.9
Retained Earnings Note Disclosure [Abstract]
Undistributed earnings of investees accounted for under equity method | $	$ 12
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Income target attainment measurement period	3 years
Share based compensation expense | $	$ 5.5	$ 2.4	$ 11.3
Unrecognized compensation expense | $	17.9
Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense | $	$ 12
TSR/TSRP Minimum Shares	0
TSR/TSRP Target Shares	869,000
TSR/TSRP Maximum Shares	1,738,000
PRSP 2015 [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (shares)	461,215
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (shares)	461,215
Long-Term Shareholder Value (LTSV) 2015 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Metric, Percent Expected to be Attained	85.00%
Long-Term Shareholder Value (LTSV) 2015 [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (shares)	126,421
Award vesting period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (shares)	126,421
Long-Term Shareholder Value (LTSV) 2014 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Metric, Percent Expected to be Attained	100.00%
PRSP 2012 [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Forfeited (shares)		(171,083)
PRSP 2013 [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Forfeited (shares)	(244,899)
TSRP 2013-2015 [Member] | Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
TSR/TSRP Award Fair Value | $	$ 10.5
Unrecognized compensation expense | $	$ 0
TSR/TSRP Minimum Shares	0
TSR/TSRP Target Shares	296,000
TSR/TSRP Maximum Shares	592,000
TSR 2014-2016 [Member] | Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Target share award level	328,564
TSR/TSRP Award Fair Value | $	$ 13.4
Unrecognized compensation expense | $	$ 8.9
TSR/TSRP Minimum Shares	0
TSR/TSRP Target Shares	296,000
TSR/TSRP Maximum Shares	592,000
TSR and TSRP Awards [Member] | Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense | $	$ 10.6	$ 9.8	$ 12.3
Performance measurement period	3 years
Common stock shares available for future awards	2,050,000
TSR 2014-2016 [Member] | Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
TSR/TSRP Award Fair Value | $	$ 9.3
Unrecognized compensation expense | $	$ 3.1
TSR/TSRP Minimum Shares	0
TSR/TSRP Target Shares	277,000
TSR/TSRP Maximum Shares	554,000
Maximum [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period	5 years
Maximum [Member] | TSR and TSRP Awards [Member] | Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award multiplier	2
Minimum [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period	3 years
Minimum [Member] | TSR and TSRP Awards [Member] | Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award multiplier	0

Schedule of Income Tax Provisio

Schedule of Income Tax Provision (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components Of Income Tax Expense Benefit Continuing Operations Abstract
Current: Federal	$ (60.7)	$ (47.9)	$ (127.5)
Current: State	(0.4)	(4)	(10.2)
Current: Foreign	9.4	9.8	7.9
Total Current	(51.7)	(42.1)	(129.8)
Deferred: Federal	(90.9)	34.1	62.7
Deferred: State	30.4	(0.2)	4.6
Deferred: Foreign	0.1	(0.5)	(1.1)
Total Deferred	(60.4)	33.4	66.2
Income tax benefit from continuing operations	(112.1)	(8.7)	(63.6)
Income tax provision (benefit) from discontinued operations	0	(0.3)	161.4
Total company income tax provision (benefit)	$ (112.1)	$ (9)	$ 97.8

Reconciliation of Federal Tax R

Reconciliation of Federal Tax Rate to Effective Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Taxes computed at the federal rate	$ (167.3)	$ 0.5	$ (54.2)
State and local income taxes, net of federal tax benefit	(20.6)	(2)	(11.8)
Tax reserve adjustments	3.9	(0.5)	(10.2)
Repatriation of foreign earnings	13.4	0.3	9.4
Valuation allowance	74.5	0.5	9.1
Adjustment to prior years’ taxes	(5.4)	0.1	(5.3)
Foreign earnings taxed at different rate	(11.2)	(6.6)	(2.5)
Other	0.6	(1)	1.9
Income tax benefit from continuing operations	$ (112.1)	$ (8.7)	$ (63.6)

Income Taxes Deferred Tax Liabi

Income Taxes Deferred Tax Liability not Recognized (Details) $ in Millions	Dec. 31, 2015USD ($)
Income Tax Disclosure [Abstract]
Undistributed earnings of foreign subsidiaries	$ 168

Schedule of Income Taxes by Reg

Schedule of Income Taxes by Region (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest [Abstract]
U.S.	$ (534.6)	$ (46.1)	$ (180)
Non-U.S.	56.6	47.6	25.2
Income (loss) from continuing operations before income taxes	$ (478)	$ 1.5	$ (154.8)

Schedule of Income Taxes Paid a

Schedule of Income Taxes Paid and Refunded (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes Paid, Net [Abstract]
Income Taxes Paid	$ 10.8	$ 15.1	$ 21.4
Income tax refunds received	63.3	20.2	18.3
Income Taxes Paid (Received), Net, Total	(52.5)	$ (5.1)	$ 3.1
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	166
Tax credit carryforwards	43
Income Taxes Paid, Net [Abstract]
Income tax refunds received	$ 59.9

Schedule of Deferred Tax Assets

Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Deferred income tax assets
Pensions	$ 281	$ 251.8
Postretirement benefits other than pensions	144.7	169
Federal and state net operating loss tax carryovers	228.1	122.7
Federal and state tax credits	52.2	53.6
Deferred compensation and other benefit plans	25.9	25.6
Self insurance reserves	10.8	10.1
Other items	85.2	79.1
Gross deferred income tax assets	827.9	711.9
Valuation allowance for deferred tax assets	(105.1)	(34.4)
Total deferred income tax assets	722.8	677.5
Deferred income tax liabilities
Bases of property, plant and equipment	664.1	579.5
Inventory valuation	62.2	111.7
Bases of amortizable intangible assets	25.4	75.5
Other items	46.7	53.9
Total deferred tax liabilities	798.4	820.6
Net deferred tax liability	$ (75.6)	$ (143.1)

Income Tax Valuation Allowance

Income Tax Valuation Allowance (Details6) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)year	Dec. 31, 2014USD ($)year
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets		$ 105.1	$ 34.4
Number of Years in Cumulative Loss Profit Position | year		3	3
Deferred tax asset valuation allowance charge	$ 63.9	$ 68.4
Amount of valuation allowance in the effective tax rate (percent)		4.00%
Discrete Item [Member]
Valuation Allowance [Line Items]
Deferred tax asset valuation allowance charge		$ 49.3
Part of Effective Tax Rate [Member]
Valuation Allowance [Line Items]
Deferred tax asset valuation allowance charge		19.1
Federal [Member]
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets		24.8
State net operating loss carryforwards [Member]
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets		61.8
Foreign Net Operating Losses and Credits [Member]
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets		1.4
State tax credits [Member]
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets		13.8
State temporary differences [Member]
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets		$ 3.3
State [Member]
Valuation Allowance [Line Items]
Operating loss carryforward period		20 years
Maximum tax benefit available per year amount		$ 5
Maximum tax benefit available per year percent of income		30.00%

Schedule of Changes in Unrecogn

Schedule of Changes in Unrecognized Income Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2012
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Increases in prior period tax positions	$ 4.2	$ 2	$ 0.1
Decreases in prior period tax positions	(0.6)	(0.6)	(5.8)
Increases in current period tax positions	1.3	0.7	60.4
Unrecognized tax benefits	15	73.4	72.8	$ 15	$ 29.2
Expiration of the statute of limitations	(0.7)	(0.5)	(0.7)
Settlements	(62.1)	(0.7)	(8.6)
Interest and penalties, net	(0.5)	(0.3)	(1.8)
Ending balance	$ 15	73.4	$ 72.8
Income tax penalties and interest accrued				3.9
Unrecognized tax benefits that would impact effective tax rate				12
Unrecognized tax benefits that will be recognized within 12 months of year end				$ 4
Temporary difference [Member]
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Unrecognized tax benefits		60.9
Ending balance		$ 60.9

Tax Years Subject To Examinatio

Tax Years Subject To Examination (Details)	12 Months Ended
	Dec. 31, 2015
Internal Revenue Service IRS [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,014
Alabama Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,012
Illinois Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,012
North Carolina Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,010
Oregon Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,012
Pennsylvania Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,012
China Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,011
Germany Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,014
Poland Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,011
United Kingdom Tax [Member]
Income Tax Examination [Line Items]
Earliest Tax Year Open To Examination	2,012

Business Segments - Narrative (

Business Segments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total direct international sales		$ 1,577	$ 1,607.5	$ 1,585.1
Sales by U.S. operations to foreign countries		1,215.8	1,201.8	1,175.1
LIFO-related net realizable value charge	$ (136.4)	(136.4)	(4.8)
Inventory valuation reserves	206.3	206.3	68.8
Closed company and other expense		22.1	28.3	30.9
Closed companies environmental costs		4.5	8	3.9
Closed companies insurance obligations			3.8
Other corporate expense		15.3	9.4	10.3
Asset Impairment Charges	$ 54.5			55.1
Flat Rolled Products [Member]
Segment Reporting Information [Line Items]
Income (loss) from equity method investments		$ (0.1)	(8.9)	(7.1)
High Performance Materials & Components [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges				8
STAL Precision Stainless Steel Company Limited [Member]
Segment Reporting Information [Line Items]
Joint venture ownership percentage	60.00%	60.00%
Corporate Joint Venture [Member]
Segment Reporting Information [Line Items]
Equity method investment ownership percentage	50.00%	50.00%
Revenue from related parties		$ 55.4	75.3	95.9
Corporate Joint Venture [Member] | VSMPO [Member]
Segment Reporting Information [Line Items]
Joint venture ownership percentage by unaffiliated entity	50.00%	50.00%
Corporate, Non-Segment [Member] | Closed Company and Other [Member]
Segment Reporting Information [Line Items]
Retirement Benefit Expense		$ 2.3	$ 7.1	$ 16.7
Inventory Valuation Reserve [Member] | Non-PQ grade titanium sponge [Member]
Segment Reporting Information [Line Items]
Lower of cost or market charges	$ (25.4)

Business Segments (Details)

Business Segments (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Sales	$ 738.9	$ 832.7	$ 1,022.5	$ 1,125.5	$ 1,047.5	$ 1,069.6	$ 1,119	$ 987.3	$ 3,719.6	$ 4,223.4	$ 4,043.5
External Sales [Member]
Segment Reporting Information [Line Items]
Sales									3,719.6	4,223.4	4,043.5
Operating Segments [Member]
Segment Reporting Information [Line Items]
Sales									3,870.6	4,404.8	4,163.3
Operating Segments [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Sales									151	181.4	119.8
Operating Segments [Member] | External Sales [Member]
Segment Reporting Information [Line Items]
Sales									3,719.6	4,223.4	4,043.5
Operating Segments [Member] | High Performance Materials & Components [Member]
Segment Reporting Information [Line Items]
Sales									2,062.7	2,084.6	2,016.7
Operating Segments [Member] | High Performance Materials & Components [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Sales									76.8	77.8	71.9
Operating Segments [Member] | High Performance Materials & Components [Member] | External Sales [Member]
Segment Reporting Information [Line Items]
Sales									1,985.9	2,006.8	1,944.8
Operating Segments [Member] | Flat Rolled Products [Member]
Segment Reporting Information [Line Items]
Sales									1,807.9	2,320.2	2,146.6
Operating Segments [Member] | Flat Rolled Products [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Sales									74.2	103.6	47.9
Operating Segments [Member] | Flat Rolled Products [Member] | External Sales [Member]
Segment Reporting Information [Line Items]
Sales									$ 1,733.7	$ 2,216.6	$ 2,098.7

Business Segments (Details8)

Business Segments (Details8) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Inventory valuation reserves	$ 206.3	$ 206.3	$ 68.8
Segment Operating Profit Loss		(84.8)	187.8	$ 11.8
Lifo Provision Benefit and Change in Debit LIFO NRV reserve, net		(0.1)	(0.3)	(45.9)
Corporate expenses		(44.7)	(49.6)	(48.9)
Interest expense, net		(110.2)	(108.7)	(65.2)
Closed company and other expense		(22.1)	(28.3)	(30.9)
Impairment of goodwill		(126.6)	0	0
Restructuring and other charges		(89.7)	0	(67.5)
Income (loss) from continuing operations before income taxes		(478)	1.5	(154.8)
Flat Rolled Products [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Impairment of goodwill	$ (126.6)
Operating Segments [Member] | High Performance Materials & Components [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment Operating Profit Loss		157.1	234.8	159.6
Operating Segments [Member] | Flat Rolled Products [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment Operating Profit Loss		$ (241.9)	$ (47)	$ (147.8)

Business Segments (Details2)

Business Segments (Details2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Other Significant Reconciling Item [Line Items]
Depreciation and amortization	$ 189.9	$ 176.8	$ 189.9
Capital expenditures	144.5	225.7	612.7
Operating Segments [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Depreciation and amortization	189.9	176.6	180.6
Capital expenditures	144.5	225.7	607.8
Operating Segments [Member] | High Performance Materials & Components [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Depreciation and amortization	131.8	124.4	127.4
Capital expenditures	75.8	51.9	39.5
Operating Segments [Member] | Flat Rolled Products [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Depreciation and amortization	55.6	49.3	49.5
Capital expenditures	68	172.1	568.1
Operating Segments [Member] | Corporate [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Depreciation and amortization	2.5	2.9	3.7
Capital expenditures	$ 0.7	$ 1.7	$ 0.2

Business Segments (Details3)

Business Segments (Details3) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Asset Reconciling Item [Line Items]
Identifiable Assets	$ 5,751.7	$ 6,571.7	$ 6,885
High Performance Materials & Components [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Identifiable Assets	3,355.5	3,555.8	3,452.2
Flat Rolled Products [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Identifiable Assets	2,189.5	2,601.6	2,320.9
Discontinued Operations [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Identifiable Assets	0.9	1.8	9.8
Corporate Prepaid Pension Cost [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Identifiable Assets	0	0	5.1
Corporate: Cash and cash equivalents and other [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Identifiable Assets	$ 205.8	$ 412.5	$ 1,097

Business Segments (Details4)

Business Segments (Details4) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales		$ 738.9	$ 832.7	$ 1,022.5	$ 1,125.5	$ 1,047.5	$ 1,069.6	$ 1,119	$ 987.3	$ 3,719.6	$ 4,223.4	$ 4,043.5
Identifiable Assets		$ 5,751.7				$ 6,571.7				$ 5,751.7	$ 6,571.7	$ 6,885
Percent of total		100.00%				100.00%				100.00%	100.00%	100.00%
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets		$ 5,073.1				$ 5,868.7				$ 5,073.1	$ 5,868.7	$ 6,131.9
Percent of total		88.00%				90.00%				88.00%	90.00%	89.00%
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets		$ 154.3				$ 196.3				$ 154.3	$ 196.3	$ 208
Percent of total		3.00%				3.00%				3.00%	3.00%	3.00%
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets		$ 260				$ 280.5				$ 260	$ 280.5	$ 258.1
Percent of total		5.00%				4.00%				5.00%	4.00%	4.00%
Luxembourg [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets	[1]	$ 124.4				$ 81.8				$ 124.4	$ 81.8	$ 145.9
Percent of total	[1]	2.00%				1.00%				2.00%	1.00%	2.00%
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets		$ 139.9				$ 144.4				$ 139.9	$ 144.4	$ 141.1
Percent of total		2.00%				2.00%				2.00%	2.00%	2.00%
External Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 3,719.6	$ 4,223.4	$ 4,043.5
Percent of total										100.00%	100.00%	100.00%
External Sales [Member] | United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 2,142.6	$ 2,615.9	$ 2,458.4
Percent of total										58.00%	62.00%	61.00%
External Sales [Member] | United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 198.2	$ 228.4	$ 251.5
Percent of total										5.00%	5.00%	6.00%
External Sales [Member] | China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 246.9	$ 249.6	$ 237.7
Percent of total										7.00%	6.00%	6.00%
External Sales [Member] | Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 193.3	$ 207.7	$ 215.4
Percent of total										5.00%	5.00%	5.00%
External Sales [Member] | France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 153.3	$ 168.1	$ 152.8
Percent of total										4.00%	4.00%	4.00%
External Sales [Member] | Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 154.5	$ 147	$ 141
Percent of total										4.00%	3.00%	4.00%
External Sales [Member] | Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 65	$ 160.7	$ 132.3
Percent of total										2.00%	4.00%	3.00%
External Sales [Member] | Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 202.3	$ 89.3	$ 124.7
Percent of total										5.00%	2.00%	3.00%
External Sales [Member] | Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 78.4	$ 76.5	$ 54.9
Percent of total										2.00%	2.00%	1.00%
External Sales [Member] | Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales										$ 285.1	$ 280.2	$ 274.8
Percent of total										8.00%	7.00%	7.00%
[1]	Comprises assets held by the Company’s European Treasury Center operation.

Restructuring Costs (Details)

Restructuring Costs (Details) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2015USD ($)employee	Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)employee$ / shares
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 64.3	$ 0	$ 67.5
Restructuring costs net of tax			$ 41.6		$ 41.2
Restructuring costs, per share (in dollars per share) | $ / shares			$ 0.39		$ 0.39
Asset Impairment Charges		$ 54.5			$ 55.1
Revision of estimates			$ (0.2)	(1)	4.2
Severance and termination benefit costs					8.2
Restructuring reserve	$ 8	8	8		2
Restructuring and other charges			89.7	0	67.5
Inventory Valuation Reserve [Member] | Non-PQ grade titanium sponge [Member]
Restructuring Cost and Reserve [Line Items]
Lower of cost or market charges		(25.4)
Inventory Valuation Reserve [Member] | Industrial titanium products [Member]
Restructuring Cost and Reserve [Line Items]
Lower of cost or market charges			$ (24.5)	$ (23.2)	(20.5)
Facility Idling Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs		3.5
Restructuring costs net of tax		2.2
High Performance Materials & Components and Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Severance and termination benefit costs		$ 6.3
Number of employees affected by restructuring | employee		100
High Performance Materials & Components [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges					8
Severance and termination benefit costs					$ 1.1
Number of employees affected by restructuring | employee					75
High Performance Materials & Components [Member] | Benefit Termination [Member]
Restructuring Cost and Reserve [Line Items]
Severance and termination benefit costs					$ 1.1
Midland, Pennsylvania Facility [Member] | Flat Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges	24.2
Grain-Oriented Electrical Steel (GOES) Operations in Western Pennsylvania [Member] | Flat Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges	$ 30.3
Albany, Oregon Standard-grade Titanium Sponge Facility [Member] | High Performance Materials & Components [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges					38.1
Revision of estimates					3.5
New Castle, Indiana Stainless Finishing Facility [Member] | Flat Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges					6.3
Revision of estimates					0.3
Wallingford, Connecticut Stainless Finishing Facility [Member] | Flat Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges					2.7
Revision of estimates					0.4
Severance and termination benefit costs					$ 1
Number of employees affected by restructuring | employee					65
Wallingford, Connecticut Stainless Finishing Facility [Member] | Flat Rolled Products [Member] | Benefit Termination [Member]
Restructuring Cost and Reserve [Line Items]
Severance and termination benefit costs					$ 5

Redeemable Noncontrolling In112

Redeemable Noncontrolling Interest - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Change in redeemable noncontrolling interest		$ 0	$ 0
Redeemable noncontrolling interest		12.1	12.1
Retained Earnings
Noncontrolling Interest [Line Items]
Change in redeemable noncontrolling interest		$ (0.3)	$ (0.3)
ATI Flowform [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest held by others (percent)		15.00%
Subsequent Event [Member] | ATI Flowform [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest held by others (percent)	7.50%
Noncontrolling interest reacquired (percent)	7.50%
Redeemable noncontrolling interest reacquired	$ 6.1

Per Share Information (Details)

Per Share Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share Reconciliation [Abstract]
Loss from continuing operations, net of tax	$ (226.9)	$ (144.6)	$ (16.4)	$ 10	$ 19.9	$ 0	$ (3.8)	$ (18.1)	$ (377.9)	$ (2)	$ (98.8)
Redeemable noncontrolling interest									(0.3)	(0.3)	0
Redeemable noncontrolling interest									0	0
Effect of dilutive securities: 4.25% Convertible Notes due 2014									0	0	0
Numerator for diluted net income (loss) per common share - Income (loss) from continuing operations attributable to ATI after assumed conversions									$ (378.2)	$ (2.3)	$ (98.8)
Denominator for basic net income per common share - weighted average shares (shares)	109,171,124	109,204,307	109,190,876	108,854,720	108,704,983	108,712,682	108,628,024	108,173,581	107,300,000	107,100,000	106,800,000
Effect of dilutive securities: Share-based compensation									0	0	0
Effect of dilutive securities: 4.25% Convertible Notes due 2014									0	0	0
Denominator for diluted net loss per common share—adjusted weighted average shares and assumed conversions									107,300,000	107,100,000	106,800,000
Basic income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	$ (2.12)	$ (1.35)	$ (0.15)	$ 0.09	$ 0.18	$ 0	$ (0.03)	$ (0.17)	$ (3.53)	$ (0.02)	$ (0.93)
Diluted income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	$ (2.12)	$ (1.35)	$ (0.15)	$ 0.09	$ 0.18	$ 0	$ (0.03)	$ (0.17)	$ (3.53)	$ (0.02)	$ (0.93)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share amount									800,000	4,700,000	10,000,000
Allegheny Technologies $402.5 million 4.25% Convertible Senior Notes due 2014 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt instrument interest rate stated percentage											4.25%

Financial Information for Su114

Financial Information for Subsidiary and Guarantor Parent - Narrative (Details) - Allegheny Ludlum 6.95% Debentures due 2025 [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Debt instrument carrying amount	$ 150	$ 150
Debt instrument interest rate stated percentage	6.95%	6.95%

Financial Information for Su115

Financial Information for Subsidiary and Guarantor Parent (B.S.) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 149.8	$ 269.5	$ 1,026.8	$ 304.6
Accounts receivable, net	400.3	603.6
Intercompany notes receivable	0	0
Inventories, net	1,271.6	1,472.8
Prepaid expenses and other current assets	45.9	136.2
Total Current Assets	1,867.6	2,482.1
Property, plant and equipment, net	2,928.2	2,961.8
Goodwill	651.4	780.4
Intercompany notes receivable	0	0
Investments in subsidiaries	0	0
Other assets	304.5	347.4
Total Assets	5,751.7	6,571.7	6,885
Accounts payable	380.8	556.7
Accrued liabilities	301.8	323.2
Intercompany notes payable	0	0
Short-term debt and current portion of long-term debt	3.9	17.8
Total Current Liabilities	686.5	897.7
Long-term debt	1,491.8	1,498.2
Intercompany notes payable	0	0
Accrued postretirement benefits	359.2	415.8
Pension liabilities	833.8	739.3
Deferred income taxes	75.6	143.1
Other long-term liabilities	108.3	156.2
Total Liabilities	3,555.2	3,850.3
Redeemable noncontrolling interest	12.1	12.1
Total Stockholders’ Equity	2,184.4	2,709.3	$ 2,994.7	$ 2,587.1
Total Liabilities and Stockholders’ Equity	5,751.7	6,571.7
Guarantor Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0.4	2.2
Accounts receivable, net	0.1	0.1
Intercompany notes receivable	0	0
Inventories, net	0	0
Prepaid expenses and other current assets	9.3	63.7
Total Current Assets	9.8	66
Property, plant and equipment, net	2.2	2.2
Goodwill	0	0
Intercompany notes receivable	0	0
Investments in subsidiaries	5,742.5	6,149.4
Other assets	13.4	13.3
Total Assets	5,767.9	6,230.9
Accounts payable	4.8	4.5
Accrued liabilities	42.1	47.5
Intercompany notes payable	1,325.4	1,232.6
Short-term debt and current portion of long-term debt	0.7	0.5
Total Current Liabilities	1,373	1,285.1
Long-term debt	1,341.7	1,340.2
Intercompany notes payable	0	0
Accrued postretirement benefits	0	0
Pension liabilities	778	675.5
Deferred income taxes	75.6	143.1
Other long-term liabilities	15.2	77.7
Total Liabilities	3,583.5	3,521.6
Redeemable noncontrolling interest	0	0
Total Stockholders’ Equity	2,184.4	2,709.3
Total Liabilities and Stockholders’ Equity	5,767.9	6,230.9
Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	2.8	13.8
Accounts receivable, net	100.3	209.1
Intercompany notes receivable	0	0
Inventories, net	239.9	387.7
Prepaid expenses and other current assets	3.8	13.2
Total Current Assets	346.8	623.8
Property, plant and equipment, net	1,559.9	1,545.1
Goodwill	0	126.6
Intercompany notes receivable	0	0
Investments in subsidiaries	37.7	37.7
Other assets	23	27.5
Total Assets	1,967.4	2,360.7
Accounts payable	171.1	302
Accrued liabilities	74	72
Intercompany notes payable	1,276.1	1,158.2
Short-term debt and current portion of long-term debt	0.1	0.1
Total Current Liabilities	1,521.3	1,532.3
Long-term debt	149.7	149.8
Intercompany notes payable	200	200
Accrued postretirement benefits	280	153
Pension liabilities	5.2	6
Deferred income taxes	0	0
Other long-term liabilities	20.7	22.5
Total Liabilities	2,176.9	2,063.6
Redeemable noncontrolling interest	0	0
Total Stockholders’ Equity	(209.5)	297.1
Total Liabilities and Stockholders’ Equity	1,967.4	2,360.7
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	146.6	253.5
Accounts receivable, net	299.9	394.4
Intercompany notes receivable	2,601.5	2,390.8
Inventories, net	1,031.7	1,085.1
Prepaid expenses and other current assets	32.8	59.3
Total Current Assets	4,112.5	4,183.1
Property, plant and equipment, net	1,366.1	1,414.5
Goodwill	651.4	653.8
Intercompany notes receivable	200	200
Investments in subsidiaries	0	0
Other assets	268.1	306.6
Total Assets	6,598.1	6,758
Accounts payable	204.9	250.2
Accrued liabilities	185.7	203.7
Intercompany notes payable	0	0
Short-term debt and current portion of long-term debt	3.1	17.2
Total Current Liabilities	393.7	471.1
Long-term debt	0.4	8.2
Intercompany notes payable	0	0
Accrued postretirement benefits	79.2	262.8
Pension liabilities	50.6	57.8
Deferred income taxes	0	0
Other long-term liabilities	72.4	56
Total Liabilities	596.3	855.9
Redeemable noncontrolling interest	12.1	12.1
Total Stockholders’ Equity	5,989.7	5,890
Total Liabilities and Stockholders’ Equity	6,598.1	6,758
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0
Accounts receivable, net	0	0
Intercompany notes receivable	(2,601.5)	(2,390.8)
Inventories, net	0	0
Prepaid expenses and other current assets	0	0
Total Current Assets	(2,601.5)	(2,390.8)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intercompany notes receivable	(200)	(200)
Investments in subsidiaries	(5,780.2)	(6,187.1)
Other assets	0	0
Total Assets	(8,581.7)	(8,777.9)
Accounts payable	0	0
Accrued liabilities	0	0
Intercompany notes payable	(2,601.5)	(2,390.8)
Short-term debt and current portion of long-term debt	0	0
Total Current Liabilities	(2,601.5)	(2,390.8)
Long-term debt	0	0
Intercompany notes payable	(200)	(200)
Accrued postretirement benefits	0	0
Pension liabilities	0	0
Deferred income taxes	0	0
Other long-term liabilities	0	0
Total Liabilities	(2,801.5)	(2,590.8)
Redeemable noncontrolling interest	0	0
Total Stockholders’ Equity	(5,780.2)	(6,187.1)
Total Liabilities and Stockholders’ Equity	$ (8,581.7)	$ (8,777.9)

Financial Information for Su116

Financial Information for Subsidiary and Guarantor Parent (I.S.) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Sales	$ 738.9	$ 832.7	$ 1,022.5	$ 1,125.5	$ 1,047.5	$ 1,069.6	$ 1,119	$ 987.3	$ 3,719.6	$ 4,223.4	$ 4,043.5
Cost of sales									3,659.3	3,844.8	3,790.9
Selling and administrative expenses									238.8	272.5	276.4
Impairment of goodwill									126.6	0	0
Restructuring charges									64.3	0	67.5
Income (loss) before interest, other income and income taxes									(369.4)	106.1	(91.3)
Interest expense, net									(110.2)	(108.7)	(65.2)
Other income (expense) including equity in income of unconsolidated subsidiaries									1.6	4.1	1.7
Income (loss) from continuing operations before income taxes									(478)	1.5	(154.8)
Income tax benefit									(112.1)	(8.7)	(63.6)
Income (loss) from continuing operations									(365.9)	10.2	(91.2)
Income (loss) from discontinued operations, net of tax									0	(0.6)	252.8
Net income (loss)	(223.3)	(141.3)	(13.9)	12.6	25.3	2.9	(0.7)	(17.9)	(365.9)	9.6	161.6
Less: Net income attributable to noncontrolling interests									12	12.2	7.6
Net income (loss) attributable to ATI	$ (226.9)	$ (144.6)	$ (16.4)	$ 10	$ 22.1	$ (0.7)	$ (4)	$ (20)	(377.9)	(2.6)	154
Guarantor Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Sales									0	0	0
Cost of sales									27.3	45.3	75.2
Selling and administrative expenses									88.2	103.9	124.3
Impairment of goodwill									0
Restructuring charges									1.6		1.1
Income (loss) before interest, other income and income taxes									(117.1)	(149.2)	(200.6)
Interest expense, net									(117.3)	(111)	(63.4)
Other income (expense) including equity in income of unconsolidated subsidiaries									(243.6)	261.7	109.2
Income (loss) from continuing operations before income taxes									(478)	1.5	(154.8)
Income tax benefit									(112.1)	(8.7)	(63.6)
Income (loss) from continuing operations									(365.9)	10.2	(91.2)
Income (loss) from discontinued operations, net of tax									0	(0.6)	252.8
Net income (loss)									(365.9)	9.6	161.6
Less: Net income attributable to noncontrolling interests									0	0	0
Net income (loss) attributable to ATI									(365.9)	9.6	161.6
Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Sales									1,453.2	1,878	1,769.4
Cost of sales									1,643.2	1,874.8	1,748.8
Selling and administrative expenses									29.4	44	34.9
Impairment of goodwill									126.6
Restructuring charges									58		15.7
Income (loss) before interest, other income and income taxes									(404)	(40.8)	(30)
Interest expense, net									(50.9)	(44.9)	(37.2)
Other income (expense) including equity in income of unconsolidated subsidiaries									1.1	1.1	0.9
Income (loss) from continuing operations before income taxes									(453.8)	(84.6)	(66.3)
Income tax benefit									(165.7)	(29.3)	(20)
Income (loss) from continuing operations									(288.1)	(55.3)	(46.3)
Income (loss) from discontinued operations, net of tax									0	0	0
Net income (loss)									(288.1)	(55.3)	(46.3)
Less: Net income attributable to noncontrolling interests									0	0	0
Net income (loss) attributable to ATI									(288.1)	(55.3)	(46.3)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Sales									2,266.4	2,345.4	2,274.1
Cost of sales									1,988.8	1,924.7	1,966.9
Selling and administrative expenses									121.2	124.6	117.2
Impairment of goodwill									0
Restructuring charges									4.7		50.7
Income (loss) before interest, other income and income taxes									151.7	296.1	139.3
Interest expense, net									58	47.2	35.4
Other income (expense) including equity in income of unconsolidated subsidiaries									0.8	2.9	0.8
Income (loss) from continuing operations before income taxes									210.5	346.2	175.5
Income tax benefit									51.6	116.7	40.4
Income (loss) from continuing operations									158.9	229.5	135.1
Income (loss) from discontinued operations, net of tax									0	(0.6)	252.8
Net income (loss)									158.9	228.9	387.9
Less: Net income attributable to noncontrolling interests									12	12.2	7.6
Net income (loss) attributable to ATI									146.9	216.7	380.3
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Sales									0	0	0
Cost of sales									0	0	0
Selling and administrative expenses									0	0	0
Impairment of goodwill									0
Restructuring charges									0		0
Income (loss) before interest, other income and income taxes									0	0	0
Interest expense, net									0	0	0
Other income (expense) including equity in income of unconsolidated subsidiaries									243.3	(261.6)	(109.2)
Income (loss) from continuing operations before income taxes									243.3	(261.6)	(109.2)
Income tax benefit									114.1	(87.4)	(20.4)
Income (loss) from continuing operations									129.2	(174.2)	(88.8)
Income (loss) from discontinued operations, net of tax									0	0.6	(252.8)
Net income (loss)									129.2	(173.6)	(341.6)
Less: Net income attributable to noncontrolling interests									0	0	0
Net income (loss) attributable to ATI									$ 129.2	$ (173.6)	$ (341.6)

Financial Information for Su117

Financial Information for Subsidiary and Guarantor Parent (Comp Inc.) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ (223.3)	$ (141.3)	$ (13.9)	$ 12.6	$ 25.3	$ 2.9	$ (0.7)	$ (17.9)	$ (365.9)	$ 9.6	$ 161.6
Currency translation adjustment arising during the period									(37)	(33.6)	15.3
Unrealized holding gain (loss) on securities									0		0.1
Net derivative loss on hedge transactions									(32)	25.9	(6.9)
Pension and postretirement benefits									(19.7)	(212.6)	311.1
Other comprehensive income (loss), net of tax									(88.7)	(220.3)	319.6
Comprehensive income (loss)									(454.6)	(210.7)	481.2
Less: Comprehensive income attributable to noncontrolling interest									6.4	10.1	11
Comprehensive income (loss) attributable to ATI									(461)	(220.8)	470.2
Guarantor Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									(365.9)	9.6	161.6
Currency translation adjustment arising during the period									(37)	(33.6)	15.3
Unrealized holding gain (loss) on securities									0		0.1
Net derivative loss on hedge transactions									(32)	25.9	(6.9)
Pension and postretirement benefits									(19.7)	(212.6)	311.1
Other comprehensive income (loss), net of tax									(88.7)	(220.3)	319.6
Comprehensive income (loss)									(454.6)	(210.7)	481.2
Less: Comprehensive income attributable to noncontrolling interest									0	0	0
Comprehensive income (loss) attributable to ATI									(454.6)	(210.7)	481.2
Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									(288.1)	(55.3)	(46.3)
Currency translation adjustment arising during the period									0	0	0
Unrealized holding gain (loss) on securities									0		0
Net derivative loss on hedge transactions									0	0	0
Pension and postretirement benefits									29.8	1.8	22
Other comprehensive income (loss), net of tax									29.8	1.8	22
Comprehensive income (loss)									(258.3)	(53.5)	(24.3)
Less: Comprehensive income attributable to noncontrolling interest									0	0	0
Comprehensive income (loss) attributable to ATI									(258.3)	(53.5)	(24.3)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									158.9	228.9	387.9
Currency translation adjustment arising during the period									(37)	(33.6)	15.3
Unrealized holding gain (loss) on securities									0		0.1
Net derivative loss on hedge transactions									0	0	0
Pension and postretirement benefits									3.1	(28.4)	27.6
Other comprehensive income (loss), net of tax									(33.9)	(62)	43
Comprehensive income (loss)									125	166.9	430.9
Less: Comprehensive income attributable to noncontrolling interest									6.4	10.1	11
Comprehensive income (loss) attributable to ATI									118.6	156.8	419.9
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									129.2	(173.6)	(341.6)
Currency translation adjustment arising during the period									37	33.6	(15.3)
Unrealized holding gain (loss) on securities									0		(0.1)
Net derivative loss on hedge transactions									0	0	0
Pension and postretirement benefits									(32.9)	26.6	(49.6)
Other comprehensive income (loss), net of tax									4.1	60.2	(65)
Comprehensive income (loss)									133.3	(113.4)	(406.6)
Less: Comprehensive income attributable to noncontrolling interest									0	0	0
Comprehensive income (loss) attributable to ATI									$ 133.3	$ (113.4)	$ (406.6)

Financial Information for Su118

Financial Information for Subsidiary and Guarantor Parent (Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	$ 131.4	$ 55.9	$ 368.4
Purchases of property, plant and equipment	(144.5)	(225.7)	(612.7)
Net receipts (payments) on intercompany activity	0	0	0
Purchases of businesses, net of cash acquired	(0.5)	(92.9)	0
Proceeds from sale of business, net of transaction costs	0	0	600.9
Asset disposals and other	(0.1)	2.4	0.8
Cash flows provided by (used in) investing activities	(145.1)	(316.2)	(11)
Borrowings on long-term debt	0	0	500
Payments on long-term debt and capital leases	(23.6)	(414.9)	(17.1)
Net receipts (payments) on intercompany activity	0	0	0
Dividends paid to stockholders	(66.5)	(77.1)	(76.9)
Dividends paid to noncontrolling interests	(16)	0	(18)
Other	0.1	(5)	(58.3)
Cash provided by (used in) financing activities	(106)	(497)	364.8
Increase (decrease) in cash and cash equivalents	(119.7)	(757.3)	722.2
Guarantor Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	(70)	(66.9)	(41.1)
Purchases of property, plant and equipment	(0.6)	(0.1)	(0.2)
Net receipts (payments) on intercompany activity	0	0	0
Purchases of businesses, net of cash acquired	0	0
Proceeds from sale of business, net of transaction costs			(7.9)
Asset disposals and other	0	0	0
Cash flows provided by (used in) investing activities	(0.6)	(0.1)	(8.1)
Borrowings on long-term debt			500
Payments on long-term debt and capital leases	(0.6)	(397.9)
Net receipts (payments) on intercompany activity	137.3	544.4	(366.7)
Dividends paid to stockholders	(66.5)	(77.1)	(76.9)
Dividends paid to noncontrolling interests	0
Other	(1.4)	(3.8)	(9.1)
Cash provided by (used in) financing activities	68.8	65.6	47.3
Increase (decrease) in cash and cash equivalents	(1.8)	(1.4)	(1.9)
Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	(134.8)	(313.8)	(50.4)
Purchases of property, plant and equipment	(66.9)	(170.8)	(564.8)
Net receipts (payments) on intercompany activity	0	0	0
Purchases of businesses, net of cash acquired	0	0
Proceeds from sale of business, net of transaction costs			0
Asset disposals and other	0.2	1.7	0.2
Cash flows provided by (used in) investing activities	(66.7)	(169.1)	(564.6)
Borrowings on long-term debt			0
Payments on long-term debt and capital leases	(0.1)	(0.1)
Net receipts (payments) on intercompany activity	190.6	483.3	615.5
Dividends paid to stockholders	0	0	0
Dividends paid to noncontrolling interests	0
Other	0	0	(0.1)
Cash provided by (used in) financing activities	190.5	483.2	615.4
Increase (decrease) in cash and cash equivalents	(11)	0.3	0.4
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	360.2	436.6	484.2
Purchases of property, plant and equipment	(77)	(54.8)	(47.7)
Net receipts (payments) on intercompany activity	(327.9)	(1,027.7)	(248.8)
Purchases of businesses, net of cash acquired	(0.5)	(92.9)
Proceeds from sale of business, net of transaction costs			608.8
Asset disposals and other	(0.3)	0.7	0.6
Cash flows provided by (used in) investing activities	(405.7)	(1,174.7)	312.9
Borrowings on long-term debt			0
Payments on long-term debt and capital leases	(22.9)	(16.9)
Net receipts (payments) on intercompany activity	0	0	0
Dividends paid to stockholders	(24)	0	(24.3)
Dividends paid to noncontrolling interests	(16)
Other	1.5	(1.2)	(49.1)
Cash provided by (used in) financing activities	(61.4)	(18.1)	(73.4)
Increase (decrease) in cash and cash equivalents	(106.9)	(756.2)	723.7
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	(24)	0	(24.3)
Purchases of property, plant and equipment	0	0	0
Net receipts (payments) on intercompany activity	327.9	1,027.7	248.8
Purchases of businesses, net of cash acquired	0	0
Proceeds from sale of business, net of transaction costs			0
Asset disposals and other	0	0	0
Cash flows provided by (used in) investing activities	327.9	1,027.7	248.8
Borrowings on long-term debt			0
Payments on long-term debt and capital leases	0	0
Net receipts (payments) on intercompany activity	(327.9)	(1,027.7)	(248.8)
Dividends paid to stockholders	24	0	24.3
Dividends paid to noncontrolling interests	0
Other	0	0	0
Cash provided by (used in) financing activities	(303.9)	(1,027.7)	(224.5)
Increase (decrease) in cash and cash equivalents	$ 0	$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Leases, Operating [Abstract]
Rent expense	$ 23.1	$ 22.4	$ 20.5
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,016	19.7
2,017	12.8
2,018	11
2,019	9.2
2,020	8.5
Thereafter	21.9
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligation, property, plant, and equipment	92.3
Accrual for Environmental Loss Contingencies [Abstract]
Accrual for environmental remediation obligations	15
Accrued environmental loss contingencies recorded in other current liabilities	8
Components of Environmental Loss Accrual [Abstract]
Federal Superfund and comparable state-managed sites	4
Formerly owned or operated sites	9
Owned or controlled sites at which Company operations have been discontinued	1
Sites utilized by the company in its ongoing operations	1
Reasonably possible amount by which current matters may exceed reserves	$ 16

Selected Quarterly Financial120

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Sales	$ 738.9	$ 832.7	$ 1,022.5	$ 1,125.5	$ 1,047.5	$ 1,069.6	$ 1,119	$ 987.3	$ 3,719.6	$ 4,223.4	$ 4,043.5
Gross Profit	(97.5)	(28.7)	77	109.5	121.9	97	89.5	70.2
Income (loss) from continuing operations attributable to ATI	(226.9)	(144.6)	(16.4)	10	19.9	0	(3.8)	(18.1)	(377.9)	(2)	(98.8)
Net income (loss)	(223.3)	(141.3)	(13.9)	12.6	25.3	2.9	(0.7)	(17.9)	(365.9)	9.6	161.6
Net income (loss) attributable to ATI	$ (226.9)	$ (144.6)	$ (16.4)	$ 10	$ 22.1	$ (0.7)	$ (4)	$ (20)	$ (377.9)	$ (2.6)	$ 154
Basic income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	$ (2.12)	$ (1.35)	$ (0.15)	$ 0.09	$ 0.18	$ 0	$ (0.03)	$ (0.17)	$ (3.53)	$ (0.02)	$ (0.93)
Basic net income attributable to ATI per common share (in dollars per share)	(2.12)	(1.35)	(0.15)	0.09	0.20	(0.01)	(0.03)	(0.19)	(3.53)	(0.03)	1.44
Diluted income (loss) from continuing operations attributable to ATI per common share (in dollars per share)	(2.12)	(1.35)	(0.15)	0.09	0.18	0	(0.03)	(0.17)	(3.53)	(0.02)	(0.93)
Diluted net income attributable to ATI per common share (in dollars per share)	$ (2.12)	$ (1.35)	$ (0.15)	$ 0.09	$ 0.20	$ (0.01)	$ (0.03)	$ (0.19)	$ (3.53)	$ (0.03)	$ 1.44
Average shares outstanding (shares)	109,171,124	109,204,307	109,190,876	108,854,720	108,704,983	108,712,682	108,628,024	108,173,581	107,300,000	107,100,000	106,800,000

Selected Quarterly Financial121

Selected Quarterly Financial Data (Unaudited) - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unusual Or Infrequent Item [Line Items]
NRV charge	$ 51.2	$ 76		$ 131.5	$ (25)	$ 35
NRV charge net of tax	32	49.5
Deferred tax asset valuation allowance charge		$ (63.9)		(68.4)
Restructuring charges				64.3	0	67.5
Impairment of goodwill				126.6	$ 0	0
Asset Impairment Charges	54.5					55.1
Impairment of Long-Lived Assets Held-for-use, After Tax	34.1
Restructuring costs net of tax				$ 41.6		41.2
Severance and termination benefit costs						$ 8.2
Other Postretirement Benefits [Member]
Unusual Or Infrequent Item [Line Items]
Settlements and curtailments gains			$ 25.5
Settlements and curtailments gains net of tax			$ 18.4
Flat Rolled Products [Member]
Unusual Or Infrequent Item [Line Items]
Impairment of goodwill	126.6
Impairment of goodwill net of tax	79.2
High Performance Materials & Components and Corporate [Member]
Unusual Or Infrequent Item [Line Items]
Severance and termination benefit costs	6.3
Severance and termination benefit costs net of tax	3.9
Facility Idling Costs [Member]
Unusual Or Infrequent Item [Line Items]
Restructuring costs	3.5
Restructuring costs net of tax	2.2
Inventory Valuation Reserve [Member] | Non-PQ grade titanium sponge [Member]
Unusual Or Infrequent Item [Line Items]
Lower of cost or market charges	(25.4)
Lower of cost or market charges net of tax	$ 15.9