Summary Of Significant Accounting Policies (Policy)	12 Months Ended
Summary Of Significant Accounting Policies (Policy)	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Consolidation Policy	Consolidation Policy. The consolidated financial statements and accompanying data in this report include the accounts of AWI and its majority-owned subsidiaries. All significant intercompany transactions have been eliminated from the consolidated financial statements.
Use Of Estimates	Use of Estimates. We prepare our financial statements in conformity with U.S. generally accepted accounting principles, which requires management to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets, liabilities, revenues and expenses. When preparing an estimate, management determines the amount based upon the consideration of relevant internal and external information. Actual results may differ from these estimates.
Reclassifications	Reclassifications. Certain amounts in the prior year’s Consolidated Financial Statements and related notes and schedule thereto have been recast to conform to the 2015 presentation.
Revenue Recognition	Revenue Recognition. We recognize revenue from the sale of products when persuasive evidence of an arrangement exists, title and risk of loss transfers to the customers, prices are fixed and determinable, and it is reasonably assured the related accounts receivable is collectible. Our standard sales terms are Free On Board (“FOB”) shipping point. We have some sales terms that are FOB destination. Our products are sold with normal and customary return provisions. Sales discounts are deducted immediately from the sales invoice. Provisions, which are recorded as a reduction of revenue, are made for the estimated cost of rebates, promotional programs and warranties. We defer recognizing revenue if special sales agreements, established at the time of sale, warrant this treatment.
Sales Incentives	Sales Incentives. Sales incentives are reflected as a reduction of net sales.
Shipping And Handling Costs	Shipping and Handling Costs. Shipping and handling costs are reflected in cost of goods sold.
Advertising Costs	Advertising Costs. We recognize advertising expenses as they are incurred.
Research And Development Costs	Research and Development Costs. We recognize research and development costs as they are incurred.
Pension And Postretirement Benefits	Pension and Postretirement Benefits. We have benefit plans that provide for pension, medical and life insurance benefits to certain eligible employees when they retire from active service. See Note 16 to the Consolidated Financial Statements for disclosures on pension and postretirement benefits.
Taxes	Taxes. The provision for income taxes has been determined using the asset and liability approach of accounting for income taxes to reflect the expected future tax consequences of events recognized in the financial statements. Deferred income tax assets and liabilities are recognized by applying enacted tax rates to temporary differences that exist as of the balance sheet date which result from differences in the timing of reported taxable income between tax and financial reporting. We reduce the carrying amounts of deferred tax assets by a valuation allowance if, based on the available evidence, it is more likely than not that such assets will not be realized. The need to establish valuation allowances for deferred tax assets is assessed quarterly. In assessing the requirement for, and amount of, a valuation allowance in accordance with the more likely than not standard, we give appropriate consideration to all positive and negative evidence related to the realization of the deferred tax assets. This assessment considers, among other matters, the nature, frequency and severity of current and cumulative losses, forecasts of future profitability and foreign source income, the duration of statutory carryforward periods, and our experience with operating loss and tax credit carryforward expirations. A history of cumulative losses is a significant piece of negative evidence used in our assessment. If a history of cumulative losses is incurred for a tax jurisdiction, forecasts of future profitability are generally not used as positive evidence related to the realization of the deferred tax assets in the assessment. We recognize the tax benefits of an uncertain tax position if those benefits are more likely than not to be sustained based on existing tax law. Additionally, we establish a reserve for tax positions that are more likely than not to be sustained based on existing tax law, but uncertain in the ultimate benefit to be sustained upon examination by the relevant taxing authorities. Unrecognized tax benefits are subsequently recognized at the time the more likely than not recognition threshold is met, the tax matter is effectively settled or the statute of limitations for the relevant taxing authority to examine and challenge the tax position has expired, whichever is earlier. Taxes collected from customers and remitted to governmental authorities are reported on a net basis.
Earnings Per Share	Earnings per Share. Basic earnings per share is computed by dividing the earnings attributable to common shares by the weighted average number of shares of common stock outstanding during the period. Diluted earnings per share reflects the potential dilution of securities that could share in the earnings.
Cash And Cash Equivalents	Cash and Cash Equivalents. Cash and cash equivalents include cash on hand and short-term investments that have maturities of three months or less when purchased.
Concentration Of Credit	Concentration of Credit. We principally sell products to customers in the building products industries in various geographic regions. No one customer accounted for 10% or more of our total consolidated net sales in the years 2015, 2014, and 2013. We monitor the creditworthiness of our customers and generally do not require collateral.
Receivables	Receivables. We sell the vast majority of our products to select, pre-approved customers using customary trade terms that allow for payment in the future. Customer trade receivables, customer notes receivable and miscellaneous receivables (which include supply related rebates and other), net of allowances for doubtful accounts, customer credits and warranties are reported in accounts and notes receivable, net. Cash flows from the collection of current receivables are classified as operating cash flows on the consolidated statements of cash flows. We establish credit-worthiness prior to extending credit. We estimate the recoverability of receivables each period. This estimate is based upon new information in the period, which can include the review of any available financial statements and forecasts, as well as discussions with legal counsel and the management of the debtor company. As events occur, which impact the collectability of the receivable, all or a portion of the receivable is reserved. Account balances are charged off against the allowance when the potential for recovery is considered remote. We do not have any off-balance-sheet credit exposure related to our customers.
Inventories	Inventories. Inventories are valued at the lower of cost or market. Inventories also include certain samples used in ongoing sales and marketing activities. See Note 6 to the Consolidated Financial Statements for further information on our accounting for inventories.
Property Plant And Equipment	Property Plant and Equipment. Property plant and equipment is recorded at cost reduced by accumulated depreciation. Depreciation expense is recognized on a straight-line basis over the assets’ estimated useful lives. Machinery and equipment includes manufacturing equipment (depreciated over 3 to 15 years), computer equipment (depreciated over 3 to 5 years) and office furniture and equipment (depreciated over 5 to 7 years). Within manufacturing equipment, assets that are subject to quick obsolescence or wear out quickly, such as tooling and engraving equipment, are depreciated over shorter periods (3 to 7 years). Heavy production equipment, such as conveyors and production presses, are depreciated over longer periods (10 to 15 years). Buildings are depreciated over 15 to 30 years, depending on factors such as type of construction and use. Computer software is depreciated over 3 to 7 years. Property, plant and equipment are tested for impairment when indicators of impairment are present, such as operating losses and/or negative cash flows. If an indication of impairment exists, we compare the carrying amount of the asset group to the estimated undiscounted future cash flows expected to be generated by the assets. The estimate of an asset group’s fair value is based on discounted future cash flows expected to be generated by the asset group, or based on management’s estimated exit price assuming the assets could be sold in an orderly transaction between market participants, or estimated salvage value if no sale is assumed. If the fair value is less than the carrying value of the asset group, we record an impairment charge equal to the difference between the fair value and carrying value of the asset group. Impairments of assets related to our manufacturing operations are recorded in cost of goods sold. When assets are disposed of or retired, their costs and related depreciation are removed from the financial statements, and any resulting gains or losses normally are reflected in cost of goods sold or selling, general and administrative (“SG&A”) expenses depending on the nature of the asset.
Asset Retirement Obligations	Asset Retirement Obligations. We recognize the fair value of obligations associated with the retirement of tangible long-lived assets in the period in which they are incurred. Upon initial recognition of a liability, the discounted cost is capitalized as part of the related long-lived asset and depreciated over the corresponding asset’s useful life. Over time, accretion of the liability is recognized as an operating expense to reflect the change in the liability’s present value.
Intangible Assets	Intangible Assets. Our definite-lived intangible assets are primarily customer relationships (amortized over 20 years) and developed technology (amortized over 15 years). We review significant definite-lived intangible assets for impairment when indicators of impairment exist. We review our businesses for indicators of impairment such as operating losses and/or negative cash flows. If an indication of impairment exists, we compare the carrying amount of the asset group to the estimated undiscounted future cash flows expected to be generated by the assets. The estimate of an asset group’s fair value is based on discounted future cash flows expected to be generated by the asset group, or based on management’s estimated exit price assuming the assets could be sold in an orderly transaction between market participants. If the fair value is less than the carrying value of the asset group, we record an impairment charge equal to the difference between the fair value and carrying value of the asset group. Our indefinite-lived intangibles are primarily trademarks and brand names, which are integral to our corporate identity and expected to contribute indefinitely to our cash flows. Accordingly, they have been assigned an indefinite life. We perform annual impairment tests during the fourth quarter on these indefinite-lived intangibles. These assets undergo more frequent tests if an indication of possible impairment exists. The principal assumption used in our impairment tests for definite-lived intangible assets is future operating profit adjusted for depreciation and amortization. The principal assumptions used in our impairment tests for indefinite-lived intangible assets include revenue growth rate, discount rate and royalty rate. Revenue growth rate and future operating profit assumptions are derived from those utilized in our operating plan and strategic planning processes. The discount rate assumption is calculated based upon an estimated weighted average cost of equity which reflects the overall level of inherent risk and the rate of return a market participant would expect to achieve. The royalty rate assumption represents the estimated contribution of the intangible asset to the overall profits of the reporting unit. Methodologies used for valuing our intangible assets did not change from prior periods. See Note 10 to the Consolidated Financial Statements for disclosure on intangible assets.
Foreign Currency Transactions	Foreign Currency Transactions. Assets and liabilities of our subsidiaries operating outside the United States which account in a functional currency other than U.S. dollars are translated using the period end exchange rate. Revenues and expenses are translated at exchange rates effective during each month. Foreign currency translation gains or losses are included as a component of accumulated other comprehensive income (loss) within shareholders' equity. Gains or losses on foreign currency transactions are recognized through the statement of earnings.
Financial Instruments And Derivatives	Financial Instruments and Derivatives. From time to time, we use derivatives and other financial instruments to offset the effect of currency, interest rate and commodity price variability. See Notes 17 and 18 to the Consolidated Financial Statements for further discussion.
Share-Based Employee Compensation	Share-based Employee Compensation. For awards with only service and performance conditions that have a graded vesting schedule, we recognize compensation expense on a straight-line basis over the vesting period for the entire award. See Note 21 to the Consolidated Financial Statements for additional information on share-based employee compensation.
Subsequent Events	Subsequent Events. We have evaluated subsequent events for potential recognition and disclosure through the date the consolidated financial statements included in the Annual Report on Form 10-K were issued.
Recently Adopted And Recently Issued Accounting Standards	Recently Adopted Accounting Standards In April 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-08 “Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity” which is part of ASC 205: Presentation of Financial Statements and ASC 360: Property, Plant and Equipment. The amendments in this guidance change the requirements for reporting discontinued operations. Under the new guidance a disposal of a component of an entity or a group of components is required to be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results. The guidance is effective prospectively for disposals that occur within annual periods beginning on or after December 15, 2014. There was no impact on our financial condition, results of operations or cash flows as a result of the adoption of this guidance. In May 2015, the FASB issued ASU 2015-07, “Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent).” This standard removes the requirement to categorize investments within the fair value hierarchy when fair value is measured using the net asset value per share practical expedient. We do not hold any such investments on our Consolidated Balance Sheets, however, the assets held in trust for our defined benefit pension plan include such investments. The new guidance is effective for annual reporting periods beginning after December 15, 2015, but early adoption is permitted. We early adopted this guidance as of December 31, 2015 and have applied this guidance to our disclosures of defined benefit pension plan assets as of and for the years ended December 31, 2015 and 2014. See Note 16 to the Consolidated Financial Statements for disclosures on pension and postretirement benefits. Recently Issued Accounting Standards In May 2014, the FASB issued ASU 2014-09 “Revenue from Contracts with Customers”. The guidance requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to a customer. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In August 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers: Deferral of the Effective Date” which defers the effective date for ASU 2014-09 by one year to January 1, 2018, however, public business entities would be permitted to adopt the standard as of the original effective date. We have not selected a transition method and are currently evaluating the impact this guidance will have on our financial condition, results of operations and cash flows. In June 2014, the FASB issued ASU 2014-12 “Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period” which is part of ASC 718: Compensation-Stock Compensation. The guidance requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition and should not be reflected in the estimate of the grant-date fair value of the award. The guidance is effective for annual periods beginning after December 15, 2015. The guidance can be applied prospectively for all awards granted or modified after the effective date or retrospectively to all awards with performance targets outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter. We do not expect a material impact on our financial condition, results of operations or cash flows from the adoption of this guidance. In April 2015, the FASB issued ASU 2015-03, “Simplifying the Presentation of Debt Issuance Costs.” This standard amends existing guidance to require the presentation of debt issuance costs in the balance sheet as a deduction from the carrying amount of the related debt liability instead of a deferred charge. The new guidance is effective for annual reporting periods beginning after December 15, 2015, but early adoption is permitted. In August 2015, the FASB issued ASU 2015-15, “Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements,” which was issued to address the presentation and subsequent measurement of debt issuance costs related to line-of-credit arrangements. We are currently evaluating the impact the adoption of these standards will have on our financial condition and cash flows. In April 2015, the FASB issued ASU 2015-05, “Customer's Accounting for Fees Paid in a Cloud Computing Arrangement” which provides guidance to determine when a customer's fees paid in a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If the arrangement does not include a software license, the customer should account for a cloud computing arrangement as a service contract. The new guidance is effective for annual reporting periods beginning after December 15, 2015, but early adoption is permitted. We are currently evaluating the impact the adoption of this standard would have on our financial condition, results of operations and cash flows. In July 2015, the FASB issued ASU 2015-11, “Simplifying the Measurement of Inventory” which requires inventory that is measured on a first-in, first-out or average cost basis to be measured at lower of cost and net realizable value, as opposed to the lower of cost or market. For inventory that is measured under the last-in, first-out (“LIFO”) basis or the retail recovery method, there is no change to current measurement requirements. This new guidance is effective for annual reporting periods beginning after December 15, 2016, but early adoption is permitted. We are currently evaluating the impact the adoption of this standard would have on our financial condition, results of operations and cash flows. In November 2015, the FASB issued ASU 2015-17, “Balance Sheet Classification of Deferred Taxes” which requires entities with a classified balance sheet to present all deferred tax assets and liabilities as noncurrent. This new guidance is effective for annual reporting periods beginning after December 15, 2016. We are currently evaluating the impact the adoption of this standard would have on our financial condition and cash flows. In January 2016, the FASB issued ASU 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities” which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. Most notably, this new guidance requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. This new guidance is effective for annual reporting periods beginning after December 15, 2017. We are currently evaluating the impact the adoption of this standard would have on our financial condition, results of operations and cash flows.