SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Aug. 02, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements for NCI Building Systems, Inc. (together with its subsidiaries, unless otherwise indicated, the “Company,” “NCI,” “we,” “us” or “our”) have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, the unaudited consolidated financial statements included herein contain all adjustments, which consist of normal recurring adjustments, necessary to fairly present our financial position, results of operations and cash flows for the periods indicated. Operating results for the fiscal three and nine month periods ended August 2, 2015 are not necessarily indicative of the results that may be expected for the fiscal year ending November 1, 2015. Our sales and earnings are subject to both seasonal and cyclical trends and are influenced by general economic conditions, interest rates, the price of steel relative to other building materials, the level of nonresidential construction activity, roof repair and retrofit demand and the availability and cost of financing for construction projects. For further information, refer to the consolidated financial statements and footnotes thereto included in our Annual Report on Form 10-K for the fiscal year ended November 2, 2014 filed with the Securities and Exchange Commission (the “SEC”) on December 22, 2014.
Reporting Periods	Reporting Periods We use a four-four-five week calendar each quarter with our fiscal year end being on the Sunday closest to October 31. The year end for fiscal 2015 is November 1, 2015.
Reclassifications	Reclassifications Certain reclassifications have been made to prior period amounts to conform to the current presentation. The net effect of these reclassifications was not material to our consolidated financial statements.
Revenue Recognition	Revenue Recognition We recognize revenues when the following conditions are met: persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collectability is reasonably assured. Generally, these criteria are met at the time product is shipped or services are complete. A portion of our revenue, exclusively within our engineered building systems segment, includes multiple-element revenue arrangements due to multiple deliverables. Each deliverable is generally determined based on customer-specific manufacturing and delivery requirements. Because the separate deliverables have value to the customer on a stand-alone basis, they are typically considered separate units of accounting. A portion of the entire job order value is allocated to each unit of accounting. Revenue allocated to each deliverable is recognized upon shipment. We use estimated selling price (“ESP”) based on underlying cost plus a reasonable margin to determine how to separate multiple-element revenue arrangements into separate units of accounting, and how to allocate the arrangement consideration among those separate units of accounting. We determine ESP based on our normal pricing and discounting practices. Our sales arrangements do not include a general right of return of the delivered product(s). In certain cases, the cancellation terms of a job order provide us with the opportunity to bill for certain incurred costs. In those instances, revenue is not recognized until all revenue recognition criteria are met, including reasonable assurance of collectability. In our metal coil coating segment, our revenue activities broadly consist of cleaning, treating, painting and packaging various flat rolled metals as well as slitting and/or embossing the metal. We enter into two types of sales arrangements with our customers: toll processing sales and package sales. The primary distinction between these two arrangements relates to ownership of the underlying metal coil during treatment. In toll processing arrangements, we do not maintain ownership of the underlying metal coil during treatment and only recognize revenue for the toll processing activities, typically, cleaning, painting, slitting, embossing and packaging. In package sales arrangements, we have ownership of the metal coil during treatment and recognize revenue on both the toll processing activities and the sale of the underlying metal coil. Under either arrangement, revenue and the related direct and indirect costs are recognized when all of the recognition criteria are met, which is generally when the products are shipped to the customer.
New Accounting Pronouncements	Adopted Accounting Pronouncements In July 2013, the FASB issued ASU 2013-11, Income Taxes (Topic 740): Presentation of Unrecognized Tax Benefit When a Net Operating Loss Carryforward, A Similar Tax Loss, or a Tax Credit Carryforward Exists (A Consensus of the FASB Emerging Issues Task Force). ASU 2013-11 requires an entity to present an unrecognized tax benefit as a reduction of a deferred tax asset for a net operating loss carryforward, or similar tax loss or tax credit carryforward, rather than as a liability when the uncertain tax position would reduce the net operating loss or other carryforward under the tax law of the applicable jurisdiction and the entity intends to use the deferred tax asset for that purpose. We adopted ASU 2013-11 prospectively for our first quarter in fiscal 2015. The adoption of ASU 2013-11 did not have a material impact on our consolidated financial statements. Recent Accounting Pronouncements In April 2014, the FASB issued ASU 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. ASU 2014-08 changes the requirement for reporting discontinued operations. A disposal of a component of an entity or a group of components of an entity will be 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 when the entity or group of components of an entity meets the criteria to be classified as held for sale or when it is disposed of by sale or other than by sale. The update also requires additional disclosures about discontinued operations, a disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation in the financial statements, and an entity’s significant continuing involvement with a discontinued operation. This update is effective prospectively for our first quarter in fiscal 2016. Early adoption is permitted, but only for disposals (or classifications as held for sale) that have not been reported in previously issued financial statements. We are currently evaluating the potential impact of this authoritative guidance on our consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). ASU 2014-09 supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition, and most industry-specific guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance is effective for our first quarter in fiscal 2018 under either full or modified retrospective adoption. Early application is not permitted. On July 9, 2015, the FASB deferred the effective date by one year to annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Entities can still adopt the amendments as of the original effective date. We are currently assessing the potential effects of these changes to our consolidated financial statements. 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. ASU 2014-12 requires that a performance target that affects vesting and could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance in FASB Accounting Standards Codification 718, Compensation — Stock Compensation, as it relates to such awards. ASU 2014-12 is effective for our first quarter in fiscal 2017, with early adoption permitted. We do not expect that the adoption of this guidance will have a material impact on our consolidated financial statements. In January 2015, the FASB issued ASU 2015-01, Income Statement — Extraordinary and Unusual Items (Subtopic 225-20): Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items. ASU 2015-01 eliminates from U.S. GAAP the concept of extraordinary items. The guidance is effective for our fiscal year ended October 29, 2017. A reporting entity may apply the amendments prospectively. We do not expect that the adoption of this guidance will have a material impact on our consolidated financial statements. In April 2015, the FASB issued ASU 2015-03, Interest — Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. ASU 2015-03 requires debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability instead of being presented as a separate asset. In circumstances where the costs are incurred before the debt liability is recorded, the costs will be reported on the balance sheet as an asset until the debt liability is recorded. Debt disclosures will include the face amount of the debt liability and the effective interest rate. The update requires retrospective application and is effective for our fiscal year ended October 29, 2017. Early adoption is permitted for financial statements that have not been previously issued. We do not expect that the adoption of this guidance will have a material impact on our consolidated financial statements. In April 2015, the FASB issued ASU 2015-05, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement. ASU 2015-05 provides guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the guidance specifies that the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. ASU 2015-05 further specifies that the customer should account for a cloud computing arrangement as a service contract if the arrangement does not include a software license. The guidance is effective for our fiscal year ended October 29, 2017. We are currently assessing the impact of this guidance on our consolidated financial statements. In May 2015, the FASB issued ASU 2015-07, Fair Value Measurement (Topic 820); Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share. ASU 2015-07 removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient and certain related disclosures. The update requires retrospective application and is effective for our fiscal year ended October 29, 2017. Early adoption is permitted for financial statements that have not been previously issued. We do not expect that the adoption of this guidance will have a material impact on our consolidated financial statements. In July 2015, the FASB issues ASU 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory. ASU 2015-11 requires that inventory that has historically been measured using first-in, first-out (FIFO) or average cost method should now be measured at the lower of cost and net realizable value. The update requires prospective application and is effective for our fiscal year ended October 28, 2018. Early adoption is permitted for financial statements that have not been previously issued. We do not expect that the adoption of this guidance will have a material impact on our consolidated financial statements.

Disclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.