Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Apr. 25, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Dycom Industries, Inc. ("Dycom" or the "Company") is a leading provider of specialty contracting services throughout the United States and in Canada. The Company's services include engineering, construction, maintenance and installation services to telecommunications providers, underground facility locating services to various utilities, including telecommunications providers, and other construction and maintenance services to electric and gas utilities. The accompanying unaudited condensed consolidated financial statements include the results of Dycom and its subsidiaries, all of which are wholly-owned. All intercompany accounts and transactions have been eliminated and the financial statements reflect all adjustments, consisting of only normal recurring accruals that are, in the opinion of management, necessary for a fair presentation of such statements. These financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the Securities and Exchange Commission ("SEC"). Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. Operating results for the interim period are not necessarily indicative of the results expected for any other interim period or for the full fiscal year. These condensed consolidated financial statements and accompanying notes should be read in conjunction with Management's Discussion and Analysis of Financial Condition and Results of Operations contained in this report and the Company's audited financial statements for the year ended July 26, 2014 included in the Company's Annual Report on Form 10-K for the year ended July 26, 2014, filed with the SEC on September 9, 2014.
Segment Information	Segment Information – The Company operates in one reportable segment as a specialty contractor, providing engineering, construction, maintenance and installation services to telecommunications providers, underground facility locating services to various utilities, including telecommunications providers, and other construction and maintenance services to electric and gas utilities. The Company's services are provided by its operating segments, each of which consists of a subsidiary (or in limited instances, the combination of two or more subsidiaries). Management of the operating segments report to the Company's Chief Operating Officer who reports to the Chief Executive Officer, the chief operating decision maker. All of the Company's operating segments have been aggregated into one reportable segment due to their similar economic characteristics, nature of services and production processes, type of customers, and service distribution methods. The Company's operating segments provide services throughout the United States and in Canada. Revenues from services provided in Canada were approximately $2.0 million and $9.8 million during the three and nine months ended April 25, 2015, respectively, and $2.5 million and $7.9 million during the three and nine months ended April 26, 2014, respectively. The Company had no material long-lived assets in Canada at April 25, 2015 or July 26, 2014.
Accounting Period	Accounting Period – The Company uses a fiscal year ending on the last Saturday in July. As a result, each fiscal year may be comprised of fifty-two weeks or fifty-three weeks (with an additional week of operations occurring in the fourth quarter).
Significant Accounting Policies & Estimates	Significant Accounting Policies & Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in these condensed consolidated financial statements and accompanying notes. At the time they are made, the Company believes that such estimates are fair when considered in conjunction with the consolidated financial position and results of operations taken as a whole. However, actual results could differ materially from those estimates. There have been no material changes to the Company's significant accounting policies and critical accounting estimates described in the Company's Annual Report on Form 10-K for the year ended July 26, 2014.
Restricted Cash	Restricted Cash – As of April 25, 2015 and July 26, 2014, the Company had approximately $4.5 million and $4.0 million, respectively, in restricted cash which is held as collateral in support of the Company's insurance obligations. Restricted cash is included in other current assets and other assets in the condensed consolidated balance sheets and changes in restricted cash are reported in cash flows used in investing activities in the condensed consolidated statements of cash flows.
Fair Value of Financial Instruments	Fair Value of Financial Instruments – The Company's financial instruments consist primarily of cash and equivalents, restricted cash, accounts receivables, income taxes receivable and payable, accounts payable and certain accrued expenses, and long-term debt. The carrying amounts of these items approximate fair value due to their short maturity, except for the Company's outstanding 7.125% senior subordinated notes due 2021 (the "2021 Notes") which are based on observable market-based inputs (Level 2) as of April 25, 2015 and July 26, 2014. See Note 10, Debt, for further information regarding the fair value of the 2021 Notes. The Company's cash and equivalents are based on quoted market prices in active markets for identical assets (Level 1) as of April 25, 2015 and July 26, 2014. During the three and nine months ended April 25, 2015 and April 26, 2014 the Company had no material non-recurring fair value measurements of assets or liabilities subsequent to their initial recognition.
Other Assets	Other Assets – Other assets consists of deferred financing costs, long-term deposits, contract acquisition costs and other non-current assets. During the third quarter of fiscal 2015, the Company made an investment of $4.0 million in non-voting senior units of a customer. The investment was made in connection with this customer's restructuring plan and will accrue dividends at a rate of 5.25% per year.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Accounting Standards Not Yet Adopted In April 2014, the FASB issued Accounting Standards Update No. 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"). ASU 2014-08 changes the criteria for reporting discontinued operations. In accordance with ASU 2014-08, a disposal of a component of an entity or a group of components of an entity is required to be reported in 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. ASU 2014-08 also requires expanded disclosures about the assets, liabilities, income, and expenses of discontinued operations as well as disclosure of the pre-tax income rising from a disposal of a significant part of an organization that does not qualify for discontinued operations reporting. ASU 2014-08 will be effective for the Company beginning in fiscal 2016 and interim reporting periods within that year. Early adoption is permitted only for disposals that have not been reported in financial statements previously issued or available for issuance. The adoption of this guidance is not expected to have a material effect on the Company's consolidated financial statements. In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606), ("ASU 2014-09"). ASU 2014-09 requires entities to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 requires entities to disclose both qualitative and quantitative information that enables users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers, including disclosure of significant judgments affecting the recognition of revenue. ASU 2014-09 will be effective for the Company beginning in fiscal 2018 and interim reporting periods within that year, using either the retrospective or cumulative effect transition method. Early adoption is not permitted. The Company is currently evaluating the effect of the adoption of this guidance on the consolidated financial statements. In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern ("ASU 2014-15"). ASU 2014-15 requires management to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern for a period of one year after the date that financial statements are issued. If such conditions or events exist, an entity should disclose that there is substantial doubt about the entity’s ability to continue as a going concern for a period of one year after the date that financial statements are issued. Disclosure should include the principal conditions or events that raise substantial doubt, management’s evaluation of the significance of those conditions or events in relation to the entity’s ability to meet its obligations, and management’s plans that are intended to mitigate those conditions or events. ASU 2014-15 will be effective for the Company beginning in fiscal 2017 and interim reporting periods within that year. Early adoption is permitted. The adoption of this guidance is not expected to have a material effect on the Company's consolidated financial statements. In January 2015, the FASB issued Accounting Standards Update No. 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"). ASU 2015-01 eliminates the concept of an extraordinary item from GAAP. As a result, an entity is no longer required to separately classify, present, or disclose extraordinary events and transactions; however, the presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be retained. ASU 2015-01 will be effective for the Company beginning in fiscal 2016 and interim reporting periods within that year. The adoption of this guidance is not expected to have a material effect on the Company's consolidated financial statements. In April 2015, the FASB issued Accounting Standards Update No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs ("ASU2015-03"), which requires debt issuance costs to be presented as a direct deduction from the associated debt liability on the balance sheet. ASU 2015-03 will be effective for the Company in fiscal 2017 and interim reporting periods within that year, using the retrospective method. Early adoption is permitted. See Note 10, Debt, for further information regarding the Company’s debt financing.

Entity's cash and cash equivalents accounting policy with respect to restricted balances. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits.

+ References+ Details

- Definition

Disclosure of accounting policy for determining an entity's fiscal year or other fiscal period. This disclosure may include identification of the fiscal period end-date, the length of the fiscal period, any reporting period lag between the entity and its subsidiaries, or equity investees. If a reporting lag exists, the closing date of the entity having a different period end is generally noted, along with an explanation of the necessity for using different closing dates. Any intervening events that materially affect the entity's financial position or results of operations are generally also disclosed.

+ References+ Details