Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Apr. 26, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation - Dycom Industries, Inc. and its wholly-owned subsidiaries (collectively, "Dycom" or the "Company") is a leading provider of specialty contracting services throughout the United States and in Canada. These 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 and others. The accompanying unaudited condensed consolidated financial statements of Dycom 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. The condensed consolidated financial statements and accompanying notes reflect all adjustments, consisting of only normal recurring accruals that are, in the opinion of management, necessary for a fair presentation of such 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 27, 2013 included in the Company's 2013 Annual Report on Form 10-K, filed with the SEC on September 13, 2013. The condensed consolidated financial statements include the accounts of the Company. All significant transactions and balances between Dycom Industries, Inc. and its subsidiaries have been eliminated. 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 and others. The Company operates on a decentralized basis through its operating segments, each of which consists of a legal subsidiary (or in limited cases, 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 services are provided by its operating segments throughout the United States and in Canada. Revenues from services provided in Canada were approximately $2.5 million and $7.9 million during the three and nine months ended April 26, 2014, respectively, and $3.3 million and $9.7 million during the three and nine months ended April 27, 2013, respectively. The Company had no material long-lived assets in Canada at April 26, 2014 or July 27, 2013.
Business Combinations	Acquisitions - On December 3, 2012, the Company acquired substantially all of the telecommunications infrastructure services subsidiaries of Quanta Services, Inc. The results of operations of these subsidiaries are included in the accompanying condensed consolidated financial statements from the date of acquisition.
Accounting Period	Accounting Period - The Company uses a fiscal year ending on the last Saturday in July.
Use of 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.
Restricted Cash	Restricted Cash - As of April 26, 2014 and July 27, 2013, the Company had approximately $4.0 million and $3.7 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 26, 2014 and July 27, 2013. See Note 10, Debt, for further information regarding the fair value of the 2021 Notes. The Company's cash and equivalents as of April 26, 2014 and July 27, 2013 are based on quoted market prices in active markets for identical assets (Level 1). During the three and nine months ended April 26, 2014 and April 27, 2013, the Company had no non-recurring fair value measurements of assets or liabilities subsequent to their initial recognition.

Disclosure of accounting policy for completed business combinations (purchase method, acquisition method or combination of entities under common control). This accounting policy may include a general discussion of the purchase method or acquisition method of accounting (including for example, the treatment accorded contingent consideration, the identification of assets and liabilities, the purchase price allocation process, how the fair values of acquired assets and liabilities are determined) and the entity's specific application thereof. An entity that acquires another entity in a leveraged buyout transaction generally discloses the accounting policy followed by the acquiring entity in determining the basis used to value its interest in the acquired entity, and the rationale for that accounting policy.

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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.

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- 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.

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