Basis of Presentation (Policies)	3 Months Ended
	Apr. 25, 2020
Basis of Presentation [Abstract]
Basis of Presentation	Dycom Industries, Inc. (“Dycom” or the “Company”) is a leading provider of specialty contracting services throughout the United States. These services include program management; planning; engineering and design; aerial, underground, and wireless construction; maintenance; and fulfillment services for telecommunications providers. Additionally, Dycom provides underground facility locating services for various utilities, including telecommunications providers, and other construction and maintenance services for electric and gas utilities. Dycom supplies the labor, tools, and equipment necessary to provide these services to its customers.
Accounting Period	The Company uses a 52/53 week fiscal year ending on the last Saturday in January. Fiscal 2020 consisted of 52 weeks of operations and fiscal year ending January 30, 2021 consists of 53 weeks of operation.
Segment Reporting Disclosure	Segment Information. The Company operates in one reportable segment. Its services are provided by its operating segments on a decentralized basis. Each operating segment consists of a subsidiary (or in certain instances, the combination of two or more subsidiaries), the results of which are regularly reviewed by the Company’s Chief Executive Officer, the chief operating decision maker. All of the Company’s operating segments have been aggregated into one reportable segment based on their similar economic characteristics, nature of services and production processes, type of customers, and service distribution methods. The economy of the United States has been severely impacted by the nation’s response to the COVID-19 pandemic. Measures taken include travel restrictions, social distancing requirements, quarantines, and shelter in place orders. As a result, businesses have been closed and certain business activities curtailed or modified. During the COVID-19 pandemic, our services have generally been considered essential in nature and have not been materially interrupted. As the situation continues to evolve, we are closely monitoring the impact of the COVID-19 pandemic on all aspects of our business, including how it impacts our customers, subcontractors, suppliers, vendors and employees, in addition to how the COVID-19 pandemic impacts our ability to provide services to our customers. We believe the ultimate impact of the COVID-19 pandemic on our operating results, cash flows and financial condition is likely to be determined by factors which are uncertain, unpredictable and outside of our control. The situation surrounding COVID-19 remains fluid, and if disruptions do arise, they could materially adversely impact our business.