Commitments and Contingencies	9 Months Ended
Apr. 26, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In October 2012, a former employee of UtiliQuest, LLC ("UtiliQuest"), a wholly-owned subsidiary of the Company, commenced a lawsuit against UtiliQuest in the Superior Court of California. The lawsuit alleges that UtiliQuest violated the California Labor Code, the California Business & Professions Code and the Labor Code Private Attorneys General Act of 2004 by failing to pay for all hours worked (including overtime) and failing to provide meal breaks and accurate wage statements. The plaintiff seeks unspecified damages and other relief on behalf of himself and a putative class of current and former employees of UtiliQuest who worked as locators in the State of California in the four years preceding the filing date of the lawsuit. In January 2013, UtiliQuest removed the case to the United States District Court for the Northern District of California and the plaintiff subsequently filed a Motion to Remand the case back to the California Superior Court. In April 2013, the parties exchanged initial disclosures and in July 2013, the District Court granted plaintiff's Motion to Remand. UtiliQuest filed its second removal of the case to the District Court in October 2013. On January 8, 2014, the District Court remanded the matter back to the California Superior Court. It is too early to evaluate the likelihood of an outcome to this matter or estimate the amount or range of potential loss, if any. The Company intends to vigorously defend itself against this lawsuit. From time to time, the Company is party to various other claims and legal proceedings. It is the opinion of management, based on information available at this time, that such other pending claims or proceedings will not have a material effect on its financial statements. As part of the Company's insurance program, it retains the risk of loss, up to certain limits, for claims related to automobile liability, general liability, workers' compensation, employee group health, and locate damages, and the Company has established reserves that it believes to be adequate based on current evaluations and experience with these types of claims. For these claims, the effect on the Company's financial statements is generally limited to the amount needed to satisfy insurance deductibles or retentions. Performance Bonds and Guarantees The Company has obligations under performance and other surety contract bonds related to certain of its customer contracts. Performance bonds generally provide the Company’s customer with the right to obtain payment and/or performance from the issuer of the bond if the Company fails to perform its contractual obligations. As of April 26, 2014 and July 27, 2013, the Company had $415.7 million and $446.5 million of outstanding performance and other surety contract bonds, respectively. There has been no material impact on the Company's financial statements as a result of customers exercising their rights under the bonds. The Company has periodically guaranteed certain obligations of its subsidiaries, including obligations in connection with obtaining state contractor licenses and leasing real property and equipment. Letters of Credit The Company has standby letters of credit issued under its Credit Agreement as part of its insurance program. These standby letters of credit collateralize the Company’s obligations to its insurance carriers in connection with the settlement of potential claims. As of April 26, 2014 and July 27, 2013, the Company had $49.6 million and $46.7 million, respectively, of outstanding standby letters of credit issued under the Credit Agreement.

Commitments and Contingencies

In October 2012, a former employee of UtiliQuest, LLC ("UtiliQuest"), a wholly-owned subsidiary of the Company, commenced a lawsuit against UtiliQuest in the Superior Court of California. The lawsuit alleges that UtiliQuest violated the California Labor Code, the California Business & Professions Code and the Labor Code Private Attorneys General Act of 2004 by failing to pay for all hours worked (including overtime) and failing to provide meal breaks and accurate wage statements. The plaintiff seeks unspecified damages and other relief on behalf of himself and a putative class of current and former employees of UtiliQuest who worked as locators in the State of California in the four years preceding the filing date of the lawsuit. In January 2013, UtiliQuest removed the case to the United States District Court for the Northern District of California and the plaintiff subsequently filed a Motion to Remand the case back to the California Superior Court. In April 2013, the parties exchanged initial disclosures and in July 2013, the District Court granted plaintiff's Motion to Remand. UtiliQuest filed its second removal of the case to the District Court in October 2013. On January 8, 2014, the District Court remanded the matter back to the California Superior Court. It is too early to evaluate the likelihood of an outcome to this matter or estimate the amount or range of potential loss, if any. The Company intends to vigorously defend itself against this lawsuit.

From time to time, the Company is party to various other claims and legal proceedings. It is the opinion of management, based on information available at this time, that such other pending claims or proceedings will not have a material effect on its financial statements.

As part of the Company's insurance program, it retains the risk of loss, up to certain limits, for claims related to automobile liability, general liability, workers' compensation, employee group health, and locate damages, and the Company has established reserves that it believes to be adequate based on current evaluations and experience with these types of claims. For these claims, the effect on the Company's financial statements is generally limited to the amount needed to satisfy insurance deductibles or retentions.

Performance Bonds and Guarantees

The Company has obligations under performance and other surety contract bonds related to certain of its customer contracts. Performance bonds generally provide the Company’s customer with the right to obtain payment and/or performance from the issuer of the bond if the Company fails to perform its contractual obligations. As of April 26, 2014 and July 27, 2013, the Company had $415.7 million and $446.5 million of outstanding performance and other surety contract bonds, respectively. There has been no material impact on the Company's financial statements as a result of customers exercising their rights under the bonds.

The Company has periodically guaranteed certain obligations of its subsidiaries, including obligations in connection with obtaining state contractor licenses and leasing real property and equipment.

Letters of Credit

The Company has standby letters of credit issued under its Credit Agreement as part of its insurance program. These standby letters of credit collateralize the Company’s obligations to its insurance carriers in connection with the settlement of potential claims. As of April 26, 2014 and July 27, 2013, the Company had $49.6 million and $46.7 million, respectively, of outstanding standby letters of credit issued under the Credit Agreement.