Commitments and Contingencies	9 Months Ended
Apr. 29, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In May 2013, CertusView Technologies, LLC (“CertusView”), a wholly-owned subsidiary of the Company, filed suit against S & N Communications, Inc. and S&N Locating Services, LLC (together, “S&N”) in the United States District Court for the Eastern District of Virginia alleging infringement of certain United States patents. In January 2015, the District Court granted S&N’s motion for judgment on the pleadings for failure to claim patent-eligible subject matter, and entered final judgment. In May 2015, the District Court reopened the case to allow S&N to proceed with inequitable conduct counterclaims. A bench trial in the District Court on the inequitable conduct counterclaims whereby S&N was seeking additional grounds to find the patents unenforceable took place in March 2016. In August 2016, the District Court ruled against S&N and in favor of CertusView on the inequitable conduct counterclaims and entered final judgment. Subsequent to the judgment being entered, on August 24, 2016, S&N filed a motion requesting the District Court make a finding that the suit was an exceptional case and award S&N recovery of its attorney fees. On September 1, 2016, CertusView appealed to the Federal Circuit Court the January 2015 District Court judgment of patent invalidity. CertusView expects its appeal will be decided during the second half of calendar 2017. Additionally, on November 21, 2016, the District Court denied S&N’s motion for an exceptional case finding while allowing S&N permission to refile after conclusion of CertusView’s appeal to the Federal Circuit Court. In September 2016, certain former employees of two subcontractors of TESINC, LLC (“TESINC”), a wholly owned subsidiary of the Company, commenced a lawsuit against those subcontractors, TESINC and a customer of TESINC in the United States District Court for the Eastern District of Pennsylvania. The lawsuit alleges violation of the Fair Labor Standards Act, the Pennsylvania Minimum Wage Act of 1968, the Pennsylvania Wage Payment and Collection Law, and the New Jersey Wage and Hour Law by failing to comply with applicable minimum wage and overtime pay requirements as a result of the misclassification of workers as independent contractors. The plaintiffs sought unspecified damages and other relief on behalf of themselves and a putative class of similarly situated workers who had performed work between April 1, 2016 and June 30, 2016. The parties agreed to settle the lawsuit in March 2017 for an immaterial amount. The parties are preparing the agreement and intend to seek court approval of the proposed settlement. In March 2016, the Company filed suit against Quanta Services, Inc. (“Quanta”) in the United States District Court for the Southern District of New York alleging violation of certain restrictive covenants, including noncompetition and non-solicitation of employees and customers in a Stock Purchase Agreement executed by the parties in December 2012 (the “SPA”). The Company sought equitable and declaratory relief. In May 2016, Quanta answered the complaint and brought a separate counterclaim against the Company seeking a declaration regarding the permissible boundaries of customer solicitation. In March 2017, the parties reached a confidential settlement that resolved all outstanding claims on terms not material to the Company. In April 2016, a former employee of Prince Telecom, LLC (“Prince”), a wholly owned subsidiary of the Company, commenced a lawsuit against Prince in the Superior Court of California under the California Labor Code Private Attorneys General Act (“PAGA”). The lawsuit alleges that Prince violated the California Labor Code by, among other things, failing to pay the California minimum wage, failing to pay for all hours worked (including overtime), failing to provide meal breaks and failing to provide accurate wage statements. The plaintiff seeks to recover all penalties arising from each alleged PAGA violation on behalf of himself and a putative class of current and former employees of Prince who worked as technicians in the State of California in the year preceding the filing date of the lawsuit. In December 2016, the plaintiff’s attorney and Prince agreed to settle the lawsuit for an immaterial amount. The parties are preparing the agreement and intend to seek court approval of the proposed settlement. During the fourth quarter of fiscal 2016, one of the Company’s subsidiaries ceased operations. This subsidiary contributed to a multiemployer pension plan, the Pension, Hospitalization and Benefit Plan of the Electrical Industry - Pension Trust Fund (the “Plan”). In October 2016, the Plan demanded payment for a claimed withdrawal liability of approximately $13.0 million. In December 2016, the Company submitted a formal request to the Plan seeking review of the Plan’s withdrawal liability determination. The Company is disputing the claim of a withdrawal liability demanded by the Plan as it believes there is a statutory exemption available under the Employee Retirement Income Security Act for multiemployer pension plans that primarily cover employees in the building and construction industry. However, there can be no assurance that the Company will be successful in asserting the statutory exemption as a defense. As required by the Employee Retirement Income Security Act, in November 2016, the subsidiary began making monthly payments of the claimed withdrawal liability to the Plan in the amount of approximately $0.1 million. If the Company prevails in disputing the withdrawal liability all such payments will be refunded to the Company. With respect to the July 2016 acquisition from Goodman, $20.0 million is escrowed as of April 29, 2017 and is available to the Company for the indemnification obligations of the seller. Of the amount escrowed, $10.0 million will be released to the seller upon the occurrence of certain conditions or the twelve-month anniversary of the closing date. The remaining $10.0 million will be released to the seller when the seller satisfies certain conditions with respect to a dispute with the state of Texas over a Sales Tax Liability of approximately $31.7 million. Under the asset purchase agreement, Goodman has retained responsibility for this Sales Tax Liability. Should Goodman not resolve this matter, the state may assert that the Company is a successor to the operations and seek to recover from the Company. In such event the Company would seek indemnification for recovery from Goodman, including from the funds contained in the escrow account, for any amount the Company pays. 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. For claims within its insurance program, the Company retains the risk of loss, up to certain limits, for matters related to automobile liability, general liability (including damages associated with underground facility locating services), workers’ compensation, and employee group health. 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 a 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 29, 2017 and July 30, 2016, the Company had $130.9 million and $165.8 million of outstanding performance and other surety contract bonds, respectively. The Company periodically guarantees 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 both April 29, 2017 and July 30, 2016, the Company had $57.6 million of outstanding standby letters of credit issued under the Credit Agreement.

Commitments and Contingencies

In May 2013, CertusView Technologies, LLC (“CertusView”), a wholly-owned subsidiary of the Company, filed suit against S & N Communications, Inc. and S&N Locating Services, LLC (together, “S&N”) in the United States District Court for the Eastern District of Virginia alleging infringement of certain United States patents. In January 2015, the District Court granted S&N’s motion for judgment on the pleadings for failure to claim patent-eligible subject matter, and entered final judgment. In May 2015, the District Court reopened the case to allow S&N to proceed with inequitable conduct counterclaims. A bench trial in the District Court on the inequitable conduct counterclaims whereby S&N was seeking additional grounds to find the patents unenforceable took place in March 2016. In August 2016, the District Court ruled against S&N and in favor of CertusView on the inequitable conduct counterclaims and entered final judgment. Subsequent to the judgment being entered, on August 24, 2016, S&N filed a motion requesting the District Court make a finding that the suit was an exceptional case and award S&N recovery of its attorney fees. On September 1, 2016, CertusView appealed to the Federal Circuit Court the January 2015 District Court judgment of patent invalidity. CertusView expects its appeal will be decided during the second half of calendar 2017. Additionally, on November 21, 2016, the District Court denied S&N’s motion for an exceptional case finding while allowing S&N permission to refile after conclusion of CertusView’s appeal to the Federal Circuit Court.

In September 2016, certain former employees of two subcontractors of TESINC, LLC (“TESINC”), a wholly owned subsidiary of the Company, commenced a lawsuit against those subcontractors, TESINC and a customer of TESINC in the United States District Court for the Eastern District of Pennsylvania. The lawsuit alleges violation of the Fair Labor Standards Act, the Pennsylvania Minimum Wage Act of 1968, the Pennsylvania Wage Payment and Collection Law, and the New Jersey Wage and Hour Law by failing to comply with applicable minimum wage and overtime pay requirements as a result of the misclassification of workers as independent contractors. The plaintiffs sought unspecified damages and other relief on behalf of themselves and a putative class of similarly situated workers who had performed work between April 1, 2016 and June 30, 2016. The parties agreed to settle the lawsuit in March 2017 for an immaterial amount. The parties are preparing the agreement and intend to seek court approval of the proposed settlement.

In March 2016, the Company filed suit against Quanta Services, Inc. (“Quanta”) in the United States District Court for the Southern District of New York alleging violation of certain restrictive covenants, including noncompetition and non-solicitation of employees and customers in a Stock Purchase Agreement executed by the parties in December 2012 (the “SPA”). The Company sought equitable and declaratory relief. In May 2016, Quanta answered the complaint and brought a separate counterclaim against the Company seeking a declaration regarding the permissible boundaries of customer solicitation. In March 2017, the parties reached a confidential settlement that resolved all outstanding claims on terms not material to the Company.

In April 2016, a former employee of Prince Telecom, LLC (“Prince”), a wholly owned subsidiary of the Company, commenced a lawsuit against Prince in the Superior Court of California under the California Labor Code Private Attorneys General Act (“PAGA”). The lawsuit alleges that Prince violated the California Labor Code by, among other things, failing to pay the California minimum wage, failing to pay for all hours worked (including overtime), failing to provide meal breaks and failing to provide accurate wage statements. The plaintiff seeks to recover all penalties arising from each alleged PAGA violation on behalf of himself and a putative class of current and former employees of Prince who worked as technicians in the State of California in the year preceding the filing date of the lawsuit. In December 2016, the plaintiff’s attorney and Prince agreed to settle the lawsuit for an immaterial amount. The parties are preparing the agreement and intend to seek court approval of the proposed settlement.

During the fourth quarter of fiscal 2016, one of the Company’s subsidiaries ceased operations. This subsidiary contributed to a multiemployer pension plan, the Pension, Hospitalization and Benefit Plan of the Electrical Industry - Pension Trust Fund (the “Plan”). In October 2016, the Plan demanded payment for a claimed withdrawal liability of approximately $13.0 million. In December 2016, the Company submitted a formal request to the Plan seeking review of the Plan’s withdrawal liability determination. The Company is disputing the claim of a withdrawal liability demanded by the Plan as it believes there is a statutory exemption available under the Employee Retirement Income Security Act for multiemployer pension plans that primarily cover employees in the building and construction industry. However, there can be no assurance that the Company will be successful in asserting the statutory exemption as a defense. As required by the Employee Retirement Income Security Act, in November 2016, the subsidiary began making monthly payments of the claimed withdrawal liability to the Plan in the amount of approximately $0.1 million. If the Company prevails in disputing the withdrawal liability all such payments will be refunded to the Company.

With respect to the July 2016 acquisition from Goodman, $20.0 million is escrowed as of April 29, 2017 and is available to the Company for the indemnification obligations of the seller. Of the amount escrowed, $10.0 million will be released to the seller upon the occurrence of certain conditions or the twelve-month anniversary of the closing date. The remaining $10.0 million will be released to the seller when the seller satisfies certain conditions with respect to a dispute with the state of Texas over a Sales Tax Liability of approximately $31.7 million. Under the asset purchase agreement, Goodman has retained responsibility for this Sales Tax Liability. Should Goodman not resolve this matter, the state may assert that the Company is a successor to the operations and seek to recover from the Company. In such event the Company would seek indemnification for recovery from Goodman, including from the funds contained in the escrow account, for any amount the Company pays.

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.

For claims within its insurance program, the Company retains the risk of loss, up to certain limits, for matters related to automobile liability, general liability (including damages associated with underground facility locating services), workers’ compensation, and employee group health. 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 a 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 29, 2017 and July 30, 2016, the Company had $130.9 million and $165.8 million of outstanding performance and other surety contract bonds, respectively.

The Company periodically guarantees 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 both April 29, 2017 and July 30, 2016, the Company had $57.6 million of outstanding standby letters of credit issued under the Credit Agreement.