Commitments and Contingencies	6 Months Ended
Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 16 - Commitments and Contingencies In addition to the matters discussed below, MasTec is subject to a variety of legal cases, claims and other disputes that arise from time to time in the ordinary course of its business. MasTec cannot provide assurance that it will be successful in recovering all or any of the potential damages it has claimed or in defending claims against it. The outcome of such cases, claims and disputes, including the one set forth below, cannot be predicted with certainty and an unfavorable resolution of one or more of them could have a material adverse effect on the Company's business, financial condition, results of operations, cash flows and the trading price of its common stock. SunLight Entities. In 2011, Power Partners MasTec, LLC., a MasTec, Inc. subsidiary (“Power Partners”), entered into engineering, procurement, and construction agreements with special purpose entities, SunLight General Somerset Solar, LLC, SunLight General Morris Solar, LLC and SunLight General Sussex Solar, LLC (collectively, the “SunLight Entities”), respectively, to perform design and construction services for three public solar projects in New Jersey located in Somerset, Morris and Sussex Counties (the “Projects”). The initial contract price of each of the Projects was, subject to adjustment, approximately as follows: Somerset ($29 million); Morris ($36 million); and Sussex ($26 million). The Projects were funded on a project finance basis, including the proceeds of municipal bonds issued by the Morris County and Somerset Improvement Authorities (collectively, the “Authorities”). Power Partners and the SunLight Entities commenced three separate arbitration proceedings against each other to address various disputes that presently exist between the parties on the three Projects. The parties allege, among other things, breach of contract against each other. The arbitrations began in January 2014 and an award is anticipated in the third quarter of 2014. Power Partners believes it has presented meritorious support of its claims against Sunlight and, additionally, believes that it has meritorious defenses against Sunlight’s claims. Power Partners is vigorously pursuing its claims against Sunlight and vigorously defending against Sunlight’s claims. Power Partners filed municipal liens and construction liens of approximately $50 million for the work performed but the liens were challenged by the SunLight Entities and the Authorities. In March 2014, the New Jersey appellate court found that Power Partners did not have municipal or construction liens on the proceeds of the municipal bonds, and the New Jersey Supreme Court denied Power Partner’s emergency motion to stay the adverse ruling. The Company petitioned the New Jersey Supreme Court to review the New Jersey appellate court’s adverse ruling, and, in July 2014, the New Jersey Supreme Court agreed to review the appellate court's ruling. The timing of the hearing is unknown. Power Partners also filed a federal lawsuit in the United States District Court of New Jersey against the Authorities and the principals of the SunLight Entities in June 2013. The claims against the Authorities include violations of the New Jersey Public Works Bond Act and the New Jersey Construction Trust Fund Act, tortious interference and unjust enrichment and quantum meruit. The Authorities and the SunLight principals have filed motions to dismiss. Power Partners has filed a response to the motions to dismiss. The litigation is in the early stages. Other Commitments and Contingencies Leases. In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facility, vehicle and equipment needs, including related party leases. See Note 10 - Lease Obligations. Letters of Credit. In the ordinary course of business, the Company is required to post letters of credit for its insurance carriers, surety bond providers and in support of performance under certain contracts. Such letters of credit are generally issued by a bank or similar financial institution. The letter of credit commits the issuer to pay specified amounts to the holder of the letter of credit under certain conditions. If this were to occur, the Company would be required to reimburse the issuer of the letter of credit, which, depending upon the circumstances, could result in a charge to earnings. As of June 30, 2014 and December 31, 2013, there were $132.8 million and $134.8 million, respectively, of letters of credit issued under the Company's Credit Facility. In addition, there were $10.5 million of letters of credit issued under other credit facilities as of June 30, 2014. See Note 9 - Debt. The Company was not aware of any material claims relating to outstanding letters of credit as of June 30, 2014 or December 31, 2013. Performance and Payment Bonds. In the ordinary course of business, MasTec is required by certain customers to provide performance and payment bonds for some of the Company’s contractual commitments related to projects in process. These bonds provide a guarantee to the customer that the Company will perform under the terms of a contract and that the Company will pay subcontractors and vendors. If the Company fails to perform under a contract or to pay subcontractors and vendors, the customer may demand that the surety make payments or provide services under the bond. The Company must reimburse the surety for any expenses or outlays it incurs. As of June 30, 2014, the estimated cost to complete projects secured by the Company’s $0.5 billion in performance and payment bonds was $177.7 million. As of December 31, 2013, the estimated cost to complete projects secured by the Company’s $1.1 billion in performance and payment bonds was $297.1 million. Investments in Affiliates and Other Entities. The Company holds an undivided interest in a contractual joint venture with a third party for the purpose of providing infrastructure services under certain customer contracts. Losses incurred by the joint venture are generally shared equally by the joint venture members, with members of the joint venture jointly and severally liable for all of the obligations of the joint venture. The joint venture agreement provides that each joint venturer indemnify the other parties for any liabilities incurred. Thus, it is possible that the Company could be required to pay or perform obligations in excess of its share if the other joint venturer fails or refuses to pay or perform its share of the obligations. As of June 30, 2014, the Company was not aware of any circumstances that would lead to future claims against it for material amounts. As of June 30, 2014, the Company has outstanding commitments associated with its investments in unconsolidated affiliates of approximately $3 million, which are expected to be paid in the third quarter of 2014. Self-Insurance. MasTec maintains insurance policies for workers’ compensation, general liability and automobile liability, which are subject to per claim deductibles. The Company also maintains excess umbrella coverage. As of June 30, 2014 and December 31, 2013, MasTec’s liability for unpaid claims and associated expenses, including incurred but not reported losses related to its workers compensation, general liability and automobile liability insurance policies, totaled $55.0 million and $50.8 million, respectively, of which $34.1 million and $31.3 million, respectively, was reflected within non-current other liabilities in the condensed unaudited consolidated balance sheets. MasTec also maintains an insurance policy with respect to employee group medical claims, which is subject to annual per employee maximum losses. MasTec’s liability for employee group medical claims as of June 30, 2014 and December 31, 2013 totaled $2.0 million and $2.1 million, respectively. The Company is required to post letters of credit and provide cash collateral to certain of its insurance carriers and to provide surety bonds in certain states. These letters of credit amounted to $57.4 million as of both June 30, 2014 and December 31, 2013, respectively. In addition, cash collateral deposited with insurance carriers, which is included in other long-term assets in the condensed unaudited consolidated balance sheets, amounted to $1.3 million and $1.4 million as of June 30, 2014 and December 31, 2013, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $10.9 million as of both June 30, 2014 and December 31, 2013. Employment Agreements. The Company has employment agreements with certain executives and other employees, which provide for compensation and certain other benefits and for severance payments under certain circumstances. Certain employment agreements also contain clauses that become effective upon a change of control of the Company. Upon the occurrence of any of the defined events in the various employment agreements, the Company would be obligated to pay certain amounts to the relevant employees, which vary with the level of the employees’ respective responsibility. Collective Bargaining Agreements and Multi-Employer Plans. Certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The agreements require the subsidiaries party to the agreements to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to the ones contained in the expiring agreements. The Employee Retirement Income Security Act of 1974, as amended by the Multi-Employer Pension Plan Amendments Act of 1980 (collectively, “ERISA”), which governs U.S. registered multi-employer pension plans, subjects employers to substantial liabilities in the event of the employer’s complete or partial withdrawal from, or upon termination of, such plans. Under current law regarding employers who are contributors to U.S. registered multi-employer defined benefit plans, a plan’s termination, an employer’s voluntary withdrawal from, or the mass withdrawal of all contributing employers from, an underfunded multi-employer defined benefit plan requires participating employers to make payments to the plan for their proportionate share of the multi-employer plan’s unfunded vested liabilities. Furthermore, the Pension Protection Act of 2006 added new funding rules to U.S. registered plans that are generally applicable to plan years beginning after 2007 for multi-employer plans that are classified as “endangered,” “seriously endangered,” or “critical” status. If plans in which the Company’s subsidiaries participate are in critical status, benefit reductions may apply and/or the Company could be required to make additional contributions. Based upon the information available to the Company from plan administrators as of June 30, 2014, several of the multi-employer pension plans in which it participates are underfunded and, as a result, the Company could be required to increase its contributions. On November 15, 2011, the Company, along with other members of the Pipe Line Contractors Association (“PLCA”), voluntarily withdrew from the Central States Southeast and Southwest Areas Pension Fund (“Central States”), a defined benefit multi-employer pension plan that is in critical status. In connection with this withdrawal, a $6.4 million withdrawal liability was established based on an estimate provided by the Central States administrator of such liability as of the date of withdrawal. The Company began paying installments towards this withdrawal liability in 2013, of which $4.8 million was outstanding as of June 30, 2014. The Company withdrew from Central States in order to mitigate its liability in connection with the plan; however, Central States has asserted that the PLCA members did not effectively withdraw in 2011 and are, therefore, responsible for a withdrawal liability that includes 2011 contribution amounts. By letter dated March 14, 2013, Central States demanded $11 million in withdrawal liability from the Company, which included 2011 contribution amounts. The Company is vigorously opposing this demand because it believes that it legally and effectively withdrew from Central States on November 15, 2011. If Central States were to prevail in its assertion that the Company withdrew after that date, then the initial amount of the Company’s withdrawal liability would increase to approximately $11 million. In addition, if Central States were to undergo a mass withdrawal, as defined by ERISA and the Pension Benefit Guaranty Corporation, there could be additional liability. The Company currently does not have plans to withdraw from any other multi-employer pension plan. Indemnities. The Company generally indemnifies its customers for the services it provides under its contracts, as well as other specified liabilities, which may subject the Company to indemnity claims, liabilities and related litigation. As of June 30, 2014 and December 31, 2013, the Company was not aware of any material asserted or unasserted claims in connection with these indemnity obligations. Other Guarantees. In the ordinary course of its business, from time to time, MasTec guarantees the obligations of its subsidiaries, including obligations under certain contracts with customers, certain lease obligations and in some states, obligations in connection with obtaining contractors’ licenses. The Company has also issued performance and other guarantees in connection with its undivided interest in a contractual joint venture and certain of its equity investees. See Note 3 - Acquisitions. MasTec also generally warrants the work it performs for a one to two year period following substantial completion of a project. MasTec has not historically accrued any reserves for potential warranty claims as they have been immaterial. Concentrations of Risk. The Company had approximately 410 customers for the six month period ended June 30, 2014. For both the three month periods ended June 30, 2014 and 2013, the Company derived 70% of revenues from its top ten customers. For the six month periods ended June 30, 2014 and 2013, the Company derived 69% and 68%, respectively, of revenues from its top ten customers. See Note 15 - Segments and Related Information for significant customer revenue concentration information.

Note 16 - Commitments and Contingencies

In addition to the matters discussed below, MasTec is subject to a variety of legal cases, claims and other disputes that arise from time to time in the ordinary course of its business. MasTec cannot provide assurance that it will be successful in recovering all or any of the potential damages it has claimed or in defending claims against it. The outcome of such cases, claims and disputes, including the one set forth below, cannot be predicted with certainty and an unfavorable resolution of one or more of them could have a material adverse effect on the Company's business, financial condition, results of operations, cash flows and the trading price of its common stock.

SunLight Entities. In 2011, Power Partners MasTec, LLC., a MasTec, Inc. subsidiary (“Power Partners”), entered into engineering, procurement, and construction agreements with special purpose entities, SunLight General Somerset Solar, LLC, SunLight General Morris Solar, LLC and SunLight General Sussex Solar, LLC (collectively, the “SunLight Entities”), respectively, to perform design and construction services for three public solar projects in New Jersey located in Somerset, Morris and Sussex Counties (the “Projects”). The initial contract price of each of the Projects was, subject to adjustment, approximately as follows: Somerset ($29 million); Morris ($36 million); and Sussex ($26 million). The Projects were funded on a project finance basis, including the proceeds of municipal bonds issued by the Morris County and Somerset Improvement Authorities (collectively, the “Authorities”).

Power Partners and the SunLight Entities commenced three separate arbitration proceedings against each other to address various disputes that presently exist between the parties on the three Projects. The parties allege, among other things, breach of contract against each other. The arbitrations began in January 2014 and an award is anticipated in the third quarter of 2014. Power Partners believes it has presented meritorious support of its claims against Sunlight and, additionally, believes that it has meritorious defenses against Sunlight’s claims. Power Partners is vigorously pursuing its claims against Sunlight and vigorously defending against Sunlight’s claims.

Power Partners filed municipal liens and construction liens of approximately $50 million for the work performed but the liens were challenged by the SunLight Entities and the Authorities. In March 2014, the New Jersey appellate court found that Power Partners did not have municipal or construction liens on the proceeds of the municipal bonds, and the New Jersey Supreme Court denied Power Partner’s emergency motion to stay the adverse ruling. The Company petitioned the New Jersey Supreme Court to review the New Jersey appellate court’s adverse ruling, and, in July 2014, the New Jersey Supreme Court agreed to review the appellate court's ruling. The timing of the hearing is unknown.

Power Partners also filed a federal lawsuit in the United States District Court of New Jersey against the Authorities and the principals of the SunLight Entities in June 2013. The claims against the Authorities include violations of the New Jersey Public Works Bond Act and the New Jersey Construction Trust Fund Act, tortious interference and unjust enrichment and quantum meruit. The Authorities and the SunLight principals have filed motions to dismiss. Power Partners has filed a response to the motions to dismiss. The litigation is in the early stages.

Other Commitments and Contingencies

Leases. In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facility, vehicle and equipment needs, including related party leases. See Note 10 - Lease Obligations.

Letters of Credit. In the ordinary course of business, the Company is required to post letters of credit for its insurance carriers, surety bond providers and in support of performance under certain contracts. Such letters of credit are generally issued by a bank or similar financial institution. The letter of credit commits the issuer to pay specified amounts to the holder of the letter of credit under certain conditions. If this were to occur, the Company would be required to reimburse the issuer of the letter of credit, which, depending upon the circumstances, could result in a charge to earnings. As of June 30, 2014 and December 31, 2013, there were $132.8 million and $134.8 million, respectively, of letters of credit issued under the Company's Credit Facility. In addition, there were $10.5 million of letters of credit issued under other credit facilities as of June 30, 2014. See Note 9 - Debt. The Company was not aware of any material claims relating to outstanding letters of credit as of June 30, 2014 or December 31, 2013.

Performance and Payment Bonds. In the ordinary course of business, MasTec is required by certain customers to provide performance and payment bonds for some of the Company’s contractual commitments related to projects in process. These bonds provide a guarantee to the customer that the Company will perform under the terms of a contract and that the Company will pay subcontractors and vendors. If the Company fails to perform under a contract or to pay subcontractors and vendors, the customer may demand that the surety make payments or provide services under the bond. The Company must reimburse the surety for any expenses or outlays it incurs. As of June 30, 2014, the estimated cost to complete projects secured by the Company’s $0.5 billion in performance and payment bonds was $177.7 million. As of December 31, 2013, the estimated cost to complete projects secured by the Company’s $1.1 billion in performance and payment bonds was $297.1 million.

Investments in Affiliates and Other Entities. The Company holds an undivided interest in a contractual joint venture with a third party for the purpose of providing infrastructure services under certain customer contracts. Losses incurred by the joint venture are generally shared equally by the joint venture members, with members of the joint venture jointly and severally liable for all of the obligations of the joint venture. The joint venture agreement provides that each joint venturer indemnify the other parties for any liabilities incurred. Thus, it is possible that the Company could be required to pay or perform obligations in excess of its share if the other joint venturer fails or refuses to pay or perform its share of the obligations. As of June 30, 2014, the Company was not aware of any circumstances that would lead to future claims against it for material amounts. As of June 30, 2014, the Company has outstanding commitments associated with its investments in unconsolidated affiliates of approximately $3 million, which are expected to be paid in the third quarter of 2014.

Self-Insurance. MasTec maintains insurance policies for workers’ compensation, general liability and automobile liability, which are subject to per claim deductibles. The Company also maintains excess umbrella coverage. As of June 30, 2014 and December 31, 2013, MasTec’s liability for unpaid claims and associated expenses, including incurred but not reported losses related to its workers compensation, general liability and automobile liability insurance policies, totaled $55.0 million and $50.8 million, respectively, of which $34.1 million and $31.3 million, respectively, was reflected within non-current other liabilities in the condensed unaudited consolidated balance sheets. MasTec also maintains an insurance policy with respect to employee group medical claims, which is subject to annual per employee maximum losses. MasTec’s liability for employee group medical claims as of June 30, 2014 and December 31, 2013 totaled $2.0 million and $2.1 million, respectively.

The Company is required to post letters of credit and provide cash collateral to certain of its insurance carriers and to provide surety bonds in certain states. These letters of credit amounted to $57.4 million as of both June 30, 2014 and December 31, 2013, respectively. In addition, cash collateral deposited with insurance carriers, which is included in other long-term assets in the condensed unaudited consolidated balance sheets, amounted to $1.3 million and $1.4 million as of June 30, 2014 and December 31, 2013, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $10.9 million as of both June 30, 2014 and December 31, 2013.

Employment Agreements. The Company has employment agreements with certain executives and other employees, which provide for compensation and certain other benefits and for severance payments under certain circumstances. Certain employment agreements also contain clauses that become effective upon a change of control of the Company. Upon the occurrence of any of the defined events in the various employment agreements, the Company would be obligated to pay certain amounts to the relevant employees, which vary with the level of the employees’ respective responsibility.

Collective Bargaining Agreements and Multi-Employer Plans. Certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The agreements require the subsidiaries party to the agreements to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to the ones contained in the expiring agreements.

The Employee Retirement Income Security Act of 1974, as amended by the Multi-Employer Pension Plan Amendments Act of 1980 (collectively, “ERISA”), which governs U.S. registered multi-employer pension plans, subjects employers to substantial liabilities in the event of the employer’s complete or partial withdrawal from, or upon termination of, such plans. Under current law regarding employers who are contributors to U.S. registered multi-employer defined benefit plans, a plan’s termination, an employer’s voluntary withdrawal from, or the mass withdrawal of all contributing employers from, an underfunded multi-employer defined benefit plan requires participating employers to make payments to the plan for their proportionate share of the multi-employer plan’s unfunded vested liabilities. Furthermore, the Pension Protection Act of 2006 added new funding rules to U.S. registered plans that are generally applicable to plan years beginning after 2007 for multi-employer plans that are classified as “endangered,” “seriously endangered,” or “critical” status. If plans in which the Company’s subsidiaries participate are in critical status, benefit reductions may apply and/or the Company could be required to make additional contributions. Based upon the information available to the Company from plan administrators as of June 30, 2014, several of the multi-employer pension plans in which it participates are underfunded and, as a result, the Company could be required to increase its contributions.

On November 15, 2011, the Company, along with other members of the Pipe Line Contractors Association (“PLCA”), voluntarily withdrew from the Central States Southeast and Southwest Areas Pension Fund (“Central States”), a defined benefit multi-employer pension plan that is in critical status. In connection with this withdrawal, a $6.4 million withdrawal liability was established based on an estimate provided by the Central States administrator of such liability as of the date of withdrawal. The Company began paying installments towards this withdrawal liability in 2013, of which $4.8 million was outstanding as of June 30, 2014. The Company withdrew from Central States in order to mitigate its liability in connection with the plan; however, Central States has asserted that the PLCA members did not effectively withdraw in 2011 and are, therefore, responsible for a withdrawal liability that includes 2011 contribution amounts. By letter dated March 14, 2013, Central States demanded $11 million in withdrawal liability from the Company, which included 2011 contribution amounts. The Company is vigorously opposing this demand because it believes that it legally and effectively withdrew from Central States on November 15, 2011. If Central States were to prevail in its assertion that the Company withdrew after that date, then the initial amount of the Company’s withdrawal liability would increase to approximately $11 million. In addition, if Central States were to undergo a mass withdrawal, as defined by ERISA and the Pension Benefit Guaranty Corporation, there could be additional liability. The Company currently does not have plans to withdraw from any other multi-employer pension plan.

Indemnities. The Company generally indemnifies its customers for the services it provides under its contracts, as well as other specified liabilities, which may subject the Company to indemnity claims, liabilities and related litigation. As of June 30, 2014 and December 31, 2013, the Company was not aware of any material asserted or unasserted claims in connection with these indemnity obligations.

Other Guarantees. In the ordinary course of its business, from time to time, MasTec guarantees the obligations of its subsidiaries, including obligations under certain contracts with customers, certain lease obligations and in some states, obligations in connection with obtaining contractors’ licenses. The Company has also issued performance and other guarantees in connection with its undivided interest in a contractual joint venture and certain of its equity investees. See Note 3 - Acquisitions. MasTec also generally warrants the work it performs for a one to two year period following substantial completion of a project. MasTec has not historically accrued any reserves for potential warranty claims as they have been immaterial.

Concentrations of Risk. The Company had approximately 410 customers for the six month period ended June 30, 2014. For both the three month periods ended June 30, 2014 and 2013, the Company derived 70% of revenues from its top ten customers. For the six month periods ended June 30, 2014 and 2013, the Company derived 69% and 68%, respectively, of revenues from its top ten customers. See Note 15 - Segments and Related Information for significant customer revenue concentration information.