Commitments and Contingencies	12 Months Ended
Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 15 - 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 those 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 and cash flows. PPL. In October 2012, PPL Electric Utilities Corporation (“PPL”) and T&D Power, Inc., a MasTec, Inc. subsidiary (“T&D”), entered into a $206 million overhead transmission line construction contract (the “Contract”), pursuant to which T&D agreed to construct an approximately 100 mile transmission line in Pennsylvania. In September 2013, PPL issued a notice terminating the Contract for convenience. T&D then submitted termination invoices to recover certain pre-termination costs, overhead and profit, as well as termination-related demobilization costs, along with the applicable overhead and profit. PPL disputes these invoices. As a result of the dispute, T&D sued PPL in December 2013 in federal court in the Eastern District of Pennsylvania, and pursued claims in excess of $40 million for breach of contract, including PPL’s breach of its implied duty of good faith and fair dealing. After the parties completed discovery, in July 2015, PPL filed a motion for partial summary judgment, which was subsequently denied by the federal court. On October 5, 2015, trial proceedings commenced and during this process, the federal court required the parties to mediate, resulting in a settlement agreement in which the Company was awarded monies that were received in the fourth quarter of 2015. This settlement resulted in a charge of $12.2 million, related to the reduction of receivables associated with this contract. This charge was recorded within other expense of the Electrical Transmission segment in the third quarter of 2015. SunLight Entities. In 2011, Power Partners MasTec, LLC., a MasTec, Inc. subsidiary (“Power Partners”), entered into engineering, procurement, and construction agreements (the “EPC 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”). Power Partners and the SunLight Entities engaged in three separate arbitration proceedings against each other to address various disputes that existed between the parties regarding the Projects. In August 2014, the arbitration panel rendered awards in Power Partners’ favor in the aggregate amount of approximately $68 million, including fees and expenses. Power Partners also filed a lawsuit in June 2013 in federal court in New Jersey against the Somerset and Morris Authorities (the “Authorities”) and the principals of the SunLight Entities with claims exceeding $60 million as part of its efforts to seek payment of amounts that were also the subject of the arbitration proceedings. In March 2015, the Authorities, the SunLight Entities and principals and Power Partners entered into separate settlement agreements. As part of the settlement, Power Partners received amounts that were substantially equal to the previously recorded amounts, and all of the parties executed mutual releases. Wrigley v. MasTec, Inc. On May 7, 2015, a putative class action lawsuit (the “Lawsuit”), Wrigley v. MasTec, Inc., et. al. (Case No. 1:15-cv-21740) was filed in the United States District Court, Southern District of Florida, naming the Company, the Company’s Chief Executive Officer, José R. Mas, and the Company’s Chief Financial Officer, George L. Pita, as defendants. On August 5, 2015, co-lead plaintiffs were appointed, and an amended complaint was filed on October 13, 2015. The Lawsuit has been purportedly brought by a shareholder, both individually and on behalf of a putative class of shareholders, alleging violations of the federal securities laws arising from alleged false or misleading statements contained in, or alleged material omissions from, certain of the Company’s filings with the SEC and other statements, in each case with respect to accounting matters that are the subject of the Audit Committee’s independent internal investigation. The amended complaint seeks damages stemming from losses Plaintiffs claim to have suffered as a result of purchasing Company securities at an allegedly inflated market price. On December 14, 2015, the Company filed a motion to dismiss the amended complaint. On February 12, 2016, the Plaintiffs responded to the Company’s motion to dismiss. The District Court also scheduled a two-week trial period beginning on March 20, 2017 pending its ruling on the Company’s motion to dismiss. The Company believes that the Lawsuit is without merit and intends to vigorously defend against it; however, there can be no assurance that the Company will be successful in its defense. Other Commitments and Contingencies Regulatory Matters. As previously disclosed, the Company self-reported to the staff of the SEC (the “Staff”) regarding the previously disclosed Audit Committee’s independent investigation. On December 2, 2015, the Company was notified by the Staff that it had commenced a formal civil investigation relating to the previously disclosed adjustments to the 2014 financial statements and Audit Committee independent investigation. The Company intends to continue full cooperation with the SEC. 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 9 - Lease Obligations and Note 16 - Related Party Transactions. 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 as well as certain obligations associated with the Company’s equity method investments. 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 December 31, 2015 and 2014, there were $292.8 million and $153.6 million, respectively, of letters of credit issued under the Company’s Credit Facility. The Company is not aware of material claims relating to outstanding letters of credit as of December 31, 2015 or 2014. 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 expenses or outlays it incurs. As of December 31, 2015, the estimated cost to complete projects secured by the Company’s $539.3 million in performance and payment bonds was $36.0 million. As of December 31, 2014, the estimated cost to complete projects secured by the Company’s $748.3 million in performance and payment bonds was $60.1 million. These amounts do not include performance and payment bonds associated with the Company’s equity method investments and proportionately consolidated non-controlled Canadian joint venture, which are separately disclosed in Note 3 - Acquisitions. Investments in Affiliates and Other Entities. The Company holds an undivided interest in a proportionately consolidated non-controlled Canadian contractual joint venture, which is managed by a third party, for the purpose of providing infrastructure construction services for a civil construction project. This joint venture automatically terminates upon completion of the project. Losses incurred by the joint venture are generally shared proportionally 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 venture partner indemnify the other party for any liabilities incurred by such joint venture in excess of its ratable portion of such liabilities. Thus, it is possible that the Company could be required to pay or perform obligations in excess of its share if the other joint venture partner fails or refuses to pay or perform its share of the obligations. As of December 31, 2015, the Company was not aware of circumstances that would reasonably lead to future claims against it for material amounts. The Company has other investment arrangements, including equity investments in joint ventures, as discussed in Note 3 - Acquisitions and Note 5 - Fair Value of Financial Instruments. From time to time, the Company may provide financing, performance, financial and/or other guarantees to or on behalf of its unconsolidated affiliates, including its equity method investees and/or proportionately consolidated non-controlled Canadian joint venture. 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 December 31, 2015 and 2014, MasTec’s liability for unpaid claims and associated expenses, including incurred but not reported losses related to these policies, totaled $76.1 million and $70.3 million, respectively, of which $47.5 million and $39.6 million, respectively, were reflected within other long-term liabilities in the 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 December 31, 2015 and 2014 totaled $1.6 million and $4.4 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. Insurance-related letters of credit for the Company’s workers’ compensation, general liability and automobile liability policies amounted to $83.2 million and $75.0 million as of December 31, 2015 and 2014, respectively. In addition, cash collateral deposited with insurance carriers, which is included within other long-term assets in the consolidated balance sheets, amounted to $1.3 million and $1.2 million for these policies as of December 31, 2015 and 2014, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $13.4 million and $13.0 million as of December 31, 2015 and 2014, respectively. 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 in 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 Multiemployer Plans. As discussed in Note 11 - Other Retirement Plans, certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The Employee Retirement Income Security Act of 1974, as amended by the Multiemployer Pension Plan Amendments Act of 1980 (collectively, “ERISA”), which governs U.S.-registered multiemployer 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 pertaining to employers that are contributors to U.S.-registered multiemployer defined benefit plans, a plan’s termination, an employer’s voluntary withdrawal from, or the mass withdrawal of contributing employers from, an underfunded multiemployer defined benefit plan requires participating employers to make payments to the plan for their proportionate share of the multiemployer plan’s unfunded vested liabilities. These liabilities include an allocable share of the unfunded vested benefits of the plan for all plan participants, not only for benefits payable to participants of the contributing employer. As a result, participating employers may bear a higher proportion of liability for unfunded vested benefits if the other participating employers cease to contribute to, or withdraw from, the plan. The allocable portion of liability to participating employers could be more disproportionate if employers that have withdrawn from the plan are insolvent, or if they otherwise fail to pay their proportionate share of the withdrawal liability. The Company currently contributes, and in the past has contributed to, plans that are underfunded, and, therefore, could have potential liability associated with a voluntary or involuntary withdrawal from, or termination of, these plans. Other than the Company’s 2011 withdrawal from Central States, as discussed in Note 11 - Other Retirement Plans, the Company does not have plans to withdraw from, and is not aware of related liabilities associated with these plans. However, there can be no assurance that the Company will not be assessed liabilities in the future. The PPA requires that underfunded pension plans improve their funding ratios within prescribed intervals based on their level of underfunding, under which benefit reductions may apply and/or participating employers could be required to make additional contributions. In addition, if a multiemployer defined benefit plan fails to satisfy certain minimum funding requirements, the IRS may impose on the employers contributing to such plan a non-deductible excise tax of 5% of the amount of the accumulated funding deficiency. Based upon the information available to the Company from plan administrators as of December 31, 2015, several of the multiemployer pension plans in which it participates are underfunded and, as a result, the Company could be required to increase its contributions, including in the form of a surcharge on future benefit contributions. The amount of additional funds the Company may be obligated to contribute in the future cannot be estimated, as these amounts are based on future levels of work of the union employees covered by these plans, investment returns and the level of underfunding of such plans. As discussed in Note 11 - Other Retirement Plans, in November 2014, the Company, along with other members of the PLCA, voluntarily terminated its participation in several defined benefit multiemployer pension plans. Additionally, in November 2011, the Company, along with other members of the PLCA, voluntarily withdrew from Central States. Subsequent to the Company’s withdrawal in 2011, Central States asserted that the PLCA members did not effectively withdraw in 2011. In September 2015, the withdrawal date dispute was resolved in the PLCA’s favor by the U.S. Court of Appeals for the Seventh Circuit in a decision finding that the PLCA members lawfully and effectively withdrew from Central States by and through their actions in 2011. Based on current discussions with Central States, the plan will be providing the PLCA members with updated withdrawal liability information, taking into consideration payments to date. The Company does not expect a material impact to the recorded withdrawal liability, however there can be no assurance as to the final amount as determined by the plan administrator. 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 December 31, 2015 and 2014, the Company was not aware of 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. MasTec has also issued performance and other guarantees in connection with its undivided interest in a proportionately consolidated non-controlled Canadian joint venture and certain of its equity investees. See Note 3 - Acquisitions and Note 5 - Fair Value of Financial Instruments for discussion of certain of the Company’s equity method investees and other investment arrangements, including related guarantees. MasTec also generally warrants the work it performs for a one to two-year period following substantial completion of a project. Much of the work performed by the Company is evaluated for defects shortly after the work is completed. MasTec has not historically accrued reserves for potential warranty claims as they have not been material. However, if warranty claims occur, the Company could be required to repair or replace warrantied items, or, if customers elect to repair or replace the warrantied item using the services of another provider, the Company could be required to pay for the cost of the repair or replacement. Concentrations of Risk. The Company is subject to certain risk factors, including, but not limited to: risks related to fluctuations in the market price of oil and/or natural gas; changes in customers’ capital spending plans; the nature of its contracts, which do not obligate MasTec’s customers to undertake any infrastructure projects and may be canceled on short notice; customer consolidation; seasonality; adverse weather conditions; fluctuations in geographic or other operational factors; economic downturns; technological, legislative and/or regulatory changes affecting the Company’s businesses; competition; exposure related to foreign operations; collectibility of receivables; exposure from system or information technology interruptions; acquisition integration and financing; recoverability of goodwill; availability of qualified employees; exposure to litigation; exposure to multiemployer pension plan liabilities; and potential exposure to environmental liabilities. The Company grants credit, generally without collateral, to its customers. Consequently, the Company is subject to potential credit risk related to changes in business and economic factors. However, MasTec generally has certain lien rights on that work and maintains a diverse customer base. The Company believes its billing and collection policies are adequate to minimize potential credit risk. MasTec’s customers include public and private energy providers, pipeline operators, wireless service providers, satellite and broadband operators, local and long distance carriers and government entities. The industries served by MasTec’s customers include, among others: communications (including wireless, wireline/fiber and satellite communications) and utilities (including petroleum and natural gas pipeline infrastructure; electrical utility transmission and distribution; power generation; and industrial infrastructure). In the third quarter of 2015, DIRECTV® was acquired by AT&T. Revenue from DIRECTV® is presented on a combined basis with AT&T for all periods presented. Giving retroactive effect to the acquisition of DIRECTV® by AT&T, the Company had approximately 530 customers for the year ended December 31, 2015. As of December 31, 2015 one customer accounted for approximately 12% of the Company’s consolidated net accounts receivable position, which represents accounts receivable, net, less billings in excess of costs and earnings, and, as of December 31, 2014, a separate customer accounted for approximately 19% of the Company’s consolidated net accounts receivable position. In addition, the Company derived 61%, 66% and 71%, of revenue from its top ten customers for the for the years ended December 31, 2015, 2014 and 2013, respectively.

Note 15 - 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 those 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 and cash flows.

PPL. In October 2012, PPL Electric Utilities Corporation (“PPL”) and T&D Power, Inc., a MasTec, Inc. subsidiary (“T&D”), entered into a $206 million overhead transmission line construction contract (the “Contract”), pursuant to which T&D agreed to construct an approximately 100 mile transmission line in Pennsylvania. In September 2013, PPL issued a notice terminating the Contract for convenience. T&D then submitted termination invoices to recover certain pre-termination costs, overhead and profit, as well as termination-related demobilization costs, along with the applicable overhead and profit. PPL disputes these invoices. As a result of the dispute, T&D sued PPL in December 2013 in federal court in the Eastern District of Pennsylvania, and pursued claims in excess of $40 million for breach of contract, including PPL’s breach of its implied duty of good faith and fair dealing. After the parties completed discovery, in July 2015, PPL filed a motion for partial summary judgment, which was subsequently denied by the federal court. On October 5, 2015, trial proceedings commenced and during this process, the federal court required the parties to mediate, resulting in a settlement agreement in which the Company was awarded monies that were received in the fourth quarter of 2015. This settlement resulted in a charge of $12.2 million, related to the reduction of receivables associated with this contract. This charge was recorded within other expense of the Electrical Transmission segment in the third quarter of 2015.

SunLight Entities. In 2011, Power Partners MasTec, LLC., a MasTec, Inc. subsidiary (“Power Partners”), entered into engineering, procurement, and construction agreements (the “EPC 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”). Power Partners and the SunLight Entities engaged in three separate arbitration proceedings against each other to address various disputes that existed between the parties regarding the Projects. In August 2014, the arbitration panel rendered awards in Power Partners’ favor in the aggregate amount of approximately $68 million, including fees and expenses. Power Partners also filed a lawsuit in June 2013 in federal court in New Jersey against the Somerset and Morris Authorities (the “Authorities”) and the principals of the SunLight Entities with claims exceeding $60 million as part of its efforts to seek payment of amounts that were also the subject of the arbitration proceedings. In March 2015, the Authorities, the SunLight Entities and principals and Power Partners entered into separate settlement agreements. As part of the settlement, Power Partners received amounts that were substantially equal to the previously recorded amounts, and all of the parties executed mutual releases.

Wrigley v. MasTec, Inc. On May 7, 2015, a putative class action lawsuit (the “Lawsuit”), Wrigley v. MasTec, Inc., et. al. (Case No. 1:15-cv-21740) was filed in the United States District Court, Southern District of Florida, naming the Company, the Company’s Chief Executive Officer, José R. Mas, and the Company’s Chief Financial Officer, George L. Pita, as defendants. On August 5, 2015, co-lead plaintiffs were appointed, and an amended complaint was filed on October 13, 2015. The Lawsuit has been purportedly brought by a shareholder, both individually and on behalf of a putative class of shareholders, alleging violations of the federal securities laws arising from alleged false or misleading statements contained in, or alleged material omissions from, certain of the Company’s filings with the SEC and other statements, in each case with respect to accounting matters that are the subject of the Audit Committee’s independent internal investigation. The amended complaint seeks damages stemming from losses Plaintiffs claim to have suffered as a result of purchasing Company securities at an allegedly inflated market price. On December 14, 2015, the Company filed a motion to dismiss the amended complaint. On February 12, 2016, the Plaintiffs responded to the Company’s motion to dismiss. The District Court also scheduled a two-week trial period beginning on March 20, 2017 pending its ruling on the Company’s motion to dismiss. The Company believes that the Lawsuit is without merit and intends to vigorously defend against it; however, there can be no assurance that the Company will be successful in its defense.

Other Commitments and Contingencies

Regulatory Matters. As previously disclosed, the Company self-reported to the staff of the SEC (the “Staff”) regarding the previously disclosed Audit Committee’s independent investigation. On December 2, 2015, the Company was notified by the Staff that it had commenced a formal civil investigation relating to the previously disclosed adjustments to the 2014 financial statements and Audit Committee independent investigation. The Company intends to continue full cooperation with the SEC.

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 9 - Lease Obligations and Note 16 - Related Party Transactions.

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 as well as certain obligations associated with the Company’s equity method investments. 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 December 31, 2015 and 2014, there were $292.8 million and $153.6 million, respectively, of letters of credit issued under the Company’s Credit Facility. The Company is not aware of material claims relating to outstanding letters of credit as of December 31, 2015 or 2014.

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 expenses or outlays it incurs. As of December 31, 2015, the estimated cost to complete projects secured by the Company’s $539.3 million in performance and payment bonds was $36.0 million. As of December 31, 2014, the estimated cost to complete projects secured by the Company’s $748.3 million in performance and payment bonds was $60.1 million. These amounts do not include performance and payment bonds associated with the Company’s equity method investments and proportionately consolidated non-controlled Canadian joint venture, which are separately disclosed in Note 3 - Acquisitions.

Investments in Affiliates and Other Entities. The Company holds an undivided interest in a proportionately consolidated non-controlled Canadian contractual joint venture, which is managed by a third party, for the purpose of providing infrastructure construction services for a civil construction project. This joint venture automatically terminates upon completion of the project. Losses incurred by the joint venture are generally shared proportionally 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 venture partner indemnify the other party for any liabilities incurred by such joint venture in excess of its ratable portion of such liabilities. Thus, it is possible that the Company could be required to pay or perform obligations in excess of its share if the other joint venture partner fails or refuses to pay or perform its share of the obligations. As of December 31, 2015, the Company was not aware of circumstances that would reasonably lead to future claims against it for material amounts.

The Company has other investment arrangements, including equity investments in joint ventures, as discussed in Note 3 - Acquisitions and Note 5 - Fair Value of Financial Instruments. From time to time, the Company may provide financing, performance, financial and/or other guarantees to or on behalf of its unconsolidated affiliates, including its equity method investees and/or proportionately consolidated non-controlled Canadian joint venture.

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 December 31, 2015 and 2014, MasTec’s liability for unpaid claims and associated expenses, including incurred but not reported losses related to these policies, totaled $76.1 million and $70.3 million, respectively, of which $47.5 million and $39.6 million, respectively, were reflected within other long-term liabilities in the 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 December 31, 2015 and 2014 totaled $1.6 million and $4.4 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. Insurance-related letters of credit for the Company’s workers’ compensation, general liability and automobile liability policies amounted to $83.2 million and $75.0 million as of December 31, 2015 and 2014, respectively. In addition, cash collateral deposited with insurance carriers, which is included within other long-term assets in the consolidated balance sheets, amounted to $1.3 million and $1.2 million for these policies as of December 31, 2015 and 2014, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $13.4 million and $13.0 million as of December 31, 2015 and 2014, respectively.

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 in 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 Multiemployer Plans. As discussed in Note 11 - Other Retirement Plans, certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The Employee Retirement Income Security Act of 1974, as amended by the Multiemployer Pension Plan Amendments Act of 1980 (collectively, “ERISA”), which governs U.S.-registered multiemployer 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 pertaining to employers that are contributors to U.S.-registered multiemployer defined benefit plans, a plan’s termination, an employer’s voluntary withdrawal from, or the mass withdrawal of contributing employers from, an underfunded multiemployer defined benefit plan requires participating employers to make payments to the plan for their proportionate share of the multiemployer plan’s unfunded vested liabilities. These liabilities include an allocable share of the unfunded vested benefits of the plan for all plan participants, not only for benefits payable to participants of the contributing employer. As a result, participating employers may bear a higher proportion of liability for unfunded vested benefits if the other participating employers cease to contribute to, or withdraw from, the plan. The allocable portion of liability to participating employers could be more disproportionate if employers that have withdrawn from the plan are insolvent, or if they otherwise fail to pay their proportionate share of the withdrawal liability. The Company currently contributes, and in the past has contributed to, plans that are underfunded, and, therefore, could have potential liability associated with a voluntary or involuntary withdrawal from, or termination of, these plans. Other than the Company’s 2011 withdrawal from Central States, as discussed in Note 11 - Other Retirement Plans, the Company does not have plans to withdraw from, and is not aware of related liabilities associated with these plans. However, there can be no assurance that the Company will not be assessed liabilities in the future. The PPA requires that underfunded pension plans improve their funding ratios within prescribed intervals based on their level of underfunding, under which benefit reductions may apply and/or participating employers could be required to make additional contributions. In addition, if a multiemployer defined benefit plan fails to satisfy certain minimum funding requirements, the IRS may impose on the employers contributing to such plan a non-deductible excise tax of 5% of the amount of the accumulated funding deficiency.

Based upon the information available to the Company from plan administrators as of December 31, 2015, several of the multiemployer pension plans in which it participates are underfunded and, as a result, the Company could be required to increase its contributions, including in the form of a surcharge on future benefit contributions. The amount of additional funds the Company may be obligated to contribute in the future cannot be estimated, as these amounts are based on future levels of work of the union employees covered by these plans, investment returns and the level of underfunding of such plans. As discussed in Note 11 - Other Retirement Plans, in November 2014, the Company, along with other members of the PLCA, voluntarily terminated its participation in several defined benefit multiemployer pension plans. Additionally, in November 2011, the Company, along with other members of the PLCA, voluntarily withdrew from Central States. Subsequent to the Company’s withdrawal in 2011, Central States asserted that the PLCA members did not effectively withdraw in 2011. In September 2015, the withdrawal date dispute was resolved in the PLCA’s favor by the U.S. Court of Appeals for the Seventh Circuit in a decision finding that the PLCA members lawfully and effectively withdrew from Central States by and through their actions in 2011. Based on current discussions with Central States, the plan will be providing the PLCA members with updated withdrawal liability information, taking into consideration payments to date. The Company does not expect a material impact to the recorded withdrawal liability, however there can be no assurance as to the final amount as determined by the plan administrator.

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 December 31, 2015 and 2014, the Company was not aware of 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. MasTec has also issued performance and other guarantees in connection with its undivided interest in a proportionately consolidated non-controlled Canadian joint venture and certain of its equity investees. See Note 3 - Acquisitions and Note 5 - Fair Value of Financial Instruments for discussion of certain of the Company’s equity method investees and other investment arrangements, including related guarantees. MasTec also generally warrants the work it performs for a one to two-year period following substantial completion of a project. Much of the work performed by the Company is evaluated for defects shortly after the work is completed. MasTec has not historically accrued reserves for potential warranty claims as they have not been material. However, if warranty claims occur, the Company could be required to repair or replace warrantied items, or, if customers elect to repair or replace the warrantied item using the services of another provider, the Company could be required to pay for the cost of the repair or replacement.

Concentrations of Risk. The Company is subject to certain risk factors, including, but not limited to: risks related to fluctuations in the market price of oil and/or natural gas; changes in customers’ capital spending plans; the nature of its contracts, which do not obligate MasTec’s customers to undertake any infrastructure projects and may be canceled on short notice; customer consolidation; seasonality; adverse weather conditions; fluctuations in geographic or other operational factors; economic downturns; technological, legislative and/or regulatory changes affecting the Company’s businesses; competition; exposure related to foreign operations; collectibility of receivables; exposure from system or information technology interruptions; acquisition integration and financing; recoverability of goodwill; availability of qualified employees; exposure to litigation; exposure to multiemployer pension plan liabilities; and potential exposure to environmental liabilities. The Company grants credit, generally without collateral, to its customers. Consequently, the Company is subject to potential credit risk related to changes in business and economic factors. However, MasTec generally has certain lien rights on that work and maintains a diverse customer base. The Company believes its billing and collection policies are adequate to minimize potential credit risk. MasTec’s customers include public and private energy providers, pipeline operators, wireless service providers, satellite and broadband operators, local and long distance carriers and government entities. The industries served by MasTec’s customers include, among others: communications (including wireless, wireline/fiber and satellite communications) and utilities (including petroleum and natural gas pipeline infrastructure; electrical utility transmission and distribution; power generation; and industrial infrastructure). In the third quarter of 2015, DIRECTV® was acquired by AT&T. Revenue from DIRECTV® is presented on a combined basis with AT&T for all periods presented. Giving retroactive effect to the acquisition of DIRECTV® by AT&T, the Company had approximately 530 customers for the year ended December 31, 2015. As of December 31, 2015 one customer accounted for approximately 12% of the Company’s consolidated net accounts receivable position, which represents accounts receivable, net, less billings in excess of costs and earnings, and, as of December 31, 2014, a separate customer accounted for approximately 19% of the Company’s consolidated net accounts receivable position. In addition, the Company derived 61%, 66% and 71%, of revenue from its top ten customers for the for the years ended December 31, 2015, 2014 and 2013, respectively.