Commitments and Contingencies	3 Months Ended
Mar. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	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. Legacy Litigation. MasTec is subject to litigation, some of which dates from the period 2001 through 2006. Outstanding Legacy Litigation The labor union representing the workers of Sistemas e Instalaciones de Telecomunicacion S.A. (“Sintel”), a former MasTec subsidiary that was sold in 1998, filed a claim that initiated an investigative action with the Audiencia Nacional, a Spanish federal court, against Telefonica and dozens of other defendants including current and former officers and directors of MasTec (including Jorge Mas, Chairman of the Company’s Board of Directors) and Sintel, relating to Sintel’s 2000 bankruptcy. The labor union alleged Sintel and its creditors were damaged in the approximate amount of 300 million euros (approximately $385 million as of March 31, 2013). In June 2009, the Audiencia Nacional issued an order that the trial phase was commencing against the MasTec defendants and other defendants. On June 14, 2012, the Sintel trial began. As a consequence of the MasTec defendants' arguments and presentation of evidence, a meeting with the prosecutor took place on July 24, 2012. At that meeting, a tentative agreement (the “Agreement”) was reached which would result in the exoneration of the MasTec defendants and the dismissal of all the charges against them (including Jorge Mas, our Chairman). The Agreement includes an acknowledgment that the MasTec defendants acted in good faith and did not cause Sintel’s bankruptcy. We entered into the Agreement in order to avoid significant legal fees and the potential liabilities resulting from the actions of other Spanish defendants for which MasTec may be financially responsible under a theory of subsidiary (or vicarious) liability, the uncertainty of a trial before a foreign tribunal such as the Audiencia Nacional and to eliminate management time devoted to this matter. MasTec recorded a pre-tax charge of $9.6 million in 2012 in connection with this Agreement. As part of this Agreement, MasTec would be dismissed from the case with prejudice. This Agreement was subject to further negotiation and satisfaction of several conditions, which currently have not been met. There can be no assurance that the Agreement will be completed. A trial is expected to occur if the Agreement is not completed. Other Outstanding Litigation During 2010 and 2011, pursuant to a written contract, the Company provided certain construction services for the City of Marathon in Marathon, Florida. We completed those services in 2011. At the end of 2011, the Company had still not been paid for all of the work performed on the project. In December 2011, the Company filed a lawsuit seeking in excess of $6 million against the City of Marathon for breach of contract and against the City of Marathon’s engineers for professional negligence. The City of Marathon and the engineers filed answers denying liability and claiming that the Company breached the contract. Discovery is ongoing. The Company will continue to vigorously pursue these claims. 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 11 - Lease Obligations for additional details. 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 March 31, 2013 and December 31, 2012, the Company had $119.3 million and $120.8 million, respectively, of letters of credit issued under its Credit Facility, of which $53.2 million pertained to certain of the Company's insurance carriers as of both March 31, 2013 and December 31, 2012. The Company is not aware of any material claims relating to outstanding letters of credit as of March 31, 2013 or December 31, 2012. 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 March 31, 2013, the estimated cost to complete projects secured by the Company’s $1.1 billion in performance and payment bonds was $162.2 million. As of December 31, 2012, the estimated cost to complete projects secured by the Company’s $1.1 billion in performance and payment bonds was $284.5 million. Self-Insurance. MasTec maintains insurance policies subject to per claim deductibles of $1 million for its workers’ compensation policy, $2 million for its general liability policy and $2 million for its automobile liability policy. The Company has excess umbrella coverage up to $100 million per claim and in the aggregate. As of March 31, 2013 and December 31, 2012, 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, was $49.8 million and $48.1 million, respectively, of which $29.7 million and $28.5 million, respectively, was reflected within non-current other liabilities in the condensed unaudited consolidated financial statements. MasTec also maintains an insurance policy with respect to employee group health claims, which is subject to annual per employee maximum losses of $0.4 million. MasTec’s liability for employee group claims as of both March 31, 2013 and December 31, 2012 was $1.1 million. 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 in which the Company is self-insured. As of both March 31, 2013 and December 31, 2012, these letters of credit amounted to $53.2 million. In addition, cash collateral deposited with insurance carriers, which is included in other long-term assets in the consolidated balance sheets, amounted to $1.4 million and $2.0 million as of March 31, 2013 and December 31, 2012, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $9.0 million as of both March 31, 2013 and December 31, 2012, 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 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 Pension 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 multi-employer pension plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls. The required amount of future contributions cannot be determined for future periods because the number of union employees employed at any given time, and the plans in which they participate, vary depending upon the location and number of ongoing projects and the need for union resources in connection with those projects. 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 ("ERISA"), 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 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 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 if the plans are determined to be underfunded. Based upon the information available to the Company from plan administrators as of March 31, 2013, several of the multi-employer pension plans in which the Company’s subsidiaries participate are underfunded. The Pension Protection Act requires that underfunded pension plans improve their funding ratios within prescribed intervals based on the level of their underfunding. In addition, if a multi-employer defined benefit plan fails to satisfy certain minimum funding requirements, the Internal Revenue Service may impose on the employers contributing to such plan a nondeductible excise tax of 5% on the amount of the accumulated funding deficiency. The Company’s subsidiaries have been notified that certain plans to which they contribute are in “critical” status and require additional contributions in the form of a surcharge on future benefit contributions required for future work performed by union employees covered by these plans. As a result, the Company's required contributions to these plans could increase in the future. The amount of additional funds the Company may be obligated to contribute in the future cannot be estimated, as such amounts will be based on future levels of work that require the specific use of those union employees covered by these plans. 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 condition. In connection with this withdrawal, the Company recorded a $6.4 million withdrawal liability based on an estimate provided by the Central States administrator of such liability as of the date of withdrawal. The Company withdrew from Central States in order to mitigate its liability in connection with the plan. Central States, however, 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 made a demand on the Company for the sum of $10.8 million in withdrawal liability, which sum 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, in fact, withdrew after that date, then the amount of the Company’s withdrawal liability would increase to approximately $10.8 million. In addition, if Central States were to undergo a mass withdrawal, as defined by ERISA and the Pension Benefit Guaranty Corporation, within the three year period commencing with the beginning of the calendar year during which the Company withdrew from the plan, there could be additional liability. The Company currently does not have plans to withdraw from any other multi-employer pension plan. See Note 13 - Other Retirement Plans for additional details. 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 March 31, 2013 and December 31, 2012, 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. 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.

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.

Legacy Litigation. MasTec is subject to litigation, some of which dates from the period 2001 through 2006.

Outstanding Legacy Litigation

The labor union representing the workers of Sistemas e Instalaciones de Telecomunicacion S.A. (“Sintel”), a former MasTec subsidiary that was sold in 1998, filed a claim that initiated an investigative action with the Audiencia Nacional, a Spanish federal court, against Telefonica and dozens of other defendants including current and former officers and directors of MasTec (including Jorge Mas, Chairman of the Company’s Board of Directors) and Sintel, relating to Sintel’s 2000 bankruptcy. The labor union alleged Sintel and its creditors were damaged in the approximate amount of 300 million euros (approximately $385 million as of March 31, 2013). In June 2009, the Audiencia Nacional issued an order that the trial phase was commencing against the MasTec defendants and other defendants.

On June 14, 2012, the Sintel trial began. As a consequence of the MasTec defendants' arguments and presentation of evidence, a meeting with the prosecutor took place on July 24, 2012. At that meeting, a tentative agreement (the “Agreement”) was reached which would result in the exoneration of the MasTec defendants and the dismissal of all the charges against them (including Jorge Mas, our Chairman). The Agreement includes an acknowledgment that the MasTec defendants acted in good faith and did not cause Sintel’s bankruptcy.

We entered into the Agreement in order to avoid significant legal fees and the potential liabilities resulting from the actions of other Spanish defendants for which MasTec may be financially responsible under a theory of subsidiary (or vicarious) liability, the uncertainty of a trial before a foreign tribunal such as the Audiencia Nacional and to eliminate management time devoted to this matter. MasTec recorded a pre-tax charge of $9.6 million in 2012 in connection with this Agreement. As part of this Agreement, MasTec would be dismissed from the case with prejudice. This Agreement was subject to further negotiation and satisfaction of several conditions, which currently have not been met. There can be no assurance that the Agreement will be completed. A trial is expected to occur if the Agreement is not completed.

Other Outstanding Litigation

During 2010 and 2011, pursuant to a written contract, the Company provided certain construction services for the City of Marathon in Marathon, Florida. We completed those services in 2011. At the end of 2011, the Company had still not been paid for all of the work performed on the project. In December 2011, the Company filed a lawsuit seeking in excess of $6 million against the City of Marathon for breach of contract and against the City of Marathon’s engineers for professional negligence. The City of Marathon and the engineers filed answers denying liability and claiming that the Company breached the contract. Discovery is ongoing. The Company will continue to vigorously pursue these claims.

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 11 - Lease Obligations for additional details.

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 March 31, 2013 and December 31, 2012, the Company had $119.3 million and $120.8 million, respectively, of letters of credit issued under its Credit Facility, of which $53.2 million pertained to certain of the Company's insurance carriers as of both March 31, 2013 and December 31, 2012. The Company is not aware of any material claims relating to outstanding letters of credit as of March 31, 2013 or December 31, 2012.

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 March 31, 2013, the estimated cost to complete projects secured by the Company’s $1.1 billion in performance and payment bonds was $162.2 million. As of December 31, 2012, the estimated cost to complete projects secured by the Company’s $1.1 billion in performance and payment bonds was $284.5 million.

Self-Insurance. MasTec maintains insurance policies subject to per claim deductibles of $1 million for its workers’ compensation policy, $2 million for its general liability policy and $2 million for its automobile liability policy. The Company has excess umbrella coverage up to $100 million per claim and in the aggregate. As of March 31, 2013 and December 31, 2012, 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, was $49.8 million and $48.1 million, respectively, of which $29.7 million and $28.5 million, respectively, was reflected within non-current other liabilities in the condensed unaudited consolidated financial statements.

MasTec also maintains an insurance policy with respect to employee group health claims, which is subject to annual per employee maximum losses of $0.4 million. MasTec’s liability for employee group claims as of both March 31, 2013 and December 31, 2012 was $1.1 million.

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 in which the Company is self-insured. As of both March 31, 2013 and December 31, 2012, these letters of credit amounted to $53.2 million. In addition, cash collateral deposited with insurance carriers, which is included in other long-term assets in the consolidated balance sheets, amounted to $1.4 million and $2.0 million as of March 31, 2013 and December 31, 2012, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $9.0 million as of both March 31, 2013 and December 31, 2012, 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 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 Pension 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 multi-employer pension plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls. The required amount of future contributions cannot be determined for future periods because the number of union employees employed at any given time, and the plans in which they participate, vary depending upon the location and number of ongoing projects and the need for union resources in connection with those projects. 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 ("ERISA"), 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 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 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 if the plans are determined to be underfunded.

Based upon the information available to the Company from plan administrators as of March 31, 2013, several of the multi-employer pension plans in which the Company’s subsidiaries participate are underfunded. The Pension Protection Act requires that underfunded pension plans improve their funding ratios within prescribed intervals based on the level of their underfunding. In addition, if a multi-employer defined benefit plan fails to satisfy certain minimum funding requirements, the Internal Revenue Service may impose on the employers contributing to such plan a nondeductible excise tax of 5% on the amount of the accumulated funding deficiency. The Company’s subsidiaries have been notified that certain plans to which they contribute are in “critical” status and require additional contributions in the form of a surcharge on future benefit contributions required for future work performed by union employees covered by these plans. As a result, the Company's required contributions to these plans could increase in the future. The amount of additional funds the Company may be obligated to contribute in the future cannot be estimated, as such amounts will be based on future levels of work that require the specific use of those union employees covered by these plans.

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 condition. In connection with this withdrawal, the Company recorded a $6.4 million withdrawal liability based on an estimate provided by the Central States administrator of such liability as of the date of withdrawal. The Company withdrew from Central States in order to mitigate its liability in connection with the plan. Central States, however, 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 made a demand on the Company for the sum of $10.8 million in withdrawal liability, which sum 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, in fact, withdrew after that date, then the amount of the Company’s withdrawal liability would increase to approximately $10.8 million. In addition, if Central States were to undergo a mass withdrawal, as defined by ERISA and the Pension Benefit Guaranty Corporation, within the three year period commencing with the beginning of the calendar year during which the Company withdrew from the plan, there could be additional liability. The Company currently does not have plans to withdraw from any other multi-employer pension plan.

See Note 13 - Other Retirement Plans for additional details.

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 March 31, 2013 and December 31, 2012, 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. 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.