Business, Basis of Presentation and Significant Accounting Policies	9 Months Ended
Sep. 30, 2013
Accounting Policies [Abstract]
Business, Basis of Presentation and Significant Accounting Policies	Business, Basis of Presentation and Significant Accounting Policies Nature of the Business MasTec, Inc. (collectively with its subsidiaries, “MasTec” or the “Company”) is a leading infrastructure construction company operating mainly throughout North America across a range of industries. The Company’s primary activities include the engineering, building, installation, maintenance and upgrade of energy, utility and communications infrastructure, such as: electrical utility transmission and distribution; natural gas and petroleum pipeline infrastructure; wireless, wireline and satellite communications; power generation, including renewable energy infrastructure; and industrial infrastructure. MasTec’s customers are primarily in these industries. Basis of Presentation The accompanying condensed unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X. Pursuant to these rules and regulations, certain information and footnote disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The accompanying condensed consolidated balance sheet as of December 31, 2012 is derived from the Company’s audited financial statements as of that date. Because certain information and footnote disclosures have been condensed or omitted, these condensed unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2012 contained in the Company’s most recent Annual Report on Form 10-K. In management’s opinion, all normal and recurring adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows for the periods presented have been included. Certain prior year amounts have been reclassified to conform to the current period presentation. Interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. The Company believes that the disclosures made in these condensed unaudited consolidated financial statements are adequate to make the information not misleading. Principles of Consolidation The accompanying condensed unaudited consolidated financial statements include MasTec, Inc. and its subsidiaries and include the accounts of all majority-owned subsidiaries over which the Company exercises control and, when applicable, entities in which the Company has a controlling financial interest. Other parties’ interests in companies for which MasTec exercises control and has a controlling financial interest are reported as non-controlling interests within shareholders’ equity. Net income or loss attributable to non-controlling interests is reported as a separate line item below net income. The Company’s investments in entities in which the Company does not have a controlling interest, but has the ability to exert significant influence, are accounted for using the equity method of accounting. Equity method investments are recorded as long-term assets in the condensed unaudited consolidated balance sheets. Income or loss from these investments is recorded within other income or expense, net, in the condensed unaudited consolidated statements of operations. The cost method is used for investments in entities over which the Company does not have the ability to exert significant influence. All significant intercompany balances and transactions have been eliminated in consolidation. Management Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Key estimates include: the recognition of revenue, in particular, on long-term construction contracts, including estimates of costs to complete projects and provisions for contract losses; allowances for doubtful accounts; accrued self-insured claims; estimated fair values of goodwill and intangible assets, acquisition-related contingent consideration, assets and liabilities classified as held-for-sale, convertible debt obligations, available for sale securities and investments in cost and equity method investees; asset lives used in computing depreciation and amortization, including amortization of intangible assets; accounting for income taxes; and the estimated impact of contingencies and ongoing litigation. While management believes that such estimates are fair when considered in conjunction with the consolidated financial position and results of operations taken as a whole, actual results could differ from those estimates and such differences may be material to the condensed unaudited consolidated financial statements. Significant Accounting Policies Except for adoption of the accounting pronouncements discussed below, there have been no material changes to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012. New accounting pronouncements Recently Issued Accounting Standards, Not Adopted as of September 30, 2013 In March 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-05, Foreign Currency Matters (Topic 830): Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-05”). The objective of ASU 2013-05 is to resolve diversity in practice regarding the release of the cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. ASU 2013-05 is effective prospectively for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements. In February 2013, the FASB issued ASU 2013-04, Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-04”). ASU 2013-04 provides guidance related to the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. The guidance requires an entity to measure those obligations as the sum of the amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and any additional amount the reporting entity expects to pay on behalf of its co-obligors. The guidance in ASU 2013-04 also requires an entity to disclose the nature and amount of the obligation. ASU 2013-05 is effective for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. Retrospective application is required for all periods presented. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements. In July 2013, the FASB issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-11”). ASU 2013-11 provides guidance on the presentation in the financial statements of an unrecognized tax benefit, or a portion of an unrecognized tax benefit, and explains that unrecognized tax benefits should be presented as a reduction to deferred tax assets for net operating loss carryforwards, similar tax losses or tax credit carryforwards. To the extent a net operating loss carryforward, similar tax loss or tax credit carryforward is not available as of the reporting date under the tax law of the applicable jurisdiction, or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. ASU 2013-11 applies to all entities that have unrecognized tax benefits when a net operating loss carryforward, similar tax loss, or tax credit carryforward exists as of the reporting date. ASU 2013-11 is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013. Retrospective application is permitted. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements. Recently Adopted Accounting Pronouncements In February 2013, the FASB issued ASU No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (“ASU 2013-02”). The amendment requires disclosure of information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, disclosure is required, either on the face of the statement where net income is presented, or in the notes, of significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. The new requirements are effective for public companies in interim and annual reporting periods beginning after December 15, 2012. The Company adopted ASU 2013-02 as of January 1, 2013. See Note 14 - Shareholders' Equity for related disclosures.

Business, Basis of Presentation and Significant Accounting Policies

Nature of the Business

MasTec, Inc. (collectively with its subsidiaries, “MasTec” or the “Company”) is a leading infrastructure construction company operating mainly throughout North America across a range of industries. The Company’s primary activities include the engineering, building, installation, maintenance and upgrade of energy, utility and communications infrastructure, such as: electrical utility transmission and distribution; natural gas and petroleum pipeline infrastructure; wireless, wireline and satellite communications; power generation, including renewable energy infrastructure; and industrial infrastructure. MasTec’s customers are primarily in these industries.

Basis of Presentation

The accompanying condensed unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X. Pursuant to these rules and regulations, certain information and footnote disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The accompanying condensed consolidated balance sheet as of December 31, 2012 is derived from the Company’s audited financial statements as of that date. Because certain information and footnote disclosures have been condensed or omitted, these condensed unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2012 contained in the Company’s most recent Annual Report on Form 10-K. In management’s opinion, all normal and recurring adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows for the periods presented have been included. Certain prior year amounts have been reclassified to conform to the current period presentation. Interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. The Company believes that the disclosures made in these condensed unaudited consolidated financial statements are adequate to make the information not misleading.

Principles of Consolidation

The accompanying condensed unaudited consolidated financial statements include MasTec, Inc. and its subsidiaries and include the accounts of all majority-owned subsidiaries over which the Company exercises control and, when applicable, entities in which the Company has a controlling financial interest. Other parties’ interests in companies for which MasTec exercises control and has a controlling financial interest are reported as non-controlling interests within shareholders’ equity. Net income or loss attributable to non-controlling interests is reported as a separate line item below net income. The Company’s investments in entities in which the Company does not have a controlling interest, but has the ability to exert significant influence, are accounted for using the equity method of accounting. Equity method investments are recorded as long-term assets in the condensed unaudited consolidated balance sheets. Income or loss from these investments is recorded within other income or expense, net, in the condensed unaudited consolidated statements of operations. The cost method is used for investments in entities over which the Company does not have the ability to exert significant influence. All significant intercompany balances and transactions have been eliminated in consolidation.

Management Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Key estimates include: the recognition of revenue, in particular, on long-term construction contracts, including estimates of costs to complete projects and provisions for contract losses; allowances for doubtful accounts; accrued self-insured claims; estimated fair values of goodwill and intangible assets, acquisition-related contingent consideration, assets and liabilities classified as held-for-sale, convertible debt obligations, available for sale securities and investments in cost and equity method investees; asset lives used in computing depreciation and amortization, including amortization of intangible assets; accounting for income taxes; and the estimated impact of contingencies and ongoing litigation. While management believes that such estimates are fair when considered in conjunction with the consolidated financial position and results of operations taken as a whole, actual results could differ from those estimates and such differences may be material to the condensed unaudited consolidated financial statements.

Significant Accounting Policies

Except for adoption of the accounting pronouncements discussed below, there have been no material changes to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.

New accounting pronouncements

Recently Issued Accounting Standards, Not Adopted as of September 30, 2013

In March 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-05, Foreign Currency Matters (Topic 830): Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-05”). The objective of ASU 2013-05 is to resolve diversity in practice regarding the release of the cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. ASU 2013-05 is effective prospectively for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements.

In February 2013, the FASB issued ASU 2013-04, Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-04”). ASU 2013-04 provides guidance related to the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. The guidance requires an entity to measure those obligations as the sum of the amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and any additional amount the reporting entity expects to pay on behalf of its co-obligors. The guidance in ASU 2013-04 also requires an entity to disclose the nature and amount of the obligation. ASU 2013-05 is effective for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. Retrospective application is required for all periods presented. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements.

In July 2013, the FASB issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-11”). ASU 2013-11 provides guidance on the presentation in the financial statements of an unrecognized tax benefit, or a portion of an unrecognized tax benefit, and explains that unrecognized tax benefits should be presented as a reduction to deferred tax assets for net operating loss carryforwards, similar tax losses or tax credit carryforwards. To the extent a net operating loss carryforward, similar tax loss or tax credit carryforward is not available as of the reporting date under the tax law of the applicable jurisdiction, or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. ASU 2013-11 applies to all entities that have unrecognized tax benefits when a net operating loss carryforward, similar tax loss, or tax credit carryforward exists as of the reporting date. ASU 2013-11 is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013. Retrospective application is permitted. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements.

Recently Adopted Accounting Pronouncements

In February 2013, the FASB issued ASU No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (“ASU 2013-02”). The amendment requires disclosure of information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, disclosure is required, either on the face of the statement where net income is presented, or in the notes, of significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. The new requirements are effective for public companies in interim and annual reporting periods beginning after December 15, 2012. The Company adopted ASU 2013-02 as of January 1, 2013. See Note 14 - Shareholders' Equity for related disclosures.