MasTec (MTZ) 10-Q 30 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 27, 2014
Document and Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Entity Registrant Name	'MASTEC INC	'
Trading Symbol	'MTZ	'
Entity Central Index Key	'0000015615	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	81,875,111

Condensed_Unaudited_Consolidat

Condensed Unaudited Consolidated Statements Of Operations (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Income Statement [Abstract]	'		'		'		'
Revenue	$1,309,596		$1,269,385		$3,378,180		$3,165,657
Costs of revenue, excluding depreciation and amortization	1,122,961		1,081,132		2,914,904		2,695,287
Depreciation and amortization	41,747		37,756		111,996		103,111
General and administrative expenses	59,889		58,976		167,454		159,761
Interest expense, net	12,643		12,666		37,595		34,549
Loss on extinguishment of debt	0		0		0		5,624
Other income, net	-1,416		-2,778		-5,424		-3,283
Income from continuing operations before income taxes	73,772		81,633		151,655		170,608
Provision for income taxes	-28,042		-31,698		-57,671		-65,822
Net income from continuing operations	45,730		49,935		93,984		104,786
Discontinued operations:	'		'		'		'
Net loss from discontinued operations, including loss on disposal and impairment charges (See Note 4)	-320		-3,735		-592		-5,165
Net income	45,410		46,200		93,392		99,621
Net income attributable to non-controlling interests	139		62		48		172
Net income attributable to MasTec, Inc.	$45,271		$46,138		$93,344		$99,449
Basic earnings (loss) per share:	'		'		'		'
Continuing operations	$0.56		$0.65		$1.19		$1.36
Discontinued operations	$0		($0.05)		($0.01)		($0.07)
Total basic earnings per share	$0.55	[1]	$0.60	[1]	$1.18	[1]	$1.29	[1]
Basic weighted average common shares outstanding	81,811		77,093		79,158		76,816
Diluted earnings (loss) per share:	'		'		'		'
Continuing operations	$0.53		$0.59		$1.09		$1.24
Discontinued operations	$0		($0.04)		($0.01)		($0.06)
Total diluted earnings per share	$0.53	[1]	$0.54	[1]	$1.08	[1]	$1.18	[1]
Diluted weighted average common shares outstanding	85,824		85,464		86,416		84,733
[1]	Earnings per share calculations may contain slight summation differences due to rounding.

Condensed_Unaudited_Consolidat1

Condensed Unaudited Consolidated Statements Of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income	$45,410	$46,200	$93,392	$99,621
Other comprehensive (loss) income:	'	'	'	'
Other comprehensive (loss) income (See Note 13)	-12,944	2,844	-10,601	-4,397
Comprehensive income	32,466	49,044	82,791	95,224
Comprehensive income attributable to non-controlling interests	139	62	48	172
Comprehensive income attributable to MasTec, Inc.	32,327	48,982	82,743	95,052
Foreign Currency Translation Adjustments [Member]	'	'	'	'
Other comprehensive (loss) income:	'	'	'	'
Other comprehensive (loss) income (See Note 13)	-12,944	2,936	-10,601	-3,839
Available-for-Sale-Securities [Member]	'	'	'	'
Other comprehensive (loss) income:	'	'	'	'
Other comprehensive (loss) income (See Note 13)	$0	($92)	$0	($558)

Condensed_Unaudited_Consolidat2

Condensed Unaudited Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
Current assets	'	'
Cash and cash equivalents	$7,067,000	$22,927,000
Accounts receivable, net of allowance	1,389,903,000	1,134,693,000
Inventories, net	105,038,000	70,185,000
Prepaid expenses and other current assets, including discontinued operations (See Note 4)	71,944,000	79,221,000
Total current assets	1,573,952,000	1,307,026,000
Property and equipment, net	614,359,000	488,132,000
Goodwill	1,000,024,000	902,044,000
Other intangible assets, net	222,212,000	165,606,000
Other long-term assets, including discontinued operations (See Note 4)	59,579,000	60,390,000
Total assets	3,470,126,000	2,923,198,000
Current liabilities	'	'
Current maturities of long-term debt	71,798,000	51,376,000
Accounts payable	481,840,000	424,917,000
Accrued salaries and wages	82,083,000	66,455,000
Other accrued expenses	82,054,000	71,448,000
Acquisition-related contingent consideration, current	39,126,000	67,226,000
Billings in excess of costs and earnings	130,997,000	121,641,000
Other current liabilities, including discontinued operations (See Note 4)	22,976,000	26,162,000
Total current liabilities	910,874,000	829,225,000
Acquisition-related contingent consideration, net of current portion	115,649,000	112,370,000
Long-term debt	1,088,289,000	765,425,000
Long-term deferred tax liabilities, net	180,449,000	154,763,000
Other liabilities	45,978,000	40,357,000
Total liabilities	2,341,239,000	1,902,140,000
Commitments and contingencies (See Note 16)	'	'
Equity	'	'
Preferred stock, $1.00 par value; authorized shares - 5,000,000; issued and outstanding shares - none	0	0
Common stock, $0.10 par value; authorized shares - 145,000,000; issued shares - 87,106,042 and 86,725,372 as of September 30, 2014 and December 31, 2013, respectively	8,711,000	8,672,000
Capital surplus	781,400,000	822,836,000
Contributed shares	6,002,000	6,002,000
Retained earnings	435,208,000	341,864,000
Accumulated other comprehensive loss	-23,887,000	-13,286,000
Treasury stock, at cost; 5,262,831 and 9,467,286 shares as of September 30, 2014 and December 31, 2013, respectively	-83,385,000	-150,000,000
Total MasTec, Inc. shareholders' equity	1,124,049,000	1,016,088,000
Non-controlling interests	4,838,000	4,970,000
Total equity	1,128,887,000	1,021,058,000
Total liabilities and equity	$3,470,126,000	$2,923,198,000

Condensed_Unaudited_Consolidat3

Condensed Unaudited Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]	'	'
Preferred stock, par value	$1	$1
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.10	$0.10
Common stock, shares authorized	145,000,000	145,000,000
Common stock, shares issued	87,106,042	86,725,372
Treasury stock, shares	5,262,831	9,467,286

Condensed_Unaudited_Consolidat4

Condensed Unaudited Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Cash flows from operating activities:	'		'
Net income	$93,392		$99,621
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Depreciation and amortization	111,996		103,111
Non-cash interest expense, including write-off of deferred financing costs on redeemed debt	6,052		8,397
Non-cash stock-based compensation expense	11,584		9,647
Excess tax benefit from stock-based compensation	-3,494	[1]	-4,446	[1]
Provision for deferred income taxes	4,294		9,439
(Gains) losses on sales of assets, including impairment charges on discontinued operations	-4,068		1,152
Changes in assets and liabilities, net of acquisitions:	'		'
Accounts receivable	-131,175		-271,010
Inventories	-27,553		20,484
Other assets, current and non-current portion	5,202		18,610
Accounts payable and accrued expenses	14,521		126,784
Billings in excess of costs and earnings	4,171		-19,776
Book overdrafts	-10,399		2,791
Other liabilities, current and non-current portion	5,857		16,027
Net cash provided by operating activities	81,019		129,256
Cash flows (used in) provided by investing activities:	'		'
Cash paid for acquisitions, net of cash acquired	-162,901		-146,598
Capital expenditures	-90,962		-101,411
Proceeds from sale of property and equipment	12,204		8,288
Proceeds from disposal of business, net of cash divested	0		-4,332
(Payments for) proceeds from other investments, net	-1,046		3,852
Net cash used in investing activities	-242,705		-240,201
Cash flows provided by (used in) financing activities:	'		'
Proceeds from credit facility	1,319,623		766,154
Repayments of credit facility	-955,151		-860,070
Proceeds from issuance of senior notes	0		400,000
Repayment of senior notes, including convertible notes	-105,325		-150,000
Repayments of other borrowings	-15,827		-24,246
Payments of capital lease obligations	-38,358		-32,214
Excess tax benefit from stock-based compensation	3,494		4,446
Payments of financing costs, including call premiums on extinguishment of debt	-1,455		-11,835
Net cash provided by financing activities	146,978		87,144
Effect of currency translation on cash	-1,152		-118
Net decrease in cash and cash equivalents	-15,860		-23,919
Cash and cash equivalents - beginning of period	22,927		26,767
Cash and cash equivalents - end of period	7,067		2,848
Supplemental cash flow information:	'		'
Interest paid	35,106		30,851
Income taxes paid, net of refunds	46,423		49,722
Supplemental disclosure of non-cash information:	'		'
Equipment acquired under capital lease	55,488		82,737
2011 4.0% Notes [Member]	'		'
Supplemental disclosure of non-cash information:	'		'
Premium shares, conversion of convertible notes	114,785		0
Equipment [Member]	'		'
Supplemental disclosure of non-cash information:	'		'
Equipment acquired under financing arrangements	6,851		24,100
Earn-Out Arrangements [Member]	'		'
Cash flows provided by (used in) financing activities:	'		'
Payments of acquisition-related contingent consideration	-60,341		-12,848
Supplemental disclosure of non-cash information:	'		'
Acquisition-related contingent consideration, new business combinations	34,988		29,971
Stock Compensation Plan [Member]	'		'
Cash flows provided by (used in) financing activities:	'		'
Proceeds from stock-based awards, net of tax withholdings	318		7,757
Payments of acquisition-related contingent consideration	3,800		12,200
Operating Expense [Member]	'		'
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Provision for losses on operating assets	1,136		6,300
Contracts Accounted for Under Percentage of Completion [Member]	'		'
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Provision for losses on construction projects, net	($497)		$2,125
[1]	Excess tax benefits, which represent cash flows from tax deductions in excess of the recorded tax effect of compensation expense recognized for stock options exercised and vested restricted shares, are classified as financing cash flows in the Company’s condensed unaudited consolidated statements of cash flows.

Business_Basis_of_Presentation

Business, Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Business, Basis of Presentation and Significant Accounting Policies	'
	Note 1 – 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: petroleum and natural gas pipeline infrastructure; wireless, wireline/fiber and satellite communications; electrical utility transmission and distribution; power generation; and industrial infrastructure. MasTec’s customers are in these industries. MasTec reports its results in five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial; and (5) Other. See Note 15 - Segments and Related Information.
	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, 2013 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, 2013 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 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 in other income or expense, net, in the condensed unaudited consolidated statements of operations. The Company's investments in entities in which the Company does not have the ability to exert significant influence are accounted for using the cost method of accounting. All significant intercompany balances and transactions have been eliminated in consolidation. The assets and liabilities of foreign subsidiaries are translated into U.S. dollars at period-end exchange rates, with resulting translation gains or losses accumulated within other comprehensive income or loss. Revenue and expenses are translated into U.S. dollars at average rates of exchange prevailing during the applicable period. Gains or losses resulting from transactions executed in a foreign currency are included in other income or expense, net. The Company does not currently have any subsidiaries that operate in highly inflationary environments. The results of operations and financial position of any discontinued operations are aggregated and presented separately from the Company's continuing operations in the condensed unaudited consolidated financial statements for all periods presented.
	Investments in Affiliates and Other Entities
	In the ordinary course of business, the Company enters into various investment arrangements, which may include equity or other interests in business entities, including contractual joint ventures or other forms of equity participation. These investment arrangements may also include certain forms of financing, such as the extension of loans. In connection with certain of these investment arrangements, the Company provides infrastructure construction services to or through its equity investees and/or contractual joint ventures. Management determines whether such investment arrangements involve a variable interest entity (“VIE”) based on the characteristics of the particular entity. If an entity is determined to be a VIE, then management determines if the Company is the primary beneficiary of the entity and whether or not consolidation of the VIE within the Company's financial statements is required. The primary beneficiary consolidating the VIE must normally have both (i) the power to direct the activities of a VIE that most significantly affect the VIE’s economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE, which, in either case, could be significant to the VIE. If management determines that the Company is the primary beneficiary of a VIE, then the VIE would be consolidated, and the other party’s equity interest in the VIE would be accounted for as a non-controlling interest. As of September 30, 2014, the Company was not the primary beneficiary of any VIE. In cases where the Company has an undivided interest in the assets, liabilities, revenues and profits of an unincorporated entity, such amounts are consolidated on a basis proportional to the Company’s ownership interest in the unincorporated entity.
	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 and gross profit or loss, in particular, on long-term construction contracts, which rely upon estimates of costs to complete projects, ultimate project gross profit and the amount of contract price adjustments that are probable; allowances for doubtful accounts; accrued self-insured claims; estimated fair values of goodwill and intangible assets, acquisition-related contingent consideration, convertible debt obligations and investments in cost and equity method investees; asset lives used in computing depreciation and amortization, including amortization of intangible assets; share-based compensation; 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
	Revenue Recognition
	Revenues are derived from projects performed under master and other service agreements as well as from fixed price contracts for specific projects or jobs requiring the construction and installation of an entire infrastructure system or specified units within an entire infrastructure system. Revenue and related costs for master and other service agreements billed on a time and materials basis are recognized as the services are rendered. The Company also performs services under master and other service agreements on a fixed fee basis, under which MasTec furnishes specified units of service for a fixed price per unit of service and revenue is recognized as the services are rendered. Revenues from fixed price contracts provide for a fixed amount of revenue for the entire project, subject to certain additions for changed scope or specifications. Revenues from these contracts are recognized using the percentage-of-completion method. Under this method, the percentage of revenue to be recognized for a given project is measured by the percentage of costs incurred to date on the contract to the total estimated costs for the contract. Such contracts provide that the customer accept completion of progress to date and compensate the Company for services rendered, which may be measured in terms of costs incurred, units installed, hours expended or some other measure of progress.
	The Company may incur costs subject to change orders, whether approved or unapproved by the customer, and/or claims related to certain contracts. Management determines the probability that such costs will be recovered based upon evidence such as engineering studies and legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer. The Company treats project costs as a cost of contract performance in the period incurred if it is not probable that the costs will be recovered, or defers costs and/or recognizes revenue up to the amount of the related cost if it is probable that the contract price will be adjusted and can be reliably estimated. As of September 30, 2014 and December 31, 2013, the Company had approximately $78 million and $79 million, respectively, of change orders and/or claims that had been included as contract price adjustments on certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, in arbitration and other proceedings. These contract price adjustments represent management's best estimate of additional contract revenues that have been or will be earned and that management believes are probable of collection. The amounts ultimately realized upon final acceptance by its customers could be higher or lower than such estimated amounts, which are primarily expected to be billed and collected within one year.
	Except for adoption of the accounting pronouncement 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, 2013.
	New Accounting Pronouncements
	Accounting Standards Not Yet Adopted
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of this ASU is that a company will recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under current guidance and will be required to disclose information about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including disclosure of assumptions and estimates where significant judgment has been applied. ASU 2014-09 is effective using either the retrospective or cumulative effect transition method for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early application is not permitted. The Company is currently evaluating the potential impact of this ASU on its consolidated financial statements.
	In April 2014, the FASB issued ASU 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (“ASU 2014-08”). ASU 2014-08 changes the requirements for reporting discontinued operations and requires additional disclosures about discontinued operations. Only disposals of components of an entity representing a strategic shift that has, or will have, a major effect on an entity’s operations and financial results should be reported as discontinued operations under ASU 2014-08. Examples include a disposal of a major geographical area, a major line of business, or a major equity method investment. ASU 2014-08 also requires expanded disclosures about discontinued operations and requires disclosures about individually significant dispositions that do not qualify as discontinued operations. ASU 2014-08 is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014. Early adoption is permitted only for disposals that have not been previously reported. The Company is currently evaluating the potential impact of this ASU on its consolidated financial statements.
	Recently Adopted Accounting Pronouncements
	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 adopted ASU 2013-11 as of January 1, 2014. The adoption of this ASU did not have a material impact on the condensed unaudited consolidated financial statements.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Note 2 – Earnings Per Share
	Basic earnings per share is computed by dividing earnings available to MasTec’s common shareholders by the weighted average number of common shares outstanding for the period. Diluted earnings per share is computed by dividing earnings by the number of fully diluted shares, which includes the effect of dilutive potential issuances of common shares as determined using earnings from continuing operations. The potential issuance of common shares upon the exercise, conversion or vesting of outstanding stock options and unvested restricted share awards, as calculated under the treasury stock method, as well as shares associated with the Company’s outstanding convertible debt securities, may be dilutive.
	The following table provides details underlying the Company’s earnings per share calculations for the periods indicated (in thousands):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2014			2013			2014			2013
	Net income attributable to MasTec:
	Net income, continuing operations - basic (a)	$	45,591		$	49,960		$	93,936		$	104,702
	Interest expense, net of tax, 2009 Convertible Notes	20			79			166			236
	Net income, continuing operations - diluted	$	45,611		$	50,039		$	94,102		$	104,938
	Net loss from discontinued operations - basic and diluted (a)	(320		)	(3,822		)	(592		)	(5,253		)
	Net income attributable to MasTec - diluted	$	45,291		$	46,217		$	93,510		$	99,685
	Weighted average shares outstanding:
	Weighted average shares outstanding - basic	81,811			77,093			79,158			76,816
	Dilutive common stock equivalents	814			775			798			774
	Dilutive premium shares, 2011 Convertible Notes	3,005			6,790			5,900			6,337
	Dilutive shares, 2009 Convertible Notes	194			806			560			806
	Weighted average shares outstanding - diluted	85,824			85,464			86,416			84,733
	(a)	Calculated as total net income (loss) less amounts attributable to non-controlling interests.
	Outstanding Convertibles Notes - Diluted Share Impact
	As of September 30, 2014, the Company had $100 million aggregate principal amount of 4.25% senior convertible notes outstanding (the "4.25% Convertible Notes"), composed of $97.0 million of 4.25% Convertible Notes issued in 2011 (the “2011 4.25% Notes”) and approximately $3.0 million of 4.25% Convertible Notes issued in 2009 (the “2009 4.25% Notes”). In June 2014, $115 million aggregate principal amount of 4.0% senior convertible notes (the "4.0% Convertible Notes") matured, at which time the holders elected to convert the notes and the Company paid $105.3 million in cash and issued 4.2 million shares of common stock in respect of such notes. The 4.0% Convertible Notes were composed of $105.3 million of 4.0% Convertible Notes issued in 2011 (the "2011 4.0% Notes") and approximately $9.6 million of 4.0% Convertible Notes issued in 2009 (the "2009 4.0% Notes"). The 2009 4.0% Notes and the 2009 4.25% Notes are collectively referred to as the "2009 Convertible Notes," and the 2011 4.0% Notes and the 2011 4.25% Notes are collectively referred to as the "2011 Convertible Notes." See Note 9 - Debt for additional information.
	Dilutive shares associated with the 2009 Convertible Notes are attributable to the underlying principal amounts. The number of common shares issuable upon conversion of the Company’s 2009 Convertible Notes is reflected in the calculation of weighted average diluted earnings per share for the corresponding periods by application of the “if-converted” method to the extent its effect on the computation of earnings per share from continuing operations is dilutive. Under the “if-converted” method, net income from continuing operations is adjusted to add back the after-tax amount of interest recognized for the period associated with the 2009 Convertible Notes, and correspondingly, the 2009 Convertible Notes are assumed to have been converted, with the resulting common shares added to the number of weighted average shares outstanding. The 2011 Convertible Notes have an optional cash settlement feature under which, in June 2014, the Company settled the principal amount of the 2011 4.0% Notes in cash, and the Company intends to settle the principal amount of the 2011 4.25% Notes in cash in December 2014. Given the Company's intention, dilutive shares associated with the 2011 Convertible Notes are derived from the premium value of the notes in excess of their principal amount, calculated using the treasury stock method. The Company refers to these shares as the "premium shares."
	The 2011 4.0% Notes, which were settled in June 2014, were convertible at $15.76 per share, and the 2011 4.25% Notes, which mature in December 2014, are convertible at $15.48 per share. The calculations underlying the number of premium shares included in the Company’s diluted share count for the periods indicated are as follows (in thousands, except per share amounts):
		As of and for the Three Months										As of and for the Nine Months
		Ended September 30,										Ended September 30,
		2014				2013						2014			2013
	Premium Share Information:		2011 4.25%			2011 4.0%			2011 4.25%				2011 4.25%		2011 4.0%		2011 4.25%
			Notes			Notes			Notes				Notes		Notes		Notes
	Number of conversion shares, principal amount		6,268			6,683			6,268				6,268		6,683		6,268
	Per share price, actual average		$	29.73		$	32.84		$	32.84			$	35.06	$	30.59	$	30.59
	Premium value		$	89,341		$	114,176		$	108,864			$	122,748	$	99,104	$	94,728
	Premium shares		3,005			3,476			3,314				3,501		3,240		3,097
	In addition to the premium shares described above, there were 2.4 million equivalent premium shares included in the Company's dilutive share calculation for the nine month period ended September 30, 2014 related to the 2011 4.0% Notes, as calculated based on the average price per share of the Company's common stock from the beginning of the period through June 15, 2014, the date of maturity.
	Diluted Shares, Other Information
	A total of 304,486 and 223,422 weighted average anti-dilutive common stock equivalents were not included in the Company's diluted earnings per share calculations for the three and nine month periods ended September 30, 2014, respectively. For the three and nine month periods ended September 30, 2013, there were no anti-dilutive common stock equivalents.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	Note 3 – Acquisitions
	Allocations of purchase prices for acquisitions are based on estimates of the fair value of consideration paid and of the net assets acquired and are subject to adjustment upon finalization of these fair value estimates. The Company acquired several businesses during 2013 and 2014, as discussed below and in Note 3 - Acquisitions in the notes to the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2013. As of September 30, 2014, the allocations of purchase price to the fair values of tangible and intangible assets and liabilities, including the estimated values of contingent earn-out obligations and the estimated useful lives of acquired assets for the Company's 2014 acquisitions are provisional and remain preliminary. Management continues to assess the valuation of these items and any ultimate purchase price adjustments that may result based on the final net assets and net working capital of the acquired businesses, as prescribed in the corresponding purchase agreements.
	The Company will revise its preliminary allocations for acquired businesses if new information is obtained about the facts and circumstances existing as of the date of acquisition, or for purchase price adjustments, based on the final net assets and net working capital of the acquired businesses, as prescribed in the applicable purchase agreement. Such adjustments result in the recognition of, or adjust the fair values of, acquired assets and assumed liabilities, and are presented as if the adjustments had been taken into account as of the date of acquisition, which results in the revision of comparative prior period financial information. All changes that do not qualify as measurement period adjustments are included in current period results. See table below for measurement period adjustments relating to balances as previously disclosed.
	2014 Acquisitions
	Pacer
	Effective June 1, 2014, MasTec acquired all of the issued and outstanding equity interests of Pacer Construction Holdings Corporation and its affiliated operating companies (collectively, "Pacer"). Pacer is a western Canadian civil construction services company, headquartered in Calgary, Alberta, Canada.  Pacer’s services include infrastructure construction primarily in support of oil and gas production, processing, mining and transportation. Pacer, a leading contractor in the Canadian oil sands, is expected to significantly enhance MasTec's ability to lead the development of energy infrastructure work in western Canada and take advantage of the associated rapidly expanding opportunities anticipated for energy infrastructure work in North America in the coming years. Pacer is reported within the Company's Oil and Gas segment.
	The following table summarizes the preliminary estimated fair values of consideration paid and identifiable assets acquired and liabilities assumed, as adjusted, as of the date of acquisition (in millions):
	Acquisition consideration:	1-Jun-14
	Cash	$	126.5
	Fair value of contingent consideration (earn-out liability)	25.7
	Total consideration transferred	$	152.2
	Identifiable assets acquired and liabilities assumed:
	Current assets	$	118.4
	Equity method investments	2.3
	Other long-term assets	0.1
	Property and equipment	72.8
	Pre-qualifications	41.2
	Finite-lived intangible assets	20.3
	Current liabilities	(55.8		)
	Long-term debt	(87.0		)
	Deferred income taxes	(29.6		)
	Total identifiable net assets	$	82.7
	Goodwill	$	69.5
	Total net assets acquired, including goodwill	$	152.2
	As a result of the ongoing review of the acquired net working capital and acquired net assets of Pacer, in the third quarter of 2014, the Company recorded a $9.8 million reduction of certain long-term assets, a $7.8 million increase in pre-acquisition liabilities, a $2.7 million increase in intangible assets and a $1.4 million increase to the contingent earn-out liability. These adjustments resulted in a $16.6 million increase to the previously recorded amount of goodwill associated with the Pacer acquisition.
	The fair values and weighted average useful lives of Pacer's acquired finite-lived intangible assets, as adjusted, as of the date of acquisition were assigned as follows:
		Fair Value			Weighted Average Useful Life
	Finite-lived intangible assets:	(in millions)			(in years)
	Backlog	$	6.1		2
	Non-compete agreements	2.3			8
	Customer relationships	11.9			8
	Total acquired finite-lived intangible assets	$	20.3		6
	Finite-lived intangible assets will be amortized in a manner consistent with the pattern in which the related benefits are expected to be consumed. The intangible asset related to Pacer's pre-qualifications with selected customer companies has been assigned an indefinite life as the pre-qualifications are not expected to expire or diminish in value, and the companies to which they relate have extremely long operating histories. Goodwill arising from the acquisition represents the estimated value of Pacer's geographic presence in key high-growth Canadian markets, its assembled workforce, its management team's industry-specific project management expertise and synergies expected to be achieved from the combined operations of Pacer and MasTec. The goodwill balance is not tax deductible.
	The values of certain of the assets acquired and liabilities assumed include the proportionate values of Pacer’s undivided interest in an unincorporated contractual joint venture, which provides civil construction services and is accounted for on a proportional basis. The equity method investments identified in the table above represent investments in entities that provide heavy civil construction services. For the three and nine month periods ended September 30, 2014, revenue recognized by the Company for infrastructure construction services on behalf of these business entities totaled $2.0 million and $3.0 million, respectively. As of September 30, 2014, receivables from infrastructure construction services provided by Pacer, including acquired receivables, totaled $2.5 million. Other amounts due Pacer from its equity method investees and contractual joint venture as of September 30, 2014 included aggregate financing receivables of $14.8 million, which is included in other current assets. In connection with these business entities, there are performance guarantees, for which Pacer is obligated on a joint and several basis with its other joint venture partners or other shareholders in such entities, of a gross amount of approximately $219.0 million ($92.0 million based on ownership percentage) on the full contract value of certain projects. These projects are in varying stages of completion as of September 30, 2014. There are also approximately $31.0 million of other financial guarantees associated with these entities for which Pacer is obligated on a joint and several basis. The Company believes these receivables and guarantees represent variable interests; however, Pacer does not have the power to control the primary activities of, nor is it the primary beneficiary of, these business entities. The Company may provide financial support to these business entities in the future.
	The contingent consideration included in the table above is equal to 25% of the excess, if any, of Pacer’s earnings from continuing operations before interest, taxes, depreciation and amortization (“EBITDA”) above certain thresholds for a five-year period, as set forth in the purchase agreement, and is payable annually in Canadian dollars. The fair value of the earn-out liability was estimated using an income approach and incorporates significant inputs not observable in the market. Key assumptions in the estimated valuation include the discount rate and probability-weighted EBITDA projections. The range of potential undiscounted payments that MasTec could be required to make under the earn-out arrangement is estimated to be between $0 and $69 million U.S. dollars; however, there is no maximum earn-out payment amount.
	Other 2014 Acquisitions
	Effective April 1, 2014, MasTec acquired 100% of a telecommunications services firm that specializes in the installation of in-home security systems for an aggregate purchase price composed of approximately $17.2 million in cash and a five year earn-out, valued at $0.6 million as of the date of acquisition. Additionally, effective January 1, 2014, MasTec acquired 100% of a telecommunications services firm that specializes in the engineering, installation, furnishing and integration of telecommunications equipment for an aggregate purchase price composed of approximately $23.8 million in cash and a five year earn-out, valued at $8.7 million as of the date of acquisition. These companies are included in MasTec's Communications segment.
	2013 Acquisitions
	Effective May 1, 2013, MasTec acquired all of the issued and outstanding interests of Big Country Energy Services, Inc. and its affiliated operating companies (collectively, "Big Country"). Big Country, which is included in the Company's Oil and Gas segment, is a North American oil and gas pipeline and facility construction services company, headquartered in Calgary, Alberta, Canada. In addition, effective April 1, 2013, MasTec acquired a former subcontractor to its wireless business, which provides self-perform communications tower construction, installation, maintenance and other services in support of telecommunications infrastructure construction in the Company's Communications segment. MasTec also acquired, effective August 1, 2013, an electrical transmission services company that provides substation construction activities. This company is included within the Company's Electrical Transmission segment.
	Measurement Period Adjustments
	Measurement period adjustments associated with the Company's 2013 acquisitions have been reflected as follows (in millions):
	As of December 31, 2013:		As Previously Reported			Measurement Period Adjustments				As Revised
	Current assets		$	1,306.00		$	1			$	1,307.00
	Goodwill		$	899.4		$	2.6			$	902
	Current liabilities		$	825.5		$	3.7			$	829.2
	Long-term deferred tax liabilities, net		$	154.9		$	(0.1	)		$	154.8
	Unaudited Pro Forma Information
	The following unaudited supplemental pro forma financial information includes the results of operations of each of the companies acquired in 2014 and 2013 and is presented as if the acquired companies had been consolidated as of the beginning of the year immediately preceding the year in which the company was acquired. The unaudited supplemental pro forma financial information has been provided for illustrative purposes only. The unaudited supplemental pro forma financial information does not purport to be indicative of the actual results that would have been achieved by the combined companies for the periods presented, or of the results that may be achieved by the combined companies in the future. Future results may vary significantly from the results reflected in the following unaudited supplemental pro forma financial information because of future events and transactions, as well as other factors, many of which are beyond MasTec’s control.
	The unaudited supplemental pro forma financial information presented below has been prepared by adjusting the historical results of MasTec to include the historical results of the acquired businesses described above. The unaudited supplemental pro forma combined historical results were then adjusted (i) to remove one-time acquisition costs; (ii) to increase amortization expense resulting from the incremental intangible assets acquired in such acquisitions; (iii) to increase interest expense as a result of the cash consideration paid; and (iv) to reduce interest expense from the repayment of acquired debt. The unaudited supplemental pro forma financial information does not include any adjustments to reflect the impact of cost savings or other synergies that may result from these acquisitions. As noted above, the unaudited supplemental pro forma financial information does not purport to be indicative of the actual results that would have been achieved by the combined companies for the periods presented or that may be achieved by the combined companies in the future.
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2014			2013				2014			2013
	Pro forma financial information:	(unaudited, in millions)							(unaudited, in millions)
	Revenue	$	1,309.60		$	1,417.50			$	3,496.00		$	3,667.30
	Net income from continuing operations	$	46		$	52.4			$	96.5		$	118
	Results of Businesses Acquired
	Revenues and net income resulting from the year over year incremental impact of acquired businesses, which are included within the Company's consolidated results of operations for the periods indicated, were as follows:
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2014			2013				2014			2013
	Actual of acquiree (year over year impact):	(unaudited, in millions)							(unaudited, in millions)
	Revenue	$	133.2		$	141.6			$	342.5		$	270.4
	Net income from continuing operations (a)	$	2.3		$	7.5			$	4.5		$	12.8
	(a)	The above results do not include acquisition costs totaling $0.4 million and $0.3 million for the three month periods ended September 30, 2014 and 2013, respectively, and $2.0 million and $1.6 million for the nine month periods ended September 30, 2014 and 2013, respectively. Acquisition costs are included within general and administrative costs in the Company's consolidated unaudited statements of operations. The above results also do not include interest expense associated with consideration paid for these acquisitions.

Discontinued_Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Note 4 – Discontinued Operations
	Globetec
	In 2012, the Company's board of directors approved a plan of sale for Globetec Construction, LLC ("Globetec"). Accordingly, Globetec's projects and assets are reflected as assets and liabilities of discontinued operations, and Globetec's results of operations are presented as discontinued operations in the condensed unaudited consolidated financial statements for all periods presented. Effective August 31, 2013, the Company sold all of its membership interests in Globetec for nominal consideration and retained certain contingent assets and liabilities. As of September 30, 2014, the Company had certain outstanding surety bonds associated with Globetec, for which the work had been substantially completed, and for which the Company believes there was an insignificant amount at risk. The Company is not obligated to support, and does not intend to support, Globetec in the future.
	The following table contains a summary of the contingent assets and liabilities associated with Globetec that were retained by the Company as of September 30, 2014 and as of December 31, 2013 (in millions):
		September 30,			December 31,
		2014			2013
	Current assets	$	5		$	2.3
	Long-term assets	7.1			10.1
	Assets of discontinued operations	$	12.1		$	12.4
	Current liabilities of discontinued operations	$	1.2		$	1.2
	The following table presents Globetec's results from discontinued operations for the periods indicated (in millions):
		For the Three Months Ended September 30, 2013			For the Nine Months Ended September 30, 2013
	Revenue	$	4.8		$	18
	Loss from operations, before tax	(0.5		)	(2.7		)
	Impairment of assets, before tax	(5.7		)	(6.0		)
	Income tax benefit	2.5			3.5
	Net loss from discontinued operations	$	(3.7	)	$	(5.2	)

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Other Intangible Assets	'
	Note 5 - Goodwill and Other Intangible Assets
	The following table provides a reconciliation of changes in goodwill by reportable segment (in millions):
		Communications			Oil and Gas				Electrical				Power				Total Goodwill
									Transmission				Generation and Industrial
	Balance as of December 31, 2013	$	326.8		$	307.7			$	149.9			$	117.6			$	902
	Additions from new business combinations	28.6			69.5				—				—				98.1
	Accruals of acquisition-related contingent consideration, net (a)	4.6			—				—				—				4.6
	Currency translation adjustments	—			(4.7		)		—				—				(4.7		)
	Balance as of September 30, 2014	$	360		$	372.5			$	149.9			$	117.6			$	1,000.00
	(a)	Represents contingent consideration for acquisitions prior to January 1, 2009, which is accrued as earned, in accordance with U.S. GAAP.
	The following table provides a reconciliation of changes in other intangible assets (in millions):
			Other Intangible Assets
			Non-amortizing							Amortizing
			Trade Names			Pre-Qualifications				Customer Relationships and Backlog				Other (a)				Total
	Gross carrying amount as of December 31, 2013		$	34.8		$	59.4			$	128.4			$	22.5			$	245.1
	Accumulated amortization									$	(67.7	)		$	(11.8	)		$	(79.5	)
	Other intangible assets, net, as of December 31, 2013		$	34.8		$	59.4			$	60.7			$	10.7			$	165.6
	Additions from new business combinations		—			41.2				33.1				2.7				77
	Amortization expense									(15.7		)		(1.3		)		(17.0		)
	Currency translation adjustments		—			(2.6		)		(0.8		)		—				(3.4		)
	Other intangible assets, net, as of September 30, 2014		$	34.8		$	98			$	77.3			$	12.1			$	222.2
	(a)	Consists principally of amortizing trade names and non-compete agreements.
	Amortization expense associated with intangible assets for the three month periods ended September 30, 2014 and 2013 totaled $6.6 million and $5.8 million, respectively, and totaled $17.0 million and $15.2 million, respectively, for the nine month periods ended September 30, 2014 and 2013.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	Note 6 – Fair Value of Financial Instruments
	The Company’s financial instruments include cash and cash equivalents, accounts and notes receivable, cash collateral deposited with insurance carriers, life insurance assets, cost and equity method investments, deferred compensation plan assets and liabilities, accounts payable and other current liabilities, acquisition-related contingent consideration and debt obligations.
	Fair value is the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value guidance establishes a valuation hierarchy, which requires maximizing the use of observable inputs when measuring fair value. The three levels of inputs that may be used are: (i) Level 1 - quoted market prices in active markets for identical assets or liabilities; (ii) Level 2 - observable market based inputs or other observable inputs; and (iii) Level 3 - significant unobservable inputs that cannot be corroborated by observable market data, which are generally determined using valuation models incorporating management’s estimates of market participant assumptions.
	In instances in which the inputs used to measure fair value fall into different levels of the fair value hierarchy, the fair value measurement classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety.  Management’s assessment of the significance of a particular item to the fair value measurement in its entirety requires judgment, including the consideration of inputs specific to the asset or liability.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	As of September 30, 2014, financial instruments required to be measured at fair value on a recurring basis consisted primarily of acquisition-related contingent consideration. This acquisition-related contingent consideration represents the estimated fair value of additional future earn-outs payable for acquisitions of businesses that closed after January 1, 2009, in accordance with U.S. GAAP ("ASC 805 contingent consideration"). The fair value of the Company's ASC 805 contingent consideration, which was determined using Level 3 inputs, totaled $149.6 million and $165.4 million, respectively, as of September 30, 2014 and December 31, 2013. The fair value of ASC 805 contingent consideration is based on management estimates and entity-specific assumptions and is evaluated on an on-going basis.
	There were no additions to ASC 805 contingent consideration from new business combinations for the three month period ended September 30, 2014. Additions to ASC 805 contingent consideration totaled $35.0 million for the nine month period ended September 30, 2014, and totaled $3.3 million and $30.0 million for the three and nine month periods ended September 30, 2013, respectively. The Company paid approximately $1.3 million and $48.3 million of ASC 805 contingent consideration for the three and nine month periods ended September 30, 2014, respectively. There were no ASC 805 contingent consideration payments made for the three month period ended September 30, 2013. For the nine month period ended September 30, 2013, the Company paid approximately $2.7 million of ASC 805 contingent consideration. Foreign currency translation gains and/or losses associated with ASC 805 contingent consideration are included in other comprehensive income. For the three and nine month periods ended September 30, 2014, foreign currency translation gains associated with ASC 805 contingent consideration totaled $2.9 million and $2.5 million, respectively. For the three month period ended September 30, 2013, foreign currency translation losses associated with ASC 805 contingent consideration totaled $0.7 million, and for the nine month period ended September 30, 2013, foreign currency translation gains associated with ASC 805 contingent consideration totaled $1.1 million.
	Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis
	Assets and liabilities recognized or disclosed at fair value on a non-recurring basis, which are initially measured at fair value, and are subsequently remeasured in the event of an impairment or other measurement event, if applicable, include items such as cost and equity method investments, life insurance assets, long-lived assets, goodwill, other intangible assets and debt.
	Carrying amounts and estimated fair values of selected financial instruments measured on a non-recurring basis as of the dates indicated were as follows (in millions):
		September 30, 2014				December 31, 2013
		Carrying		Fair		Carrying		Fair
		Amount		Value		Amount		Value
	4.875% Senior Notes	$	400	$	377	$	400	$	380
	2009 Convertible Notes	$	3	$	5.9	$	12.6	$	26.6
	2011 Convertible Notes	$	97	$	192.1	$	198.3	$	428.3
	The estimated fair values of the Company’s 4.875% Senior Notes, 2009 Convertible Notes and 2011 Convertible Notes are based on quoted market prices, a Level 1 input.
	Cost and Equity Method Investments. The aggregate carrying value of the Company's cost and equity method investments, including long-term receivables from investees and contractual joint ventures, totaled approximately $15.0 million and $15.8 million as of September 30, 2014 and December 31, 2013, respectively. The fair values of the Company's cost and equity method investments are not readily available nor has the Company estimated the fair value of these investments. The Company is not aware of any events or changes in circumstance that would have a significant adverse effect on the carrying value of its cost or equity method investments as of September 30, 2014 or December 31, 2013.

Accounts_Receivable_Net_of_All

Accounts Receivable, Net of Allowance	9 Months Ended
	Sep. 30, 2014
Receivables [Abstract]	'
Accounts Receivable, Net of Allowance	'
	Note 7 - Accounts Receivable, Net of Allowance
	The following table provides details of accounts receivable, net of allowance, as of the dates indicated (in millions):
		September 30,			December 31,
		2014			2013
	Contract billings	$	775.6		$	606.5
	Retainage	179.3			159.3
	Costs and earnings in excess of billings	451.7			384.6
	Accounts receivable, gross	$	1,406.60		$	1,150.40
	Less allowance for doubtful accounts	(16.7		)	(15.7		)
	Accounts receivable, net	$	1,389.90		$	1,134.70
	Provisions for doubtful accounts for the three month periods ended September 30, 2014 and 2013 totaled $0.3 million and $1.9 million, respectively, and totaled $1.1 million and $4.4 million, respectively, for the nine month periods ended September 30, 2014 and 2013.

Property_and_Equipment_Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Property and Equipment, Net	'
	Note 8 - Property and Equipment, Net
	The following table provides details of property and equipment, net, including property and equipment held under capital leases as of the dates indicated (in millions):
		September 30,			December 31,
		2014			2013
	Land	$	4.6		$	4.8
	Buildings and leasehold improvements	19.2			18
	Machinery and equipment	901.6			727.1
	Office furniture and equipment	118.1			102.5
	Construction in progress	17.2			11
	Total property and equipment	$	1,060.70		$	863.4
	Less accumulated depreciation and amortization	(446.3		)	(375.3		)
	Property and equipment, net	$	614.4		$	488.1
	Depreciation and amortization expense associated with property and equipment for the three month periods ended September 30, 2014 and 2013 totaled $35.2 million and $32.0 million, respectively, and totaled $95.0 million and $87.9 million, respectively, for the nine month periods ended September 30, 2014 and 2013.

Debt

Debt	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Debt	'
	Note 9 - Debt
	The following table provides details of the carrying values of long-term debt as of the dates indicated (in millions):
	Description		Maturity Date		September 30,			December 31,
					2014			2013
	Senior secured credit facility		October 29, 2018		$	449.5		$	53
	4.875% senior notes		March 15, 2023		400			400
	2011 4.0% senior convertible notes		June 15, 2014		—			103.8
	2011 4.25% senior convertible notes		December 15, 2014		96.4			94.5
	2009 4.0% senior convertible notes		June 15, 2014		—			9.6
	2009 4.25% senior convertible notes		December 15, 2014		3			3
	Other credit facilities		Varies		4.8			—
	Capital lease obligations, weighted average interest rate of 2.8%		In installments through June 13, 2021		163.6			126
	Notes payable, equipment, weighted average interest rate of 2.9%		In installments through September 1, 2018		42.8			26.9
	Total debt				$	1,160.10		$	816.8
	Less current maturities				(71.8		)	(51.4		)
	Long-term debt				$	1,088.30		$	765.4
	Senior Secured Credit Facility
	In June 2014, the Company amended its senior secured credit facility, referred to as the Credit Facility, to increase aggregate borrowing commitments from $750 million to $1 billion, add the capability to borrow in Mexican pesos in addition to Canadian dollars, and increase the maximum amount that can be borrowed in alternate currencies to $200 million from $100 million. The amended Credit Facility, which matures on October 29, 2018, has an accordion feature permitting the Company to increase revolving commitments and/or establish additional term loan tranches in an aggregate amount of up to $250 million. As of September 30, 2014 and December 31, 2013, the Company had outstanding revolving loans under the Credit Facility of $449.5 million and $53.0 million, respectively, which accrued interest at weighted average rates of approximately 2.12% and 2.14% per annum, respectively. Letters of credit of approximately $135.6 million and $134.8 million were issued as of September 30, 2014 and December 31, 2013, respectively. As of September 30, 2014, interest on letters of credit accrued at 0.875% per annum for performance standby letters of credit and at 1.75% per annum for financial standby letters of credit. As of December 31, 2013, interest on letters of credit accrued at 0.75% per annum for performance standby letters of credit and at 1.5% per annum for financial standby letters of credit. Outstanding letters of credit mature at various dates and most have automatic renewal provisions, subject to prior notice of cancellation. As of September 30, 2014 and December 31, 2013, the remaining borrowing capacity of the Company's Credit Facility of $262.5 million and $562.1 million, respectively, was available for revolving loans, or up to $262.5 million and $315.2 million, respectively, of new letters of credit. Total remaining borrowing capacity as of September 30, 2014 included a temporary reduction of approximately $152 million, which will be restored once the Company's 4.25% Convertible Notes mature and are repaid or converted in December 2014. The unused facility fee was 0.35% and 0.30% as of September 30, 2014 and December 31, 2013, respectively. The Credit Facility is guaranteed by certain subsidiaries of the Company.
	Other Credit Facilities. To support the working capital requirements of its foreign operations, primarily in Canada, the Company has entered into certain other credit facilities. Borrowings under these other credit facilities are primarily denominated in Canadian dollars. As of September 30, 2014, the Company had maximum borrowing capacity under these credit facilities of $35.0 million Canadian dollars, or approximately $31.3 million U.S. dollars. Outstanding borrowings totaled approximately $5.4 million Canadian dollars, or approximately $4.8 million U.S. dollars, as of September 30, 2014, and accrued interest at a weighted average rate of 4.00%. The Company's other credit facilities, which have varying dates of maturity through March 3, 2015, are generally renewed on an annual basis. Outstanding borrowings under the Company's other credit facilities that are not renewed are repaid with borrowings under the Credit Facility. Accordingly, the carrying amounts of the Company's borrowings under other credit facilities are classified within long-term debt in the Company's condensed unaudited consolidated balance sheet as of September 30, 2014. The Company's other credit facilities are subject to customary provisions and covenants.
	Senior Convertible Notes
	The Company's 4.0% Convertible Notes, composed of $105.3 million principal amount of 2011 4.0% Notes and $9.6 million principal amount of 2009 4.0% Notes, matured and were converted in June 2014. The 2009 4.0% Notes were convertible at a rate of 63.4417 shares of MasTec common stock per $1,000 principal amount thereof, representing an initial conversion price of approximately $15.76 per share, resulted in MasTec issuing an aggregate of 0.6 million shares of its common stock. The 2011 4.0% Notes were substantially identical to the 2009 4.0% Notes, except that the 2011 4.0% Notes had an optional physical (share), cash or combination settlement feature. In accordance with the Company's previously stated intent, it settled the principal amount of the 2011 4.0% Notes in cash, using proceeds from the Credit Facility, and the premium value in shares of common stock. Pursuant to the formula contained in the indenture governing the 2011 4.0% Notes, the Company issued 3.6 million shares of common stock to settle the premium value of the 2011 4.0% Notes. The value of the shares issued to settle the premium was $114.8 million, based on the closing price of the Company's common stock on the date the shares were issued. The 4.2 million aggregate shares issued in settlement of the 4.0% Convertible Notes were issued from the Company's treasury stock. See Note 13 - Equity.
	The 4.25% Convertible Notes mature in December 2014. The Company expects to settle the principal amount of its 2011 4.25% Notes on a long-term basis with proceeds from the Credit Facility, or through other sources of available funding, and the premium value in shares, consistent with the settlement of the 2011 4.0% Notes in June 2014. Therefore, the Company has reflected the carrying amounts of these notes within long-term debt in the condensed unaudited consolidated balance sheets. Unamortized debt discount and financing costs associated with the 2011 4.25% Notes totaled $0.6 million as of September 30, 2014. Unamortized debt discount and financing costs associated with both the 2011 4.25% Notes and the 2011 4.0% Notes totaled $4.0 million as of December 31, 2013.
	Debt Guarantees and Covenants
	The Company’s 4.875% Senior Notes, 2011 Convertible Notes and 2009 Convertible Notes are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company's existing and future 100%-owned direct and indirect domestic subsidiaries that are guarantors of the Credit Facility or other outstanding indebtedness. See Note 18 - Supplemental Guarantor Condensed Unaudited Consolidating Financial Information.
	MasTec was in compliance with the provisions and covenants of its outstanding debt instruments as of September 30, 2014 and December 31, 2013.
	Interest Expense, Net
	The following table provides details of interest expense, net, for the periods indicated (in millions):
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2014				2013			2014			2013
	Interest expense:
	Contractual and other interest expense	$	11.3			$	10.4		$	31.6		$	27.9
	Accretion of senior convertible note discount	0.6				1.3			3.4			3.9
	Amortization of deferred financing costs	0.8				1			2.7			3
	Total interest expense	$	12.7			$	12.7		$	37.7		$	34.8
	Interest income	(0.1		)		—			(0.1		)	(0.3		)
	Interest expense, net	$	12.6			$	12.7		$	37.6		$	34.5
	For additional information regarding the Company's debt instruments, see Note 9 - Debt in the notes to the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2013.

Lease_Obligations

Lease Obligations	9 Months Ended
	Sep. 30, 2014
Leases [Abstract]	'
Lease Obligations	'
	Note 10 - Lease Obligations
	Capital Leases
	MasTec enters into agreements that provide financing for machinery and equipment, which expire on various dates. The gross amount of assets held under capital leases as of September 30, 2014 and December 31, 2013 totaled $276.2 million and $199.6 million, respectively. Assets held under capital leases, net of accumulated depreciation, totaled $203.7 million and $141.3 million as of September 30, 2014 and December 31, 2013, respectively.
	Operating 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. Rent expense relating to operating leases that have non-cancelable terms in excess of one year was approximately $18.1 million and $12.7 million for the three month periods ended September 30, 2014 and 2013, respectively, and $51.5 million and $37.1 million for the nine month periods ended September 30, 2014 and 2013, respectively. The Company also incurred expenses relating to facilities, vehicles and equipment having original terms of one year or less of approximately $54.5 million and $63.0 million for the three month periods ended September 30, 2014 and 2013, respectively, and $142.6 million and $138.9 million for the nine month periods ended September 30, 2014 and 2013, respectively.

StockBased_Compensation_and_Ot

Stock-Based Compensation and Other Employee Benefit Plans	9 Months Ended
	Sep. 30, 2014
Share-based Compensation [Abstract]	'
Stock-Based Compensation and Other Employee Benefit Plans	'
	Note 11 – Stock-Based Compensation and Other Employee Benefit Plans
	The Company has stock-based compensation plans, under which stock options and restricted share awards are available for issuance or outstanding. Under stock-based compensation plans in effect as of September 30, 2014, there were a total of 6,193,235 shares available for grant or issuance.
	Restricted Share Awards
	MasTec grants restricted share awards, which are valued based on the market price of MasTec common stock on the date of grant. Total unearned compensation related to restricted share awards as of September 30, 2014 was approximately $16.0 million, which is expected to be recognized over a weighted average period of approximately 1.1 years. The intrinsic value, or fair value, of restricted share awards that vested, which is based on the market price on the date of vesting, totaled $1.1 million and $0.9 million for the three month periods ended September 30, 2014 and 2013, respectively, and totaled $7.1 million and $2.0 million for the nine month periods ended September 30, 2014 and 2013, respectively.
	Activity, restricted share awards:	Restricted		Per Share Weighted Average Grant Date Fair Value
		Shares
	Non-vested restricted shares, as of December 31, 2013	1,123,545		$	23.78
	Granted	323,249		41.05
	Vested	(181,195	)	20.26
	Canceled/forfeited	(22,442	)	17.38
	Non-vested restricted shares, as of September 30, 2014	1,243,157		$	28.9
	Stock Options
	The Company has granted options to purchase its common stock to employees and members of the Board of Directors and affiliates under various stock option plans. All outstanding stock options are fully vested.
	Activity, stock options:	Stock		Per Share Weighted Average			Weighted Average		Aggregate Intrinsic
		Options		Exercise Price			Remaining		Value (a)
							Contractual Life (in years)		(in millions)
	Options outstanding as of December 31, 2013	495,571		$	11.17		1.96		$	10.7
	Exercised	(210,900	)	9.97
	Canceled/forfeited	—		—
	Options outstanding as of September 30, 2014	284,671		$	12.06		1.54		$	5.3
	Options exercisable as of September 30, 2014	284,671		$	12.06		1.54		$	5.3
	(a)	Amount represents the difference between the exercise price and the market price of the Company’s stock on the last trading day of the corresponding period, multiplied by the number of in-the-money options.
	The total intrinsic value of options exercised was based on the difference between the exercise price and the market price of the Company’s stock on the date of exercise. During the three month period ended September 30, 2014, there were no options exercised. For the three month period ended September 30, 2013, the intrinsic value of options exercised totaled $4.6 million. The total intrinsic value of options exercised during the nine month periods ended September 30, 2014 and 2013 totaled $6.5 million and $10.4 million, respectively. Proceeds from options exercised during the three month period ended September 30, 2013 totaled $0.4 million. Proceeds from options exercised during the nine month periods ended September 30, 2014 and 2013 totaled $0.8 million and $3.8 million, respectively.
	Employee Stock Purchase Plans
	The Company's employee stock purchase plans allow qualified employees to purchase MasTec common stock at 85% of its fair market value at the lower of (i) the date of commencement of the offering period or (ii) the last day of the exercise period, as defined in the plan documents. The fair value of purchases under the Company's employee stock purchase plans is estimated using the Black-Scholes option-pricing valuation model.
		Nine Months Ended September 30,
	Activity, employee stock purchase plan:	2014			2013
	Cash proceeds (in millions)	$	2.5		$	6
	Common shares issued	94,761			436,925
	Weighted average per share price	$	26.6		$	13.69
	Weighted average per share grant date fair value	$	6.34		$	5.55
	Stock-Based Compensation Expense and Tax Benefits
	Details of stock-based compensation expense, which is included within general and administrative expense in the condensed unaudited consolidated statement of operations for the periods indicated are as follows (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Stock-based compensation expense	$	4.1		$	3		$	11.6		$	9.6
	Income Tax Effects:
	Income tax benefit from stock-based compensation	$	1.8		$	4.5		$	8.4		$	7.7
	Excess tax benefit from stock-based compensation (a)	$	0.1		$	3		$	3.5		$	4.4
	(a)	Excess tax benefits, which represent cash flows from tax deductions in excess of the recorded tax effect of compensation expense recognized for stock options exercised and vested restricted shares, are classified as financing cash flows in the Company’s condensed unaudited consolidated statements of cash flows.

Other_Retirement_Plans

Other Retirement Plans	9 Months Ended
	Sep. 30, 2014
Multiemployer Plans [Abstract]	'
Other Retirement Plans	'
	Note 12 – Other Retirement Plans
	Multi-Employer Plans. Certain of MasTec’s subsidiaries contribute amounts to multi-employer pension and other multi-employer benefit plans and trusts. Contributions are generally based on fixed amounts per hour per employee for employees covered under these plans. Multi-employer plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls. Union payrolls cannot be determined for future periods because the number of union employees employed at any given time, and the plans in which they may participate, vary depending upon the location and number of ongoing projects at a given time and the need for union resources in connection with those projects. Total contributions to multi-employer plans, and the related number of employees covered by these plans, for the periods indicated ranged as follows:
		Multi-Employer Plans
		Covered Employees		Contributions (in millions)
	For the Three Months Ended September 30:	Low	High	Pension		Post-Retirement Benefit		Total
	2014	2,029	2,167	$	11.6	$	1.1	$	12.7
	2013	2,392	2,734	$	14.9	$	1	$	15.9
	For the Nine Months Ended September 30:	Low	High	Pension		Post-Retirement Benefit		Total
	2014	1,098	2,167	$	27.3	$	2.5	$	29.8
	2013	778	2,734	$	30.2	$	3	$	33.2

Equity

Equity	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Equity	'
	Note 13 – Equity
	Share Activity (in thousands):	Common Shares			Treasury
		Outstanding			Shares
	Balance as of December 31, 2013	77,258			9,467
	Shares issued:
	Stock option exercises	211
	Restricted share awards	181
	Convertible notes	4,204			(4,204	)
	Other, net	(11	)
	Balance as of September 30, 2014	81,843			5,263
	In June 2014, the Company reissued a total of 4.2 million shares of its treasury stock, which had a cost basis of $66.6 million, related to the settlement of its 4.0% Convertible Notes. See Note 9 - Debt.
	Accumulated Other Comprehensive Loss
	Changes in accumulated other comprehensive loss by component during the periods indicated are as follows (in thousands):
		For the Nine Months Ended September 30,
		2014										2013
		Unrealized (Losses) Gains
		Foreign Currency				Other			Total			Foreign Currency			Other			Total
	Balance as of January 1	$	(7,998	)		$	(5,288	)	$	(13,286	)	$	(106	)	$	(5,395	)	$	(5,501	)
	Activity before reclassifications, net of tax	(10,601		)		—			(10,601		)	(3,839		)	(118		)	(3,957		)
	Reclassifications, net of tax	—				—			—			—			(440		)	(440		)
	Activity, net of tax	(10,601		)		—			(10,601		)	(3,839		)	(558		)	(4,397		)
	Balance as of September 30	$	(18,599	)		$	(5,288	)	$	(23,887	)	$	(3,945	)	$	(5,953	)	$	(9,898	)
	Foreign currency activity is primarily related to the Company's Canadian operations. The Company's Canadian presence has grown in recent years due to acquisitions. See Note 3 - Acquisitions.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Note 14 - Income Taxes
	The Company’s consolidated tax rates on income from continuing operations for the three month periods ended September 30, 2014 and 2013 were 38.0% and 38.8%, respectively, and for the nine month periods ended September 30, 2014 and 2013 were 38.0% and 38.6%, respectively. In determining the quarterly provision for income taxes, management uses an estimated annual effective tax rate based on forecasted annual pre-tax income, permanent tax differences, statutory tax rates and tax planning opportunities in the various jurisdictions in which the Company operates. The impact of significant discrete items is separately recognized in the quarter(s) in which they occur.
	As of September 30, 2014, the Company had $9.3 million of current deferred tax assets, net, and $180.4 million of long-term deferred tax liabilities, net. As of December 31, 2013, current deferred tax assets, net, totaled $16.3 million and long-term deferred tax liabilities, net, totaled $154.8 million.

Segments_and_Related_Informati

Segments and Related Information	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segments and Related Information	'
	Note 15 - Segments and Related Information
	Segment Discussion
	MasTec presents its continuing operations in five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial and (5) Other. This structure is generally focused on broad end-user markets for MasTec's labor-based construction services. All five reportable segments derive their revenues from the engineering, installation and maintenance of infrastructure, primarily in North America.
	The Communications segment performs engineering, construction and maintenance of communications infrastructure primarily related to wireless and wireline/fiber communications and install-to-the-home customers, and, to a lesser extent, infrastructure for electrical utilities. MasTec performs engineering, construction and maintenance services on oil and natural gas pipelines and processing facilities for the energy and utilities industries through its Oil and Gas segment. The Electrical Transmission segment primarily serves the energy and utility industries through the engineering, construction and maintenance of electrical transmission lines and substations. The Power Generation and Industrial segment primarily serves energy, utility and other end-markets through the installation and construction of conventional and renewable power facilities, related electrical transmission infrastructure, ethanol facilities and various types of industrial infrastructure. The Other segment primarily includes small business units that perform construction services for a variety of end markets in Mexico and elsewhere internationally.
	Earnings before interest, taxes, depreciation and amortization (“EBITDA”) is the measure of profitability used by management to manage its segments and, accordingly, in its segment reporting. As appropriate, the Company supplements the reporting of consolidated financial information determined in accordance with U.S. GAAP with certain non-U.S. GAAP financial measures, including EBITDA. The Company believes these non-U.S. GAAP measures provide meaningful information that helps investors understand the Company's financial results and assess its prospects for future performance. The Company uses EBITDA to evaluate its performance, both internally and versus that of its peers, because it excludes certain items that may not be indicative of the Company's reportable segment results, as well as items that can vary widely across different industries or among companies within the same industry. Segment EBITDA is calculated in a manner consistent with consolidated EBITDA.
	Summarized financial information for MasTec’s reportable segments is presented and reconciled to consolidated continuing operations financial information for total MasTec in the following tables (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	Revenue:	2014			2013			2014			2013
	Communications (a)	$	505.2		$	543		$	1,480.40		$	1,464.50
	Oil and Gas	557.4			519.1			1,302.90			1,134.80
	Electrical Transmission	132.6			118.8			327.2			321.9
	Power Generation and Industrial	114.3			85.1			263.1			237.3
	Other	1.1			3.5			6.5			9.2
	Eliminations	(1.0		)	(0.1		)	(1.9		)	(2.0		)
	Consolidated revenue	$	1,309.60		$	1,269.40		$	3,378.20		$	3,165.70
	(a)	Revenue generated by utilities customers represented 7.6% and 6.9% of Communications segment revenue for the three month periods ended September 30, 2014 and 2013, respectively, and 7.0% and 7.2% of Communications segment revenue for the nine month periods ended September 30, 2014 and 2013, respectively.
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	EBITDA:	2014			2013			2014			2013
	Communications	$	52.4		$	71.8		$	153.7		$	181.6
	Oil and Gas	73			68.1			143.5			161.7
	Electrical Transmission	12.7			12.1			33.2			27
	Power Generation and Industrial	4.9			(6.4		)	9.4			(14.6		)
	Other	(0.3		)	0.1			0.1			0.5
	Corporate	(14.5		)	(13.6		)	(38.7		)	(47.9		)
	Consolidated EBITDA	$	128.2		$	132.1		$	301.2		$	308.3
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	Depreciation and Amortization:	2014			2013			2014			2013
	Communications	$	10.1		$	9.5		$	30.1		$	26.8
	Oil and Gas	23.3			22.5			61.3			60.1
	Electrical Transmission	5.2			3.2			11.9			8.4
	Power Generation and Industrial	1.7			1.7			4.8			5.1
	Corporate	1.4			0.9			3.9			2.7
	Consolidated Depreciation and Amortization	$	41.7		$	37.8		$	112		$	103.1
	The following table presents a reconciliation of EBITDA to consolidated income from continuing operations before income taxes (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	EBITDA Reconciliation:	2014			2013			2014			2013
	EBITDA	$	128.2		$	132.1		$	301.2		$	308.3
	Less:
	Interest expense, net	(12.6		)	(12.7		)	(37.6		)	(34.5		)
	Depreciation and amortization	(41.7		)	(37.8		)	(112.0		)	(103.1		)
	Income from continuing operations before income taxes	$	73.8		$	81.6		$	151.7		$	170.6
	Foreign Operations. MasTec operates throughout North America, primarily in the U.S. and Canada, as well as in parts of Latin America. For the three month periods ended September 30, 2014 and 2013, revenues of $1.1 billion and $1.2 billion, respectively, were derived from U.S. operations, and $219.4 million and $90.9 million, respectively, were derived from foreign operations, primarily in Canada. For the nine month periods ended September 30, 2014 and 2013, revenues of $2.9 billion and $3.0 billion, respectively, were derived from U.S. operations, and $460.0 million and $172.0 million, respectively, were derived from foreign operations, primarily in Canada. Long-lived assets held in the U.S. included property and equipment, net, of $497.6 million and $436.9 million as of September 30, 2014 and December 31, 2013, respectively. Long-lived assets held in foreign countries, primarily in Canada, included property and equipment, net, of $116.8 million and $51.2 million as of September 30, 2014 and December 31, 2013, respectively. Intangible assets and goodwill, net, of approximately $1.0 billion as of both September 30, 2014 and December 31, 2013 related to the Company's U.S. operations. Intangible assets and goodwill, net, of approximately $211.5 million and $92.9 million as of September 30, 2014 and December 31, 2013, respectively, related to businesses in foreign countries, primarily in Canada.
	Significant Customers
	Revenue concentration information for significant customers as a percentage of total consolidated revenue was as follows:
		For the Three Months Ended September 30,			For the Nine Months Ended September 30,
		2014		2013	2014		2013
	Customer:
	AT&T (a)	16%		16%	21%		18%
	DIRECTV® (b)	12%		13%	13%		15%
	Enbridge, Inc. (c)	10%		20%	10%		14%
	(a)	The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for AT&T's wireless, wireline/fiber and home security and automation businesses. Revenue from AT&T is included in the Communications segment.
	(b)	The Company's relationship with DIRECTV® is based upon an agreement to provide installation and maintenance services for DIRECTV®. Revenue from DIRECTV® is included in the Communications segment.
	(c)	The Company's relationship with Enbridge, Inc. is based upon various construction contracts for natural gas pipelines. Revenue from Enbridge, Inc. is included in the Oil and Gas segment.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Note 16 - Commitments and Contingencies
	In addition to the matters discussed below, MasTec is subject to a variety of legal cases, claims and other disputes that arise from time to time in the ordinary course of its business. MasTec cannot provide assurance that it will be successful in recovering all or any of the potential damages it has claimed or in defending claims against it. The outcome of such cases, claims and disputes, including 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.
	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”). The initial contract price of each of the Projects was, subject to adjustment, approximately as follows: Somerset ($29 million); Morris ($36 million); and Sussex ($26 million). The Projects were funded, in part, with proceeds of municipal bonds issued by the Morris County and Somerset County Improvement Authorities (collectively, the “Authorities”).
	Power Partners and the SunLight Entities engaged in three separate arbitration proceedings against each other to address various disputes that existed between the parties on the Projects. The arbitration panel rendered awards in Power Partners’ favor in the aggregate amount of $59.6 million in August 2014. The arbitrators found that SunLight breached the EPC Agreements, that Power Partners had the right to terminate the EPC Agreements for cause because of the SunLight Entities’ breach of contract and breach of the covenant of good faith and fair dealing. The arbitrators dismissed all of the SunLight Entities’ affirmative claims. Power Partners has filed a petition in federal court in New Jersey as part of the process of confirming the arbitration awards into final judgments against the SunLight Entities. The arbitrators also held that Power Partners was the prevailing party and that it is entitled to an additional award of interest, attorney’s fees and costs. Power Partners has filed an application with the arbitration panel to set the amount of interest, attorney’s fees and costs and expects a ruling before the end of the year.
	Power Partners intends to vigorously pursue collection of all arbitration awards including interest, attorney's fees and costs. Power Partners believes it will successfully collect the arbitration awards, however, there can be no assurance that its collection efforts will be successful or that Power Partners will recover all amounts previously recorded. As part of its collection efforts, Power Partners filed municipal mechanic’s liens and construction liens of approximately $50 million against the solar projects and public construction funds for the work Power Partners had performed on the Projects. SunLight Entities and the Authorities challenged the mechanic’s liens and construction liens in court. In March 2014, a New Jersey appellate court found that Power Partners did not have municipal mechanic’s liens or construction liens on the municipal bond funds that are held in trust to pay for construction of the Projects. Power Partners petitioned the New Jersey Supreme Court to review the appellate court’s ruling, and, in July 2014, the New Jersey Supreme Court agreed to accept the case for review and also entered an order staying the appellate court’s ruling.
	Power Partners also filed a lawsuit in June 2013 in federal court in New Jersey against 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. The claims against the Authorities include violations of the New Jersey Public Works Bond Act, violations of the New Jersey Construction Trust Fund Act, tortious interference with Power Partners' contract rights, unjust enrichment and quantum meruit for the value of the work performed by Power Partners.
	Other Commitments and Contingencies
	Leases. In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facility, vehicle and equipment needs, including related party leases. See Note 10 - Lease Obligations.
	Letters of Credit. In the ordinary course of business, the Company is required to post letters of credit for its insurance carriers, surety bond providers and in support of performance under certain contracts. Such letters of credit are generally issued by a bank or similar financial institution. The letter of credit commits the issuer to pay specified amounts to the holder of the letter of credit under certain conditions. If this were to occur, the Company would be required to reimburse the issuer of the letter of credit, which, depending upon the circumstances, could result in a charge to earnings. As of September 30, 2014 and December 31, 2013, there were $135.6 million and $134.8 million, respectively, of letters of credit issued under the Company's Credit Facility. See Note 9 - Debt. The Company was not aware of any material claims relating to outstanding letters of credit as of September 30, 2014 or December 31, 2013.
	Performance and Payment Bonds. In the ordinary course of business, MasTec is required by certain customers to provide performance and payment bonds for certain of its contractual commitments associated with 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 September 30, 2014, the estimated cost to complete projects secured by the Company’s $748.6 million in performance and payment bonds was $53.1 million. As of December 31, 2013, the estimated cost to complete projects secured by the Company’s $1.1 billion in performance and payment bonds was $297.1 million.
	Investments in Affiliates and Other Entities. The Company holds an undivided interest in a contractual joint venture with a third party for the purpose of providing infrastructure construction services under certain customer contracts. 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 venturer indemnify the other parties for any liabilities incurred. Thus, it is possible that the Company could be required to pay or perform obligations in excess of its share if the other joint venturer fails or refuses to pay or perform its share of the obligations. As of September 30, 2014, the Company was not aware of any circumstances that would lead to future claims against it for material amounts. In addition, from time to time, the Company may provide financing to its unconsolidated affiliates. As of September 30, 2014, there were no amounts committed under such financing arrangements.
	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 September 30, 2014 and December 31, 2013, MasTec’s liability for unpaid claims and associated expenses, including incurred but not reported losses related to its workers compensation, general liability and automobile liability insurance policies, totaled $60.3 million and $50.8 million, respectively, of which $36.3 million and $31.3 million, respectively, was reflected within non-current other liabilities in the condensed unaudited consolidated balance sheets. MasTec also maintains an insurance policy with respect to employee group medical claims, which is subject to annual per employee maximum losses. MasTec’s liability for employee group medical claims as of September 30, 2014 and December 31, 2013 totaled $1.9 million and $2.1 million, respectively.
	The Company is required to post letters of credit and provide cash collateral to certain of its insurance carriers and to provide surety bonds in certain states. Insurance-related letters of credit for the Company's workers' compensation, general liability and automobile liability policies amounted to $57.2 million and $57.4 million as of September 30, 2014 and December 31, 2013, respectively. In addition, cash collateral deposited with insurance carriers, which is included in other long-term assets in the condensed unaudited consolidated balance sheets, amounted to $1.1 million and $1.4 million for these policies as of September 30, 2014 and December 31, 2013, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $13.0 million and $10.9 million as of September 30, 2014 and December 31, 2013, 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 Plans. Certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The agreements require the subsidiaries party to the agreements to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to the ones contained in the expiring agreements.
	The Employee Retirement Income Security Act of 1974, as amended by the Multi-Employer Pension Plan Amendments Act of 1980 (collectively, “ERISA”), which governs U.S. registered multi-employer pension plans, subjects employers to substantial liabilities in the event of the employer’s complete or partial withdrawal from, or upon termination of, such plans. Under current law regarding employers who are contributors to U.S. registered multi-employer defined benefit plans, a plan’s termination, an employer’s voluntary withdrawal from, or the mass withdrawal of contributing employers from, an underfunded multi-employer defined benefit plan requires participating employers to make payments to the plan for their proportionate share of the multi-employer plan’s unfunded vested liabilities. Furthermore, the Pension Protection Act of 2006 added new funding rules to U.S. registered plans that are generally applicable to plan years beginning after 2007 for multi-employer plans classified as “endangered,” “seriously endangered,” or “critical” status. If plans in which the Company’s subsidiaries participate are in critical status, benefit reductions may apply and/or the Company could be required to make additional contributions. Based upon the information available to the Company from plan administrators as of September 30, 2014, several of the multi-employer pension plans in which it participates are underfunded and, as a result, the Company could be required to increase its contributions.
	On November 15, 2011, the Company, along with other members of the Pipe Line Contractors Association (“PLCA”), voluntarily withdrew from the Central States Southeast and Southwest Areas Pension Fund (“Central States”), a defined benefit multi-employer pension plan that is in critical status. In connection with this withdrawal, a $6.4 million withdrawal liability was established based on an estimate provided by the Central States administrator of such liability as of the date of withdrawal. The Company began paying installments towards this withdrawal liability in 2013, of which $4.5 million was outstanding as of September 30, 2014. The Company withdrew from Central States in order to mitigate its liability in connection with the plan; however, Central States has asserted that the PLCA members did not effectively withdraw in 2011 and are, therefore, responsible for a withdrawal liability that includes 2011 contribution amounts. By letter dated March 14, 2013, Central States demanded $11 million in withdrawal liability from the Company, which included 2011 contribution amounts. The Company is vigorously opposing this demand because it believes that it legally and effectively withdrew from Central States on November 15, 2011. If Central States were to prevail in its assertion that the Company withdrew after that date, then the initial amount of the Company’s withdrawal liability would increase to approximately $11 million. The Company currently does not have plans to withdraw from any other multi-employer pension plan.
	Indemnities. The Company generally indemnifies its customers for the services it provides under its contracts, as well as other specified liabilities, which may subject the Company to indemnity claims, liabilities and related litigation. As of September 30, 2014 and December 31, 2013, the Company was not aware of any material asserted or unasserted claims in connection with these indemnity obligations.
	Other Guarantees. In the ordinary course of its business, from time to time, MasTec guarantees the obligations of its subsidiaries, including obligations under certain contracts with customers, certain lease obligations and in some states, obligations in connection with obtaining contractors’ licenses. MasTec has also issued performance and other guarantees in connection with its undivided interest in a contractual joint venture and certain of its equity investees. See Note 3 - Acquisitions. MasTec generally warrants the work it performs for a one to two year period following substantial completion of a project. MasTec has not historically accrued any reserves for potential warranty claims as they have been immaterial.
	Concentrations of Risk. The Company had approximately 480 customers for the nine month period ended September 30, 2014. For the three month periods ended September 30, 2014 and 2013, the Company derived 64% and 73% respectively, of revenues from its top ten customers. For the nine month periods ended September 30, 2014 and 2013, the Company derived 66% and 69%, respectively, of revenues from its top ten customers. See Note 15 - Segments and Related Information for significant customer revenue concentration information.

Related_Party_Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2014
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Note 17 - Related Party Transactions
	MasTec purchases, rents and leases equipment used in its business from a number of different vendors on a non-exclusive basis, including Cross Country Pipeline Supply, Inc. (“CCP”), in which MasTec invested $15 million in the fourth quarter of 2013, and which is accounted for as a cost method investment. Juan Carlos Mas, who is the brother of Jorge Mas, Chairman of MasTec's Board of Directors, and Jose Mas, MasTec's Chief Executive Officer, serves as the chairman of CCP. In addition, an entity owned by the Mas family, including Jorge and Jose Mas, is a minority shareholder of CCP. MasTec paid CCP approximately $1.9 million and $4.6 million for equipment rentals, leases and servicing for the three and nine month periods ended September 30, 2014, respectively.
	MasTec leases employees to a customer, in which Jorge Mas and Jose Mas own a minority interest. For the three month periods ended September 30, 2014 and 2013, MasTec charged approximately $0.2 million and $0.1 million, respectively, to this customer. For the nine month periods ended September 30, 2014 and 2013, MasTec charged approximately $0.5 million and $0.4 million, respectively, to this customer. As of both September 30, 2014 and December 31, 2013, receivables of $0.1 million attributable to this arrangement were outstanding. The Company also provides satellite communication services to this customer. For the three month periods ended September 30, 2014 and 2013, satellite communication revenues relating to this customer were approximately $0.3 million and $0.4 million, respectively. For the nine month periods ended September 30, 2014 and 2013, satellite communication revenues relating to this customer were approximately $0.8 million and $1.0 million, respectively. As of both September 30, 2014 and December 31, 2013, outstanding receivables from this arrangement totaled $0.4 million.
	See Note 3 - Acquisitions for discussion of the Company's equity method investments and contractual joint venture.
	Split Dollar Agreements
	In August 2014, Jose Mas, the Company and Jorge Mas, Juan Carlos Mas and Patricia Mas, as trustees of the Jose Ramon Mas Irrevocable Trust, dated December 7, 2012 (the “trust”) entered into a split dollar life insurance agreement that replaces the prior split dollar agreement and eliminates the deferred bonus agreement with Jose Mas. Under the new split dollar agreement, MasTec is the sole owner of each of the policies subject to the agreement. The Company will make the premium payments under each of such policies. Upon the death of Jose Mas or the survivor of Jose Mas and his wife (collectively, the “insureds”) under the applicable policy, MasTec is entitled to receive a portion of the death benefit under such policy equal to the greater of (i) premiums paid by the Company on such policy and (ii) the then cash value of such policy (excluding surrender charges or other similar charges or reductions) immediately before the triggering death. The balance of the death benefit is payable to the trust or other beneficiary designated by the trustees. In the event of the Company’s bankruptcy or dissolution, the trust shall have the assignable option to purchase any or all of the policies subject to the split dollar agreement from the Company. The purchase price for each policy shall be the greater of (x) premiums paid by the Company on such policy or (y) the then cash value of such policy (excluding surrender charges or other similar charges or reductions). The total maximum face amount of the insurance for policies subject to the split dollar agreement is capped at $75 million. The Company is designated as the named fiduciary under the split dollar agreement, and the policy may not be surrendered without the express written consent of the trust.
	For the three month period ended September 30, 2014, the Company made no payments in connection with the agreements for Jose Mas, and for the nine month period ended September 30, 2014, payments were less than $0.1 million. There were no payments made in connection with the agreements for Jose Mas in either of the three or nine month periods ended September 30, 2013. MasTec also has a split dollar agreement with Jorge Mas. The Company paid approximately $1.3 million and $1.8 million in connection with this agreement for the three and nine month periods ended September 30, 2014, respectively, and paid approximately $1.1 million and $1.2 million in connection with this agreement for the three and nine month periods ended September 30, 2013, respectively. As of September 30, 2014 and December 31, 2013, life insurance assets associated with these agreements of $11.1 million and $10.2 million, respectively, were included within other long-term assets in the condensed unaudited consolidated balance sheets. For additional information regarding the split dollar and deferred bonus agreements with Jorge Mas, see Note 17 - Related Party Transactions in the notes to the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2013.

Supplemental_Guarantor_Condens

Supplemental Guarantor Condensed Unaudited Consolidating Financial Information	9 Months Ended
	Sep. 30, 2014
Condensed Unaudited Financial Statements, Supplemental Guarantor Information [Abstract]	'
Supplemental Guarantor Condensed Unaudited Consolidating Financial Information	'
	Note 18 – Supplemental Guarantor Condensed Unaudited Consolidating Financial Information
	The 2011 Convertible Notes, 2009 Convertible Notes and 4.875% Senior Notes are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company's existing and future 100%-owned direct and indirect domestic subsidiaries that are each guarantors of the Company's Credit Facility or other outstanding indebtedness (the “Guarantor Subsidiaries”). The Company's subsidiaries organized outside of the United States and certain domestic subsidiaries (collectively, the “Non-Guarantor Subsidiaries”) do not guarantee any of these notes. A Guarantor Subsidiary's guarantee is subject to release in certain customary circumstances, including upon the sale of a majority of the capital stock or substantially all of the assets of such Subsidiary Guarantor, if such Subsidiary Guarantor's guarantee under the Company's Credit Facility and other indebtedness is released or discharged (other than due to payment under such guarantee), or when the requirements for legal defeasance are satisfied or the obligations are discharged in accordance with the related indentures.
	The following supplemental financial information sets forth the condensed unaudited consolidating balance sheets and the condensed unaudited consolidating statements of operations and comprehensive income and cash flows for the parent company (MasTec, Inc.), the Guarantor Subsidiaries on a combined basis, the Non-Guarantor Subsidiaries on a combined basis and the eliminations necessary to arrive at the information for the Company as reported on a consolidated basis. Eliminations represent adjustments to eliminate investments in subsidiaries and intercompany balances and transactions between or among MasTec, Inc., the Guarantor Subsidiaries and the Non-Guarantor Subsidiaries.  Investments in subsidiaries are accounted for using the equity method for this presentation.
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (in millions)
	For the Three Months Ended September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,043.10		$	268.5		$	(2.0	)	$	1,309.60
	Costs of revenue, excluding depreciation and amortization	—			892.6			232.4			(2.0		)	1,123.00
	Depreciation and amortization	—			30.8			10.9			—			41.7
	General and administrative expenses	0.6			50.8			8.5			—			59.9
	Interest expense, net	—			11.5			1.1			—			12.6
	Other (income) expense, net	—			(1.6		)	0.2			—			(1.4		)
	(Loss) income from continuing operations before income taxes	$	(0.6	)	$	59		$	15.4		$	—		$	73.8
	Benefit from (provision for) income taxes	0.2			(22.0		)	(6.2		)	—			(28.0		)
	Net (loss) income from continuing operations	$	(0.4	)	$	37		$	9.2		$	—		$	45.7
	Net loss from discontinued operations	—			—			(0.3		)	—			(0.3		)
	Equity in income from subsidiaries, net of tax	45.7			—			—			(45.7		)	—
	Net income (loss)	$	45.3		$	37		$	8.9		$	(45.7	)	$	45.4
	Net income attributable to non-controlling interests	—			—			0.1			—			0.1
	Net income (loss) attributable to MasTec, Inc.	$	45.3		$	37		$	8.8		$	(45.7	)	$	45.3
	Comprehensive income (loss)	$	32.3		$	37		$	(4.1	)	$	(32.7	)	$	32.5
	For the Three Months Ended September 30, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,140.90		$	129		$	(0.5	)	$	1,269.40
	Costs of revenue, excluding depreciation and amortization	—			969.5			112.1			(0.5		)	1,081.10
	Depreciation and amortization	—			31.6			6.2			—			37.8
	General and administrative expenses	0.5			50.1			8.4			—			59
	Interest expense, net	—			12			0.7			—			12.7
	Other income, net	—			(2.3		)	(0.5		)	—			(2.8		)
	(Loss) income from continuing operations before income taxes	$	(0.5	)	$	80		$	2.1		$	—		$	81.6
	Benefit from (provision for) income taxes	0.2			(31.5		)	(0.4		)	—			(31.7		)
	Net (loss) income from continuing operations	$	(0.3	)	$	48.5		$	1.7		$	—		$	49.9
	Net loss from discontinued operations	—			—			(3.7		)	—			(3.7		)
	Equity in income from subsidiaries, net of tax	46.4			—			—			(46.4		)	—
	Net income (loss)	$	46.1		$	48.5		$	(2.0	)	$	(46.4	)	$	46.2
	Net income attributable to non-controlling interests	—			—			0.1			—			0.1
	Net income (loss) attributable to MasTec, Inc.	$	46.1		$	48.5		$	(2.1	)	$	(46.4	)	$	46.1
	Comprehensive income (loss)	$	49		$	48.5		$	0.8		$	(49.3	)	$	49
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (in millions)
	For the Nine Months Ended September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	2,798.60		$	581.7		$	(2.1	)	$	3,378.20
	Costs of revenue, excluding depreciation and amortization	—			2,402.00			515			(2.1		)	2,914.90
	Depreciation and amortization	—			88.4			23.6			—			112
	General and administrative expenses	1.8			146.6			19.1			—			167.5
	Interest expense, net	—			35.6			2			—			37.6
	Other (income) expense, net	—			(5.8		)	0.3			—			(5.5		)
	(Loss) income from continuing operations before income taxes	$	(1.8	)	$	131.8		$	21.7		$	—		$	151.7
	Benefit from (provision for) income taxes	0.7			(51.2		)	(7.2		)	—			(57.7		)
	Net (loss) income from continuing operations	$	(1.1	)	$	80.6		$	14.5		$	—		$	94
	Net loss from discontinued operations	—			—			(0.6		)	—			(0.6		)
	Equity in income from subsidiaries, net of tax	94.5			—			—			(94.5		)	—
	Net income (loss)	$	93.4		$	80.6		$	13.9		$	(94.5	)	$	93.4
	Net income attributable to non-controlling interests	—			—			—			—			—
	Net income (loss) attributable to MasTec, Inc.	$	93.4		$	80.6		$	13.8		$	(94.5	)	$	93.3
	Comprehensive income (loss)	$	82.8		$	80.5		$	3.4		$	(83.9	)	$	82.8
	For the Nine Months Ended September 30, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	2,881.10		$	289		$	(4.4	)	$	3,165.70
	Costs of revenue, excluding depreciation and amortization	—			2,447.70			252			(4.4		)	2,695.30
	Depreciation and amortization	—			88.8			14.3			—			103.1
	General and administrative expenses	1.4			138.5			19.9			—			159.8
	Interest expense, net	—			33.5			1			—			34.5
Loss on extinguishment of debt	—			5.6			—			—			5.6
Other income, net	—			(2.4		)	(0.8		)	—			(3.2		)
(Loss) income from continuing operations before income taxes	$	(1.4	)	$	169.4		$	2.6		$	—		$	170.6
Benefit from (provision for) income taxes	0.6			(66.0		)	(0.4		)	—			(65.8		)
Net (loss) income from continuing operations	$	(0.8	)	$	103.4		$	2.2		$	—		$	104.8
Net loss from discontinued operations	—			—			(5.2		)	—			(5.2		)
Equity in income from subsidiaries, net of tax	100.3			—			—			(100.3		)	—
Net income (loss)	$	99.5		$	103.4		$	(3.0	)	$	(100.3	)	$	99.6
Net income attributable to non-controlling interests	—			—			0.2			—			0.2
Net income (loss) attributable to MasTec, Inc.	$	99.5		$	103.4		$	(3.2	)	$	(100.3	)	$	99.4
Comprehensive income (loss)	$	95.1		$	102.8		$	(6.8	)	$	(95.9	)	$	95.2
CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS (in millions)
As of September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Assets
Current assets, including discontinued operations	$	—		$	1,251.50		$	322.5		$	—		$	1,574.00
Property and equipment, net	—			475.5			138.9			—			614.4
Goodwill and other intangible assets, net	—			972.6			249.5			—			1,222.10
Investments in and advances to consolidated affiliates, net	1,114.80			—			107.3			(1,222.1		)	—
Other long-term assets, including discontinued operations	9.3			35.3			15			—			59.6
Total assets	$	1,124.10		$	2,734.90		$	833.2		$	(1,222.1	)	$	3,470.10
Liabilities and Equity
Total current liabilities	$	—		$	736.6		$	174.3		$	—		$	910.9
Long-term debt	—			1,053.60			34.7			—			1,088.30
Advances from consolidated affiliates, net	—			23.8			—			(23.8		)	—
Other liabilities	—			190.8			151.2			—			342
Total liabilities	$	—		$	2,004.80		$	360.2		$	(23.8	)	$	2,341.20
Total equity	$	1,124.10		$	730.1		$	473		$	(1,198.3	)	$	1,128.90
Total liabilities and equity	$	1,124.10		$	2,734.90		$	833.2		$	(1,222.1	)	$	3,470.10
As of December 31, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Assets
Current assets, including discontinued operations	$	—		$	1,156.70		$	150.3		$	—		$	1,307.00
Property and equipment, net	—			420.2			67.9			—			488.1
Goodwill and other intangible assets, net	—			932.8			134.9			—			1,067.70
Investments in and advances to consolidated affiliates, net	1,006.80			170.8			—			(1,177.6		)	—
Other long-term assets, including discontinued operations	9.3			36.2			14.9			—			60.4
Total assets	$	1,016.10		$	2,716.70		$	368		$	(1,177.6	)	$	2,923.20
Liabilities and Equity
Total current liabilities	$	—		$	773.3		$	55.9		$	—		$	829.2
Long-term debt	—			760.9			4.5			—			765.4
Advances from consolidated affiliates, net	—			—			22.5			(22.5		)	—
Other liabilities	—			236.4			71.1			—			307.5
Total liabilities	$	—		$	1,770.60		$	154		$	(22.5	)	$	1,902.10
Total equity	$	1,016.10		$	946.1		$	214		$	(1,155.1	)	$	1,021.10
Total liabilities and equity	$	1,016.10		$	2,716.70		$	368		$	(1,177.6	)	$	2,923.20
CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS (in millions)
For the Nine Months Ended September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Net cash (used in) provided by operating activities	$	(1.1	)	$	39.6		$	42.5		$	—		$	81
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	—			(39.9		)	(123.0		)	—			(162.9		)
Capital expenditures	—			(75.6		)	(15.4		)	—			(91.0		)
Proceeds from sale of property and equipment	—			10.3			1.9			—			12.2
Payments for other investments, net	—			(1.0		)	—			—			(1.0		)
Net cash used in investing activities	$	—		$	(106.2	)	$	(136.5	)	$	—		$	(242.7	)
Cash flows provided by (used in) financing activities:
Proceeds from credit facility	—			1,122.40			197.2			—			1,319.60
Repayments of credit facility	—			(723.2		)	(232.0		)	—			(955.2		)
Repayments of senior convertible notes	—			(105.3		)	—			—			(105.3		)
Repayments of other borrowings and capital lease obligations	—			(45.3		)	(8.8		)	—			(54.1		)
Excess tax benefits and net proceeds from stock-based awards	2.9			0.9			—			—			3.8
Payments of acquisition-related contingent consideration	—			(60.3		)	—			—			(60.3		)
Payments of financing costs	—			(1.5		)	—			—			(1.5		)
Net financing activities and advances (to) from consolidated affiliates	(1.8		)	(124.1		)	125.9			—			—
Net cash provided by financing activities	$	1.1		$	63.6		$	82.3		$	—		$	147
Effect of currency translation on cash	—			—			(1.2		)	—			(1.2		)
Net decrease in cash and cash equivalents	$	—		$	(3.0	)	$	(12.9	)	$	—		$	(15.9	)
Cash and cash equivalents - beginning of period	—			5.3			17.7			—			23
Cash and cash equivalents - end of period	$	—		$	2.3		$	4.8		$	—		$	7.1
For the Nine Months Ended September 30, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Net cash (used in) provided by operating activities	$	(2.4	)	$	103.2		$	28.5		$	—		$	129.3
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	—			(43.0		)	(103.6		)	—			(146.6		)
Capital expenditures	—			(96.8		)	(4.6		)	—			(101.4		)
Proceeds from sale of property and equipment	—			7.6			0.7			—			8.3
Proceeds from disposal of business, net of cash divested	$	—		$	(4.3	)	$	—		$	—		$	(4.3	)
Proceeds from other investments, net	$	—		$	3.8		$	—		$	—		$	3.8
Net cash used in investing activities	$	—		$	(132.7	)	$	(107.5	)	$	—		$	(240.2	)
Cash flows provided by (used in) financing activities:
Proceeds from credit facility	$	—		$	639.6		$	126.6		$	—		$	766.2
Repayments of credit facility	—			(737.2		)	(123.0		)	—			(860.2		)
Proceeds from senior notes, net	—			250			—			—			250
Repayments of other borrowings and capital lease obligations	—			(55.5		)	(1.0		)	—			(56.5		)
Excess tax benefits and net proceeds from stock-based awards	9.2			3			—			—			12.2
Payments of acquisition-related contingent consideration	—			(12.8		)	—			—			(12.8		)
Payments of financing costs, including call premiums on extinguishment of debt	—			(11.8		)	—			—			(11.8		)
Net financing activities and advances (to) from consolidated affiliates	(6.8		)	(56.4		)	63.2			—			—
Net cash provided by financing activities	$	2.4		$	18.9		$	65.8		$	—		$	87.1
Effect of currency translation on cash	—			—			(0.1		)	—			(0.1		)
Net decrease in cash and cash equivalents	$	—		$	(10.6	)	$	(13.3	)	$	—		$	(23.9	)
Cash and cash equivalents - beginning of period	—			12.7			14			—			26.7
Cash and cash equivalents - end of period	$	—		$	2.1		$	0.7		$	—		$	2.8

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	Note 19 - Subsequent Events
	Effective October 1, 2014, the Company acquired all of the issued and outstanding equity interests of WesTower Communications Inc., a Delaware corporation (“WesTower”), for approximately $199 million in cash, subject to customary purchase price adjustments. WesTower is a telecommunications services firm, focusing on construction and maintenance of communications infrastructure related to wireless networks throughout the United States. WesTower currently provides services to a number of major wireless carriers through regional operating offices located throughout the Eastern, Central and Western United States. WesTower will be included in the Company’s Communications segment. Due to the limited amount of time since the acquisition of WesTower, the initial accounting for the acquisition is incomplete. The Company will complete an initial allocation of purchase price to total net assets acquired for the WesTower acquisition in the fourth quarter of 2014 and include the related disclosures in the Company’s consolidated financial statements for the year ended December 31, 2014.
	In connection with the WesTower acquisition, the Company amended its Credit Facility in October 2014. The amendment used a portion of the Credit Facility's $250 million accordion feature to make available an additional $75 million term loan (the "Term Loan"), which increased aggregate borrowing commitments to $1.075 billion. The interest, maturity and other provisions of the Term Loan are substantially identical to those of all other loans under the Credit Facility. For additional information regarding loan provisions under the Credit Facility, see Note 9 - Debt in the notes to the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2013.

Business_Basis_of_Presentation1

Business, Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Nature of the Business	'
	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: petroleum and natural gas pipeline infrastructure; wireless, wireline/fiber and satellite communications; electrical utility transmission and distribution; power generation; and industrial infrastructure. MasTec’s customers are in these industries. MasTec reports its results in five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial; and (5) Other. See Note 15 - Segments and Related Information.
Basis of Presentation	'
	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, 2013 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, 2013 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.
Reclassifications	'
	Certain prior year amounts have been reclassified to conform to the current period presentation.
Principles of Consolidation	'
	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 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 in other income or expense, net, in the condensed unaudited consolidated statements of operations. The Company's investments in entities in which the Company does not have the ability to exert significant influence are accounted for using the cost method of accounting. All significant intercompany balances and transactions have been eliminated in consolidation. The assets and liabilities of foreign subsidiaries are translated into U.S. dollars at period-end exchange rates, with resulting translation gains or losses accumulated within other comprehensive income or loss. Revenue and expenses are translated into U.S. dollars at average rates of exchange prevailing during the applicable period. Gains or losses resulting from transactions executed in a foreign currency are included in other income or expense, net. The Company does not currently have any subsidiaries that operate in highly inflationary environments. The results of operations and financial position of any discontinued operations are aggregated and presented separately from the Company's continuing operations in the condensed unaudited consolidated financial statements for all periods presented.
Translation of Foreign Currencies	'
	The assets and liabilities of foreign subsidiaries are translated into U.S. dollars at period-end exchange rates, with resulting translation gains or losses accumulated within other comprehensive income or loss. Revenue and expenses are translated into U.S. dollars at average rates of exchange prevailing during the applicable period. Gains or losses resulting from transactions executed in a foreign currency are included in other income or expense, net. The Company does not currently have any subsidiaries that operate in highly inflationary environments.
Investments in Affiliates and Other Entities	'
	Investments in Affiliates and Other Entities
	In the ordinary course of business, the Company enters into various investment arrangements, which may include equity or other interests in business entities, including contractual joint ventures or other forms of equity participation. These investment arrangements may also include certain forms of financing, such as the extension of loans. In connection with certain of these investment arrangements, the Company provides infrastructure construction services to or through its equity investees and/or contractual joint ventures. Management determines whether such investment arrangements involve a variable interest entity (“VIE”) based on the characteristics of the particular entity. If an entity is determined to be a VIE, then management determines if the Company is the primary beneficiary of the entity and whether or not consolidation of the VIE within the Company's financial statements is required. The primary beneficiary consolidating the VIE must normally have both (i) the power to direct the activities of a VIE that most significantly affect the VIE’s economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE, which, in either case, could be significant to the VIE. If management determines that the Company is the primary beneficiary of a VIE, then the VIE would be consolidated, and the other party’s equity interest in the VIE would be accounted for as a non-controlling interest. As of September 30, 2014, the Company was not the primary beneficiary of any VIE. In cases where the Company has an undivided interest in the assets, liabilities, revenues and profits of an unincorporated entity, such amounts are consolidated on a basis proportional to the Company’s ownership interest in the unincorporated entity.
Variable Interest Entities	'
	In the ordinary course of business, the Company enters into various investment arrangements, which may include equity or other interests in business entities, including contractual joint ventures or other forms of equity participation. These investment arrangements may also include certain forms of financing, such as the extension of loans. In connection with certain of these investment arrangements, the Company provides infrastructure construction services to or through its equity investees and/or contractual joint ventures. Management determines whether such investment arrangements involve a variable interest entity (“VIE”) based on the characteristics of the particular entity. If an entity is determined to be a VIE, then management determines if the Company is the primary beneficiary of the entity and whether or not consolidation of the VIE within the Company's financial statements is required. The primary beneficiary consolidating the VIE must normally have both (i) the power to direct the activities of a VIE that most significantly affect the VIE’s economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE, which, in either case, could be significant to the VIE. If management determines that the Company is the primary beneficiary of a VIE, then the VIE would be consolidated, and the other party’s equity interest in the VIE would be accounted for as a non-controlling interest.
Unincorporated Joint Ventures, Proportionate Consolidation	'
	In cases where the Company has an undivided interest in the assets, liabilities, revenues and profits of an unincorporated entity, such amounts are consolidated on a basis proportional to the Company’s ownership interest in the unincorporated entity.
Management Estimates	'
	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 and gross profit or loss, in particular, on long-term construction contracts, which rely upon estimates of costs to complete projects, ultimate project gross profit and the amount of contract price adjustments that are probable; allowances for doubtful accounts; accrued self-insured claims; estimated fair values of goodwill and intangible assets, acquisition-related contingent consideration, convertible debt obligations and investments in cost and equity method investees; asset lives used in computing depreciation and amortization, including amortization of intangible assets; share-based compensation; 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.
Revenue Recognition	'
	Revenue Recognition
	Revenues are derived from projects performed under master and other service agreements as well as from fixed price contracts for specific projects or jobs requiring the construction and installation of an entire infrastructure system or specified units within an entire infrastructure system. Revenue and related costs for master and other service agreements billed on a time and materials basis are recognized as the services are rendered. The Company also performs services under master and other service agreements on a fixed fee basis, under which MasTec furnishes specified units of service for a fixed price per unit of service and revenue is recognized as the services are rendered. Revenues from fixed price contracts provide for a fixed amount of revenue for the entire project, subject to certain additions for changed scope or specifications. Revenues from these contracts are recognized using the percentage-of-completion method. Under this method, the percentage of revenue to be recognized for a given project is measured by the percentage of costs incurred to date on the contract to the total estimated costs for the contract. Such contracts provide that the customer accept completion of progress to date and compensate the Company for services rendered, which may be measured in terms of costs incurred, units installed, hours expended or some other measure of progress.
	The Company may incur costs subject to change orders, whether approved or unapproved by the customer, and/or claims related to certain contracts. Management determines the probability that such costs will be recovered based upon evidence such as engineering studies and legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer. The Company treats project costs as a cost of contract performance in the period incurred if it is not probable that the costs will be recovered, or defers costs and/or recognizes revenue up to the amount of the related cost if it is probable that the contract price will be adjusted and can be reliably estimated. As of September 30, 2014 and December 31, 2013, the Company had approximately $78 million and $79 million, respectively, of change orders and/or claims that had been included as contract price adjustments on certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, in arbitration and other proceedings. These contract price adjustments represent management's best estimate of additional contract revenues that have been or will be earned and that management believes are probable of collection. The amounts ultimately realized upon final acceptance by its customers could be higher or lower than such estimated amounts, which are primarily expected to be billed and collected within one year.
New Accounting Pronouncements	'
	New Accounting Pronouncements
	Accounting Standards Not Yet Adopted
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of this ASU is that a company will recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under current guidance and will be required to disclose information about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including disclosure of assumptions and estimates where significant judgment has been applied. ASU 2014-09 is effective using either the retrospective or cumulative effect transition method for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early application is not permitted. The Company is currently evaluating the potential impact of this ASU on its consolidated financial statements.
	In April 2014, the FASB issued ASU 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (“ASU 2014-08”). ASU 2014-08 changes the requirements for reporting discontinued operations and requires additional disclosures about discontinued operations. Only disposals of components of an entity representing a strategic shift that has, or will have, a major effect on an entity’s operations and financial results should be reported as discontinued operations under ASU 2014-08. Examples include a disposal of a major geographical area, a major line of business, or a major equity method investment. ASU 2014-08 also requires expanded disclosures about discontinued operations and requires disclosures about individually significant dispositions that do not qualify as discontinued operations. ASU 2014-08 is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014. Early adoption is permitted only for disposals that have not been previously reported. The Company is currently evaluating the potential impact of this ASU on its consolidated financial statements.
	Recently Adopted Accounting Pronouncements
	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 adopted ASU 2013-11 as of January 1, 2014. The adoption of this ASU did not have a material impact on the condensed unaudited consolidated financial statements.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Line Items]	'
Schedule of Earnings Per Share Information	'
	The following table provides details underlying the Company’s earnings per share calculations for the periods indicated (in thousands):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2014			2013			2014			2013
	Net income attributable to MasTec:
	Net income, continuing operations - basic (a)	$	45,591		$	49,960		$	93,936		$	104,702
	Interest expense, net of tax, 2009 Convertible Notes	20			79			166			236
	Net income, continuing operations - diluted	$	45,611		$	50,039		$	94,102		$	104,938
	Net loss from discontinued operations - basic and diluted (a)	(320		)	(3,822		)	(592		)	(5,253		)
	Net income attributable to MasTec - diluted	$	45,291		$	46,217		$	93,510		$	99,685
	Weighted average shares outstanding:
	Weighted average shares outstanding - basic	81,811			77,093			79,158			76,816
	Dilutive common stock equivalents	814			775			798			774
	Dilutive premium shares, 2011 Convertible Notes	3,005			6,790			5,900			6,337
	Dilutive shares, 2009 Convertible Notes	194			806			560			806
	Weighted average shares outstanding - diluted	85,824			85,464			86,416			84,733
	(a)	Calculated as total net income (loss) less amounts attributable to non-controlling interests.
2011 Convertible Notes [Member]	'
Earnings Per Share [Line Items]	'
Schedule of Convertible Note Premium Share Information	'
	The calculations underlying the number of premium shares included in the Company’s diluted share count for the periods indicated are as follows (in thousands, except per share amounts):
		As of and for the Three Months										As of and for the Nine Months
		Ended September 30,										Ended September 30,
		2014				2013						2014			2013
	Premium Share Information:		2011 4.25%			2011 4.0%			2011 4.25%				2011 4.25%		2011 4.0%		2011 4.25%
			Notes			Notes			Notes				Notes		Notes		Notes
	Number of conversion shares, principal amount		6,268			6,683			6,268				6,268		6,683		6,268
	Per share price, actual average		$	29.73		$	32.84		$	32.84			$	35.06	$	30.59	$	30.59
	Premium value		$	89,341		$	114,176		$	108,864			$	122,748	$	99,104	$	94,728
	Premium shares		3,005			3,476			3,314				3,501		3,240		3,097

Acquisitions_Tables

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2014
Business Combinations [Line Items]	'
Schedule of Pro Forma Information, Business Acquisitions	'
	The unaudited supplemental pro forma financial information presented below has been prepared by adjusting the historical results of MasTec to include the historical results of the acquired businesses described above. The unaudited supplemental pro forma combined historical results were then adjusted (i) to remove one-time acquisition costs; (ii) to increase amortization expense resulting from the incremental intangible assets acquired in such acquisitions; (iii) to increase interest expense as a result of the cash consideration paid; and (iv) to reduce interest expense from the repayment of acquired debt. The unaudited supplemental pro forma financial information does not include any adjustments to reflect the impact of cost savings or other synergies that may result from these acquisitions. As noted above, the unaudited supplemental pro forma financial information does not purport to be indicative of the actual results that would have been achieved by the combined companies for the periods presented or that may be achieved by the combined companies in the future.
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2014			2013				2014			2013
	Pro forma financial information:	(unaudited, in millions)							(unaudited, in millions)
	Revenue	$	1,309.60		$	1,417.50			$	3,496.00		$	3,667.30
	Net income from continuing operations	$	46		$	52.4			$	96.5		$	118
	Results of Businesses Acquired
	Revenues and net income resulting from the year over year incremental impact of acquired businesses, which are included within the Company's consolidated results of operations for the periods indicated, were as follows:
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2014			2013				2014			2013
	Actual of acquiree (year over year impact):	(unaudited, in millions)							(unaudited, in millions)
	Revenue	$	133.2		$	141.6			$	342.5		$	270.4
	Net income from continuing operations (a)	$	2.3		$	7.5			$	4.5		$	12.8
	(a)	The above results do not include acquisition costs totaling $0.4 million and $0.3 million for the three month periods ended September 30, 2014 and 2013, respectively, and $2.0 million and $1.6 million for the nine month periods ended September 30, 2014 and 2013, respectively. Acquisition costs are included within general and administrative costs in the Company's consolidated unaudited statements of operations. The above results also do not include interest expense associated with consideration paid for these acquisitions.
Pacer [Member]	'
Business Combinations [Line Items]	'
Schedule of Consideration Paid and Net Assets Acquired, Business Acquisitions	'
	The following table summarizes the preliminary estimated fair values of consideration paid and identifiable assets acquired and liabilities assumed, as adjusted, as of the date of acquisition (in millions):
	Acquisition consideration:	1-Jun-14
	Cash	$	126.5
	Fair value of contingent consideration (earn-out liability)	25.7
	Total consideration transferred	$	152.2
	Identifiable assets acquired and liabilities assumed:
	Current assets	$	118.4
	Equity method investments	2.3
	Other long-term assets	0.1
	Property and equipment	72.8
	Pre-qualifications	41.2
	Finite-lived intangible assets	20.3
	Current liabilities	(55.8		)
	Long-term debt	(87.0		)
	Deferred income taxes	(29.6		)
	Total identifiable net assets	$	82.7
	Goodwill	$	69.5
	Total net assets acquired, including goodwill	$	152.2
Schedule of Finite-Lived Intangible Assets Acquired, Business Acquisitions	'
	The fair values and weighted average useful lives of Pacer's acquired finite-lived intangible assets, as adjusted, as of the date of acquisition were assigned as follows:
		Fair Value			Weighted Average Useful Life
	Finite-lived intangible assets:	(in millions)			(in years)
	Backlog	$	6.1		2
	Non-compete agreements	2.3			8
	Customer relationships	11.9			8
	Total acquired finite-lived intangible assets	$	20.3		6
2013 Acquisitions [Member]	'
Business Combinations [Line Items]	'
Schedule of Measurement Period Adjustments, Business Acquisitions	'
	Measurement period adjustments associated with the Company's 2013 acquisitions have been reflected as follows (in millions):
	As of December 31, 2013:		As Previously Reported			Measurement Period Adjustments				As Revised
	Current assets		$	1,306.00		$	1			$	1,307.00
	Goodwill		$	899.4		$	2.6			$	902
	Current liabilities		$	825.5		$	3.7			$	829.2
	Long-term deferred tax liabilities, net		$	154.9		$	(0.1	)		$	154.8

Discontinued_Operations_Tables

Discontinued Operations (Tables) (Globetec [Member])	9 Months Ended
	Sep. 30, 2014
Globetec [Member]	'
Discontinued Operations Disclosures [Line Items]	'
Summary of Assets, Liabilities and Results of Operations from Discontinued Operations	'
	The following table contains a summary of the contingent assets and liabilities associated with Globetec that were retained by the Company as of September 30, 2014 and as of December 31, 2013 (in millions):
		September 30,			December 31,
		2014			2013
	Current assets	$	5		$	2.3
	Long-term assets	7.1			10.1
	Assets of discontinued operations	$	12.1		$	12.4
	Current liabilities of discontinued operations	$	1.2		$	1.2
	The following table presents Globetec's results from discontinued operations for the periods indicated (in millions):
		For the Three Months Ended September 30, 2013			For the Nine Months Ended September 30, 2013
	Revenue	$	4.8		$	18
	Loss from operations, before tax	(0.5		)	(2.7		)
	Impairment of assets, before tax	(5.7		)	(6.0		)
	Income tax benefit	2.5			3.5
	Net loss from discontinued operations	$	(3.7	)	$	(5.2	)

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Rollforward of Goodwill by Segment	'
	The following table provides a reconciliation of changes in goodwill by reportable segment (in millions):
		Communications			Oil and Gas				Electrical				Power				Total Goodwill
									Transmission				Generation and Industrial
	Balance as of December 31, 2013	$	326.8		$	307.7			$	149.9			$	117.6			$	902
	Additions from new business combinations	28.6			69.5				—				—				98.1
	Accruals of acquisition-related contingent consideration, net (a)	4.6			—				—				—				4.6
	Currency translation adjustments	—			(4.7		)		—				—				(4.7		)
	Balance as of September 30, 2014	$	360		$	372.5			$	149.9			$	117.6			$	1,000.00
	(a)	Represents contingent consideration for acquisitions prior to January 1, 2009, which is accrued as earned, in accordance with U.S. GAAP.
Rollforward of Other Intangible Assets	'
	The following table provides a reconciliation of changes in other intangible assets (in millions):
			Other Intangible Assets
			Non-amortizing							Amortizing
			Trade Names			Pre-Qualifications				Customer Relationships and Backlog				Other (a)				Total
	Gross carrying amount as of December 31, 2013		$	34.8		$	59.4			$	128.4			$	22.5			$	245.1
	Accumulated amortization									$	(67.7	)		$	(11.8	)		$	(79.5	)
	Other intangible assets, net, as of December 31, 2013		$	34.8		$	59.4			$	60.7			$	10.7			$	165.6
	Additions from new business combinations		—			41.2				33.1				2.7				77
	Amortization expense									(15.7		)		(1.3		)		(17.0		)
	Currency translation adjustments		—			(2.6		)		(0.8		)		—				(3.4		)
	Other intangible assets, net, as of September 30, 2014		$	34.8		$	98			$	77.3			$	12.1			$	222.2
	(a)	Consists principally of amortizing trade names and non-compete agreements.

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Fair Values of Selected Financial Instruments Measured On A Non-Recurring Basis	'
	Carrying amounts and estimated fair values of selected financial instruments measured on a non-recurring basis as of the dates indicated were as follows (in millions):
		September 30, 2014				December 31, 2013
		Carrying		Fair		Carrying		Fair
		Amount		Value		Amount		Value
	4.875% Senior Notes	$	400	$	377	$	400	$	380
	2009 Convertible Notes	$	3	$	5.9	$	12.6	$	26.6
	2011 Convertible Notes	$	97	$	192.1	$	198.3	$	428.3

Accounts_Receivable_Net_of_All1

Accounts Receivable, Net of Allowance (Tables) (Accounts Receivable [Member])	9 Months Ended
	Sep. 30, 2014
Accounts Receivable [Member]	'
Schedule of Accounts Receivable, Net of Allowance [Line Items]	'
Schedule Of Accounts Receivable, Net of Allowance	'
	The following table provides details of accounts receivable, net of allowance, as of the dates indicated (in millions):
		September 30,			December 31,
		2014			2013
	Contract billings	$	775.6		$	606.5
	Retainage	179.3			159.3
	Costs and earnings in excess of billings	451.7			384.6
	Accounts receivable, gross	$	1,406.60		$	1,150.40
	Less allowance for doubtful accounts	(16.7		)	(15.7		)
	Accounts receivable, net	$	1,389.90		$	1,134.70

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Schedule of Property And Equipment, Net	'
	The following table provides details of property and equipment, net, including property and equipment held under capital leases as of the dates indicated (in millions):
		September 30,			December 31,
		2014			2013
	Land	$	4.6		$	4.8
	Buildings and leasehold improvements	19.2			18
	Machinery and equipment	901.6			727.1
	Office furniture and equipment	118.1			102.5
	Construction in progress	17.2			11
	Total property and equipment	$	1,060.70		$	863.4
	Less accumulated depreciation and amortization	(446.3		)	(375.3		)
	Property and equipment, net	$	614.4		$	488.1

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Carrying Values of Long-Term Debt	'
	The following table provides details of the carrying values of long-term debt as of the dates indicated (in millions):
	Description		Maturity Date		September 30,			December 31,
					2014			2013
	Senior secured credit facility		October 29, 2018		$	449.5		$	53
	4.875% senior notes		March 15, 2023		400			400
	2011 4.0% senior convertible notes		June 15, 2014		—			103.8
	2011 4.25% senior convertible notes		December 15, 2014		96.4			94.5
	2009 4.0% senior convertible notes		June 15, 2014		—			9.6
	2009 4.25% senior convertible notes		December 15, 2014		3			3
	Other credit facilities		Varies		4.8			—
	Capital lease obligations, weighted average interest rate of 2.8%		In installments through June 13, 2021		163.6			126
	Notes payable, equipment, weighted average interest rate of 2.9%		In installments through September 1, 2018		42.8			26.9
	Total debt				$	1,160.10		$	816.8
	Less current maturities				(71.8		)	(51.4		)
	Long-term debt				$	1,088.30		$	765.4
Schedule of Interest Expense, Net	'
	The following table provides details of interest expense, net, for the periods indicated (in millions):
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2014				2013			2014			2013
	Interest expense:
	Contractual and other interest expense	$	11.3			$	10.4		$	31.6		$	27.9
	Accretion of senior convertible note discount	0.6				1.3			3.4			3.9
	Amortization of deferred financing costs	0.8				1			2.7			3
	Total interest expense	$	12.7			$	12.7		$	37.7		$	34.8
	Interest income	(0.1		)		—			(0.1		)	(0.3		)
	Interest expense, net	$	12.6			$	12.7		$	37.6		$	34.5

StockBased_Compensation_and_Ot1

Stock-Based Compensation and Other Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Share-based Compensation [Abstract]	'
Summary of Activity, Restricted Share Awards	'
	Activity, restricted share awards:	Restricted		Per Share Weighted Average Grant Date Fair Value
		Shares
	Non-vested restricted shares, as of December 31, 2013	1,123,545		$	23.78
	Granted	323,249		41.05
	Vested	(181,195	)	20.26
	Canceled/forfeited	(22,442	)	17.38
	Non-vested restricted shares, as of September 30, 2014	1,243,157		$	28.9
Summary of Activity, Stock Options	'
	Activity, stock options:	Stock		Per Share Weighted Average			Weighted Average		Aggregate Intrinsic
		Options		Exercise Price			Remaining		Value (a)
							Contractual Life (in years)		(in millions)
	Options outstanding as of December 31, 2013	495,571		$	11.17		1.96		$	10.7
	Exercised	(210,900	)	9.97
	Canceled/forfeited	—		—
	Options outstanding as of September 30, 2014	284,671		$	12.06		1.54		$	5.3
	Options exercisable as of September 30, 2014	284,671		$	12.06		1.54		$	5.3
	(a)	Amount represents the difference between the exercise price and the market price of the Company’s stock on the last trading day of the corresponding period, multiplied by the number of in-the-money options.
Summary of Activity, Employee Stock Purchase Plan	'
		Nine Months Ended September 30,
	Activity, employee stock purchase plan:	2014			2013
	Cash proceeds (in millions)	$	2.5		$	6
	Common shares issued	94,761			436,925
	Weighted average per share price	$	26.6		$	13.69
	Weighted average per share grant date fair value	$	6.34		$	5.55
Summary of Stock-Based Compensation Expense And Related Tax Benefits	'
	Details of stock-based compensation expense, which is included within general and administrative expense in the condensed unaudited consolidated statement of operations for the periods indicated are as follows (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Stock-based compensation expense	$	4.1		$	3		$	11.6		$	9.6
	Income Tax Effects:
	Income tax benefit from stock-based compensation	$	1.8		$	4.5		$	8.4		$	7.7
	Excess tax benefit from stock-based compensation (a)	$	0.1		$	3		$	3.5		$	4.4
	(a)	Excess tax benefits, which represent cash flows from tax deductions in excess of the recorded tax effect of compensation expense recognized for stock options exercised and vested restricted shares, are classified as financing cash flows in the Company’s condensed unaudited consolidated statements of cash flows.

Other_Retirement_Plans_Tables

Other Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Multiemployer Plans [Abstract]	'
Schedule of Covered Employees and Contributions, Multi-Employer Plans	'
	Total contributions to multi-employer plans, and the related number of employees covered by these plans, for the periods indicated ranged as follows:
		Multi-Employer Plans
		Covered Employees		Contributions (in millions)
	For the Three Months Ended September 30:	Low	High	Pension		Post-Retirement Benefit		Total
	2014	2,029	2,167	$	11.6	$	1.1	$	12.7
	2013	2,392	2,734	$	14.9	$	1	$	15.9
	For the Nine Months Ended September 30:	Low	High	Pension		Post-Retirement Benefit		Total
	2014	1,098	2,167	$	27.3	$	2.5	$	29.8
	2013	778	2,734	$	30.2	$	3	$	33.2

Equity_Tables

Equity (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Schedule of Share Activity	'
	Share Activity (in thousands):	Common Shares			Treasury
		Outstanding			Shares
	Balance as of December 31, 2013	77,258			9,467
	Shares issued:
	Stock option exercises	211
	Restricted share awards	181
	Convertible notes	4,204			(4,204	)
	Other, net	(11	)
	Balance as of September 30, 2014	81,843			5,263
Schedule of Changes in Accumulated Other Comprehensive Loss	'
	Changes in accumulated other comprehensive loss by component during the periods indicated are as follows (in thousands):
		For the Nine Months Ended September 30,
		2014										2013
		Unrealized (Losses) Gains
		Foreign Currency				Other			Total			Foreign Currency			Other			Total
	Balance as of January 1	$	(7,998	)		$	(5,288	)	$	(13,286	)	$	(106	)	$	(5,395	)	$	(5,501	)
	Activity before reclassifications, net of tax	(10,601		)		—			(10,601		)	(3,839		)	(118		)	(3,957		)
	Reclassifications, net of tax	—				—			—			—			(440		)	(440		)
	Activity, net of tax	(10,601		)		—			(10,601		)	(3,839		)	(558		)	(4,397		)
	Balance as of September 30	$	(18,599	)		$	(5,288	)	$	(23,887	)	$	(3,945	)	$	(5,953	)	$	(9,898	)

Segments_and_Related_Informati1

Segments and Related Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Schedule of Financial Information by Reportable Segment	'
	Summarized financial information for MasTec’s reportable segments is presented and reconciled to consolidated continuing operations financial information for total MasTec in the following tables (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	Revenue:	2014			2013			2014			2013
	Communications (a)	$	505.2		$	543		$	1,480.40		$	1,464.50
	Oil and Gas	557.4			519.1			1,302.90			1,134.80
	Electrical Transmission	132.6			118.8			327.2			321.9
	Power Generation and Industrial	114.3			85.1			263.1			237.3
	Other	1.1			3.5			6.5			9.2
	Eliminations	(1.0		)	(0.1		)	(1.9		)	(2.0		)
	Consolidated revenue	$	1,309.60		$	1,269.40		$	3,378.20		$	3,165.70
	(a)	Revenue generated by utilities customers represented 7.6% and 6.9% of Communications segment revenue for the three month periods ended September 30, 2014 and 2013, respectively, and 7.0% and 7.2% of Communications segment revenue for the nine month periods ended September 30, 2014 and 2013, respectively.
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	EBITDA:	2014			2013			2014			2013
	Communications	$	52.4		$	71.8		$	153.7		$	181.6
	Oil and Gas	73			68.1			143.5			161.7
	Electrical Transmission	12.7			12.1			33.2			27
	Power Generation and Industrial	4.9			(6.4		)	9.4			(14.6		)
	Other	(0.3		)	0.1			0.1			0.5
	Corporate	(14.5		)	(13.6		)	(38.7		)	(47.9		)
	Consolidated EBITDA	$	128.2		$	132.1		$	301.2		$	308.3
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	Depreciation and Amortization:	2014			2013			2014			2013
	Communications	$	10.1		$	9.5		$	30.1		$	26.8
	Oil and Gas	23.3			22.5			61.3			60.1
	Electrical Transmission	5.2			3.2			11.9			8.4
	Power Generation and Industrial	1.7			1.7			4.8			5.1
	Corporate	1.4			0.9			3.9			2.7
	Consolidated Depreciation and Amortization	$	41.7		$	37.8		$	112		$	103.1
Reconciliation of EBITDA to Consolidated Income from Continuing Operations before Income Taxes	'
	The following table presents a reconciliation of EBITDA to consolidated income from continuing operations before income taxes (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	EBITDA Reconciliation:	2014			2013			2014			2013
	EBITDA	$	128.2		$	132.1		$	301.2		$	308.3
	Less:
	Interest expense, net	(12.6		)	(12.7		)	(37.6		)	(34.5		)
	Depreciation and amortization	(41.7		)	(37.8		)	(112.0		)	(103.1		)
	Income from continuing operations before income taxes	$	73.8		$	81.6		$	151.7		$	170.6
Schedule of Significant Customers, Revenue Concentration Information	'
	Revenue concentration information for significant customers as a percentage of total consolidated revenue was as follows:
		For the Three Months Ended September 30,			For the Nine Months Ended September 30,
		2014		2013	2014		2013
	Customer:
	AT&T (a)	16%		16%	21%		18%
	DIRECTV® (b)	12%		13%	13%		15%
	Enbridge, Inc. (c)	10%		20%	10%		14%
	(a)	The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for AT&T's wireless, wireline/fiber and home security and automation businesses. Revenue from AT&T is included in the Communications segment.
	(b)	The Company's relationship with DIRECTV® is based upon an agreement to provide installation and maintenance services for DIRECTV®. Revenue from DIRECTV® is included in the Communications segment.
	(c)	The Company's relationship with Enbridge, Inc. is based upon various construction contracts for natural gas pipelines. Revenue from Enbridge, Inc. is included in the Oil and Gas segment.

Supplemental_Guarantor_Condens1

Supplemental Guarantor Condensed Unaudited Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2014
Condensed Unaudited Financial Statements, Supplemental Guarantor Information [Abstract]	'
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income	'
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (in millions)
	For the Three Months Ended September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,043.10		$	268.5		$	(2.0	)	$	1,309.60
	Costs of revenue, excluding depreciation and amortization	—			892.6			232.4			(2.0		)	1,123.00
	Depreciation and amortization	—			30.8			10.9			—			41.7
	General and administrative expenses	0.6			50.8			8.5			—			59.9
	Interest expense, net	—			11.5			1.1			—			12.6
	Other (income) expense, net	—			(1.6		)	0.2			—			(1.4		)
	(Loss) income from continuing operations before income taxes	$	(0.6	)	$	59		$	15.4		$	—		$	73.8
	Benefit from (provision for) income taxes	0.2			(22.0		)	(6.2		)	—			(28.0		)
	Net (loss) income from continuing operations	$	(0.4	)	$	37		$	9.2		$	—		$	45.7
	Net loss from discontinued operations	—			—			(0.3		)	—			(0.3		)
	Equity in income from subsidiaries, net of tax	45.7			—			—			(45.7		)	—
	Net income (loss)	$	45.3		$	37		$	8.9		$	(45.7	)	$	45.4
	Net income attributable to non-controlling interests	—			—			0.1			—			0.1
	Net income (loss) attributable to MasTec, Inc.	$	45.3		$	37		$	8.8		$	(45.7	)	$	45.3
	Comprehensive income (loss)	$	32.3		$	37		$	(4.1	)	$	(32.7	)	$	32.5
	For the Three Months Ended September 30, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,140.90		$	129		$	(0.5	)	$	1,269.40
	Costs of revenue, excluding depreciation and amortization	—			969.5			112.1			(0.5		)	1,081.10
	Depreciation and amortization	—			31.6			6.2			—			37.8
	General and administrative expenses	0.5			50.1			8.4			—			59
	Interest expense, net	—			12			0.7			—			12.7
	Other income, net	—			(2.3		)	(0.5		)	—			(2.8		)
	(Loss) income from continuing operations before income taxes	$	(0.5	)	$	80		$	2.1		$	—		$	81.6
	Benefit from (provision for) income taxes	0.2			(31.5		)	(0.4		)	—			(31.7		)
	Net (loss) income from continuing operations	$	(0.3	)	$	48.5		$	1.7		$	—		$	49.9
	Net loss from discontinued operations	—			—			(3.7		)	—			(3.7		)
	Equity in income from subsidiaries, net of tax	46.4			—			—			(46.4		)	—
	Net income (loss)	$	46.1		$	48.5		$	(2.0	)	$	(46.4	)	$	46.2
	Net income attributable to non-controlling interests	—			—			0.1			—			0.1
	Net income (loss) attributable to MasTec, Inc.	$	46.1		$	48.5		$	(2.1	)	$	(46.4	)	$	46.1
	Comprehensive income (loss)	$	49		$	48.5		$	0.8		$	(49.3	)	$	49
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (in millions)
	For the Nine Months Ended September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	2,798.60		$	581.7		$	(2.1	)	$	3,378.20
	Costs of revenue, excluding depreciation and amortization	—			2,402.00			515			(2.1		)	2,914.90
	Depreciation and amortization	—			88.4			23.6			—			112
	General and administrative expenses	1.8			146.6			19.1			—			167.5
	Interest expense, net	—			35.6			2			—			37.6
	Other (income) expense, net	—			(5.8		)	0.3			—			(5.5		)
	(Loss) income from continuing operations before income taxes	$	(1.8	)	$	131.8		$	21.7		$	—		$	151.7
	Benefit from (provision for) income taxes	0.7			(51.2		)	(7.2		)	—			(57.7		)
	Net (loss) income from continuing operations	$	(1.1	)	$	80.6		$	14.5		$	—		$	94
	Net loss from discontinued operations	—			—			(0.6		)	—			(0.6		)
	Equity in income from subsidiaries, net of tax	94.5			—			—			(94.5		)	—
	Net income (loss)	$	93.4		$	80.6		$	13.9		$	(94.5	)	$	93.4
	Net income attributable to non-controlling interests	—			—			—			—			—
	Net income (loss) attributable to MasTec, Inc.	$	93.4		$	80.6		$	13.8		$	(94.5	)	$	93.3
	Comprehensive income (loss)	$	82.8		$	80.5		$	3.4		$	(83.9	)	$	82.8
	For the Nine Months Ended September 30, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	2,881.10		$	289		$	(4.4	)	$	3,165.70
	Costs of revenue, excluding depreciation and amortization	—			2,447.70			252			(4.4		)	2,695.30
	Depreciation and amortization	—			88.8			14.3			—			103.1
	General and administrative expenses	1.4			138.5			19.9			—			159.8
	Interest expense, net	—			33.5			1			—			34.5
	Loss on extinguishment of debt	—			5.6			—			—			5.6
	Other income, net	—			(2.4		)	(0.8		)	—			(3.2		)
	(Loss) income from continuing operations before income taxes	$	(1.4	)	$	169.4		$	2.6		$	—		$	170.6
Benefit from (provision for) income taxes	0.6			(66.0		)	(0.4		)	—			(65.8		)
Net (loss) income from continuing operations	$	(0.8	)	$	103.4		$	2.2		$	—		$	104.8
Net loss from discontinued operations	—			—			(5.2		)	—			(5.2		)
Equity in income from subsidiaries, net of tax	100.3			—			—			(100.3		)	—
Net income (loss)	$	99.5		$	103.4		$	(3.0	)	$	(100.3	)	$	99.6
Net income attributable to non-controlling interests	—			—			0.2			—			0.2
Net income (loss) attributable to MasTec, Inc.	$	99.5		$	103.4		$	(3.2	)	$	(100.3	)	$	99.4
Comprehensive income (loss)	$	95.1		$	102.8		$	(6.8	)	$	(95.9	)	$	95.2
Condensed Unaudited Consolidating Balance Sheets	'
	CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS (in millions)
	As of September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Assets
	Current assets, including discontinued operations	$	—		$	1,251.50		$	322.5		$	—		$	1,574.00
	Property and equipment, net	—			475.5			138.9			—			614.4
	Goodwill and other intangible assets, net	—			972.6			249.5			—			1,222.10
	Investments in and advances to consolidated affiliates, net	1,114.80			—			107.3			(1,222.1		)	—
	Other long-term assets, including discontinued operations	9.3			35.3			15			—			59.6
	Total assets	$	1,124.10		$	2,734.90		$	833.2		$	(1,222.1	)	$	3,470.10
	Liabilities and Equity
	Total current liabilities	$	—		$	736.6		$	174.3		$	—		$	910.9
	Long-term debt	—			1,053.60			34.7			—			1,088.30
	Advances from consolidated affiliates, net	—			23.8			—			(23.8		)	—
	Other liabilities	—			190.8			151.2			—			342
	Total liabilities	$	—		$	2,004.80		$	360.2		$	(23.8	)	$	2,341.20
	Total equity	$	1,124.10		$	730.1		$	473		$	(1,198.3	)	$	1,128.90
	Total liabilities and equity	$	1,124.10		$	2,734.90		$	833.2		$	(1,222.1	)	$	3,470.10
	As of December 31, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Assets
	Current assets, including discontinued operations	$	—		$	1,156.70		$	150.3		$	—		$	1,307.00
	Property and equipment, net	—			420.2			67.9			—			488.1
	Goodwill and other intangible assets, net	—			932.8			134.9			—			1,067.70
	Investments in and advances to consolidated affiliates, net	1,006.80			170.8			—			(1,177.6		)	—
	Other long-term assets, including discontinued operations	9.3			36.2			14.9			—			60.4
	Total assets	$	1,016.10		$	2,716.70		$	368		$	(1,177.6	)	$	2,923.20
	Liabilities and Equity
	Total current liabilities	$	—		$	773.3		$	55.9		$	—		$	829.2
	Long-term debt	—			760.9			4.5			—			765.4
	Advances from consolidated affiliates, net	—			—			22.5			(22.5		)	—
	Other liabilities	—			236.4			71.1			—			307.5
	Total liabilities	$	—		$	1,770.60		$	154		$	(22.5	)	$	1,902.10
	Total equity	$	1,016.10		$	946.1		$	214		$	(1,155.1	)	$	1,021.10
	Total liabilities and equity	$	1,016.10		$	2,716.70		$	368		$	(1,177.6	)	$	2,923.20
Condensed Unaudited Consolidating Statements of Cash Flows	'
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS (in millions)
	For the Nine Months Ended September 30, 2014:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Net cash (used in) provided by operating activities	$	(1.1	)	$	39.6		$	42.5		$	—		$	81
	Cash flows (used in) provided by investing activities:
	Cash paid for acquisitions, net of cash acquired	—			(39.9		)	(123.0		)	—			(162.9		)
	Capital expenditures	—			(75.6		)	(15.4		)	—			(91.0		)
	Proceeds from sale of property and equipment	—			10.3			1.9			—			12.2
	Payments for other investments, net	—			(1.0		)	—			—			(1.0		)
	Net cash used in investing activities	$	—		$	(106.2	)	$	(136.5	)	$	—		$	(242.7	)
	Cash flows provided by (used in) financing activities:
	Proceeds from credit facility	—			1,122.40			197.2			—			1,319.60
	Repayments of credit facility	—			(723.2		)	(232.0		)	—			(955.2		)
	Repayments of senior convertible notes	—			(105.3		)	—			—			(105.3		)
	Repayments of other borrowings and capital lease obligations	—			(45.3		)	(8.8		)	—			(54.1		)
	Excess tax benefits and net proceeds from stock-based awards	2.9			0.9			—			—			3.8
	Payments of acquisition-related contingent consideration	—			(60.3		)	—			—			(60.3		)
	Payments of financing costs	—			(1.5		)	—			—			(1.5		)
	Net financing activities and advances (to) from consolidated affiliates	(1.8		)	(124.1		)	125.9			—			—
	Net cash provided by financing activities	$	1.1		$	63.6		$	82.3		$	—		$	147
	Effect of currency translation on cash	—			—			(1.2		)	—			(1.2		)
	Net decrease in cash and cash equivalents	$	—		$	(3.0	)	$	(12.9	)	$	—		$	(15.9	)
	Cash and cash equivalents - beginning of period	—			5.3			17.7			—			23
	Cash and cash equivalents - end of period	$	—		$	2.3		$	4.8		$	—		$	7.1
	For the Nine Months Ended September 30, 2013:	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Net cash (used in) provided by operating activities	$	(2.4	)	$	103.2		$	28.5		$	—		$	129.3
	Cash flows (used in) provided by investing activities:
	Cash paid for acquisitions, net of cash acquired	—			(43.0		)	(103.6		)	—			(146.6		)
	Capital expenditures	—			(96.8		)	(4.6		)	—			(101.4		)
	Proceeds from sale of property and equipment	—			7.6			0.7			—			8.3
	Proceeds from disposal of business, net of cash divested	$	—		$	(4.3	)	$	—		$	—		$	(4.3	)
	Proceeds from other investments, net	$	—		$	3.8		$	—		$	—		$	3.8
	Net cash used in investing activities	$	—		$	(132.7	)	$	(107.5	)	$	—		$	(240.2	)
	Cash flows provided by (used in) financing activities:
	Proceeds from credit facility	$	—		$	639.6		$	126.6		$	—		$	766.2
	Repayments of credit facility	—			(737.2		)	(123.0		)	—			(860.2		)
	Proceeds from senior notes, net	—			250			—			—			250
	Repayments of other borrowings and capital lease obligations	—			(55.5		)	(1.0		)	—			(56.5		)
	Excess tax benefits and net proceeds from stock-based awards	9.2			3			—			—			12.2
	Payments of acquisition-related contingent consideration	—			(12.8		)	—			—			(12.8		)
	Payments of financing costs, including call premiums on extinguishment of debt	—			(11.8		)	—			—			(11.8		)
	Net financing activities and advances (to) from consolidated affiliates	(6.8		)	(56.4		)	63.2			—			—
	Net cash provided by financing activities	$	2.4		$	18.9		$	65.8		$	—		$	87.1
	Effect of currency translation on cash	—			—			(0.1		)	—			(0.1		)
	Net decrease in cash and cash equivalents	$	—		$	(10.6	)	$	(13.3	)	$	—		$	(23.9	)
	Cash and cash equivalents - beginning of period	—			12.7			14			—			26.7
	Cash and cash equivalents - end of period	$	—		$	2.1		$	0.7		$	—		$	2.8

Business_Basis_of_Presentation2

Business, Basis of Presentation and Significant Accounting Policies (Narrative) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
	segment
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]	'	'
Number of reportable segments	5	'
Revenue Recognition [Line Items]	'	'
Unapproved change orders, description	'The Company may incur costs subject to change orders, whether approved or unapproved by the customer, and/or claims related to certain contracts. Management determines the probability that such costs will be recovered based upon evidence such as engineering studies and legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer. The Company treats project costs as a cost of contract performance in the period incurred if it is not probable that the costs will be recovered, or defers costs and/or recognizes revenue up to the amount of the related cost if it is probable that the contract price will be adjusted and can be reliably estimated. As of September 30, 2014 and DecemberB 31, 2013, the Company had approximately $78 million and $79 million, respectively, of change orders and/or claims that had been included as contract price adjustments on certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, in arbitration and other proceedings. These contract price adjustments represent management's best estimate of additional contract revenues that have been or will be earned and that management believes are probable of collection. The amounts ultimately realized upon final acceptance by its customers could be higher or lower than such estimated amounts, which are primarily expected to be billed and collected within one year.	'
Unapproved change orders, amount	$78	$79
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'	'
Accounting Standards Not Yet Adopted	'In May 2014, the Financial Accounting Standards Board (bFASBb) issued Accounting Standards Update (bASUb) 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of this ASU is that a company will recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under current guidance and will be required to disclose information about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including disclosure of assumptions and estimates where significant judgment has been applied. ASU 2014-09 is effective using either the retrospective or cumulative effect transition method for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early application is not permitted. The Company is currently evaluating the potential impact of this ASU on its consolidated financial statements. In April 2014, the FASB issued ASU 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (bASU 2014-08b). ASU 2014-08 changes the requirements for reporting discontinued operations and requires additional disclosures about discontinued operations. Only disposals of components of an entity representing a strategic shift that has, or will have, a major effect on an entitybs operations and financial results should be reported as discontinued operations under ASU 2014-08. Examples include a disposal of a major geographical area, a major line of business, or a major equity method investment. ASU 2014-08 also requires expanded disclosures about discontinued operations and requires disclosures about individually significant dispositions that do not qualify as discontinued operations. ASU 2014-08 is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014. Early adoption is permitted only for disposals that have not been previously reported. The Company is currently evaluating the potential impact of this ASU on its consolidated financial statements.	'
Recently Adopted Accounting Pronouncements	'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) (bASU 2013-11b).B 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 adopted ASU 2013-11 as of January 1, 2014. The adoption of this ASU did not have a material impact on the condensed unaudited consolidated financial statements.	'
Plan [Member] | Maximum [Member] | Unapproved Change Orders [Member] | Unbilled Revenue [Member]	'	'
Revenue Recognition [Line Items]	'	'
Unapproved change orders, period expected to be outstanding	'1 year	'

Earnings_Per_Share_Methodology

Earnings Per Share (Methodology) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Line Items]	'
Computation of earnings per share, methodology	'Basic earnings per share is computed by dividing earnings available to MasTecbs common shareholders by the weighted average number of common shares outstanding for the period. Diluted earnings per share is computed by dividing earnings by the number of fully diluted shares, which includes the effect of dilutive potential issuances of common shares as determined using earnings from continuing operations. The potential issuance of common shares upon the exercise, conversion or vesting of outstanding stock options and unvested restricted share awards, as calculated under the treasury stock method, as well as shares associated with the Companybs outstanding convertible debt securities, may be dilutive.
Convertible Debt [Member] | 2009 Convertible Notes [Member]	'
Earnings Per Share [Line Items]	'
Computation of earnings per share, methodology	'Dilutive shares associated with the 2009 Convertible Notes are attributable to the underlying principal amounts. The number of common shares issuable upon conversion of the Companybs 2009 Convertible Notes is reflected in the calculation of weighted average diluted earnings per share for the corresponding periods by application of the bif-convertedb method to the extent its effect on the computation of earnings per share from continuing operations is dilutive. Under the bif-convertedb method, net income from continuing operations is adjusted to add back the after-tax amount of interest recognized for the period associated with the 2009 Convertible Notes, and correspondingly, the 2009 Convertible Notes are assumed to have been converted, with the resulting common shares added to the number of weighted average shares outstanding.
Convertible Debt [Member] | 2011 Convertible Notes [Member]	'
Earnings Per Share [Line Items]	'
Computation of earnings per share, methodology	'The 2011 Convertible Notes have an optional cash settlement feature under which, in June 2014, the Company settled the principal amount of the 2011 4.0% Notes in cash, and the Company intends to settle the principal amount of the 2011 4.25% Notes in cash in December 2014. Given the Company's intention, dilutive shares associated with the 2011 Convertible Notes are derived from the premium value of the notes in excess of their principal amount, calculated using the treasury stock method. The Company refers to these shares as the "premium shares."

Earnings_Per_Share_Schedule_Of

Earnings Per Share (Schedule Of Earnings Per Share Information) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Net income attributable to MasTec:	'		'		'		'
Net income, continuing operations - basic	$45,591	[1]	$49,960	[1]	$93,936	[1]	$104,702	[1]
Net income attributable to MasTec - diluted	45,291		46,217		93,510		99,685
Net loss from discontinued operations - basic and diluted	-320	[1]	-3,822	[1]	-592	[1]	-5,253	[1]
Weighted average shares outstanding:	'		'		'		'
Weighted average shares outstanding - basic	81,811		77,093		79,158		76,816
Dilutive common stock equivalents	814		775		798		774
Weighted average shares outstanding - diluted	85,824		85,464		86,416		84,733
Continuing Operations [Member]	'		'		'		'
Net income attributable to MasTec:	'		'		'		'
Net income attributable to MasTec - diluted	45,611		50,039		94,102		104,938
2009 Convertible Notes [Member]	'		'		'		'
Net income attributable to MasTec:	'		'		'		'
Interest expense, net of tax, 2009 Convertible Notes	$20		$79		$166		$236
Weighted average shares outstanding:	'		'		'		'
Dilutive shares, 2009 Convertible Notes	194		806		560		806
2011 Convertible Notes [Member] | Convertible Debt [Member]	'		'		'		'
Weighted average shares outstanding:	'		'		'		'
Dilutive premium shares, 2011 Convertible Notes	3,005		6,790		5,900		6,337
[1]	Calculated as total net income (loss) less amounts attributable to non-controlling interests.

Earnings_Per_Share_Narrative_D

Earnings Per Share (Narrative) (Details) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

4.0% Convertible Notes [Member]

2011 4.0% Notes [Member]

2009 4.0% Notes [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Common Stock [Member]

Common Stock [Member]

Common Stock [Member]

4.0% Convertible Notes [Member]

2011 4.0% Notes [Member]

2009 4.0% Notes [Member]

4.25% Convertible Notes [Member]

2011 4.25% Notes [Member]

2009 4.25% Notes [Member]

2011 4.0% Notes [Member]

2011 4.25% Notes [Member]

2011 4.25% Notes [Member]

2011 4.25% Notes [Member]

2011 4.25% Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

4.0% Convertible Notes [Member]

4.0% Convertible Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

2009 4.0% Notes [Member]

2009 4.0% Notes [Member]

4.25% Convertible Notes [Member]

2011 4.25% Notes [Member]

2009 4.25% Notes [Member]

Earnings Per Share [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$100,000,000

$97,000,000

$3,000,000

Debt instrument, convertible, interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4.00%

'

4.00%

'

4.00%

4.25%

4.25%

4.25%

Debt instrument, convertible, matured and converted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

115,000,000

'

105,300,000

'

9,600,000

'

'

'

'

Debt instrument, settlement in cash

'

'

$105,325,000

$150,000,000

'

'

'

'

'

'

'

'

'

$105,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, common shares issued

'

'

'

'

4,200,000

3,600,000

600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, conversion price per share

'

'

'

'

'

'

'

$15.76

$15.76

$15.76

$15.48

$15.48

$15.48

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Premium shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,005,000

3,314,000

3,501,000

3,097,000

3,476,000

2,400,000

3,240,000

'

'

'

'

'

'

'

'

'

Weighted average anti-dilutive common stock equivalents, shares

304,486

0

223,422

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Earnings_Per_Share_Schedule_Of1

Earnings Per Share (Schedule Of Convertible Note Premium Share Information) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
2011 4.25% Notes [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Number of conversion shares, principal amount	6,268	6,268	6,268	6,268
Premium value	$89,341	$108,864	$122,748	$94,728
2011 4.25% Notes [Member] | Convertible Debt [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Per share price, actual average	$29.73	$32.84	$35.06	$30.59
Premium shares	3,005	3,314	3,501	3,097
2011 4.0% Notes [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Number of conversion shares, principal amount	'	6,683	'	6,683
Premium value	'	$114,176	'	$99,104
2011 4.0% Notes [Member] | Convertible Debt [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Per share price, actual average	'	$32.84	'	$30.59
Premium shares	'	3,476	2,400	3,240

Acquisitions_Narrative_Details

Acquisitions (Narrative) (Details)	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Business combinations, provisional information, initial accounting incomplete, items	' As of September 30, 2014, the allocations of purchase price to the fair values of tangible and intangible assets and liabilities, including the estimated values of contingent earn-out obligations and the estimated useful lives of acquired assets for the Company's 2014 acquisitions are provisional and remain preliminary. Management continues to assess the valuation of these items and any ultimate purchase price adjustments that may result based on the final net assets and net working capital of the acquired businesses, as prescribed in the corresponding purchase agreements.
Business combinations, provisional information, initial accounting incomplete, reasons	'The Company will revise its preliminary allocations for acquired businesses if new information is obtained about the facts and circumstances existing as of the date of acquisition, or for purchase price adjustments, based on the final net assets and net working capital of the acquired businesses, as prescribed in the applicable purchase agreement.

Acquisitions_2014_Acquisitions

Acquisitions (2014 Acquisitions) (Narrative) (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Jun. 01, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 01, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 01, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 01, 2014

Sep. 30, 2014

Apr. 01, 2014

Sep. 30, 2014

Apr. 01, 2014

Sep. 30, 2014

Jan. 01, 2014

Sep. 30, 2014

Jan. 01, 2014

Sep. 30, 2014

Performance Guarantees [Member]

Performance Guarantees [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

Pacer [Member]

April 2014 Acquisitions [Member]

April 2014 Acquisitions [Member]

April 2014 Acquisitions [Member]

April 2014 Acquisitions [Member]

January 2014 Acquisitions [Member]

January 2014 Acquisitions [Member]

January 2014 Acquisitions [Member]

January 2014 Acquisitions [Member]

Investee [Member]

Investee [Member]

Investee [Member]

Investee [Member]

Investee [Member]

Investee [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Current Liabilities [Member]

Liability [Member]

Liability [Member]

Other Non-Current Assets [Member]

Earn-Out Arrangements [Member]

Liability [Member]

Earn-Out Arrangements [Member]

Liability [Member]

Performance Guarantees [Member]

Performance Guarantees [Member]

Other Financial Guarantees [Member]

Financing Receivables [Member]

Related Customer [Member]

Related Customer [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Beneficial Ownership [Member]

Other Current Assets [Member]

Infrastructure Construction Services [Member]

Infrastructure Construction Services [Member]

Business Combinations [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combinations, effective date

'

'

'

'

'

'

1-Jun-14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1-Apr-14

'

'

'

1-Jan-14

'

'

Business combinations, percentage of voting interests acquired

'

'

'

'

'

100.00%

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

'

'

'

100.00%

'

'

Business combinations, name of acquired entity

'

'

'

'

'

'

'Pacer Construction Holdings Corporation and its affiliated operating companies (collectively, "Pacer")

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combinations, description of acquired entity

'

'

'

'

'

'

'Pacer is a western Canadian civil construction services company, headquartered in Calgary, Alberta, Canada.B Pacerbs services include infrastructure construction primarily in support of oil and gas production, processing, mining and transportation.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'a telecommunications services firm that specializes in the installation of in-home security systems

'

'

'

'a telecommunications services firm that specializes in the engineering, installation, furnishing and integration of telecommunications equipment

'

'

Business combination, provisional information, initial accounting incomplete, adjustment, assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

($9,800,000)

'

'

'

'

'

'

'

'

Business combinations, provisional information, initial accounting incomplete, adjustment, liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,400,000

7,800,000

'

'

'

'

'

'

'

'

'

'

'

Business combinations, provisional information, initial accounting incomplete, adjustment, intangible assets

'

'

'

'

'

2,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combinations, provisional information, initial accounting incomplete, adjustment, goodwill

'

'

'

'

'

16,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combinations, goodwill recognized, description

'

'

'

'

'

'

'Goodwill arising from the acquisition represents the estimated value of Pacer's geographic presence in key high-growth Canadian markets, its assembled workforce, its management team's industry-specific project management expertise and synergies expected to be achieved from the combined operations of Pacer and MasTec.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combinations, goodwill, expected tax deductible amount

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue, related parties

'

'

'

'

'

'

'

'

'

'

'

'

2,000,000

3,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Receivables, related parties

'

'

'

'

'

'

'

'

'

'

'

'

2,500,000

2,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other receivables, due from related parties

'

'

'

'

'

'

'

'

'

'

'

14,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Guarantees issued, related parties

748,600,000

1,100,000,000

'

'

'

'

'

'

219,000,000

92,000,000

31,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combinations, contingent consideration arrangements, basis for amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'The contingent consideration included in the table above is equal to 25% of the excess, if any, of Pacerbs earnings from continuing operations before interest, taxes, depreciation and amortization (bEBITDAb) above certain thresholds for a five-year period, as set forth in the purchase agreement, and is payable annually in Canadian dollars.

'

'

'

'

'

'

'

'

'

'

Business combinations, contingent consideration, percentage of excess EBITDA

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

25.00%

'

'

'

'

'

'

'

'

'

'

Business combinations, contingent consideration, earn-out period (in years)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'5 years

'

'

'

'5 years

Business combinations, contingent consideration, fair value measurements, significant assumptions

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'The fair value of the earn-out liability was estimated using an income approach and incorporates significant inputs not observable in the market. Key assumptions in the estimated valuation include the discount rate and probability-weighted EBITDA projections.

'

'

'

'

'

'

'

'

'

'

Business combinations, contingent consideration arrangements, range of outcomes, value, low

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

Business combinations, contingent consideration arrangements, range of outcomes, value, high

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

69,000,000

'

'

'

'

'

'

'

'

'

Business combinations, contingent consideration arrangements, range of outcomes, maximum unlimited

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'there is no maximum earn-out payment amount

'

'

'

'

'

'

'

'

'

'

Business combinations, payments in cash

'

'

'

'

126,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

17,200,000

'

'

'

23,800,000

'

'

'

Fair value of contingent consideration (earn-out liability)

'

'

$34,988,000

$29,971,000

'

'

'

'

'

'

'

'

'

'

$25,700,000

'

'

'

'

'

'

'

$600,000

'

'

'

$8,700,000

'

Acquisitions_Schedule_of_Consi

Acquisitions (Schedule of Consideration Paid And Net Assets Acquired, Business Acquisitions) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 01, 2014	Jun. 01, 2014	Jun. 01, 2014	Jun. 01, 2014	Jun. 01, 2014
			Earn-Out Arrangements [Member]	Earn-Out Arrangements [Member]	Pacer [Member]	Pacer [Member]	Pacer [Member]	Pacer [Member]	Pacer [Member]
							Pre-Qualifications [Member]	Equity Method Investments [Member]	Earn-Out Arrangements [Member]
Acquisition consideration:	'	'	'	'	'	'	'	'	'
Cash	'	'	'	'	$126,500,000	'	'	'	'
Fair value of contingent consideration (earn-out liability)	'	'	34,988,000	29,971,000	'	'	'	'	25,700,000
Total consideration transferred	'	'	'	'	152,200,000	'	'	'	'
Identifiable assets acquired and liabilities assumed:	'	'	'	'	'	'	'	'	'
Current assets	'	'	'	'	'	118,400,000	'	'	'
Equity method investments	'	'	'	'	'	'	'	2,300,000	'
Other long-term assets	'	'	'	'	'	100,000	'	'	'
Property and equipment	'	'	'	'	'	72,800,000	'	'	'
Pre-qualifications	'	'	'	'	'	'	41,200,000	'	'
Finite-lived intangible assets	'	'	'	'	'	20,300,000	'	'	'
Current liabilities	'	'	'	'	'	-55,800,000	'	'	'
Long-term debt	'	'	'	'	'	-87,000,000	'	'	'
Deferred income taxes	'	'	'	'	'	-29,600,000	'	'	'
Total identifiable net assets	'	'	'	'	'	82,700,000	'	'	'
Goodwill	1,000,024,000	902,044,000	'	'	'	69,500,000	'	'	'
Total net assets acquired, including goodwill	'	'	'	'	'	$152,200,000	'	'	'

Acquisitions_Schedule_of_Finit

Acquisitions (Schedule of Finite-Lived Intangible Assets Acquired, Business Acquisitions) (Details) (Pacer [Member], USD $)	0 Months Ended
In Millions, unless otherwise specified	Jun. 01, 2014	Jun. 01, 2014
Finite-Lived Intangible Assets Acquired [Line Items]	'	'
Finite-lived intangible assets	'	$20.30
Finite-lived intangible assets, weighted average useful life	'6 years	'
Backlog [Member]	'	'
Finite-Lived Intangible Assets Acquired [Line Items]	'	'
Finite-lived intangible assets	'	6.1
Finite-lived intangible assets, weighted average useful life	'2 years	'
Non-Compete Agreements [Member]	'	'
Finite-Lived Intangible Assets Acquired [Line Items]	'	'
Finite-lived intangible assets	'	2.3
Finite-lived intangible assets, weighted average useful life	'8 years	'
Customer Relationships [Member]	'	'
Finite-Lived Intangible Assets Acquired [Line Items]	'	'
Finite-lived intangible assets	'	$11.90
Finite-lived intangible assets, weighted average useful life	'8 years	'

Acquisitions_2013_Acquisitions

Acquisitions (2013 Acquisitions) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2014
Big Country [Member]	'
Business Combinations [Line Items]	'
Business combinations, effective date	1-May-13
Business combinations, percentage of voting interests acquired	100.00%
Business combinations, name of acquired entity	'Big Country Energy Services, Inc. and its affiliated operating companies (collectively, "Big Country").
Business combinations, description of acquired entity	'Big Country, which is included in the Company's Oil and Gas segment, is a North American oil and gas pipeline and facility construction services company, headquartered in Calgary, Alberta, Canada.
April 2013 Acquisition [Member]	'
Business Combinations [Line Items]	'
Business combinations, effective date	1-Apr-13
Business combinations, description of acquired entity	'a former subcontractor to its wireless business, which provides self-perform communications tower construction, installation, maintenance and other services in support of telecommunications infrastructure construction
August 2013 Acquisition [Member]	'
Business Combinations [Line Items]	'
Business combinations, effective date	1-Aug-13
Business combinations, description of acquired entity	'an electrical transmission services company that provides substation construction activities

Acquisitions_Schedule_of_Measu

Acquisitions (Schedule of Measurement Period Adjustments, Business Acquisitions) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Measurement Period Adjustments [Line Items]	'	'
Current assets	$1,573,952	$1,307,026
Goodwill	1,000,024	902,044
Current liabilties	910,874	829,225
Long-term deferred tax liabilities, net	180,449	154,763
As Previously Reported [Member]	'	'
Measurement Period Adjustments [Line Items]	'	'
Current assets	'	1,306,000
Goodwill	'	899,400
Current liabilties	'	825,500
Long-term deferred tax liabilities, net	'	154,900
Measurement Period Adjustments [Member] | 2013 Acquisitions [Member]	'	'
Measurement Period Adjustments [Line Items]	'	'
Current assets	'	1,000
Goodwill	'	2,600
Current liabilties	'	3,700
Long-term deferred tax liabilities, net	'	($100)

Acquisitions_Schedule_of_Pro_F

Acquisitions (Schedule of Pro Forma Information, Business Acquisitions) (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Business Combinations [Line Items]	'		'		'		'
Business combinations, pro forma information, description	'		'		'The unaudited supplemental pro forma financial information presented below has been prepared by adjusting the historical results of MasTec to include the historical results of the acquired businesses described above. The unaudited supplemental pro forma combined historical results were then adjusted (i) to remove one-time acquisition costs; (ii) to increase amortization expense resulting from the incremental intangible assets acquired in such acquisitions; (iii) to increase interest expense as a result of the cash consideration paid; and (iv) to reduce interest expense from the repayment of acquired debt. The unaudited supplemental pro forma financial information does not include any adjustments to reflect the impact of cost savings or other synergies that may result from these acquisitions. As noted above, the unaudited supplemental pro forma financial information does not purport to be indicative of the actual results that would have been achieved by the combined companies for the periods presented or that may be achieved by the combined companies in the future.		'
Business combinations, pro forma revenue	$1,309.60		$1,417.50		$3,496		$3,667.30
Business combinations, pro forma net income from continuing operations	46		52.4		96.5		118
Business combinations, acquiree revenue, year over year incremental impact	133.2		141.6		342.5		270.4
Business combinations, acquiree net income from continuing operations, year over year incremental impact	2.3	[1]	7.5	[1]	4.5	[1]	12.8	[1]
General and Administrative Costs [Member]	'		'		'		'
Business Combinations [Line Items]	'		'		'		'
Business combinations, acquisition costs	$0.40		$0.30		$2		$1.60
[1]	The above results do not include acquisition costs totaling $0.4 million and $0.3 million for the three month periods ended SeptemberB 30, 2014 and 2013, respectively, and $2.0 million and $1.6 million for the nine month periods ended SeptemberB 30, 2014 and 2013, respectively. Acquisition costs are included within general and administrative costs in the Company's consolidated unaudited statements of operations. The above results also do not include interest expense associated with consideration paid for these acquisitions.

Discontinued_Operations_Narrat

Discontinued Operations (Narrative) (Details) (Globetec [Member])	0 Months Ended	9 Months Ended
	Aug. 31, 2013	Sep. 30, 2014
Globetec [Member]	'	'
Discontinued Operations Disclosures [Line Items]	'	'
Discontinued operation, description	'	'In 2012, the Company's board of directors approved a plan of sale for Globetec Construction, LLC ("Globetec"). Accordingly, Globetec's projects and assets are reflected as assets and liabilities of discontinued operations, and Globetec's results of operations are presented as discontinued operations in the condensed unaudited consolidated financial statements for all periods presented. Effective AugustB 31, 2013, the Company sold all of its membership interests in Globetec for nominal consideration and retained certain contingent assets and liabilities.
Discontinued operation, disposal date	'	31-Aug-13
Discontinued operation, membership interests remaining	0.00%	'

Discontinued_Operations_Summar

Discontinued Operations (Summary of Assets and Liabilities) (Details) (Globetec [Member], USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Globetec [Member]	'	'
Discontinued Operations Disclosures [Line Items]	'	'
Current assets	$5	$2.30
Long-term assets	7.1	10.1
Assets of discontinued operations	12.1	12.4
Current liabilities of discontinued operations	$1.20	$1.20

Discontinued_Operations_Result

Discontinued Operations (Results of Operations) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Discontinued Operations Disclosures [Line Items]	'	'	'	'
Net loss from discontinued operations	($320,000)	($3,735,000)	($592,000)	($5,165,000)
Globetec [Member]	'	'	'	'
Discontinued Operations Disclosures [Line Items]	'	'	'	'
Revenue	'	4,800,000	'	18,000,000
Loss from operations, before tax	'	-500,000	'	-2,700,000
Impairment of assets, before tax	'	-5,700,000	'	-6,000,000
Income tax benefit	'	2,500,000	'	3,500,000
Net loss from discontinued operations	'	($3,700,000)	'	($5,200,000)

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Rollforward of Goodwill by Segment) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Goodwill [Line Items]	'
Goodwill, beginning balance	$902,044,000
Additions from new business combinations, goodwill	98,100,000
Currency translation adjustments, goodwill	-4,700,000
Goodwill, ending balance	1,000,024,000
Earn-Out Arrangements [Member]	'
Goodwill [Line Items]	'
Accruals of acquisition-related contingent consideration, net	4,600,000	[1]
Reportable Segments [Member] | Communications [Member]	'
Goodwill [Line Items]	'
Goodwill, beginning balance	326,800,000
Additions from new business combinations, goodwill	28,600,000
Currency translation adjustments, goodwill	0
Goodwill, ending balance	360,000,000
Reportable Segments [Member] | Oil and Gas [Member]	'
Goodwill [Line Items]	'
Goodwill, beginning balance	307,700,000
Additions from new business combinations, goodwill	69,500,000
Currency translation adjustments, goodwill	-4,700,000
Goodwill, ending balance	372,500,000
Reportable Segments [Member] | Electrical Transmission [Member]	'
Goodwill [Line Items]	'
Goodwill, beginning balance	149,900,000
Additions from new business combinations, goodwill	0
Currency translation adjustments, goodwill	0
Goodwill, ending balance	149,900,000
Reportable Segments [Member] | Power Generation and Industrial [Member]	'
Goodwill [Line Items]	'
Goodwill, beginning balance	117,600,000
Additions from new business combinations, goodwill	0
Currency translation adjustments, goodwill	0
Goodwill, ending balance	117,600,000
Reportable Segments [Member] | Earn-Out Arrangements [Member] | Communications [Member]	'
Goodwill [Line Items]	'
Accruals of acquisition-related contingent consideration, net	4,600,000	[1]
Reportable Segments [Member] | Earn-Out Arrangements [Member] | Oil and Gas [Member]	'
Goodwill [Line Items]	'
Accruals of acquisition-related contingent consideration, net	0	[1]
Reportable Segments [Member] | Earn-Out Arrangements [Member] | Electrical Transmission [Member]	'
Goodwill [Line Items]	'
Accruals of acquisition-related contingent consideration, net	0	[1]
Reportable Segments [Member] | Earn-Out Arrangements [Member] | Power Generation and Industrial [Member]	'
Goodwill [Line Items]	'
Accruals of acquisition-related contingent consideration, net	$0	[1]
[1]	Represents contingent consideration for acquisitions prior to January 1, 2009, which is accrued as earned, in accordance with U.S. GAAP.

Recovered_Sheet1

Goodwill And Other Intangible Assets (Rollforward of Other Intangible Assets) (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013
Other Intangible Assets [Line Items]	'		'	'		'	'
Other intangible assets, gross carrying amount	'		'	'		'	$245,100,000
Accumulated amortization	'		'	'		'	-79,500,000
Other Intangible Assets [Rollforward]	'		'	'		'	'
Other intangible assets, net, beginning balance	'		'	165,606,000		'	'
Additions from new business combinations, other intangible assets	'		'	77,000,000		'	'
Amortization expense	-6,600,000		-5,800,000	-17,000,000		-15,200,000	'
Currency translation adjustments, other intangible assets	'		'	-3,400,000		'	'
Other intangible assets, net, ending balance	222,212,000		'	222,212,000		'	'
Customer Relationships and Backlog [Member]	'		'	'		'	'
Other Intangible Assets [Line Items]	'		'	'		'	'
Other intangible assets, amortizing, gross carrying amount	'		'	'		'	128,400,000
Accumulated amortization	'		'	'		'	-67,700,000
Other Intangible Assets [Rollforward]	'		'	'		'	'
Other intangible assets, net, amortizing, beginning balance	'		'	60,700,000		'	'
Additions from new business combinations, amortizing intangible assets	'		'	33,100,000		'	'
Amortization expense	'		'	-15,700,000		'	'
Currency translation adjustments, amortizing intangible assets	'		'	-800,000		'	'
Other intangible assets, net, amortizing, ending balance	77,300,000		'	77,300,000		'	'
Other Amortizing Intangible Assets [Member]	'		'	'		'	'
Other Intangible Assets [Line Items]	'		'	'		'	'
Other intangible assets, amortizing, gross carrying amount	'		'	'		'	22,500,000	[1]
Accumulated amortization	'		'	'		'	-11,800,000	[1]
Other Intangible Assets [Rollforward]	'		'	'		'	'
Other intangible assets, net, amortizing, beginning balance	'		'	10,700,000	[1]	'	'
Additions from new business combinations, amortizing intangible assets	'		'	2,700,000	[1]	'	'
Amortization expense	'		'	-1,300,000	[1]	'	'
Currency translation adjustments, amortizing intangible assets	'		'	0	[1]	'	'
Other intangible assets, net, amortizing, ending balance	12,100,000	[1]	'	12,100,000	[1]	'	'
Trade Names [Member]	'		'	'		'	'
Other Intangible Assets [Line Items]	'		'	'		'	'
Other intangible assets, non-amortizing, gross carrying amount	34,800,000		'	34,800,000		'	'
Other Intangible Assets [Rollforward]	'		'	'		'	'
Other intangible assets, non-amortizing, beginning balance	'		'	34,800,000		'	'
Additions from new business combinations, non-amortizing intangible assets	'		'	0		'	'
Currency translation adjustments, non-amortizing intangible assets	'		'	0		'	'
Other intangible assets, non-amortizing, ending balance	34,800,000		'	34,800,000		'	'
Pre-Qualifications [Member]	'		'	'		'	'
Other Intangible Assets [Line Items]	'		'	'		'	'
Other intangible assets, non-amortizing, gross carrying amount	98,000,000		'	98,000,000		'	'
Other Intangible Assets [Rollforward]	'		'	'		'	'
Other intangible assets, non-amortizing, beginning balance	'		'	59,400,000		'	'
Additions from new business combinations, non-amortizing intangible assets	'		'	41,200,000		'	'
Currency translation adjustments, non-amortizing intangible assets	'		'	-2,600,000		'	'
Other intangible assets, non-amortizing, ending balance	$98,000,000		'	$98,000,000		'	'
[1]	Consists principally of amortizing trade names and non-compete agreements.

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'	'
Amortization expense, intangible assets	$6.60	$5.80	$17	$15.20

Recovered_Sheet2

Fair Value Of Financial Instruments (Narrative) (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Fair Value, Measurements, Non-Recurring [Member]

Fair Value, Measurements, Non-Recurring [Member]

Level 1 [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Earn-Out Arrangements [Member]

Fair Value, Measurements, Non-Recurring [Member]

Foreign Currency Translation Adjustments [Member]

Foreign Currency Translation Adjustments [Member]

Foreign Currency Translation Adjustments [Member]

Foreign Currency Translation Adjustments [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Unsecured Debt [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value [Member]

Fair Value [Member]

Senior Notes [Member]

Liability [Member]

Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

ASC 805 contingent consideration, fair value

'

'

'

'

'

'

'

'

'

'

'

'

$149,600,000

$165,400,000

Fair value measurements, valuation techniques

'

'

'The estimated fair values of the Companybs 4.875% Senior Notes, 2009 Convertible Notes and 2011 Convertible Notes are based on quoted market prices, a Level 1 input.

'

'

'

'

'

'

'

'

'The fair value of ASC 805 contingent consideration is based on management estimates and entity-specific assumptions and is evaluated on an on-going basis.

'

'

Additions from new business combinations, ASC 805 contingent consideration

'

'

'

0

3,300,000

35,000,000

30,000,000

'

'

'

'

'

'

'

Payments of ASC 805 contingent consideration

'

'

'

1,300,000

0

48,300,000

2,700,000

'

'

'

'

'

'

'

Foreign currency translation gains (losses), other comprehensive income, ASC 805 contingent consideration

'

'

'

'

'

'

'

2,900,000

-700,000

2,500,000

1,100,000

'

'

'

Cost and equity method investments, including long-term receivables from investees and joint ventures, aggregate carrying value

$15,000,000

$15,800,000

'

'

'

'

'

'

'

'

'

'

'

'

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Schedule Of Fair Values Of Selected Financial Instruments Measured On A Non-Recurring Basis) (Details) (Unsecured Debt [Member], USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Senior Notes [Member] | 4.875% Senior Notes [Member]	'	'
Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]	'	'
Debt instrument, interest rate	4.88%	'
Fair Value, Measurements, Non-Recurring [Member] | 2009 Convertible Notes [Member] | Carrying Amount [Member]	'	'
Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]	'	'
Convertible notes	$3	$12.60
Fair Value, Measurements, Non-Recurring [Member] | 2009 Convertible Notes [Member] | Fair Value [Member]	'	'
Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]	'	'
Convertible notes	5.9	26.6
Fair Value, Measurements, Non-Recurring [Member] | 2011 Convertible Notes [Member] | Carrying Amount [Member]	'	'
Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]	'	'
Convertible notes	97	198.3
Fair Value, Measurements, Non-Recurring [Member] | 2011 Convertible Notes [Member] | Fair Value [Member]	'	'
Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]	'	'
Convertible notes	192.1	428.3
Fair Value, Measurements, Non-Recurring [Member] | Senior Notes [Member] | 4.875% Senior Notes [Member] | Carrying Amount [Member]	'	'
Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]	'	'
Senior notes	400	400
Fair Value, Measurements, Non-Recurring [Member] | Senior Notes [Member] | 4.875% Senior Notes [Member] | Fair Value [Member]	'	'
Fair Value, Selected Financial Instruments Measured on A Recurring and Non-Recurring Basis [Line Items]	'	'
Senior notes	$377	$380

Recovered_Sheet3

Accounts Receivable, Net Of Allowance (Schedule Of Accounts Receivable, Net of Allowance) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Receivables [Abstract]	'	'
Contract billings	$775,600,000	$606,500,000
Retainage	179,300,000	159,300,000
Costs and earnings in excess of billings	451,700,000	384,600,000
Accounts receivable, gross	1,406,600,000	1,150,400,000
Less allowance for doubtful accounts	-16,700,000	-15,700,000
Accounts receivable, net	$1,389,903,000	$1,134,693,000

Accounts_Receivable_Net_of_All2

Accounts Receivable, Net of Allowance (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Receivables [Abstract]	'	'	'	'
Provision for doubtful accounts	$0.30	$1.90	$1.10	$4.40

Property_And_Equipment_Net_Sch

Property And Equipment, Net (Schedule Of Property And Equipment, Net) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Property and Equipment [Line Items]	'	'
Property and equipment	$1,060,700,000	$863,400,000
Less accumulated depreciation and amortization	-446,300,000	-375,300,000
Property and equipment, net	614,359,000	488,132,000
Land [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	4,600,000	4,800,000
Building and Leasehold Improvements [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	19,200,000	18,000,000
Machinery and Equipment [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	901,600,000	727,100,000
Office Furniture and Equipment [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	118,100,000	102,500,000
Construction in Progress [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	$17,200,000	$11,000,000

Property_And_Equipment_Net_Nar

Property And Equipment, Net (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Property and Equipment [Line Items]	'	'	'	'
Depreciation and amortization	$41,747	$37,756	$111,996	$103,111
Property and Equipment [Member]	'	'	'	'
Property and Equipment [Line Items]	'	'	'	'
Depreciation and amortization	$35,200	$32,000	$95,000	$87,900

Debt_Schedule_of_Carrying_Valu

Debt (Schedule of Carrying Values of Long-Term Debt) (Details)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

USD ($)

USD ($)

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Senior Notes [Member]

Senior Notes [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Other Credit Facilities [Member]

Other Credit Facilities [Member]

Other Credit Facilities [Member]

Other Credit Facilities [Member]

Capital Lease Obligations [Member]

Notes Payable [Member]

Notes Payable [Member]

Revolving Loans [Member]

Revolving Loans [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Revolving Loans [Member]

Revolving Loans [Member]

Revolving Loans [Member]

Equipment [Member]

Equipment [Member]

USD ($)

USD ($)

4.875% Senior Notes [Member]

4.875% Senior Notes [Member]

2011 4.0% Notes [Member]

2009 4.0% Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

2011 4.25% Notes [Member]

2011 4.25% Notes [Member]

2009 4.0% Notes [Member]

2009 4.0% Notes [Member]

2009 4.25% Notes [Member]

2009 4.25% Notes [Member]

USD ($)

CAD

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of credit facility, maturity date

'

'

29-Oct-18

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3-Mar-15

'

'

'

'

'

'

Debt instrument, maturity date

'

'

'

'

'

15-Mar-23

'

15-Jun-14

15-Jun-14

'

'

15-Dec-14

'

'

'

15-Dec-14

'

'

'

'

'

'

'

'

Capital lease obligations, expiration date, range, end

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13-Jun-21

'

'

Notes payable, maturity date, range, end

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1-Sep-18

'

Carrying value of debt

'

'

'

$449,500,000

$53,000,000

$400,000,000

$400,000,000

'

'

$0

$103,800,000

$96,400,000

$94,500,000

$0

$9,600,000

$3,000,000

$3,000,000

'

$4,800,000

5,400,000

$0

'

$42,800,000

$26,900,000

Capital lease obligations

163,600,000

126,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total debt

1,160,100,000

816,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Less current maturities

-71,798,000

-51,376,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt

$1,088,289,000

$765,425,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt_Schedule_of_Carrying_Valu1

Debt (Schedule of Carrying Values of Long-Term Debt) (Parenthetical) (Details)	Sep. 30, 2014
Capital Lease Obligations [Member]	'
Debt Instrument [Line Items]	'
Long-term debt instrument, weighted average interest rate	2.80%
Notes Payable [Member] | Equipment [Member]	'
Debt Instrument [Line Items]	'
Long-term debt instrument, weighted average interest rate	2.90%
Unsecured Debt [Member] | Senior Notes [Member] | 4.875% Senior Notes [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, interest rate	4.88%
Unsecured Debt [Member] | Convertible Debt [Member] | 2011 4.0% Notes [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, interest rate	4.00%
Unsecured Debt [Member] | Convertible Debt [Member] | 2009 4.0% Notes [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, interest rate	4.00%
Unsecured Debt [Member] | Convertible Debt [Member] | 2011 4.25% Notes [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, interest rate	4.25%
Unsecured Debt [Member] | Convertible Debt [Member] | 2009 4.25% Notes [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, interest rate	4.25%

Debt_Senior_Secured_Credit_Fac

Debt (Senior Secured Credit Facility) (Narrative) (Details) (USD $)	0 Months Ended		9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Credit Facility [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, maximum borrowing capacity	$1,000,000,000	'	$1,000,000,000	$750,000,000	'
Line of credit facility, maturity date	'	'	29-Oct-18	'	'
Line of credit facility, letters of credit issued	135,600,000	'	135,600,000	'	134,800,000
Line of credit facility, remaining borrowing capacity	262,500,000	'	262,500,000	'	562,100,000
Line of credit facility, reduction in remaining borrowing capacity	152,000,000	'	'	'	'
Line of credit facility, unused facility fee	0.35%	0.30%	'	'	'
Credit Facility [Member] | Revolving Credit Facility [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, amount outstanding	449,500,000	53,000,000	449,500,000	'	53,000,000
Credit Facility [Member] | Letters of Credit [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, capacity available for letters of credit	262,500,000	315,200,000	262,500,000	'	315,200,000
Credit Facility [Member] | Letters of Credit [Member] | Performance Standby [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, interest rate	0.88%	0.75%	0.88%	'	0.75%
Credit Facility [Member] | Letters of Credit [Member] | Financial Standby [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, interest rate	1.75%	1.50%	1.75%	'	1.50%
Credit Facility [Member] | Plan [Member] | Accordion [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, maximum borrowing capacity	250,000,000	'	250,000,000	'	'
Credit Facility [Member] | Maximum [Member] | Canadian Dollars and Mexican Pesos [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, revolving loan sublimit	200,000,000	'	200,000,000	'	'
Credit Facility [Member] | Maximum [Member] | Canadian Dollars [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, revolving loan sublimit	'	'	'	$100,000,000	'
Credit Facility [Member] | Weighted Average [Member] | Revolving Credit Facility [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Line of credit facility, interest rate	2.12%	2.14%	2.12%	'	2.14%
Convertible Debt [Member] | Unsecured Debt [Member] | 4.25% Convertible Notes [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Debt instrument, interest rate	4.25%	'	4.25%	'	'

Debt_Other_Credit_Facilities_N

Debt (Other Credit Facilities) (Narrative) (Details) (Other Credit Facilities [Member])	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014
	USD ($)	CAD	Plan [Member]	Revolving Loans [Member]	Revolving Loans [Member]	Revolving Loans [Member]	Revolving Loans [Member]
				USD ($)	CAD	USD ($)	Weighted Average [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'
Line of credit facility, maximum borrowing capacity	$31,300,000	35,000,000	'	'	'	'	'
Line of credit facility, amount outstanding	'	'	'	$4,800,000	5,400,000	$0	'
Line of credit facility, interest rate	'	'	'	'	'	'	4.00%
Line of credit facility, maturity date	3-Mar-15	3-Mar-15	'	'	'	'	'
Debt instrument, intent to refinance, description	'	'	'Outstanding borrowings under the Company's other credit facilities that are not renewed are repaid with borrowings under the Credit Facility. Accordingly, the carrying amounts of the Company's borrowings under other credit facilities are classified within long-term debt in the Company's condensed unaudited consolidated balance sheet as of SeptemberB 30, 2014.	'	'	'	'

Debt_Senior_Convertible_Notes_

Debt (Senior Convertible Notes) (Narrative) (Details) (USD $)

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

4.0% Convertible Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

2009 4.0% Notes [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Common Stock [Member]

Common Stock [Member]

Common Stock [Member]

4.0% Convertible Notes [Member]

4.0% Convertible Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

4.25% Convertible Notes [Member]

2011 4.25% Notes [Member]

4.0% Convertible Notes [Member]

2011 4.0% Notes [Member]

2009 4.0% Notes [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Common Stock [Member]

4.25% Convertible Notes [Member]

2011 4.25% Notes [Member]

2011 4.25% Notes [Member]

2011 Convertible Notes [Member]

4.0% Convertible Notes [Member]

4.0% Convertible Notes [Member]

2011 4.0% Notes [Member]

2011 4.0% Notes [Member]

2009 4.0% Notes [Member]

2009 4.0% Notes [Member]

Plan [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4.25%

4.25%

'

'

'

4.00%

'

4.00%

'

4.00%

Debt instrument, convertible, matured and converted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$115,000,000

'

$105,300,000

'

$9,600,000

'

Debt instrument, convertible, maturity date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15-Dec-14

15-Dec-14

'

'

'

15-Jun-14

'

15-Jun-14

'

15-Jun-14

Debt instrument, convertible, conversion ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.0634417

0.0634417

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, conversion rate denominator

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000

'

1,000

Debt instrument, convertible, conversion price per share

'

'

'

'

'

'

'

'

'

'

'

$15.48

$15.48

$15.76

$15.76

$15.76

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, common shares issued

'

'

4,200,000

'

'

3,600,000

600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, settlement in cash

105,325,000

150,000,000

'

'

'

'

'

'

'

105,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, common shares issued, value

'

'

'

114,785,000

0

'

'

'

'

'

114,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, shares reissued from treasury

'

'

'

'

'

'

'

4,200,000

4,204,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, convertible, intent to refinance, description

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'The Company expects to settle the principal amount of its 2011 4.25% Notes on a long-term basis with proceeds from the Credit Facility, or through other sources of available funding, and the premium value in shares, consistent with the settlement of the 2011 4.0% Notes in June 2014. Therefore, the Company has reflected the carrying amounts of these notes within long-term debt in the condensed unaudited consolidated balance sheets.

'

'

'

'

'

'

'

Debt instrument, convertible, unamortized debt discount and financing costs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$600,000

'

$4,000,000

'

'

'

'

'

'

Debt_Debt_Guarantees_and_Coven

Debt (Debt Guarantees and Covenants) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2014
Debt Instrument [Line Items]	'
Debt instrument, covenant compliance	'MasTec was in compliance with the provisions and covenants of its outstanding debt instruments as of September 30, 2014 and December 31, 2013.
Credit Facility [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, guarantees	'The Credit Facility is guaranteed by certain subsidiaries of the Company.
Senior Notes [Member] | Unsecured Debt [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, guarantees	'The Companybs 4.875% Senior Notes, 2011 Convertible Notes and 2009 Convertible Notes are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company's existing and future 100%-owned direct and indirect domestic subsidiaries that are guarantors of the Credit Facility or other outstanding indebtedness.
Senior Notes [Member] | Guarantor Subsidiaries [Member]	'
Debt Instrument [Line Items]	'
Guarantor subsidiaries, percentage of voting interests owned	100.00%

Debt_Schedule_Of_Interest_Expe

Debt (Schedule Of Interest Expense, Net) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Interest expense:	'	'	'	'
Contractual and other interest expense	$11,300,000	$10,400,000	$31,600,000	$27,900,000
Accretion of senior convertible note discount	600,000	1,300,000	3,400,000	3,900,000
Amortization of deferred financing costs	800,000	1,000,000	2,700,000	3,000,000
Total interest expense	12,700,000	12,700,000	37,700,000	34,800,000
Interest income	-100,000	0	-100,000	-300,000
Interest expense, net	$12,643,000	$12,666,000	$37,595,000	$34,549,000

Lease_Obligations_Capital_Leas

Lease Obligations (Capital Leases) (Narrative) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Leases [Abstract]	'	'
Assets held under capital lease, gross	$276.20	$199.60
Assets held under capital lease, net	$203.70	$141.30

Lease_Obligations_Operating_Le

Lease Obligations (Operating Leases) (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Lease Term In Excess Of One Year [Member]	'	'	'	'
Operating Leased Assets [Line Items]	'	'	'	'
Operating leases, rent expense	$18.10	$12.70	$51.50	$37.10
Lease Term In Excess Of One Year [Member] | Minimum [Member]	'	'	'	'
Operating Leased Assets [Line Items]	'	'	'	'
Operating leases, term of contract	'1 year	'1 year	'1 year	'1 year
Lease Term Of One Year Or Less [Member]	'	'	'	'
Operating Leased Assets [Line Items]	'	'	'	'
Operating leases, rent expense	$54.50	$63	$142.60	$138.90
Lease Term Of One Year Or Less [Member] | Maximum [Member]	'	'	'	'
Operating Leased Assets [Line Items]	'	'	'	'
Operating leases, term of contract	'1 year	'1 year	'1 year	'1 year

StockBased_Compensation_and_Ot2

Stock-Based Compensation and Other Employee Benefit Plans (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]	'	'	'	'	'
Shares available for grant or issuance	6,193,235	6,193,235	'	6,193,235	'
Stock options exercised	'	0	'	'	'
Stock options exercised, intrinsic value	'	'	$4.60	$6.50	$10.40
Stock options exercised, proceeds	'	'	0.4	0.8	3.8
Restricted Share Awards [Member]	'	'	'	'	'
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]	'	'	'	'	'
Stock-based compensation awards, unearned compensation	16	16	'	16	'
Stock-based compensation awards, unearned compensation, weighted average expected recognition period	'1 year 1 month 6 days	'	'	'	'
Stock-based compensation, vested awards, intrinsic value	'	$1.10	$0.90	$7.10	$2
Stock Options [Member]	'	'	'	'	'
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]	'	'	'	'	'
Stock-based compensation awards, percentage vested	'	'	'	100.00%	'
Employee Stock Purchase Plan [Member]	'	'	'	'	'
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]	'	'	'	'	'
Stock-based compensation plan, description	'	'	'	'The Company's employee stock purchase plans allow qualified employees to purchase MasTec common stock at 85% of its fair market value at the lower of (i) the date of commencement of the offering period or (ii) the last day of the exercise period, as defined in the plan documents.	'
Stock-based compensation, purchase price of common stock, percentage of fair value	'	'	'	85.00%	'
Stock-based compensation, fair value assumptions, method used	'	'	'	'The fair value of purchases under the Company's employee stock purchase plans is estimated using the Black-Scholes option-pricing valuation model.	'

StockBased_Compensation_and_Ot3

Stock-Based Compensation and Other Employee Benefit Plans (Summary of Activity, Restricted Share Awards) (Details) (Restricted Share Awards [Member], USD $)	9 Months Ended
	Sep. 30, 2014
Restricted Share Awards [Member]	'
Restricted Share Awards, Activity [Roll Forward]	'
Non-vested restricted shares, beginning balance	1,123,545
Granted	323,249
Vested	-181,195
Canceled/forfeited	-22,442
Non-vested restricted shares, ending balance	1,243,157
Restricted Share Awards, Activity, Per Share Weighted Average Grant Date Fair Value [Roll Forward]	'
Per share weighted average grant date fair value, beginning balance	$23.78
Granted	$41.05
Vested	$20.26
Canceled/forfeited	$17.38
Per share weighted average grant date fair value, ending balance	$28.90

StockBased_Compensation_and_Ot4

Stock-Based Compensation and Other Employee Benefit Plans (Summary of Activity, Stock Options) (Details) (USD $)	0 Months Ended			3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013	Sep. 30, 2014		Sep. 30, 2014		Dec. 31, 2013
Outstanding Stock Options, Activity [Roll Forward]	'		'	'		'		'
Options outstanding, vested, beginning balance	284,671		495,571	'		495,571		'
Exercised	'		'	0		'		'
Canceled/forfeited	'		'	'		0		'
Options outstanding, vested, ending balance	284,671		'	284,671		284,671		'
Outstanding Stock Options, Per Share Weighted Average Exercise Price [Roll Forward]	'		'	'		'		'
Per share weighted average exercise price, vested, beginning balance	$12.06		$11.17	'		$11.17		'
Canceled/forfeited	'		'	'		$0		'
Per share weighted average exercise price, vested, ending balance	$12.06		'	$12.06		$12.06		'
Outstanding Stock Options, Additional Disclosures	'		'	'		'		'
Options exercisable	284,671		'	284,671		284,671		'
Options exercisable, per share weighted average exercise price	$12.06		'	$12.06		$12.06		'
Options outstanding, vested, weighted average remaining contractual life (in years)	'1 year 6 months 15 days		'1 year 11 months 16 days	'		'		'
Options exercisable, weighted average remaining contractual life (in years)	'1 year 6 months 15 days		'	'		'		'
Options outstanding, vested, aggregate intrinsic value	$5.30	[1]	'	$5.30	[1]	$5.30	[1]	$10.70	[1]
Options exercisable, aggregate intrinsic value	$5.30	[1]	'	$5.30	[1]	$5.30	[1]	'
Stock Options [Member]	'		'	'		'		'
Outstanding Stock Options, Per Share Weighted Average Exercise Price [Roll Forward]	'		'	'		'		'
Exercised	'		'	'		$9.97		'
Common Stock [Member]	'		'	'		'		'
Outstanding Stock Options, Activity [Roll Forward]	'		'	'		'		'
Exercised	'		'	'		-210,900		'
[1]	Amount represents the difference between the exercise price and the market price of the Companybs stock on the last trading day of the corresponding period, multiplied by the number of in-the-money options.

StockBased_Compensation_and_Ot5

Stock-Based Compensation and Other Employee Benefit Plans (Summary of Activity, Employee Stock Purchase Plan) (Details) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Common Stock [Member]	'	'
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]	'	'
Common shares issued	94,761	436,925
Employee Stock Purchase Plan [Member]	'	'
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]	'	'
Cash proceeds (in millions)	2.5	6
Weighted average per share price	26.6	13.69
Weighted average per share grant date fair value	6.34	5.55

StockBased_Compensation_and_Ot6

Stock-Based Compensation and Other Employee Benefit Plans (Summary of Stock-Based Compensation Expense and Related Tax Benefits) (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]	'		'		'		'
Stock-based compensation expense	'		'		$11,584,000		$9,647,000
Income Tax Effects:	'		'		'		'
Income tax benefit from stock-based compensation	1,800,000		4,500,000		8,400,000		7,700,000
Excess tax benefit from stock-based compensation	100,000	[1]	3,000,000	[1]	3,494,000	[1]	4,446,000	[1]
General and Administrative Expense [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]	'		'		'		'
Stock-based compensation expense	$4,100,000		$3,000,000		$11,600,000		$9,600,000
[1]	Excess tax benefits, which represent cash flows from tax deductions in excess of the recorded tax effect of compensation expense recognized for stock options exercised and vested restricted shares, are classified as financing cash flows in the Companybs condensed unaudited consolidated statements of cash flows.

Other_Retirement_Plans_Narrati

Other Retirement Plans (Narrative) (Details)	9 Months Ended
	Sep. 30, 2014
Multiemployer Plans [Abstract]	'
Multi-employer plans, general nature	'Certain of MasTecbs subsidiaries contribute amounts to multi-employer pension and other multi-employer benefit plans and trusts. Contributions are generally based on fixed amounts per hour per employee for employees covered under these plans. Multi-employer plan contribution rates are determined annually and assessed on a bpay-as-you-gob basis based on union employee payrolls. Union payrolls cannot be determined for future periods because the number of union employees employed at any given time, and the plans in which they may participate, vary depending upon the location and number of ongoing projects at a given time and the need for union resources in connection with those projects.

Other_Retirement_Plans_Schedul

Other Retirement Plans (Schedule of Covered Employees and Contributions, Multi-Employer Plans) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Covered Employees and Contributions, Multi-Employer Plans [Line Items]	'	'	'	'
Multi-employer plans, contributions	$12.70	$15.90	$29.80	$33.20
Multi-Employer Plans, Pension [Member]	'	'	'	'
Covered Employees and Contributions, Multi-Employer Plans [Line Items]	'	'	'	'
Multi-employer plans, contributions	11.6	14.9	27.3	30.2
Multi-Employer Plans, Postretirement Benefit [Member]	'	'	'	'
Covered Employees and Contributions, Multi-Employer Plans [Line Items]	'	'	'	'
Multi-employer plans, contributions	$1.10	$1	$2.50	$3
Workforce Subject to Collective Bargaining Arrangements [Member] | Unionized Employees [Member] | Minimum [Member] | Multi-Employer Plans, Pension And Postretirement Benefit [Member]	'	'	'	'
Covered Employees and Contributions, Multi-Employer Plans [Line Items]	'	'	'	'
Multi-employer plans, covered employees	2,029	2,392	1,098	778
Workforce Subject to Collective Bargaining Arrangements [Member] | Unionized Employees [Member] | Maximum [Member] | Multi-Employer Plans, Pension And Postretirement Benefit [Member]	'	'	'	'
Covered Employees and Contributions, Multi-Employer Plans [Line Items]	'	'	'	'
Multi-employer plans, covered employees	2,167	2,734	2,167	2,734

Equity_Schedule_of_Share_Activ

Equity (Schedule of Share Activity) (Details)	3 Months Ended		1 Months Ended	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
			Convertible Debt [Member]	Convertible Debt [Member]	Common Stock [Member]	Common Stock [Member]
			4.0% Convertible Notes [Member]	4.0% Convertible Notes [Member]		Convertible Debt [Member]
						4.0% Convertible Notes [Member]
Rollforward of Share Activity:	'	'	'	'	'	'
Common shares outstanding, beginning balance	'	77,258,000	'	'	'	'
Treasury shares, beginning balance	'	9,467,286	'	'	'	'
Shares issued:	'	'	'	'	'	'
Stock option exercises	0	'	'	'	210,900	'
Restricted share awards	'	'	'	'	181,000	'
Convertible notes, common shares issued	'	'	'	'	'	4,204,000
Convertible notes, treasury shares	'	'	-4,200,000	-4,204,000	'	'
Other, net	'	'	'	'	-11,000	'
Common shares outstanding, ending balance	81,843,000	77,258,000	'	'	'	'
Treasury shares, ending balance	5,262,831	9,467,286	'	'	'	'

Equity_Narrative_Details

Equity (Narrative) (Details) (Convertible Debt [Member], 4.0% Convertible Notes [Member], USD $)	1 Months Ended	9 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2014
Convertible Debt [Member] | 4.0% Convertible Notes [Member]	'	'
Debt Conversion [Line Items]	'	'
Debt instrument, convertible, shares reissued from treasury	4,200	4,204
Share reissuances, treasury stock, value	$66.60	'

Equity_Schedule_of_Changes_in_

Equity (Schedule of Changes in Accumulated Other Comprehensive Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Loss [Line Items]	'	'	'	'
Accumulated other comprehensive loss, beginning balance	'	'	($13,286)	($5,501)
Activity before reclassifications, net of tax	'	'	-10,601	-3,957
Reclassifications, net of tax	'	'	0	-440
Activity, net of tax	-12,944	2,844	-10,601	-4,397
Accumulated other comprehensive loss, ending balance	-23,887	-9,898	-23,887	-9,898
Foreign Currency [Member]	'	'	'	'
Accumulated Other Comprehensive Loss [Line Items]	'	'	'	'
Accumulated other comprehensive loss, beginning balance	'	'	-7,998	-106
Activity before reclassifications, net of tax	'	'	-10,601	-3,839
Reclassifications, net of tax	'	'	0	0
Activity, net of tax	-12,944	2,936	-10,601	-3,839
Accumulated other comprehensive loss, ending balance	-18,599	-3,945	-18,599	-3,945
Other [Member]	'	'	'	'
Accumulated Other Comprehensive Loss [Line Items]	'	'	'	'
Accumulated other comprehensive loss, beginning balance	'	'	-5,288	-5,395
Activity before reclassifications, net of tax	'	'	0	-118
Reclassifications, net of tax	'	'	0	-440
Activity, net of tax	0	-92	0	-558
Accumulated other comprehensive loss, ending balance	($5,288)	($5,953)	($5,288)	($5,953)

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'	'	'	'	'
Effective income tax rate, continuing operations	38.00%	38.80%	38.00%	38.60%	'
Quarterly provision for income taxes, description	'	'	'In determining the quarterly provision for income taxes, management uses an estimated annual effective tax rate based on forecasted annual pre-tax income, permanent tax differences, statutory tax rates and tax planning opportunities in the various jurisdictions in which the Company operates. The impact of significant discrete items is separately recognized in the quarter(s) in which they occur.	'	'
Current deferred tax assets, net	$9,300,000	'	$9,300,000	'	$16,300,000
Long-term deferred tax liabilities, net	$180,449,000	'	$180,449,000	'	$154,763,000

Segments_and_Related_Informati2

Segments and Related Information (Descriptions) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2014
	segment
Segments and Related Information [Line Items]	'
Segment reporting information, factors used to identify entity's reportable segments	'MasTec presents its continuing operations in five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial and (5) Other. This structure is generally focused on broad end-user markets for MasTec's labor-based construction services.
Number of reportable segments	5
Segment reporting information, description of products and services	'All five reportable segments derive their revenues from the engineering, installation and maintenance of infrastructure, primarily in North America.
Segment reporting, description of all other segments	'The Other segment primarily includes small business units that perform construction services for a variety of end markets in Mexico and elsewhere internationally.
Reportable Segments [Member] | Communications [Member]	'
Segments and Related Information [Line Items]	'
Segment reporting information, description of products and services	'The Communications segment performs engineering, construction and maintenance of communications infrastructure primarily related to wireless and wireline/fiber communications and install-to-the-home customers, and, to a lesser extent, infrastructure for electrical utilities.
Reportable Segments [Member] | Oil and Gas [Member]	'
Segments and Related Information [Line Items]	'
Segment reporting information, description of products and services	'MasTec performs engineering, construction and maintenance services on oil and natural gas pipelines and processing facilities for the energy and utilities industries through its Oil and Gas segment.
Reportable Segments [Member] | Electrical Transmission [Member]	'
Segments and Related Information [Line Items]	'
Segment reporting information, description of products and services	'The Electrical Transmission segment primarily serves the energy and utility industries through the engineering, construction and maintenance of electrical transmission lines and substations.
Reportable Segments [Member] | Power Generation and Industrial [Member]	'
Segments and Related Information [Line Items]	'
Segment reporting information, description of products and services	'The Power Generation and Industrial segment primarily serves energy, utility and other end-markets through the installation and construction of conventional and renewable power facilities, related electrical transmission infrastructure, ethanol facilities and various types of industrial infrastructure.

Segments_and_Related_Informati3

Segments and Related Information (Schedule of Financial Information by Reportable Segment - Revenue) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segments and Related Information [Line Items]	'		'		'		'
Revenue	$1,309,596		$1,269,385		$3,378,180		$3,165,657
Reportable Segments [Member] | Communications [Member]	'		'		'		'
Segments and Related Information [Line Items]	'		'		'		'
Revenue	505,200	[1]	543,000	[1]	1,480,400	[1]	1,464,500	[1]
Reportable Segments [Member] | Communications [Member] | Utilities [Member] | Customer Concentration Risk [Member] | Revenue [Member]	'		'		'		'
Segments and Related Information [Line Items]	'		'		'		'
Utilities customers, percentage of consolidated Communications segment revenue	7.60%		6.90%		7.00%		7.20%
Reportable Segments [Member] | Oil and Gas [Member]	'		'		'		'
Segments and Related Information [Line Items]	'		'		'		'
Revenue	557,400		519,100		1,302,900		1,134,800
Reportable Segments [Member] | Electrical Transmission [Member]	'		'		'		'
Segments and Related Information [Line Items]	'		'		'		'
Revenue	132,600		118,800		327,200		321,900
Reportable Segments [Member] | Power Generation and Industrial [Member]	'		'		'		'
Segments and Related Information [Line Items]	'		'		'		'
Revenue	114,300		85,100		263,100		237,300
Reportable Segments [Member] | Other [Member]	'		'		'		'
Segments and Related Information [Line Items]	'		'		'		'
Revenue	1,100		3,500		6,500		9,200
Eliminations [Member]	'		'		'		'
Segments and Related Information [Line Items]	'		'		'		'
Revenue	($1,000)		($100)		($1,900)		($2,000)
[1]	Revenue generated by utilities customers represented 7.6% and 6.9% of Communications segment revenue for the three month periods ended SeptemberB 30, 2014 and 2013, respectively, and 7.0% and 7.2% of Communications segment revenue for the nine month periods ended SeptemberB 30, 2014 and 2013, respectively.

Segments_and_Related_Informati4

Segments and Related Information (Schedule of Financial Information by Reportable Segment - EBITDA) (Details) (Continuing Operations [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	$128.20	$132.10	$301.20	$308.30
Reportable Segments [Member] | Communications [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	52.4	71.8	153.7	181.6
Reportable Segments [Member] | Oil and Gas [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	73	68.1	143.5	161.7
Reportable Segments [Member] | Electrical Transmission [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	12.7	12.1	33.2	27
Reportable Segments [Member] | Power Generation and Industrial [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	4.9	-6.4	9.4	-14.6
Reportable Segments [Member] | Other [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	-0.3	0.1	0.1	0.5
Corporate [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	($14.50)	($13.60)	($38.70)	($47.90)

Segments_and_Related_Informati5

Segments and Related Information (Schedule of Financial Information by Reportable Segment - Depreciation and Amortization) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segments and Related Information [Line Items]	'	'	'	'
Depreciation and amortization	$41,747	$37,756	$111,996	$103,111
Reportable Segments [Member] | Communications [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
Depreciation and amortization	10,100	9,500	30,100	26,800
Reportable Segments [Member] | Oil and Gas [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
Depreciation and amortization	23,300	22,500	61,300	60,100
Reportable Segments [Member] | Electrical Transmission [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
Depreciation and amortization	5,200	3,200	11,900	8,400
Reportable Segments [Member] | Power Generation and Industrial [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
Depreciation and amortization	1,700	1,700	4,800	5,100
Corporate [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
Depreciation and amortization	$1,400	$900	$3,900	$2,700

Segments_and_Related_Informati6

Segments and Related Information (Reconciliation of EBITDA to Consolidated Income from Continuing Operations before Income Taxes) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Less:	'	'	'	'
Interest expense, net	($12,643,000)	($12,666,000)	($37,595,000)	($34,549,000)
Depreciation and amortization	-41,747,000	-37,756,000	-111,996,000	-103,111,000
Income from continuing operations before income taxes	73,772,000	81,633,000	151,655,000	170,608,000
Continuing Operations [Member]	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'
EBITDA	$128,200,000	$132,100,000	$301,200,000	$308,300,000

Segments_and_Related_Informati7

Segments and Related Information (Foreign Operations) (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segments and Related Information [Line Items]	'	'	'	'	'
Revenue	$1,309,596,000	$1,269,385,000	$3,378,180,000	$3,165,657,000	'
Property and equipment, net	614,359,000	'	614,359,000	'	488,132,000
Intangible assets and goodwill, net	1,222,100,000	'	1,222,100,000	'	1,067,700,000
Reportable Geographical Components [Member] | United States [Member]	'	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'	'
Revenue	1,100,000,000	1,200,000,000	2,900,000,000	3,000,000,000	'
Property and equipment, net	497,600,000	'	497,600,000	'	436,900,000
Intangible assets and goodwill, net	1,000,000,000	'	1,000,000,000	'	1,000,000,000
Reportable Geographical Components [Member] | Foreign Operations [Member]	'	'	'	'	'
Segments and Related Information [Line Items]	'	'	'	'	'
Revenue	219,400,000	90,900,000	460,000,000	172,000,000	'
Property and equipment, net	116,800,000	'	116,800,000	'	51,200,000
Intangible assets and goodwill, net	$211,500,000	'	$211,500,000	'	$92,900,000

Segments_and_Related_Informati8

Segments and Related Information (Schedule of Significant Customers, Revenue Concentration Information) (Details) (Reportable Segments [Member], Customer Concentration Risk [Member], Revenue [Member])	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
AT&T [Member] | Communications [Member]	'		'		'		'
Revenue, Significant Customers [Line Items]	'		'		'		'
Significant customers, percentage of total consolidated revenue	16.00%	[1]	16.00%	[1]	21.00%	[1]	18.00%	[1]
Segment reporting, disclosure of significant customers	'		'		'The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for AT&T's wireless, wireline/fiber and home security and automation businesses. Revenue from AT&T is included in the Communications segment.		'
DIRECTV [Member] | Communications [Member]	'		'		'		'
Revenue, Significant Customers [Line Items]	'		'		'		'
Significant customers, percentage of total consolidated revenue	12.00%	[2]	13.00%	[2]	13.00%	[2]	15.00%	[2]
Segment reporting, disclosure of significant customers	'		'		'The Company's relationship with DIRECTVB. is based upon an agreement to provide installation and maintenance services for DIRECTVB.. Revenue from DIRECTVB. is included in the Communications segment.		'
Enbridge, Inc. [Member] | Oil and Gas [Member]	'		'		'		'
Revenue, Significant Customers [Line Items]	'		'		'		'
Significant customers, percentage of total consolidated revenue	10.00%	[3]	20.00%	[3]	10.00%	[3]	14.00%	[3]
Segment reporting, disclosure of significant customers	'		'		'The Company's relationship with Enbridge, Inc. is based upon various construction contracts for natural gas pipelines. Revenue from Enbridge, Inc. is included in the Oil and Gas segment.		'
[1]	The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for AT&T's wireless, wireline/fiber and home security and automation businesses. Revenue from AT&T is included in the Communications segment.
[2]	The Company's relationship with DIRECTVB. is based upon an agreement to provide installation and maintenance services for DIRECTVB.. Revenue from DIRECTVB. is included in the Communications segment.
[3]	The Company's relationship with Enbridge, Inc. is based upon various construction contracts for natural gas pipelines. Revenue from Enbridge, Inc. is included in the Oil and Gas segment.

Commitments_and_Contingencies_

Commitments and Contingencies (Sunlight Entities) (Narrative) (Details) (Pending Litigation [Member], USD $)	1 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Aug. 31, 2014	Jun. 30, 2013	Sep. 30, 2014
Sunlight Entities [Member]	'	'	'
Loss Contingencies [Line Items]	'	'	'
Projects or proceedings, number or quantity of	'	'	3
Litigation award, pending litigation	$59.60	'	'
Liens sought, pending litigation	'	'	50
Damages sought, pending litigation	'	60	'
Sunlight Entities [Member] | Construction Contracts [Member]	'	'	'
Loss Contingencies [Line Items]	'	'	'
Projects or proceedings, number or quantity of	'	'	3
Sunlight General Somerset [Member]	'	'	'
Loss Contingencies [Line Items]	'	'	'
Contract price, pending litigation	'	'	29
Sunlight General Morris [Member]	'	'	'
Loss Contingencies [Line Items]	'	'	'
Contract price, pending litigation	'	'	36
Sunlight General Sussex [Member]	'	'	'
Loss Contingencies [Line Items]	'	'	'
Contract price, pending litigation	'	'	$26

Commitments_and_Contingencies_1

Commitments and Contingencies (Other Commitments and Contingencies) (Narrative) (Details) (USD $)	0 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Uninsured Risk [Member] | Workers Compensation, General And Automobile Policies [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Self insurance reserve	$60,300,000	$50,800,000
Uninsured Risk [Member] | Workers Compensation, General And Automobile Policies [Member] | Other Non-Current Liabilities [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Self insurance reserve, non-current	36,300,000	31,300,000
Uninsured Risk [Member] | Workers Compensation, General And Automobile Policies [Member] | Other Non-Current Assets [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Cash collateral held by insurance carriers	1,100,000	1,400,000
Uninsured Risk [Member] | Group Insurance Policies [Member] | Medical Insurance [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Self insurance reserve	1,900,000	2,100,000
Unconsolidated Affiliates [Member] | Financial Support [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Unconsolidated affiliates, outstanding commitments	0	'
Performance Guarantee [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Outstanding bonds, amount	748,600,000	1,100,000,000
Performance Guarantee [Member] | Projected Estimate [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Bonded projects, costs to complete	53,100,000	297,100,000
Financial Guarantee [Member] | Uninsured Risk [Member] | Workers Compensation, General And Automobile Policies [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Letters of credit, outstanding amount	57,200,000	57,400,000
Surety Bond [Member] | Uninsured Risk [Member] | Workers Compensation [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Outstanding bonds, amount	13,000,000	10,900,000
Credit Facility [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
Letters of credit, outstanding amount	$135,600,000	$134,800,000

Commitments_and_Contingencies_2

Commitments and Contingencies (Collective Bargaining Agreements and Multi-Employer Plans) (Narrative) (Details) (USD $)	9 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014	Nov. 15, 2011	Sep. 30, 2014
		Multi-Employer Plans, Pension [Member]	Multi-Employer Plans, Pension [Member]	Multi-Employer Plans, Pension [Member]
		Central States Southeast And Southwest Areas Pension Fund [Member]	Central States Southeast And Southwest Areas Pension Fund [Member]	Withdrawal from Multi-Employer Defined Benefit Plan [Member]
				Central States Southeast And Southwest Areas Pension Fund [Member]
Loss Contingencies [Line Items]	'	'	'	'
Multi-employer plans, collective bargaining agreements, description	'Certain of MasTecbs subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The agreements require the subsidiaries party to the agreements to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to the ones contained in the expiring agreements.	'	'	'
Loss contingency, evaluation of estimated loss	'	'	'	'On November 15, 2011, the Company, along with other members of the Pipe Line Contractors Association (bPLCAb), voluntarily withdrew from the Central States Southeast and Southwest Areas Pension Fund (bCentral Statesb), a defined benefit multi-employer pension plan that is in critical status. In connection with this withdrawal, a $6.4 million withdrawal liability was established based on an estimate provided by the Central States administrator of such liability as of the date of withdrawal. The Company began paying installments towards this withdrawal liability in 2013, of which $4.5 million was outstanding as of September 30, 2014. The Company withdrew from Central States in order to mitigate its liability in connection with the plan; however, Central States has asserted that the PLCA members did not effectively withdraw in 2011 and are, therefore, responsible for a withdrawal liability that includes 2011 contribution amounts. By letter dated March 14, 2013, Central States demanded $11 million in withdrawal liability from the Company, which included 2011 contribution amounts. The Company is vigorously opposing this demand because it believes that it legally and effectively withdrew from Central States on November 15, 2011. If Central States were to prevail in its assertion that the Company withdrew after that date, then the initial amount of the Companybs withdrawal liability would increase to approximately $11 million.
Withdrawal liability	'	$4.50	$6.40	'
Maximum loss	'	'	'	$11

Commitments_and_Contingencies_3

Commitments and Contingencies (Other Guarantees) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2014
Other Guarantees [Line Items]	'
General warranty, description	'MasTec generally warrants the work it performs for a one to two year period following substantial completion of a project.
Warranty [Member] | Minimum [Member]	'
Other Guarantees [Line Items]	'
General warranty, period	'1 year
Warranty [Member] | Maximum [Member]	'
Other Guarantees [Line Items]	'
General warranty, period	'2 years
Subsidiary [Member]	'
Other Guarantees [Line Items]	'
Other guarantees, description	'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 contractorsb licenses.

Commitments_and_Contingencies_4

Commitments and Contingencies (Concentrations of Risk) (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
	customer	customer	customer	customer
Concentration Risk [Line Items]	'	'	'	'
Number of customers	'	'	480	'
Ten Largest Customers [Member] | Customer Concentration Risk [Member] | Revenue [Member]	'	'	'	'
Concentration Risk [Line Items]	'	'	'	'
Number of customers	10	10	10	10
Significant customers, percentage of total consolidated revenue	64.00%	73.00%	66.00%	69.00%

Related_Party_Transactions_Inv

Related Party Transactions (Investments) (Narrative) (Details) (Cross Country Pipeline [Member], Management [Member], USD $)	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2014
In Millions, unless otherwise specified	Cost Method Investment [Member]	Lease And Rental Agreements [Member]	Lease And Rental Agreements [Member]
		Equipment [Member]	Equipment [Member]
Related Party Transaction [Line Items]	'	'	'
Cost method investment, original cost	$15	'	'
Expenses from transactions with related party	'	$1.90	$4.60

Related_Party_Transactions_Oth

Related Party Transactions (Other Related Party Transactions) (Narrative) (Details) (Management [Member], Related Customer [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Employee Leasing Arrangements [Member]	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Charges to related party	$0.20	$0.10	$0.50	$0.40	'
Due from related party	0.1	'	0.1	'	0.1
Satellite Communication Services [Member]	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Revenue from related party	0.3	0.4	0.8	1	'
Accounts receivable, related party	$0.40	'	$0.40	'	$0.40

Related_Party_Transactions_Spl

Related Party Transactions (Split Dollar Agreements) (Narrative) (Details) (Split Dollar Life Insurance [Member], USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Dec. 31, 2013
	Chief Executive Officer [Member]	Chief Executive Officer [Member]	Chief Executive Officer [Member]	Chief Executive Officer [Member]	Board of Directors Chairman [Member]	Board of Directors Chairman [Member]	Board of Directors Chairman [Member]	Board of Directors Chairman [Member]	Management [Member]	Management [Member]
				Maximum [Member]					Other Long-Term Assets [Member]	Other Long-Term Assets [Member]
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Life insurance, face amount	'	'	'	$75,000,000	'	'	'	'	'	'
Payments for life insurance policies	0	0	0	100,000	1,300,000	1,100,000	1,800,000	1,200,000	'	'
Carrying amount, life insurance policies	'	'	'	'	'	'	'	'	$11,100,000	$10,200,000

Supplemental_Guarantor_Condens2

Supplemental Guarantor Condensed Unaudited Consolidating Financial Information (Narrative) (Details) (Guarantor Subsidiaries [Member], Senior Notes [Member])	9 Months Ended
	Sep. 30, 2014
Guarantor Subsidiaries [Member] | Senior Notes [Member]	'
Condensed Unaudited Consolidating Financial Information [Line Items]	'
Guarantor subsidiaries, percentage of voting interests owned	100.00%

Supplemental_Guarantor_Condens3

Supplemental Guarantor Condensed Unaudited Consolidating Financial Information (Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]	'	'	'	'
Revenue	$1,309,596,000	$1,269,385,000	$3,378,180,000	$3,165,657,000
Costs of revenue, excluding depreciation and amortization	1,122,961,000	1,081,132,000	2,914,904,000	2,695,287,000
Depreciation and amortization	41,747,000	37,756,000	111,996,000	103,111,000
General and administrative expenses	59,889,000	58,976,000	167,454,000	159,761,000
Interest expense, net	12,643,000	12,666,000	37,595,000	34,549,000
Loss on extinguishment of debt	0	0	0	5,624,000
Other (income) expense, net	-1,416,000	-2,778,000	-5,424,000	-3,283,000
Income from continuing operations before income taxes	73,772,000	81,633,000	151,655,000	170,608,000
Benefit from (provision for) income taxes	-28,042,000	-31,698,000	-57,671,000	-65,822,000
Net income from continuing operations	45,730,000	49,935,000	93,984,000	104,786,000
Net loss from discontinued operations	-320,000	-3,735,000	-592,000	-5,165,000
Equity in income from subsidiaries, net of tax	0	0	0	0
Net income	45,410,000	46,200,000	93,392,000	99,621,000
Net income attributable to non-controlling interests	139,000	62,000	48,000	172,000
Net income attributable to MasTec, Inc.	45,271,000	46,138,000	93,344,000	99,449,000
Comprehensive income (loss)	32,466,000	49,044,000	82,791,000	95,224,000
Eliminations [Member]	'	'	'	'
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]	'	'	'	'
Revenue	-2,000,000	-500,000	-2,100,000	-4,400,000
Costs of revenue, excluding depreciation and amortization	-2,000,000	-500,000	-2,100,000	-4,400,000
Depreciation and amortization	0	0	0	0
General and administrative expenses	0	0	0	0
Interest expense, net	0	0	0	0
Loss on extinguishment of debt	'	'	'	0
Other (income) expense, net	0	0	0	0
Income from continuing operations before income taxes	0	0	0	0
Benefit from (provision for) income taxes	0	0	0	0
Net income from continuing operations	0	0	0	0
Net loss from discontinued operations	0	0	0	0
Equity in income from subsidiaries, net of tax	-45,700,000	-46,400,000	-94,500,000	-100,300,000
Net income	-45,700,000	-46,400,000	-94,500,000	-100,300,000
Net income attributable to non-controlling interests	0	0	0	0
Net income attributable to MasTec, Inc.	-45,700,000	-46,400,000	-94,500,000	-100,300,000
Comprehensive income (loss)	-32,700,000	-49,300,000	-83,900,000	-95,900,000
MasTec, Inc. [Member]	'	'	'	'
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]	'	'	'	'
Revenue	0	0	0	0
Costs of revenue, excluding depreciation and amortization	0	0	0	0
Depreciation and amortization	0	0	0	0
General and administrative expenses	600,000	500,000	1,800,000	1,400,000
Interest expense, net	0	0	0	0
Loss on extinguishment of debt	'	'	'	0
Other (income) expense, net	0	0	0	0
Income from continuing operations before income taxes	-600,000	-500,000	-1,800,000	-1,400,000
Benefit from (provision for) income taxes	200,000	200,000	700,000	600,000
Net income from continuing operations	-400,000	-300,000	-1,100,000	-800,000
Net loss from discontinued operations	0	0	0	0
Equity in income from subsidiaries, net of tax	45,700,000	46,400,000	94,500,000	100,300,000
Net income	45,300,000	46,100,000	93,400,000	99,500,000
Net income attributable to non-controlling interests	0	0	0	0
Net income attributable to MasTec, Inc.	45,300,000	46,100,000	93,400,000	99,500,000
Comprehensive income (loss)	32,300,000	49,000,000	82,800,000	95,100,000
Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]	'	'	'	'
Revenue	1,043,100,000	1,140,900,000	2,798,600,000	2,881,100,000
Costs of revenue, excluding depreciation and amortization	892,600,000	969,500,000	2,402,000,000	2,447,700,000
Depreciation and amortization	30,800,000	31,600,000	88,400,000	88,800,000
General and administrative expenses	50,800,000	50,100,000	146,600,000	138,500,000
Interest expense, net	11,500,000	12,000,000	35,600,000	33,500,000
Loss on extinguishment of debt	'	'	'	5,600,000
Other (income) expense, net	-1,600,000	-2,300,000	-5,800,000	-2,400,000
Income from continuing operations before income taxes	59,000,000	80,000,000	131,800,000	169,400,000
Benefit from (provision for) income taxes	-22,000,000	-31,500,000	-51,200,000	-66,000,000
Net income from continuing operations	37,000,000	48,500,000	80,600,000	103,400,000
Net loss from discontinued operations	0	0	0	0
Equity in income from subsidiaries, net of tax	0	0	0	0
Net income	37,000,000	48,500,000	80,600,000	103,400,000
Net income attributable to non-controlling interests	0	0	0	0
Net income attributable to MasTec, Inc.	37,000,000	48,500,000	80,600,000	103,400,000
Comprehensive income (loss)	37,000,000	48,500,000	80,500,000	102,800,000
Non-Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]	'	'	'	'
Revenue	268,500,000	129,000,000	581,700,000	289,000,000
Costs of revenue, excluding depreciation and amortization	232,400,000	112,100,000	515,000,000	252,000,000
Depreciation and amortization	10,900,000	6,200,000	23,600,000	14,300,000
General and administrative expenses	8,500,000	8,400,000	19,100,000	19,900,000
Interest expense, net	1,100,000	700,000	2,000,000	1,000,000
Loss on extinguishment of debt	'	'	'	0
Other (income) expense, net	200,000	-500,000	300,000	-800,000
Income from continuing operations before income taxes	15,400,000	2,100,000	21,700,000	2,600,000
Benefit from (provision for) income taxes	-6,200,000	-400,000	-7,200,000	-400,000
Net income from continuing operations	9,200,000	1,700,000	14,500,000	2,200,000
Net loss from discontinued operations	-300,000	-3,700,000	-600,000	-5,200,000
Equity in income from subsidiaries, net of tax	0	0	0	0
Net income	8,900,000	-2,000,000	13,900,000	-3,000,000
Net income attributable to non-controlling interests	100,000	100,000	0	200,000
Net income attributable to MasTec, Inc.	8,800,000	-2,100,000	13,800,000	-3,200,000
Comprehensive income (loss)	($4,100,000)	$800,000	$3,400,000	($6,800,000)

Supplemental_Guarantor_Condens4

Supplemental Guarantor Condensed Unaudited Consolidating Financial Information (Condensed Unaudited Consolidating Balance Sheets) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Assets	'	'
Current assets, including discontinued operations	$1,573,952,000	$1,307,026,000
Property and equipment, net	614,359,000	488,132,000
Goodwill and other intangible assets, net	1,222,100,000	1,067,700,000
Investments in and advances to consolidated affiliates, net	0	0
Other long-term assets, including disontinued operations	59,579,000	60,390,000
Total assets	3,470,126,000	2,923,198,000
Liabilities and Equity	'	'
Total current liabilities	910,874,000	829,225,000
Long-term debt	1,088,289,000	765,425,000
Advances from consolidated affiliates, net	0	0
Other liabilities	342,000,000	307,500,000
Total liabilities	2,341,239,000	1,902,140,000
Total equity	1,128,887,000	1,021,058,000
Total liabilities and equity	3,470,126,000	2,923,198,000
Eliminations [Member]	'	'
Assets	'	'
Current assets, including discontinued operations	0	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Investments in and advances to consolidated affiliates, net	-1,222,100,000	-1,177,600,000
Other long-term assets, including disontinued operations	0	0
Total assets	-1,222,100,000	-1,177,600,000
Liabilities and Equity	'	'
Total current liabilities	0	0
Long-term debt	0	0
Advances from consolidated affiliates, net	-23,800,000	-22,500,000
Other liabilities	0	0
Total liabilities	-23,800,000	-22,500,000
Total equity	-1,198,300,000	-1,155,100,000
Total liabilities and equity	-1,222,100,000	-1,177,600,000
MasTec, Inc. [Member]	'	'
Assets	'	'
Current assets, including discontinued operations	0	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Investments in and advances to consolidated affiliates, net	1,114,800,000	1,006,800,000
Other long-term assets, including disontinued operations	9,300,000	9,300,000
Total assets	1,124,100,000	1,016,100,000
Liabilities and Equity	'	'
Total current liabilities	0	0
Long-term debt	0	0
Advances from consolidated affiliates, net	0	0
Other liabilities	0	0
Total liabilities	0	0
Total equity	1,124,100,000	1,016,100,000
Total liabilities and equity	1,124,100,000	1,016,100,000
Guarantor Subsidiaries [Member]	'	'
Assets	'	'
Current assets, including discontinued operations	1,251,500,000	1,156,700,000
Property and equipment, net	475,500,000	420,200,000
Goodwill and other intangible assets, net	972,600,000	932,800,000
Investments in and advances to consolidated affiliates, net	0	170,800,000
Other long-term assets, including disontinued operations	35,300,000	36,200,000
Total assets	2,734,900,000	2,716,700,000
Liabilities and Equity	'	'
Total current liabilities	736,600,000	773,300,000
Long-term debt	1,053,600,000	760,900,000
Advances from consolidated affiliates, net	23,800,000	0
Other liabilities	190,800,000	236,400,000
Total liabilities	2,004,800,000	1,770,600,000
Total equity	730,100,000	946,100,000
Total liabilities and equity	2,734,900,000	2,716,700,000
Non-Guarantor Subsidiaries [Member]	'	'
Assets	'	'
Current assets, including discontinued operations	322,500,000	150,300,000
Property and equipment, net	138,900,000	67,900,000
Goodwill and other intangible assets, net	249,500,000	134,900,000
Investments in and advances to consolidated affiliates, net	107,300,000	0
Other long-term assets, including disontinued operations	15,000,000	14,900,000
Total assets	833,200,000	368,000,000
Liabilities and Equity	'	'
Total current liabilities	174,300,000	55,900,000
Long-term debt	34,700,000	4,500,000
Advances from consolidated affiliates, net	0	22,500,000
Other liabilities	151,200,000	71,100,000
Total liabilities	360,200,000	154,000,000
Total equity	473,000,000	214,000,000
Total liabilities and equity	$833,200,000	$368,000,000

Supplemental_Guarantor_Condens5

Supplemental Guarantor Condensed Unaudited Consolidating Financial Information (Condensed Unaudited Consolidating Statements of Cash Flows) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]	'	'
Net cash (used in) provided by operating activities	$81,019,000	$129,256,000
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net of cash acquired	-162,901,000	-146,598,000
Capital expenditures	-90,962,000	-101,411,000
Proceeds from sale of property and equipment	12,204,000	8,288,000
Proceeds from disposal of business, net of cash divested	0	-4,332,000
(Payments for) proceeds from other investments, net	-1,046,000	3,852,000
Net cash used in investing activities	-242,705,000	-240,201,000
Cash flows provided by (used in) financing activities:	'	'
Proceeds from credit facility	1,319,623,000	766,154,000
Repayments of credit facility	-955,151,000	-860,070,000
(Repayments of) proceeds from senior notes, including convertible notes	-105,300,000	250,000,000
Repayments of other borrowings and capital lease obligations	-54,100,000	-56,500,000
Payments of financing costs, including call premiums on extinguishment of debt	-1,455,000	-11,835,000
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash provided by financing activities	146,978,000	87,144,000
Effect of currency translation on cash	-1,152,000	-118,000
Net decrease in cash and cash equivalents	-15,860,000	-23,919,000
Cash and cash equivalents - beginning of period	22,927,000	26,767,000
Cash and cash equivalents - end of period	7,067,000	2,848,000
Earn-Out Arrangements [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	-60,341,000	-12,848,000
Stock Compensation Plan [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	3,800,000	12,200,000
Eliminations [Member]	'	'
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]	'	'
Net cash (used in) provided by operating activities	0	0
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net of cash acquired	0	0
Capital expenditures	0	0
Proceeds from sale of property and equipment	0	0
Proceeds from disposal of business, net of cash divested	'	0
(Payments for) proceeds from other investments, net	0	0
Net cash used in investing activities	0	0
Cash flows provided by (used in) financing activities:	'	'
Proceeds from credit facility	0	0
Repayments of credit facility	0	0
(Repayments of) proceeds from senior notes, including convertible notes	0	0
Repayments of other borrowings and capital lease obligations	0	0
Payments of financing costs, including call premiums on extinguishment of debt	0	0
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash provided by financing activities	0	0
Effect of currency translation on cash	0	0
Net decrease in cash and cash equivalents	0	0
Cash and cash equivalents - beginning of period	0	0
Cash and cash equivalents - end of period	0	0
Eliminations [Member] | Earn-Out Arrangements [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	0	0
Eliminations [Member] | Stock Compensation Plan [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	0	0
MasTec, Inc. [Member]	'	'
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]	'	'
Net cash (used in) provided by operating activities	-1,100,000	-2,400,000
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net of cash acquired	0	0
Capital expenditures	0	0
Proceeds from sale of property and equipment	0	0
Proceeds from disposal of business, net of cash divested	'	0
(Payments for) proceeds from other investments, net	0	0
Net cash used in investing activities	0	0
Cash flows provided by (used in) financing activities:	'	'
Proceeds from credit facility	0	0
Repayments of credit facility	0	0
(Repayments of) proceeds from senior notes, including convertible notes	0	0
Repayments of other borrowings and capital lease obligations	0	0
Payments of financing costs, including call premiums on extinguishment of debt	0	0
Net financing activities and advances (to) from consolidated affiliates	-1,800,000	-6,800,000
Net cash provided by financing activities	1,100,000	2,400,000
Effect of currency translation on cash	0	0
Net decrease in cash and cash equivalents	0	0
Cash and cash equivalents - beginning of period	0	0
Cash and cash equivalents - end of period	0	0
MasTec, Inc. [Member] | Earn-Out Arrangements [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	0	0
MasTec, Inc. [Member] | Stock Compensation Plan [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	2,900,000	9,200,000
Guarantor Subsidiaries [Member]	'	'
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]	'	'
Net cash (used in) provided by operating activities	39,600,000	103,200,000
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net of cash acquired	-39,900,000	-43,000,000
Capital expenditures	-75,600,000	-96,800,000
Proceeds from sale of property and equipment	10,300,000	7,600,000
Proceeds from disposal of business, net of cash divested	'	-4,300,000
(Payments for) proceeds from other investments, net	-1,000,000	3,800,000
Net cash used in investing activities	-106,200,000	-132,700,000
Cash flows provided by (used in) financing activities:	'	'
Proceeds from credit facility	1,122,400,000	639,600,000
Repayments of credit facility	-723,200,000	-737,200,000
(Repayments of) proceeds from senior notes, including convertible notes	-105,300,000	250,000,000
Repayments of other borrowings and capital lease obligations	-45,300,000	-55,500,000
Payments of financing costs, including call premiums on extinguishment of debt	-1,500,000	-11,800,000
Net financing activities and advances (to) from consolidated affiliates	-124,100,000	-56,400,000
Net cash provided by financing activities	63,600,000	18,900,000
Effect of currency translation on cash	0	0
Net decrease in cash and cash equivalents	-3,000,000	-10,600,000
Cash and cash equivalents - beginning of period	5,300,000	12,700,000
Cash and cash equivalents - end of period	2,300,000	2,100,000
Guarantor Subsidiaries [Member] | Earn-Out Arrangements [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	-60,300,000	-12,800,000
Guarantor Subsidiaries [Member] | Stock Compensation Plan [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	900,000	3,000,000
Non-Guarantor Subsidiaries [Member]	'	'
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]	'	'
Net cash (used in) provided by operating activities	42,500,000	28,500,000
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net of cash acquired	-123,000,000	-103,600,000
Capital expenditures	-15,400,000	-4,600,000
Proceeds from sale of property and equipment	1,900,000	700,000
Proceeds from disposal of business, net of cash divested	'	0
(Payments for) proceeds from other investments, net	0	0
Net cash used in investing activities	-136,500,000	-107,500,000
Cash flows provided by (used in) financing activities:	'	'
Proceeds from credit facility	197,200,000	126,600,000
Repayments of credit facility	-232,000,000	-123,000,000
(Repayments of) proceeds from senior notes, including convertible notes	0	0
Repayments of other borrowings and capital lease obligations	-8,800,000	-1,000,000
Payments of financing costs, including call premiums on extinguishment of debt	0	0
Net financing activities and advances (to) from consolidated affiliates	125,900,000	63,200,000
Net cash provided by financing activities	82,300,000	65,800,000
Effect of currency translation on cash	-1,200,000	-100,000
Net decrease in cash and cash equivalents	-12,900,000	-13,300,000
Cash and cash equivalents - beginning of period	17,700,000	14,000,000
Cash and cash equivalents - end of period	4,800,000	700,000
Non-Guarantor Subsidiaries [Member] | Earn-Out Arrangements [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	0	0
Non-Guarantor Subsidiaries [Member] | Stock Compensation Plan [Member]	'	'
Cash flows provided by (used in) financing activities:	'	'
Proceeds from (payments for) other financing activities	$0	$0

Subsequent_Events_Narrative_De

Subsequent Events (Narrative) (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2014	Oct. 30, 2014	Oct. 30, 2014	Oct. 01, 2014	Oct. 01, 2014
	Credit Facility [Member]	Credit Facility [Member]	Accordion [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
			Credit Facility [Member]	Credit Facility [Member]	Accordion [Member]	WesTower [Member]	WesTower [Member]
			Plan [Member]		Credit Facility [Member]
Subsequent Events [Line Items]	'	'	'	'	'	'	'
Business combinations, percentage of voting interests acquired	'	'	'	'	'	'	100.00%
Business combinations, payments in cash	'	'	'	'	'	$199,000,000	'
Line of credit facility, maximum borrowing capacity	1,000,000,000	750,000,000	250,000,000	1,075,000,000	'	'	'
Line of credit facility, term loan	'	'	'	'	$75,000,000	'	'