MasTec (MTZ) 10-Q 31 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 28, 2013
Document and Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Entity Registrant Name	'MASTEC INC	'
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	'	77,242,037

Condensed_Unaudited_Consolidat

Condensed Unaudited Consolidated Statements Of Operations (USD $)	3 Months Ended				9 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Revenue	$1,269,385,000		$1,067,300,000		$3,165,657,000		$2,794,431,000
Costs of revenue, excluding depreciation and amortization	1,081,132,000		924,304,000		2,695,287,000		2,445,056,000
Depreciation and amortization	'		'		103,111,000		65,767,000
General and administrative expenses	58,976,000		42,514,000		159,761,000		118,192,000
Interest expense, net	12,666,000		9,446,000		34,549,000		27,883,000
Loss on extinguishment of debt	0		0		5,624,000		0
Other (income) expense, net	-2,778,000		8,815,000		-3,283,000		7,989,000
Income from continuing operations before provision for income taxes	81,633,000		59,576,000		170,608,000		130,186,000
Provision for income taxes	-31,698,000		-23,478,000		-65,822,000		-51,229,000
Net income from continuing operations before non-controlling interests	49,935,000		36,098,000		104,786,000		78,957,000
Discontinued operations:	'		'		'		'
Net loss from discontinued operations, including loss on disposal and impairment charges (See Note 4)	-3,735,000		-9,281,000		-5,165,000		-7,881,000
Net income	46,200,000		26,817,000		99,621,000		71,076,000
Net income (loss) attributable to non-controlling interests	62,000		-4,000		172,000		-9,000
Net income attributable to MasTec, Inc.	46,138,000		26,821,000		99,449,000		71,085,000
Basic earnings (loss) per share:	'		'		'		'
Continuing operations, basic earnings per share	$0.65		$0.47		$1.36		$1
Discontinued operations, basic earnings (loss) per share	($0.05)		($0.12)		($0.07)		($0.10)
Total basic earnings per share	$0.60	[1]	$0.35	[1]	$1.29	[1]	$0.90	[1]
Basic weighted average common shares outstanding	77,093		76,194		76,816		79,009
Diluted earnings (loss) per share:	'		'		'		'
Continuing operations, diluted earnings per share	$0.59		$0.45		$1.24		$0.97
Discontinued operations, diluted earnings (loss) per share	($0.04)		($0.12)		($0.06)		($0.10)
Total diluted earnings per share	$0.54	[1]	$0.34	[1]	$1.18	[1]	$0.87	[1]
Diluted weighted average common shares outstanding	85,464		79,526		84,733		81,982
Continuing Operations [Member]	'		'		'		'
Revenue	1,269,400,000		1,067,300,000		3,165,700,000		2,794,400,000
Depreciation and amortization	37,756,000		22,645,000		103,111,000		65,125,000
Interest expense, net	$12,700,000		$9,400,000		$34,500,000		$27,900,000
[1]	Earnings per share tables 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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$46,200	$26,817	$99,621	$71,076
Activity, net of tax (See Note 14)	'	'	-4,397	2,643
Comprehensive income	49,044	29,381	95,224	73,719
Comprehensive income (loss) attributable to non-controlling interests	62	-4	172	-9
Comprehensive income attributable to MasTec, Inc.	48,982	29,385	95,052	73,728
Accumulated Translation Adjustment [Member]	'	'	'	'
Activity, net of tax (See Note 14)	2,936	2,176	-3,839	2,304
Accumulated Net Unrealized Investment Gain (Loss) [Member]	'	'	'	'
Activity, net of tax (See Note 14)	($92)	$388	($558)	$339

Condensed_Unaudited_Consolidat2

Condensed Unaudited Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$2,848	$26,382
Accounts receivable, net of allowance	1,225,122	877,214
Inventories	63,255	83,939
Prepaid expenses and other current assets, including discontinued operations (See Note 4)	41,091	62,106
Total current assets	1,332,316	1,049,641
Property and equipment, net	504,313	350,192
Goodwill	891,266	824,953
Other intangible assets, net	172,833	137,020
Other long-term assets, including discontinued operations (See Note 4)	53,610	54,160
Total assets	2,954,338	2,415,966
Current liabilities:	'	'
Current maturities of long-term debt	53,343	52,596
Accounts payable	475,742	400,833
Accrued salaries and wages	81,587	31,522
Other accrued expenses	64,645	45,814
Billings in excess of costs and earnings	109,655	123,435
Other current liabilities, including discontinued operations (See Note 4)	39,436	40,377
Total current liabilities	882,229	713,793
Long-term debt	779,920	546,323
Long-term deferred tax liabilities, net	151,044	119,388
Other liabilities	42,556	38,875
Total liabilities	1,975,251	1,554,091
Commitments and Contingencies (See Note 17)	'	'
Shareholders' 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 - 86,686,385 and 85,915,552 as of September 30, 2013 and December 31, 2012, respectively	8,669	8,592
Capital surplus	819,073	803,166
Retained earnings	300,366	200,915
Accumulated other comprehensive loss	-9,898	-5,501
Treasury stock, at cost; 9,467,286 shares as of both September 30, 2013 and December 31, 2012	-150,000	-150,000
Total MasTec, Inc. shareholders' equity	974,212	857,172
Non-controlling interests	4,875	4,703
Total shareholders' equity	979,087	861,875
Total liabilities and shareholders' equity	2,954,338	2,415,966
Contributed Shares [Member] | Common Stock Outstanding [Member]	'	'
Shareholders' equity:	'	'
Contributed shares (See Note 12)	6,002	0
Earn-out Arrangements [Member]	'	'
Current liabilities:	'	'
Acquisition-related contingent consideration, current	57,821	19,216
Acquisition-related contingent consideration, net of current portion	$119,502	$135,712

Condensed_Unaudited_Consolidat3

Condensed Unaudited Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
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	86,686,385	85,915,552
Treasury stock, shares	9,467,286	9,467,286

Condensed_Unaudited_Consolidat4

Condensed Unaudited Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012
Cash flows from operating activities:	'		'
Net income	$99,621		$71,076
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Depreciation and amortization	103,111		65,767
Non-cash stock-based compensation expense	9,647		3,351
Non-cash interest expense	6,890		6,424
Write-off of unamortized financing costs on redeemed debt	1,508		0
Gains on sales of assets	-4,884		-1,569
Excess tax benefit from non-cash stock-based compensation	-4,446	[1]	-302	[1]
Loss on disposal and impairment charges, discontinued operations	6,036		12,922
Changes in assets and liabilities, net of assets acquired and liabilities assumed:	'		'
Accounts receivable	-271,010		-233,220
Inventories	20,484		8,243
Deferred tax assets and liabilities, net	9,783		-3,555
Other assets, current and non-current portion	19,117		-6,383
Accounts payable and accrued expenses	126,784		176,289
Billings in excess of costs and earnings	-19,776		-3,367
Other liabilities, current and non-current portion	13,701		25,099
Net cash provided by operating activities	124,991		114,670
Cash flows (used in) provided by investing activities:	'		'
Cash paid for acquisitions, net, including contingent consideration	-159,446		-17,496
Capital expenditures	-101,411		-50,331
Proceeds from sale of property and equipment	8,288		5,808
Proceeds from sale or redemption of investments	5,025		0
Proceeds from disposal of business, net of cash divested	-4,332		97,728
Payments for other investments, net	-1,174		-284
Net cash (used in) provided by investing activities	-253,050		35,425
Cash flows provided by (used in) financing activities:	'		'
Proceeds from issuance of 4.875% senior notes	400,000		0
Repayment of 7.625% senior notes	-150,000		0
Proceeds from credit facility	766,154		631,815
Repayments of credit facility	-860,070		-681,815
Repayments of other borrowings	-24,246		-15,510
Proceeds from (repayments of) book overdrafts	2,791		-5,645
Payments of capital lease obligations	-32,214		-14,806
Proceeds from stock option exercises and other share-based awards	9,231		1,445
Excess tax benefit from non-cash stock-based compensation	4,446		302
Purchases of treasury stock	0		-75,000
Payments for debt extinguishment, call premiums	-4,116		0
Payments of financing costs	-7,718		-113
Net cash provided by (used in) financing activities	104,258		-159,327
Net decrease in cash and cash equivalents	-23,801		-9,232
Net effect of currency translation on cash	-118		135
Cash and cash equivalents - beginning of period	26,767		20,279
Cash and cash equivalents - end of period	2,848		11,182
Cash and cash equivalents of discontinued operations	0		710
Cash and cash equivalents of continuing operations	2,848		10,472
Supplemental cash flow information:	'		'
Interest paid	30,851		20,879
Income taxes paid, net of refunds	49,722		37,219
Supplemental disclosure of non-cash investing and financing information:	'		'
Equipment acquired under capital lease	82,737		29,917
Common Stock Outstanding [Member] | Investor [Member]	'		'
Supplemental cash flow information:	'		'
Non-cash transaction, value of consideration received	6,002		0
Machinery and Equipment [Member]	'		'
Supplemental disclosure of non-cash investing and financing information:	'		'
Equipment acquired under financing arrangements	24,100		4,887
Accounts Receivable [Member] | Machinery and Equipment [Member]	'		'
Supplemental cash flow information:	'		'
Non-cash transaction, value of consideration received	9,683		0
Inventories [Member]	'		'
Supplemental cash flow information:	'		'
Non-cash transaction, value of consideration received	0		12,005
Operating Expense [Member]	'		'
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Provisions for losses on assets	6,300		4,226
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	$2,125		($10,331)
[1]	Excess tax benefits, which represent cash flows from tax deductions in excess of the 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.

Business_Basis_of_Presentation

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

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	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,
		2013			2012			2013			2012
	Net income attributable to MasTec:
	Basic net income from continuing operations (1)	$	49,960		$	36,098		$	104,702		$	78,957
	Interest expense, net of tax, 2009 Convertible Notes	79			78			235			234
	Diluted net income from continuing operations	$	50,039		$	36,176		$	104,937		$	79,191
	Net loss from discontinued operations (1)	(3,822		)	(9,277		)	(5,252		)	(7,872		)
	Diluted net income attributable to MasTec	$	46,217		$	26,899		$	99,685		$	71,319
	Weighted average shares outstanding:
	Basic weighted average shares outstanding	77,093			76,194			76,816			79,009
	Dilutive common stock equivalents	775			887			774			842
	Dilutive premium shares, 2011 Convertible Notes	6,790			1,639			6,337			1,325
	Dilutive shares, 2009 Convertible Notes	806			806			806			806
	Diluted weighted average shares outstanding	85,464			79,526			84,733			81,982
	(1) Calculated as total net income less amounts attributable to non-controlling interests.
	During the nine month period ended September 30, 2012, the Company repurchased 4.9 million shares of its common stock for an aggregate purchase price of $75.0 million. Repurchased shares are held in the Company's treasury.
	Outstanding Convertibles Notes - Diluted Share Impact
	The Company has $215 million principal amount of senior convertible notes outstanding, composed of $202.3 million of senior convertible notes issued in 2011 (the "2011 Convertible Notes") and approximately $12.6 million of senior convertible notes issued in 2009 (the "2009 Convertible Notes"). Dilutive shares associated with the 2009 Convertible Notes are attributable to the underlying principal amounts. As the Company’s weighted average stock price for the three and nine month periods ended September 30, 2013 and 2012 exceeded the conversion prices of the 2011 Convertible Notes, dilutive shares associated with the 2011 Convertible Notes, which are attributable to the weighted average premium value, in shares, of the conversion shares underlying the 2011 Convertible Notes in excess of the respective principal amounts thereof, have been included in the Company's share count for the corresponding periods.
	The 2011 Convertible Notes consist of $105.3 million principal amount of 4.0% senior convertible notes, convertible at $15.76 per share (the "2011 4.0% Notes") and $97.0 million principal amount of 4.25% senior convertible notes, convertible at $15.48 per share (the "2011 4.25% Notes"). 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 Ended September 30,												As of and for the Nine Months Ended September 30,
		2013						2012						2013				2012
		2011 4.0%			2011 4.25%			2011 4.0%			2011 4.25%			2011 4.0%		2011 4.25%		2011 4.0%		2011 4.25%
		Notes			Notes			Notes			Notes			Notes		Notes		Notes		Notes
	Number of conversion shares, principal amount	6,683			6,268			6,683			6,268			6,683		6,268		6,683		6,268
	Weighted average actual per share price	$	32.84		$	32.84		$	17.89		$	17.89		$	30.59	$	30.59	$	17.4	$	17.4
	Weighted average premium value	$	114,176		$	108,864		$	14,208		$	15,106		$	99,104	$	94,728	$	10,975	$	12,073
	Weighted average equivalent premium shares	3,476			3,314			794			845			3,240		3,097		631		694
	See Note 10 - Debt for additional information.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	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. In the second and third quarters of 2013 and in December 2012, the Company acquired certain businesses, as discussed below and in Note 3 - Acquisitions and Other Investments of the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2012. As of September 30, 2013, the allocations of purchase prices 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 these acquisitions, are provisional and remain preliminary as 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.
	During the three and nine month periods ended September 30, 2013, the Company revised its preliminary allocations for certain of the 2013 and 2012 acquisitions based on new information about the facts and circumstances existing as of the respective dates of such acquisitions, or, for purchase price adjustments, based on the final net assets and net working capital of the businesses acquired, as prescribed in the relevant purchase agreements. These adjustments resulted in the recognition of, or adjusted the fair values of, certain acquired assets and assumed liabilities, which, for the 2012 acquisitions, resulted in the revision of comparative prior period financial information. Such measurement period adjustments are presented as if the adjustments had been taken into account as of the dates of the respective acquisitions. All changes that do not qualify as measurement period adjustments are included in current period earnings.
	2013 Acquisitions
	Big Country
	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 is a North American oil and gas pipeline and facility construction services company, headquartered in Calgary, Alberta, Canada.  Big Country also has construction offices in Alberta, British Columbia and Saskatchewan, as well as in Wyoming and North Dakota. Big Country's services include oil, natural gas and natural gas liquids gathering systems and pipeline construction; pipeline modification and replacement services; compressor and pumping station construction; and other related services supporting the oil and gas production, processing and transportation industries. Big Country is expected to significantly expand MasTec's ability to take advantage of the rapidly expanding opportunities anticipated for energy infrastructure work in North America in the coming years. Big Country is reported within the Company's oil and gas segment.
	The following table summarizes the preliminary estimated fair value of consideration paid and the identifiable assets acquired and liabilities assumed, as adjusted, as of the date of acquisition (in millions):
	Purchase price consideration:	1-May-13
	Cash	$	103.5
	Fair value of contingent consideration (earn-out liability)	22.8
	Total consideration transferred	$	126.3
	Identifiable assets acquired and liabilities assumed:
	Current assets	$	69
	Property and equipment	44
	Pre-qualifications	29.6
	Finite-lived intangible assets	10.7
	Current liabilities	(21.7		)
	Long-term debt	(24.4		)
	Deferred income taxes	(13.1		)
	Total identifiable net assets	$	94.1
	Goodwill	$	32.2
	Total net assets acquired, including goodwill	$	126.3
	The fair values and weighted average useful lives of Big Country's acquired finite-lived intangible assets, as adjusted, as of the date of acquisition were assigned as follows:
		Fair Value			Weighted Average Useful Life
		(in millions)			(in years)
	Backlog	$	1.9		1
	Non-compete agreements	1.8			8
	Customer relationships	7			6
	Total acquired amortizing intangibles	$	10.7		5
	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 Big Country's pre-qualifications with companies in the oil and gas industry has been assigned an indefinite life as the pre-qualifications do not 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 Big Country'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 Big Country and MasTec. As of the date of acquisition, the total amount of goodwill expected to be deductible for tax purposes was $4.0 million.
	The contingent earn-out obligation is equal to 25% of the excess, if any, of Big Country’s annual earnings 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 cash. 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 $1 million and $110 million; however, there is no maximum earn-out payment amount.
	Other 2013 Acquisitions
	Effective April 1, 2013, MasTec acquired a former subcontractor to its wireless business, which will provide self-perform communications tower construction, installation, maintenance and other services in support of telecommunications infrastructure construction in the Company's communications segment. In addition, effective August 1, 2013, MasTec acquired an electrical transmission services company, which focuses primarily on substation construction activities within the Company's electrical transmission segment.
	Unaudited Pro Forma Information - 2013 Acquisitions
	The following unaudited supplemental pro forma results of operations include the results of operations of each of the companies acquired in 2013 as if each had been consolidated as of January 1, 2012 and have been provided for illustrative purposes only. These unaudited pro forma results of operations do 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 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 pro forma combined results of operations presented below for three and nine month periods ended September 30, 2013 and 2012, respectively, have been prepared by adjusting the historical results of MasTec to include the historical results of the acquisitions described above as if they occurred on January 1, 2012. The unaudited pro forma combined historical results were then adjusted (i) to remove one-time acquisition costs; (ii) to increase amortization expense resulting from 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 pro forma results of operations do 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 pro forma results of operations do 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 company in the future.
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2013			2012				2013			2012
		(unaudited, in millions)							(unaudited, in millions)
	Revenue	$	1,273.60		$	1,158.70			$	3,284.90		$	3,026.20
	Net income from continuing operations	$	50		$	42.7			$	113.4		$	88.9
	Results of Businesses Acquired in 2013
	Revenues and net income from the Company's 2013 acquisitions for the periods indicated are as follows (in millions):
		For the Three Months Ended September 30, 2013			For the Nine Months Ended September 30, 2013
	Revenue	$	101.8		$	141.4
	Net income	$	6.2		$	7.7
	The above results do not include acquisition costs of $0.3 million and $1.5 million for the three and nine month periods ended September 30, 2013, respectively, and also do not include interest expense associated with consideration paid for these acquisitions.
	2012 Acquisitions
	Effective December 1, 2012, MasTec acquired all of the issued and outstanding interests of Bottom Line Services, LLC ("BLS"), a natural gas and petroleum pipeline infrastructure services company for an aggregate purchase price composed of approximately $67.6 million in cash and a five year earn-out, valued at $11.1 million as of the date of acquisition. BLS's services include pipeline and facilities construction, painting and maintenance services, primarily in eastern Texas.  Additionally, effective December 1, 2012, MasTec acquired a former subcontractor to MasTec's oil and gas business, which provides self-perform clearing and trenching services for natural gas and petroleum pipeline infrastructure construction, and also acquired a former subcontractor to MasTec's wireless business, which provides self-perform communications tower construction, installation, maintenance and other services in support of telecommunications infrastructure construction.
	Results of Businesses Acquired in 2012
	Revenues and net income from the Company's 2012 acquisitions for the periods indicated are as follows (in millions):
		For the Three Months Ended September 30, 2013			For the Nine Months Ended September 30, 2013
	Revenue	$	39.9		$	129
	Net income	$	1.4		$	5.2
	The above results do not include interest expense associated with consideration paid for these acquisitions.
	Measurement Period Adjustments
	Measurement period adjustments associated with the Company's 2012 acquisitions have been reflected in the Company's December 31, 2012 consolidated balance sheet as follows (in millions):
	As of December 31, 2012		As Previously Reported			Measurement Period Adjustments/Reclassifications				As Revised
	Current assets		$	1,047.10		$	2.5			$	1,049.60
	Property and equipment, net		$	350.4		$	(0.2	)		$	350.2
	Goodwill		$	820.3		$	4.7			$	825
	Other long-term assets, including discontinued operations		$	53.1		$	1.1			$	54.2
	Current liabilities		$	705.7		$	8.1			$	713.8

Discontinued_Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Discontinued Operations
	Globetec
	In September 2012, the Company's board of directors approved a plan of sale for its Globetec business. Accordingly, Globetec's projects and assets are reflected as assets and liabilities of discontinued operations in the condensed unaudited consolidated balance sheets for all periods presented, and Globetec's results of operations are presented as discontinued operations in the condensed unaudited consolidated statements of operations for all periods presented.
	Effective August 31, 2013, the Company sold all of its membership interests in Globetec Construction, LLC ("Globetec") for nominal consideration and retained certain assets, including two pre-closing, intercompany loans of $2.0 million and $5.6 million. The loans bear interest at 0.25% and 5% per annum, respectively, and mature on October 3, 2014, or earlier if Globetec collects certain amounts from its customers. The $5.6 million note has an option to extend the maturity by an additional year at an increased interest rate of 10% per annum. The $2.0 million and $5.6 million notes are classified as current assets and long-term assets, respectively. The sale agreement provides that the Company would retain certain contingent assets and liabilities of the Globetec business, which are reported in discontinued operations as set forth below.
	The Company believes the notes receivable represent a variable interest in Globetec. The Company holds no power to control the primary activities of Globetec, owns no equity interests in Globetec and is not the primary beneficiary of the Globetec business. In addition to the loans described above, the Company has issued surety bonds totaling $41.8 million that remain outstanding as of September 30, 2013 for projects that Globetec has completed as of September 30, 2013 or expects to complete before May 2014. The Company believes an immaterial amount is at risk under these surety bonds as of September 30, 2013. The Company is not obligated and does not intend to support Globetec in the future.
	The following table contains a summary of assets and liabilities associated with Globetec as of December 31, 2012, and, as of September 30, 2013, a summary of the contingent assets and liabilities, as described above, that were retained by the Company (in millions):
		September 30,			December 31,
		2013			2012
	Assets:
	Current assets	$	3.1		$	18.6
	Long-term assets	11.3			7.7
	Assets of discontinued operations	$	14.4		$	26.3
	Liabilities:
	Current liabilities of discontinued operations	$	1.3		$	10.7
	The following table presents results from discontinued operations associated with the Globetec operation for the periods indicated (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Revenue	$	4.8		$	4.8		$	18		$	13.5
	Loss from operations, before tax	(0.5		)	(2.6		)	(2.7		)	(5.8		)
	Loss on disposal and impairment charges, before tax	(5.7		)	(12.7		)	(6.0		)	(12.7		)
	Benefit from income taxes	2.5			6			3.5			6.9
	Net loss from discontinued operations	$	(3.7	)	$	(9.3	)	$	(5.2	)	$	(11.6	)
	DirectStar
	In May 2012, Red Ventures exercised its option to acquire from the Company the equity interests in DirectStar, which provides marketing and sales services on behalf of DIRECTV®. The Company consummated the sale of DirectStar to Red Ventures in June 2012 for a net sale price of $98.9 million in cash. DirectStar is presented as a discontinued operation in the Company’s condensed unaudited consolidated financial statements for all periods presented. Net income from discontinued operations for DirectStar was $3.7 million for the nine month period ended September 30, 2012. There was no activity for the three month period ended September 30, 2012.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Other Intangible Assets	'
	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, 2012	$	305.8		$	272.1			$	129.5			$	117.6			$	825
	Additions from new business combinations	10			32.3				19.2				—				61.5
	Accruals of acquisition-related contingent consideration (1)	6.5			—				—				—				6.5
	Currency translation adjustments	—			(1.7		)		—				—				(1.7		)
	Balance as of September 30, 2013	$	322.3		$	302.7			$	148.7			$	117.6			$	891.3
	(1) Represents contingent consideration for acquisitions prior to January 1, 2009, which is only accrued as earned, in accordance with U.S. GAAP.
	The following table provides a reconciliation of changes in other intangible assets, net (in millions):
			Other Intangible Assets
			Non-amortizing							Amortizing
			Trade Names			Pre-Qualifications				Customer Relationships and Backlog				Other (1)				Total
	Other intangible assets, gross carrying amount as of December 31, 2012		$	34.8		$	31.3			$	109.6			$	19.8			$	195.5
	Accumulated amortization									$	(48.2	)		$	(10.3	)		$	(58.5	)
	Other intangible assets, net, as of December 31, 2012		$	34.8		$	31.3			$	61.4			$	9.5			$	137
	Additions from new business combinations		—			29.6				19.9				2.5				52
	Amortization expense									(14.4		)		(0.8		)		(15.2		)
	Currency translation adjustments		—			(0.7		)		(0.3		)		—				(1.0		)
	Other intangible assets, net, as of September 30, 2013		$	34.8		$	60.2			$	66.6			$	11.2			$	172.8
	(1) Consists principally of trade names and non-compete agreements.
	Amortization expense associated with amortizing intangible assets for the three month periods ended September 30, 2013 and 2012 was $5.8 million and $2.8 million, respectively. Amortization expense associated with amortizing intangible assets for the nine month periods ended September 30, 2013 and 2012 was $15.2 million and $8.5 million, respectively.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	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, auction rate securities, 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:
	Level 1 - Quoted market prices in active markets for identical assets or liabilities.
	Level 2 - Observable market based inputs or other observable inputs.
	Level 3 - Significant unobservable inputs that cannot be corroborated by observable market data. These values are generally determined using valuation models incorporating management’s estimates of market participant assumptions.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	As of September 30, 2013, the Company held certain assets and liabilities required to be measured at fair value on a recurring basis. The fair values of financial assets and liabilities measured on a recurring basis were determined using the following inputs as of the dates indicated (in millions):
				Fair Value Measurements
				Using Inputs Considered as Significant
		Fair Value as of		Level 1		Level 2		Level 3
		30-Sep-13
	Assets
	Life insurance surrender values	$	5	$	5
	Auction rate securities (See Note 7)	$	9.2					$	9.2
	Liabilities
	Acquisition-related contingent consideration (1)	$	169.8					$	169.8
				Fair Value Measurements
				Using Inputs Considered as Significant
		Fair Value as of		Level 1		Level 2		Level 3
		31-Dec-12
	Assets
	Life insurance surrender values	$	11.9	$	11.9
	Auction rate securities (See Note 7)	$	14.4					$	14.4
	Liabilities
	Acquisition-related contingent consideration (1)	$	143.6					$	143.6
	(1) For acquisitions that closed after January 1, 2009.
	Changes in Acquisition-Related Contingent Consideration Measured at Fair Value on a Recurring Basis
	For the nine month period ended September 30, 2013, the Company made $2.7 million of payments for acquisition-related contingent consideration obligations. Foreign currency translation gains included in other comprehensive income totaled $1.1 million for the nine month period ended September 30, 2013. Additions from the Company's 2013 acquisitions totaled $30.0 million for the nine month period ended September 30, 2013.
	Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
	Assets and liabilities recognized or disclosed at fair value on a nonrecurring basis, which are initially measured at fair value, and are subsequently remeasured in the event of an impairment or other measurement event, include items such as cost and equity method investments, goodwill and other intangible assets, long-lived assets and debt instruments.
	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, 2013				December 31, 2012
		Carrying		Fair		Carrying				Fair
		Amount		Value		Amount				Value
	4.875% senior notes	$	400	$	378	$	—			$	—
	7.625% senior notes	$	—	$	—	$	150			$	154.9
	2009 Convertible Notes	$	12.6	$	24.7	$	12.7			$	21
	2011 Convertible Notes	$	197	$	397.8	$	193			$	338.3
	The estimated fair values of the Company’s 4.875% senior notes, 7.625% senior notes, 2009 Convertible Notes and 2011 Convertible Notes are based on quoted market prices, a Level 1 input. During the first quarter of 2013, the Company repurchased and redeemed its 7.625% senior notes. A debt extinguishment loss of $5.6 million was recorded in connection with the transaction. See Note 10 - Debt for additional information.

Auction_Rate_Securities

Auction Rate Securities	9 Months Ended
	Sep. 30, 2013
Available-for-sale Securities [Abstract]	'
Auction Rate Securities	'
	Auction Rate Securities
	The Company has available-for-sale auction rate securities, which, as of September 30, 2013, represent interests in pools of student loans guaranteed by the U.S. government under the Federal Family Education Loan Program. In May 2013, the issuer of one of the Company's student loan auction rate securities redeemed its security at the security's par value of $2.6 million. Additionally, the Company sold its structured finance security for $2.4 million in May 2013, which had a par value of $5.0 million and a cost basis of $1.7 million. A gain of $0.7 million, which is included in other income, was realized in connection with the sale.
	As of September 30, 2013, estimated fair value and unrealized losses associated with the Company’s auction rate securities, which are classified as other long-term assets in the condensed unaudited consolidated financial statements, totaled $9.2 million and $1.1 million, respectively. As of December 31, 2012, estimated fair value and unrealized losses, net of unrealized gains, associated with the Company’s auction rate securities totaled $14.4 million and $0.2 million, respectively
	Fair values of the Company's auction rate securities are estimated by an independent valuation firm, Houlihan Capital Advisors, LLC, using a probability weighted discounted cash flow model. The valuation of these securities is sensitive to market conditions and management’s judgment and can change significantly based on the assumptions used.
	As of September 30, 2013, contractual maturities of the Company’s auction rate securities ranged from 14.5 to 34.1 years.

Accounts_Receivable_Net_of_All

Accounts Receivable, Net of Allowance	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Accounts Receivable, Net of Allowance	'
	Accounts Receivable, Net of Allowance
	The following table provides details of accounts receivable, net of allowance, for our continuing operations as of the dates indicated (in millions):
		September 30,			December 31,
		2013			2012
	Contract billings	$	711.4		$	522
	Retainage	134.7			113.5
	Costs and earnings in excess of billings	393.9			253
	Accounts receivable, gross	$	1,240.00		$	888.5
	Less allowance for doubtful accounts	(14.9		)	(11.3		)
	Accounts receivable, net	$	1,225.10		$	877.2
	Provisions for doubtful accounts were $1.9 million and $1.2 million, respectively for the three month periods ended September 30, 2013 and September 30, 2012, respectively, and $4.4 million and $2.5 million for the nine month periods ended September 30, 2013 and September 30, 2012, respectively.

Debt

Debt	9 Months Ended
	Sep. 30, 2013
Long-term Debt, Unclassified [Abstract]	'
Debt	'
	Debt
	The following table provides details of the carrying value of debt as of the dates indicated (in millions):
	Description		Maturity Date	September 30,				December 31,
				2013				2012
	Credit facility		August 22, 2016	$	36.4			$	134
	4.875% senior notes		March 15, 2023	400				—
	7.625% senior notes		February 1, 2017	—				150
	2011 4.0% senior convertible notes		June 15, 2014	103.1				100.9
	2011 4.25% senior convertible notes		December 15, 2014	93.9				92.1
	2009 4.0% senior convertible notes		June 15, 2014	9.6				9.7
	2009 4.25% senior convertible notes		December 15, 2014	3				3
	Capital lease obligations, weighted average interest rate of 2.8%		In installments through March 2020	133.3				79
	Notes payable for equipment and other debt, weighted average interest rate of 3.5%		In installments through May 2018	53.9				30.2
	Total debt			$	833.2			$	598.9
	Less current maturities			(53.3		)		(52.6		)
	Long-term debt			$	779.9			$	546.3
	Issuance of 4.875% Senior Notes and Repurchase and Redemption of 7.625% Senior Notes
	On March 18, 2013, the Company issued $400 million of 4.875% senior notes due March 15, 2023 (the “4.875% Senior Notes”) in a registered public offering. The 4.875% Senior Notes bear interest at a rate of 4.875% per annum, payable on March 15 and September 15 of each year. Interest payments commenced on September 15, 2013. The 4.875% Senior Notes are senior unsecured unsubordinated obligations and rank equal in right of payment with existing and future unsubordinated debt, and rank senior in right of payment to existing and future subordinated debt.  The 4.875% Senior Notes, as well as the Company's 2011 Convertible Notes and 2009 Convertibles Notes are effectively junior to MasTec's secured debt, including the Company's credit facility, to the extent of the value of the assets securing that debt.  The 4.875% Senior Notes are guaranteed on an unsecured unsubordinated basis by MasTec's direct and indirect 100%-owned domestic subsidiaries that guarantee the Company's credit facility.
	The Company has the option to redeem all or a portion of the 4.875% Senior Notes at any time on or after March 15, 2018 at the redemption prices set forth in the indenture that governs the 4.875% Senior Notes (the “4.875% Senior Notes Indenture”) plus accrued and unpaid interest, if any, to the redemption date. At any time prior to March 15, 2018, the Company may redeem all or a part of the 4.875% Senior Notes at a redemption price equal to 100% of the principal amount of 4.875% Senior Notes redeemed plus an applicable premium, as defined in the 4.875% Senior Notes Indenture, together with accrued and unpaid interest, if any, to the redemption date. In addition, at any time prior to March 15, 2016, the Company may redeem up to 35% of the principal amount of the 4.875% Senior Notes using the net cash proceeds of one or more sales of the Company's capital stock, as defined in the 4.875% Senior Notes Indenture, at a redemption price of 104.875% of the principal amount, plus accrued and unpaid interest to the redemption date.
	The 4.875% Senior Notes Indenture, among other things, generally limits the ability of the Company and certain of its subsidiaries, subject to certain exceptions, to (i) incur additional debt and issue preferred stock, (ii) create liens, (iii) pay dividends, acquire shares of capital stock, make payments on subordinated debt or make investments, (iv) place limitations on distributions from certain subsidiaries, (v) issue guarantees, (vi) issue or sell the capital stock of certain subsidiaries, (vii) sell assets, (viii) enter into transactions with affiliates and (ix) effect mergers. The 4.875% Senior Notes Indenture provides for customary events of default, as well as customary remedies upon an event of default, as defined in the 4.875% Senior Notes Indenture, including acceleration of repayment of outstanding amounts.
	Approximately $7.7 million in financing costs were incurred in connection with the issuance of the 4.875% Senior Notes. These deferred financing costs are included in other long-term assets in the condensed unaudited consolidated financial statements and will be amortized over the term of the 4.875% Senior Notes using the effective interest method. The Company used a portion of the proceeds from the 4.875% Senior Notes offering to fund the repurchase and redemption of the Company's $150 million principal amount of 7.625% senior notes due 2017 (the “7.625% Senior Notes”), discussed below, and to repay the outstanding balance of the Company's credit facility. The remaining net proceeds were used for working capital and other general corporate purposes.
	In connection with the issuance of the 4.875% Senior Notes, the Company repurchased approximately $121.1 million of its 7.625% Senior Notes on March 18, 2013 in a tender offer at a price of 102.792% of the principal amount, which included an early tender payment of $30.00 per $1,000 principal amount of notes tendered. The holders of the tendered 7.625% Senior Notes also received accrued interest from the most recent interest payment date to, but not including, the date of repurchase. In addition, on March 29, 2013, the Company redeemed the remaining outstanding $28.9 million aggregate principal amount of the 7.625% Senior Notes in accordance with their terms at a price of 102.542% of the principal amount plus accrued interest from the most recent interest payment date to, but not including, the date of redemption.
	A pre-tax debt extinguishment loss of $5.6 million was recognized during the first quarter of 2013 in connection with the repurchase and redemption of the 7.625% Senior Notes, including $4.1 million of early payment premiums and $1.5 million of unamortized deferred financing costs. This loss is separately disclosed within the condensed unaudited consolidated statements of operations.
	Credit Facility
	As of September 30, 2013, the Company had outstanding revolving loans under its senior secured revolving credit facility (the "Credit Facility") of $36.4 million, which accrued interest at a weighted average rate of approximately 3.93% per annum. As of December 31, 2012, the Company had outstanding revolving loans under its Credit Facility of $134.0 million, which accrued interest at a weighted average rate of approximately 3.95% per annum. Letters of credit of approximately $138.5 million and $120.8 million were outstanding under the Credit Facility as of September 30, 2013 and December 31, 2012, respectively. The remaining borrowing capacity under the Credit Facility of $425.2 million and $345.2 million as of September 30, 2013 and December 31, 2012, respectively, was available for revolving loans or up to $211.5 million and $229.2 million, respectively, of new 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, 2013, interest on outstanding letters of credit accrued at either 1.125% or 2.25% per annum, based on the type of letter of credit issued. As of December 31, 2012, interest on outstanding letters of credit accrued at either 1% or 2% per annum. The unused facility fee was 0.40% and 0.35% as of September 30, 2013 and December 31, 2012, respectively. See Note 21 - Subsequent Events regarding the October 2013 amendment of the Company's Credit Facility.
	2011 Convertible Notes
	Unamortized debt discount and financing costs associated with the 2011 Convertible Notes totaled $5.3 million and $9.3 million as of September 30, 2013 and December 31, 2012, respectively. The 2011 4.0% Notes mature in June 2014. The Company expects to refinance the $105.3 million principal amount of the 2011 4.0% Notes on a long-term basis either through its Credit Facility or through other sources of funding available to the Company, and therefore, has included the carrying amount of the 2011 4.0% Notes within long-term debt in the condensed unaudited consolidated balance sheet as of September 30, 2013.
	For additional information regarding the accounting treatment of the 2011 Convertible Notes, see Note 10 - Debt in the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2012.
	Debt Guarantees and Covenants
	The Company’s 2011 Convertible Notes and 2009 Convertible Notes are, and, through March 29, 2013, the Company's 7.625% Senior Notes were, 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 Company's Credit Facility or other outstanding indebtedness. The Company's 4.875% Senior Notes are guaranteed on an unsecured, unsubordinated, joint and several basis by the Company's 100%-owned domestic subsidiaries that guarantee the Credit Facility. See Note 20 - Supplemental Guarantor Condensed Unaudited Consolidating Financial Information.
	MasTec was in compliance with all provisions and covenants pertaining to its outstanding debt instruments as of September 30, 2013 and December 31, 2012.
	Interest Expense, Net
	The following table provides details of interest expense, net, classified within continuing operations for the periods indicated (in millions):
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2013			2012				2013			2012
	Interest expense:
	Contractual and other interest expense	$	10.4		$	7.4			$	27.9		$	21.8
	Accretion of senior convertible note discount	1.3			1.2				3.9			3.7
	Amortization of deferred financing costs	1			0.9				3			2.7
	Total interest expense	$	12.7		$	9.5			$	34.8		$	28.2
	Interest income	—			(0.1		)		(0.3		)	(0.3		)
	Interest expense, net	$	12.7		$	9.4			$	34.5		$	27.9

Property_and_Equipment_Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2013
Property, Plant and Equipment [Abstract]	'
Property and Equipment, Net	'
	Property and Equipment, Net
	The following table provides details of property and equipment, net, including property and equipment held under capital leases, for our continuing operations as of the dates indicated (in millions):
		September 30,			December 31,
		2013			2012
	Land	$	4.8		$	4.8
	Buildings and leasehold improvements	18.1			15.4
	Machinery and equipment	728.7			521.5
	Office furniture and equipment	105.4			89.4
	Total property and equipment	$	857		$	631.1
	Less accumulated depreciation and amortization	(352.7		)	(280.9		)
	Property and equipment, net	$	504.3		$	350.2
	Depreciation and amortization expense associated with property and equipment of the Company's continuing operations for the three month periods ended September 30, 2013 and 2012 was $32.0 million and $19.8 million, respectively. Depreciation and amortization expense associated with property and equipment of the Company's continuing operations for the nine month periods ended September 30, 2013 and 2012 was $87.9 million and $56.6 million, respectively.

Lease_Obligations

Lease Obligations	9 Months Ended
	Sep. 30, 2013
Leases [Abstract]	'
Lease Obligations	'
	Lease Obligations
	Capital Leases
	MasTec enters into agreements that expire on various dates, which provide financing for certain machinery and equipment. Assets held under capital leases, net of accumulated depreciation, totaled $142.2 million and $102.2 million as of September 30, 2013 and December 31, 2012, 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, including short term rentals, reflected within continuing operations, was approximately $75.6 million and $69.4 million for the three month periods ended September 30, 2013 and 2012, respectively, and $176.0 million and $168.2 million for the nine month periods ended September 30, 2013 and 2012, respectively.

StockBased_Compensation_and_Ot

Stock-Based Compensation and Other Employee Benefit Plans	9 Months Ended
	Sep. 30, 2013
Share-based Compensation [Abstract]	'
Stock-Based Compensation and Other Employee Benefit Plans	'
	Stock-Based Compensation and Other Employee Benefit Plans
	The Company has certain stock-based compensation plans, under which stock options and restricted share awards are available for issuance or outstanding, including the MasTec, Inc. 2013 Incentive Plan (the "2013 Incentive Plan"), which became effective in May 2013. As of September 30, 2013, the 2013 Incentive Plan had 4,926,681 shares available for issuance. In addition, the Company has certain employee stock purchase plans under which shares of the Company's common stock are available for purchase by eligible employees. In March 2013, the Company authorized the issuance of up to 1,000,000 new shares of MasTec, Inc. common stock to eligible employees under the MasTec, Inc. Bargaining Units Employee Stock Purchase Plan (the "2013 Bargaining Units ESPP"). The 2013 Bargaining Units ESPP became effective on July 1, 2013. The MasTec, Inc. 2011 Employee Stock Purchase Plan (the “2011 ESPP" and, together with the 2013 Bargaining Units ESPP, the "ESPPs") also provides for the issuance of up to 1,000,000 shares of MasTec, Inc. common stock for eligible employees.
	Under all stock-based compensation plans in effect as of September 30, 2013, there were a total of 6,383,118 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, 2013 was approximately $17.4 million, which is expected to be recognized over a weighted average period of approximately 1.4 years. The total intrinsic value, or fair value, of restricted share awards that vested, which is based on the market price on the date of vesting, was $0.9 million and $2.0 million for the three and nine month periods ended September 30, 2013 and $0.7 million and $2.9 million for the three and nine month periods ended September 30, 2012, respectively.
	During the second quarter of 2013, the Company entered into an agreement with the previous owners of EC Source to establish an incentive program for its employees and granted 350,000 restricted share awards (the “EC Source Share Award”). The former owners of EC Source contributed cash and shares of MasTec common stock to the Company in connection with the EC Source Share Award. In the event that shares granted under the EC Source Share Award are forfeited prior to vesting, the former owners of EC Source will be re-issued the pro-rata percentage of the former owners' contributed shares to total shares awarded under the EC Source share grant. As of September 30, 2013, the Company did not anticipate the occurrence of any such forfeitures.
	Activity, restricted share awards:	Restricted		Per Share Weighted Average Grant Date
		Shares		Fair Value
	Non-vested restricted shares, as of December 31, 2012	782,281		$	19.1
	Granted	428,262		31.04
	Vested	(64,288	)	18.22
	Canceled/forfeited	(15,187	)	15.35
	Non-vested restricted shares, as of September 30, 2013	1,131,068		$	23.72
	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 at not less than the fair market value of the underlying stock on the date of grant. All outstanding stock options are fully vested.
	Activity, stock options:	Stock		Per Share Weighted Average			Weighted Average		Aggregate Intrinsic
		Options		Exercise Price			Remaining		Value (1)
							Contractual Life (years)		(in millions)
	Options outstanding as of December 31, 2012	1,043,825		$	10.5		2.33		$	15.1
	Exercised	(498,123	)	9.91
	Canceled/forfeited	(35,000	)	7.74
	Options outstanding as of September 30, 2013	510,702		$	11.27		2.19		$	9.7
	Options exercisable as of September 30, 2013	510,702		$	11.27		2.19		$	9.7
	-1	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 during the three month periods ended September 30, 2013 and 2012, which is based on the difference between the exercise price and the market price of the Company’s stock at the date of exercise, was $4.6 million and $0.4 million, respectively. The intrinsic value of options exercised during the nine month periods ended September 30, 2013 and 2012 totaled $10.4 million and $0.7 million, respectively. Proceeds from options exercised during the three month periods ended September 30, 2013 and 2012 totaled $0.4 million and $0.3 million, respectively, and totaled $3.8 million and $0.6 million for the nine months periods ended September 30, 2013 and 2012, respectively.
	Employee Stock Purchase Plan
	The Company's ESPPs allow qualified employees to purchase MasTec, Inc. common stock at 85% of the fair market value of the common stock 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 document. Through June 30, 2013, the offering period was an annual period, composed of four interim exercise periods. Effective July 1, 2013, the offering period became quarterly.
		Nine Months Ended September 30,
	Activity, employee stock purchase plan:	2013			2012
	Cash proceeds (in millions)	$	6		$	0.9
	Number of common shares	436,925			67,073
	Weighted average price per share	$	13.69		$	13.43
	Weighted average grant date fair value per share	$	5.55		$	3.96
	The fair value of purchases under the Company's ESPP is estimated using the Black-Scholes option-pricing valuation model.
	Stock Based Compensation Expense and Tax Benefits
	Details of stock based compensation expense and related tax benefits for the periods indicated are as follows (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Stock based compensation expense	$	3		$	1.2		$	9.6		$	3.4
	Income tax benefit from stock based compensation	4.5			0.7			7.7			1.6
	Excess tax benefit from stock based compensation (1)	$	3		$	0.2		$	4.4		$	0.3
	-1	Excess tax benefits, which represent cash flows from tax deductions in excess of the 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.
	Shares Withheld for Payroll Taxes
	In connection with the issuance of shares under share-based compensation awards, at the employees' election, the Company withholds shares of common stock for tax withholding obligations. These shares are repurchased or withheld in conjunction with net share settlement of the related awards upon vesting, for restricted stock awards, or upon exercise, for stock options. Withheld shares, which are valued at the share price on the date of vesting or exercise, as applicable, are classified as a reduction to additional paid-in capital. The value of shares withheld for payroll taxes under share-based compensation arrangements was $2.4 million for the nine month period ended September 30, 2013.

Other_Retirement_Plans

Other Retirement Plans	9 Months Ended
	Sep. 30, 2013
Multiemployer Plans [Abstract]	'
Other Retirement Plans	'
	Other Retirement Plans
	Multi-Employer Pension Plans. Certain of MasTec’s subsidiaries contribute amounts to multi-employer pension and other multi-employer benefit plans and trusts. 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 pension plans, and the related number of employees covered by these plans, for the periods indicated ranged as follows (dollars in millions):
		Number of Employees		Contributions (in millions)
	For the Three Months Ended September 30,	Low	High	Pension		Post-Retirement Benefit		Total
	2013	2,392	2,734	$	14.8	$	1	$	15.8
	2012	1,575	2,509	$	8.7	$	0.3	$	9
	For the Nine Months Ended September 30,	Low	High	Pension		Post-Retirement Benefit		Total
	2013	778	2,734	$	29.6	$	2.9	$	32.5
	2012	308	2,509	$	21.1	$	0.8	$	21.9
	The Company's contributions to multi-employer pension plans have increased for the nine month period ended September 30, 2013 as a result of higher activity levels, primarily in its oil and gas business.

Shareholders_Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Shareholders' Equity	'
	Shareholders' Equity
	Treasury Stock and Share Activity (in thousands):
		Common Shares			Treasury
		Outstanding			Shares
	Balance as of December 31, 2012	76,448			9,467
	Shares issued for stock option exercises	498
	Shares issued for restricted stock awards	64
	Other shares issued, net	409
	Shares contributed by shareholder, former owner of acquired business  (1)	(200	)
	Balance as of September 30, 2013	77,219			9,467
	(1) See Note 12 - Stock-Based Compensation and Other Employee Benefit Plans for contributed share details.
	Accumulated Other Comprehensive Loss
	Changes in accumulated other comprehensive (loss) income by component during the periods indicated are as follows (in thousands):
			For the Nine Months Ended September 30,
			2013										2012
			Unrealized (Losses) Gains										Unrealized (Losses) Gains
			Available-for-Sale Securities				Foreign Currency Items			Total			Available-for-Sale Securities			Foreign Currency Items			Total
	Balance as of January 1		$	(5,395	)		$	(106	)	$	(5,501	)	$	(5,917	)	$	(2,029	)	$	(7,946	)
	Activity before reclassifications, net of tax		(118		)		(3,839		)	(3,957		)	339			2,304			2,643
	Reclassifications, net of tax		(440		)	(1)	—			(440		)	—			—			—
	Activity, net of tax		(558		)		(3,839		)	(4,397		)	339			2,304			2,643
	Balance as of September 30		$	(5,953	)		$	(3,945	)	$	(9,898	)	$	(5,578	)	$	275		$	(5,303	)
	(1) Represents the reclassification adjustment for gains on securities sold, which was recognized as a component of other income. See Note 7 - Auction Rate Securities.
	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, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The Company’s consolidated tax rates on income from continuing operations for the three month periods ended September 30, 2013 and 2012 were 38.8% and 39.4%, respectively, and for the nine month periods ended September 30, 2013 and 2012 were 38.6% and 39.4%, 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.

Segments_and_Operations_by_Geo

Segments and Operations by Geographic Area	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segments and Operations by Geographic Area	'
	Segments and Operations by Geographic Area
	Segment Discussion
	MasTec presents its continuing operations under 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 and has been determined in accordance with the criteria in Accounting Standards Codification ("ASC") 280, Segment Reporting. All five reportable segments derive their revenues from the engineering, installation and maintenance of infrastructure, primarily in North America.
	Income from continuing operations before non-controlling interests 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 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).
	As of and for the three month period ended September 30, 2013:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	543		$	519.1		$	118.8		$	85.1		$	3.5	$	—		$	(0.1	)	$	1,269.40
	EBITDA	$	71.8		$	68.1		$	12.1		$	(6.4	)	$	0.1	$	(13.6	)	$	—		$	132.1
	Depreciation	$	8		$	19.3		$	2.6		$	1.2		$	—	$	0.9		$	—		$	32
	Amortization	$	1.5		$	3.2		$	0.6		$	0.5		$	—	$	—		$	—		$	5.8
	As of and for the three month period ended September 30, 2012:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	490		$	284		$	74.8		$	211.7		$	7.5	$	—		$	(0.7	)	$	1,067.30
	EBITDA	$	59.5		$	29		$	10.5		$	9.9		$	1.2	$	(18.4	)	$	—		$	91.7
	Depreciation	$	6.9		$	9.5		$	1.6		$	1		$	—	$	0.8		$	—		$	19.8
	Amortization	$	0.4		$	0.5		$	1.2		$	0.7		$	—	$	—		$	—		$	2.8
	As of and for the nine month period ended September 30, 2013:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	1,464.50		$	1,134.80		$	321.9		$	237.3		$	9.2	$	—		$	(2.0	)	$	3,165.70
	EBITDA	$	181.6		$	161.7		$	27		$	(14.6	)	$	0.5	$	(47.9	)	$	—		$	308.3
	Depreciation	$	22.8		$	51.8		$	7.1		$	3.6		$	—	$	2.6		$	—		$	87.9
	Amortization	$	4		$	8.4		$	1.3		$	1.5		$	—	$	—		$	—		$	15.2
	As of and for the nine month period ended September 30, 2012:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	1,311.10		$	715.3		$	228.2		$	527.4		$	14.1	$	—		$	(1.7	)	$	2,794.40
	EBITDA	$	139.4		$	57.3		$	31.1		$	28.2		$	1.7	$	(34.5	)	$	—		$	223.2
	Depreciation	$	19.9		$	27.2		$	4.3		$	3		$	—	$	2.2		$	—		$	56.6
	Amortization	$	1.3		$	1.4		$	3.8		$	2		$	—	$	—		$	—		$	8.5
	Revenue generated from utilities customers represented 6.9% and 11.6% of Communications segment revenues for the three month periods ended September 30, 2013 and 2012, respectively, and 7.2% and 11.2% for the nine month periods ended September 30, 2013 and 2012, respectively.
	The following table presents a reconciliation of EBITDA for our continuing operations to consolidated income from continuing operations before provision for income taxes (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	EBITDA	$	132.1		$	91.7		$	308.3		$	223.2
	Less:
	Interest expense, net	(12.7		)	(9.4		)	(34.5		)	(27.9		)
	Depreciation	(32.0		)	(19.8		)	(87.9		)	(56.6		)
	Amortization	(5.8		)	(2.8		)	(15.2		)	(8.5		)
	Income from continuing operations before provision for income taxes	$	81.6		$	59.6		$	170.6		$	130.2
	Foreign Operations. The Company has operations in Canada as well as in parts of Latin America and the Caribbean. The following table presents revenue by geographic area for the periods indicated (dollar amounts in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Continuing operations:
	Derived from foreign operations	$	90.9		$	33.7		$	172		$	133.7
	Derived in the United States	1,178.50			1,033.60			2,993.70			2,660.70
	Revenue from continuing operations	$	1,269.40		$	1,067.30		$	3,165.70		$	2,794.40
	Discontinued operations:
	Derived from foreign operations	$	2.3		$	1.9		$	7		$	4.6
	Derived in the United States	2.5			2.9			11			69.1
	Revenue from discontinued operations	$	4.8		$	4.8		$	18		$	73.7
	The following table presents long-lived assets held in foreign countries for our continuing operations as of the dates indicated (in millions):
		September 30,			December 31,
		2013			2012
	Property and equipment, net	$	48.8		$	11.4
	Goodwill and other intangible assets, net	$	94		$	30.5
	Significant Customers
	Revenue concentration information for significant customers, as a percent of total consolidated revenue from continuing operations, is as follows:
		For the Three Months Ended September 30,			For the Nine Months Ended September 30,
		2013		2012	2013		2012
Customer:
AT&T	16%		17%	18%		17%
DIRECTV®	13%		16%	15%		17%
Enbridge, Inc.	20%		3%	14%		1%
The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for both AT&T's wireless and wireline infrastructure businesses. Revenue from AT&T is included in the Communications segment.
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.
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, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	In addition to the matters discussed below, MasTec is subject to a variety of legal cases, claims and other disputes that arise from time to time in the ordinary course of its business. MasTec cannot provide assurance that it will be successful in recovering all or any of the potential damages it has claimed or in defending claims against it.
	Legacy Litigation
	MasTec is subject to litigation, some of which dates from the period 2001 through 2006.
	Sintel. The labor union representing the workers of Sistemas e Instalaciones de Telecomunicacion S.A. (“Sintel”), a former MasTec subsidiary that was sold in 1998, filed a claim that initiated an investigative action with the Audiencia Nacional, a Spanish federal court, against Telefonica and dozens of other defendants including current and former officers and directors of MasTec and Sintel, relating to Sintel’s 2000 bankruptcy.
	On June 17, 2013, MasTec, the workers and the prosecutor resolved the matter, resulting in the dismissal all of the charges and claims brought against MasTec and the MasTec defendants. The workers provided MasTec and MasTec defendants with a release and an acknowledgment that MasTec and MasTec defendants acted in good faith and did not cause Sintel's bankruptcy. On June 20, 2013, the Audiencia Nacional issued an order dismissing the charges and claims against MasTec and the MasTec defendants and finding another party guilty and liable of certain charges.
	The Company resolved the matter in order to avoid significant legal fees and the potential liabilities resulting from the actions of other Spanish defendants for which MasTec may be financially responsible under a theory of subsidiary (or vicarious) liability, the uncertainty of a trial before a foreign tribunal such as the Audiencia Nacional and to eliminate management time devoted to this matter. MasTec recorded a pre-tax charge of $9.6 million in 2012 in connection with this matter and recorded an additional pre-tax charge of $2.8 million during the second quarter of 2013 in connection with its resolution.
	Other Outstanding Litigation
	SunLight Entities. In 2011, Power Partners MasTec, LLC., a MasTec, Inc. subsidiary (“Power Partners”), entered into engineering, procurement, and construction agreements (“Contracts”) with special purpose entities, SunLight General Somerset Solar, LLC, SunLight General Morris Solar, LLC and SunLight General Sussex Solar, LLC (collectively, the “SunLight Entities”), respectively, to perform design and construction services for three public solar projects in New Jersey located in Somerset, Morris and Sussex Counties (the “Projects”). The initial contract price of each of the Projects was, subject to adjustment, approximately as follows: Somerset ($29 million), Morris ($36 million) and Sussex ($26 million). The Projects were funded on a project finance basis, including the proceeds of municipal bonds issued by county improvement authorities.
	Power Partners and the SunLight Entities have commenced three separate arbitration proceedings against each other to address various disputes that presently exist between the parties on the three Projects. The parties allege, among other things, breach of contract against each other. Discovery is ongoing. The arbitrations are scheduled to begin in January 2014.
	Power Partners has also filed municipal liens and construction liens for the work performed. The liens have been challenged, and the Company is currently appealing the trial court's adverse ruling to the New Jersey appellate court. Power Partners is vigorously pursuing its claims against the SunLight Entities and vigorously defending against claims by the SunLight Entities.
	City of Marathon. During 2010 and 2011, pursuant to a written contract, the Company provided certain construction services for the City of Marathon in Marathon, Florida.  The Company completed those services in 2011, but at the end of 2011, the Company had still not been paid for all of the work performed on the project. The Company is seeking in excess of $6 million against the City of Marathon for breach of contract and against the City of Marathon’s engineers for professional negligence. The City of Marathon and the engineers filed answers denying liability and claiming that the Company breached the contract.  Discovery is ongoing. The Company will continue to vigorously pursue these claims.
	Other Commitments and Contingencies
	Leases. In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facility, vehicle and equipment needs, including related party leases. See Note 11 - Lease Obligations.
	Letters of Credit. In the ordinary course of business, the Company is required to post letters of credit for its insurance carriers, surety bond providers and in support of performance under certain contracts. As of September 30, 2013 and December 31, 2012, the Company had $138.5 million and $120.8 million, respectively, of letters of credit issued under its Credit Facility, of which $52.2 million and $53.2 million, respectively, pertained to certain of the Company's insurance carriers. The Company is not aware of any material claims relating to outstanding letters of credit as of September 30, 2013 or December 31, 2012.
	Performance and Payment Bonds. In the ordinary course of business, MasTec is required by certain customers to provide performance and payment bonds for some of the Company’s contractual commitments related to projects in process. As of September 30, 2013, the estimated cost to complete of the projects secured by the Company’s $1.4 billion in performance and payment bonds was $383.8 million. As of December 31, 2012, the estimated cost to complete of the projects secured by the Company’s $1.1 billion in performance and payment bonds was $284.5 million.
	Self-Insurance. MasTec maintains insurance policies subject to per claim deductibles of $1 million for its workers’ compensation policy, $2 million for its general liability policy and $2 million for its automobile liability policy. The Company has excess umbrella coverage up to $100 million per claim and in the aggregate. As of September 30, 2013 and December 31, 2012, MasTec’s liability for unpaid claims and associated expenses, including incurred but not reported losses related to its workers compensation, general liability and automobile liability insurance policies, was $53.1 million and $48.1 million, respectively, of which $32.6 million and $28.5 million, respectively, was reflected within non-current other liabilities in the condensed unaudited consolidated financial statements. MasTec also maintains an insurance policy with respect to employee group health claims, which is subject to annual per employee maximum losses of $0.4 million. MasTec’s liability for employee group claims as of September 30, 2013 and December 31, 2012 was $1.0 million and $1.1 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 in which the Company is self-insured. As of September 30, 2013 and December 31, 2012, these letters of credit amounted to $52.2 million and $53.2 million, respectively. In addition, cash collateral deposited with insurance carriers, which is included in other long-term assets in the consolidated balance sheets, amounted to $1.5 million and $2.0 million as of September 30, 2013 and December 31, 2012, respectively. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $10.9 million and $9.0 million as of September 30, 2013 and December 31, 2012, respectively.
	Employment Agreements. The Company has employment agreements with certain executives and other employees, which provide for compensation and certain other benefits and for severance payments under certain circumstances. Certain employment agreements also contain clauses that become effective upon a change of control of the Company. Upon the occurrence of any of the defined events in the various employment agreements, the Company would be obligated to pay certain amounts to the relevant employees, which vary with the level of the employees’ respective responsibility.
	Collective Bargaining Agreements and Multi-Employer Pension Plans. Certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The agreements require the subsidiaries party to the agreements to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. The multi-employer pension plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls. The 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 required amount of future contributions cannot be determined for future periods because the number of union employees employed at any given time, and the plans in which they participate, vary depending upon the location and number of ongoing projects and the need for union resources in connection with those projects. Based upon the information available to the Company from plan administrators as of September 30, 2013, several of the multi-employer pension plans in which the Company’s subsidiaries participate are underfunded and the Company could be required to increase its contributions to such plans.
	On November 15, 2011, the Company, along with other members of the Pipe Line Contractors Association (“PLCA”), voluntarily withdrew from the Central States Southeast and Southwest Areas Pension Fund (“Central States”), a defined benefit multi-employer pension plan that is in critical 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 $5.7 million was outstanding as of September 30, 2013. 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 made a demand on the Company for the sum of $10.8 million in withdrawal liability, which sum included 2011 contribution amounts. The Company is vigorously opposing this demand because it believes that it legally and effectively withdrew from Central States on November 15, 2011. If Central States were to prevail in its assertion that the Company, in fact, withdrew after that date, then the amount of the Company’s withdrawal liability would increase to approximately $10.8 million. In addition, if Central States were to undergo a mass withdrawal, as defined by ERISA and the Pension Benefit Guaranty Corporation, within the three year period commencing with the beginning of the calendar year during which the Company withdrew from the plan, there could be additional liability. The Company currently does not have plans to withdraw from any other multi-employer pension plan.
	See Note 13 - Other Retirement Plans for details of the Company's participation in multi-employer pension plans.
	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, 2013 and December 31, 2012, the Company was not aware of any material asserted or unasserted claims in connection with these indemnity obligations.
	Other Guarantees. In the ordinary course of its business, from time to time, MasTec guarantees the obligations of its subsidiaries, including obligations under certain contracts with customers, certain lease obligations and in some states, obligations in connection with obtaining contractors’ licenses. MasTec also generally warrants the work it performs for a one to two year period following substantial completion of a project. MasTec has not historically accrued any reserves for potential warranty claims as they have been immaterial.

Concentrations_of_Risk

Concentrations of Risk	9 Months Ended
	Sep. 30, 2013
Risks and Uncertainties [Abstract]	'
Concentrations of Risk	'
	Concentrations of Risk
	The Company had approximately 460 customers as of September 30, 2013.
	Revenue concentration information for the Company's top ten customers, as a percent of total consolidated revenue from continuing operations, is as follows:
		For the Three Months Ended September 30,		For the Nine Months Ended September 30,
		2013	2012	2013	2012
	Revenue from top ten customers	73%	67%	69%	66%
	See Note 16 - Segments and Operations by Geographic Area for significant customer revenue concentration information.

Related_Party_Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Related Party Transactions
	MasTec leases employees to a customer, in which Jorge Mas and Jose Mas own a majority interest. For the three month periods ended September 30, 2013 and 2012, MasTec charged to the customer approximately $135,000 and $123,000, respectively, and charged $422,000 and $382,000, respectively, for the nine month periods ended September 30, 2013 and 2012. As of September 30, 2013 and December 31, 2012, receivables of $45,000 and $907,000, respectively, attributable to this arrangement were outstanding. The Company also provides satellite communication services to this customer. For the three month periods ended September 30, 2013 and 2012, revenues relating to this customer were approximately $350,000 and $318,000, respectively, and for the nine month periods ended September 30, 2013 and 2012, revenues relating to this customer were approximately $951,000 and $924,000, respectively. As of September 30, 2013 and December 31, 2012, outstanding receivables from this arrangement were approximately $414,000 and $1,232,000, respectively.
	Split Dollar and Deferred Bonus Agreements
	On October 16, 2013, Jorge Mas, the Company and Jose Ramon Mas and Juan Carlos Mas, as trustees of the Jorge Mas Irrevocable Trust, dated June 1, 2012 (the “trust”) entered into a split dollar life insurance agreement that replaces a prior split dollar agreement with Jorge Mas. Under the 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 Jorge Mas or the survivor of Jorge 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) all 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) all 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 all policies subject to the split dollar agreement was capped at $200 million. The Company is designated as the named fiduciary under the split dollar agreement. The foregoing description of the split dollar agreement for Jorge Mas is only a summary and is qualified in its entirety by reference to the full text of such agreement, which is filed as Exhibit 10.1 to this Quarterly Report on Form 10-Q, which agreement is herein incorporated by reference.
	The Company paid approximately $1.1 million in connection with the split dollar agreements for Jorge Mas for the three month period ended September 30, 2013. The Company made no payments in connection with the agreements for the three month period ended September 30, 2012. The Company paid approximately $1.2 million and $0.3 million in connection with the agreements for the nine month periods ended September 30, 2013 and 2012, respectively. MasTec also has a split dollar agreement and a deferred bonus agreement with Jose Mas. For the three and nine month periods ended September 30, 2013 and 2012, no payments were made in connection with the agreements for Jose Mas. As of September 30, 2013 and December 31, 2012, life insurance assets of $10.1 million and $8.7 million respectively, are included within other long-term assets in the condensed unaudited consolidated balance sheets.

Supplemental_Guarantor_Financi

Supplemental Guarantor Financial Information	9 Months Ended
	Sep. 30, 2013
Condensed Unaudited Financial Statements, Supplemental Guarantor Information [Abstract]	'
Supplemental Guarantor Financial Information	'
	Supplemental Guarantor Condensed Unaudited Consolidating Financial Information
	The 2011 Convertible Notes, 2009 Convertible Notes are, and, through March 29, 2013, the 7.625% Senior Notes were, 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 4.875% Senior Notes are guaranteed on an unsecured unsubordinated, joint and several basis by the Company's 100%-owned domestic subsidiaries that guarantee the Credit Facility. Certain subsidiaries included in the Company's Guarantor Subsidiaries, which are minor individually and in the aggregate, do not guarantee the 4.875% Senior Notes. The Company's subsidiaries organized outside of the U.S. and certain domestic subsidiaries (collectively, the “Non-Guarantor Subsidiaries”) do not guarantee any of these notes. The subsidiary guarantees are 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 the subsidiary guarantor; if the guarantee under our 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
	For the Three Months Ended September 30, 2013 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,086,063		$	187,689		$	(4,367	)	$	1,269,385
	Costs of revenue, excluding depreciation and amortization	—			927,295			158,204			(4,367		)	1,081,132
	Depreciation and amortization	1			30,637			7,118			—			37,756
	General and administrative expenses	457			47,967			10,552			—			58,976
	Interest expense, net	—			11,951			715			—			12,666
	Other income, net	—			(2,309		)	(469		)	—			(2,778		)
	(Loss) income from continuing operations before provision for income taxes	$	(458	)	$	70,522		$	11,569		$	—		$	81,633
	Benefit from (provision for) income taxes	174			(28,840		)	(3,032		)	—			(31,698		)
	Net (loss) income from continuing operations before non-controlling interests	$	(284	)	$	41,682		$	8,537		$	—		$	49,935
	Loss from discontinued operations, net of tax	—			(3,566		)	(169		)	—			(3,735		)
	Equity in income from subsidiaries, net of tax	46,484			—			—			(46,484		)	—
	Net income (loss)	$	46,200		$	38,116		$	8,368		$	(46,484	)	$	46,200
	Net income (loss) attributable to non-controlling interests	—			87			(25		)	—			62
	Net income (loss) attributable to MasTec, Inc.	$	46,200		$	38,029		$	8,393		$	(46,484	)	$	46,138
	Comprehensive income (loss)	$	46,200		$	38,024		$	11,304		$	(46,484	)	$	49,044
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME
	For the Three Months Ended September 30, 2012 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,028,091		$	40,222		$	(1,013	)	$	1,067,300
	Costs of revenue, excluding depreciation and amortization	—			886,198			39,119			(1,013		)	924,304
	Depreciation and amortization	—			22,065			580			—			22,645
	General and administrative expenses	303			39,251			2,960			—			42,514
	Interest expense, net	—			9,435			11			—			9,446
	Other expense, net	—			8,696			119			—			8,815
	(Loss) income from continuing operations before provision for income taxes	$	(303	)	$	62,446		$	(2,567	)	$	—		$	59,576
	Benefit from (provision for) income taxes	114			(24,564		)	972			—			(23,478		)
	Net (loss) income from continuing operations before non-controlling interests	$	(189	)	$	37,882		$	(1,595	)	$	—		$	36,098
	Loss from discontinued operations, net of tax	—			(8,852		)	(429		)	—			(9,281		)
	Equity in income from subsidiaries, net of tax	27,006			—			—			(27,006		)	—
	Net income (loss)	$	26,817		$	29,030		$	(2,024	)	$	(27,006	)	$	26,817
	Net loss attributable to non-controlling interests	—			—			(4		)	—			(4		)
	Net income (loss) attributable to MasTec, Inc.	$	26,817		$	29,030		$	(2,020	)	$	(27,006	)	$	26,821
	Comprehensive income (loss)	$	26,817		$	29,418		$	152		$	(27,006	)	$	29,381
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME
	For the Nine Months Ended September 30, 2013 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	2,751,408		$	424,616		$	(10,367	)	$	3,165,657
	Costs of revenue, excluding depreciation and amortization	—			2,348,835			356,819			(10,367		)	2,695,287
	Depreciation and amortization	2			87,426			15,683			—			103,111
	General and administrative expenses	1,443			134,460			23,858			—			159,761
	Interest expense, net	—			33,583			966			—			34,549
	Loss on extinguishment of debt	—			5,624			—			—			5,624
	Other income, net	—			(2,526		)	(757		)	—			(3,283		)
	(Loss) income from continuing operations before provision for income taxes	$	(1,445	)	$	144,006		$	28,047		$	—		$	170,608
	Benefit from (provision for) income taxes	572			(56,782		)	(9,612		)	—			(65,822		)
	Net (loss) income from continuing operations before non-controlling interests	$	(873	)	$	87,224		$	18,435		$	—		$	104,786
	Loss from discontinued operations, net of tax	—			(4,178		)	(987		)	—			(5,165		)
	Equity in income from subsidiaries, net of tax	100,494			—			—			(100,494		)	—
	Net income (loss)	$	99,621		$	83,046		$	17,448		$	(100,494	)	$	99,621
	Net income attributable to non-controlling interests	—			87			85			—			172
	Net income (loss) attributable to MasTec, Inc.	$	99,621		$	82,959		$	17,363		$	(100,494	)	$	99,449
	Comprehensive income (loss)	$	99,621		$	82,489		$	13,608		$	(100,494	)	$	95,224
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME
	For the Nine Months Ended September 30, 2012 (in thousands)
	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Revenue	$	—		$	2,644,197		$	152,267		$	(2,033	)	$	2,794,431
Costs of revenue, excluding depreciation and amortization	—			2,312,564			134,525			(2,033		)	2,445,056
Depreciation and amortization	1			63,403			1,721			—			65,125
General and administrative expenses	1,052			109,366			7,774			—			118,192
Interest expense, net	—			27,880			3			—			27,883
Other expense, net	—			7,655			334			—			7,989
(Loss) income from continuing operations before provision for income taxes	$	(1,053	)	$	123,329		$	7,910		$	—		$	130,186
Benefit from (provision for) income taxes	423			(49,766		)	(1,886		)	—			(51,229		)
Net (loss) income from continuing operations before non-controlling interests	$	(630	)	$	73,563		$	6,024		$	—		$	78,957
Loss from discontinued operations, net of tax	—			(6,099		)	(1,782		)	—			(7,881		)
Equity in income from subsidiaries, net of tax	71,706			—			—			(71,706		)	—
Net income (loss)	$	71,076		$	67,464		$	4,242		$	(71,706	)	$	71,076
Net loss attributable to non-controlling interests	—			—			(9		)	—			(9		)
Net income (loss) attributable to MasTec, Inc.	$	71,076		$	67,464		$	4,251		$	(71,706	)	$	71,085
Comprehensive income (loss)	$	71,076		$	67,803		$	6,546		$	(71,706	)	$	73,719
CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS
As of September 30, 2013 (in thousands)
	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Assets
Current assets, including discontinued operations	$	—		$	1,120,527		$	211,789		$	—		$	1,332,316
Property and equipment, net	—			431,899			72,414			—			504,313
Goodwill and other intangible assets, net	—			890,683			173,416			—			1,064,099
Net investments in and advances to (from) consolidated affiliates	974,904			147,960			(312		)	(1,122,552		)	—
Other long-term assets, including discontinued operations	9,216			42,899			1,495			—			53,610
Total assets	$	984,120		$	2,633,968		$	458,802		$	(1,122,552	)	$	2,954,338
Liabilities and Shareholders’ Equity
Total current liabilities	$	8		$	799,374		$	82,847		$	—		$	882,229
Long-term debt	—			750,841			29,079			—			779,920
Other liabilities	—			226,184			86,918			—			313,102
Total liabilities	$	8		$	1,776,399		$	198,844		$	—		$	1,975,251
Total shareholders’ equity	$	984,112		$	857,569		$	259,958		$	(1,122,552	)	$	979,087
Total liabilities and shareholders’ equity	$	984,120		$	2,633,968		$	458,802		$	(1,122,552	)	$	2,954,338
CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS
As of December 31, 2012 (in thousands)
	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Assets
Current assets, including discontinued operations	$	—		$	960,523		$	89,118		$	—		$	1,049,641
Property and equipment, net	—			326,588			23,604			—			350,192
Goodwill and other intangible assets, net	—			890,323			71,650			—			961,973
Net investments in and advances to (from) consolidated affiliates	854,992			172,150			(21,394		)	(1,005,748		)	—
Other long-term assets, including discontinued operations	7,701			43,442			3,017			—			54,160
Total assets	$	862,693		$	2,393,026		$	165,995		$	(1,005,748	)	$	2,415,966
Liabilities and Shareholders’ Equity
Total current liabilities	$	20		$	675,966		$	37,807		$	—		$	713,793
Long-term debt	—			546,262			61			—			546,323
Other liabilities	—			262,099			31,876			—			293,975
Total liabilities	$	20		$	1,484,327		$	69,744		$	—		$	1,554,091
Total shareholders’ equity	$	862,673		$	908,699		$	96,251		$	(1,005,748	)	$	861,875
Total liabilities and shareholders’ equity	$	862,693		$	2,393,026		$	165,995		$	(1,005,748	)	$	2,415,966
CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS
For the Nine Months Ended September 30, 2013 (in thousands)
	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Net cash (used in) provided by operating activities	$	(2,401	)	$	116,783		$	10,609		$	—		$	124,991
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net, including contingent consideration	$	—		$	(55,453	)	$	(103,993	)	$	—		$	(159,446	)
Capital expenditures	—			(97,602		)	(3,809		)	—			(101,411		)
Proceeds from sale of property and equipment	—			7,629			659			—			8,288
Proceeds from disposal of business, net of cash divested	—			(4,332		)	—			—			(4,332		)
Proceeds from sale or redemption of investments	—			5,025			—			—			5,025
Payments for other investments, net	—			(1,174		)	—			—			(1,174		)
Net cash used in investing activities	$	—		$	(145,907	)	$	(107,143	)	$	—		$	(253,050	)
Cash flows provided by (used in) financing activities:
Proceeds from issuance of 4.875% senior notes	$	—		$	400,000		$	—		$	—		$	400,000
Repayment of 7.625% senior notes	—			(150,000		)	—			—			(150,000		)
Proceeds from credit facility	—			664,979			101,175			—			766,154
Repayments of credit facility	—			(753,960		)	(106,110		)	—			(860,070		)
Repayments of other borrowings	—			(24,246		)	—			—			(24,246		)
Proceeds from book overdrafts	—			2,791			—			—			2,791
Payments of capital lease obligations	—			(31,249		)	(965		)	—			(32,214		)
Proceeds from stock option exercises and other share-based awards	9,231			—			—			—			9,231
Excess tax benefit from non-cash stock-based compensation	—			4,446			—			—			4,446
Payments for debt extinguishment, call premiums	—			(4,116		)	—			—			(4,116		)
Payments of financing costs	—			(7,718		)	—			—			(7,718		)
Net financing activities and advances (to) from consolidated affiliates	(6,830		)	(81,999		)	88,829			—			—
Net cash provided (used in) by financing activities	$	2,401		$	18,928		$	82,929		$	—		$	104,258
Net decrease in cash and cash equivalents	—			(10,196		)	(13,605		)	—			(23,801		)
Net effect of currency translation on cash	—			—			(118		)	—			(118		)
Cash and cash equivalents - beginning of period	—			12,969			13,798			—			26,767
Cash and cash equivalents - end of period	$	—		$	2,773		$	75		$	—		$	2,848
Cash and cash equivalents of discontinued operations	$	—		$	—		$	—		$	—		$	—
Cash and cash equivalents of continuing operations	$	—		$	2,773		$	75		$	—		$	2,848
CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS
For the Nine Months Ended September 30, 2012 (in thousands)
	MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
				Subsidiaries			Subsidiaries						MasTec, Inc.
Net cash (used in) provided by operating activities	$	(891	)	$	96,464		$	19,097		$	—		$	114,670
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net, including contingent consideration	$	—		$	(16,094	)	$	(1,402	)	$	—		$	(17,496	)
Capital expenditures	—			(49,109		)	(1,222		)	—			(50,331		)
Proceeds from sale of property and equipment	—			5,808			—			—			5,808
Proceeds from disposal of business, net of cash divested	—			97,728			—			—			97,728
Payments for other investments, net	(284		)	—			—			—			(284		)
Net cash (used in) provided by investing activities	$	(284	)	$	38,333		$	(2,624	)	$	—		$	35,425
Cash flows provided by (used in) financing activities:
Proceeds from credit facility	$	—		$	631,815		$	—		$	—		$	631,815
Repayments of credit facility	—			(681,815		)	—			—			(681,815		)
Repayments of other borrowings	—			(15,510		)	—			—			(15,510		)
Repayments of book overdrafts	—			(5,645		)	—			—			(5,645		)
Payments of capital lease obligations	—			(14,790		)	(16		)	—			(14,806		)
Proceeds from stock option exercises and other share-based awards	1,445			—			—			—			1,445
Excess tax benefit from non-cash stock-based compensation	—			302			—			—			302
Purchases of treasury stock	(75,000		)	—			—			—			(75,000		)
Payments of financing costs	—			(113		)	—			—			(113		)
Net financing activities and advances (to) from consolidated affiliates	74,730			(58,405		)	(16,325		)	—			—
Net cash provided by (used in) financing activities	$	1,175		$	(144,161	)	$	(16,341	)	$	—		$	(159,327	)
Net (decrease) increase in cash and cash equivalents	—			(9,364		)	132			—			(9,232		)
Net effect of currency translation on cash	—			20			115			—			135
Cash and cash equivalents - beginning of period	—			16,241			4,038			—			20,279
Cash and cash equivalents - end of period	$	—		$	6,897		$	4,285		$	—		$	11,182
Cash and cash equivalents of discontinued operations	$	—		$	684		$	26		$	—		$	710
Cash and cash equivalents of continuing operations	$	—		$	6,213		$	4,259		$	—		$	10,472

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	On October 29, 2013, MasTec entered into an amendment (the “Amendment”) to its Credit Facility, which, among other things, extended the maturity to October 2018 and increased the revolving commitments available from $600 million to $750 million, of which up to $100 million may be borrowed in Canadian dollars.  Additionally, the Amendment increased the amount available for letters of credit from $350 million to $450 million and the amount available for swing line loans from $50 million to $75 million.  The Amendment also reduced the rates applicable to the commitments, borrowings and letters of credit under the Credit Facility.

Business_Basis_of_Presentation1

Business, Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
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: electrical utility transmission and distribution; natural gas and petroleum pipeline infrastructure; wireless, wireline and satellite communications; power generation, including renewable energy infrastructure; and industrial infrastructure. MasTec’s customers are primarily in these industries.
Basis of Presentation	'
	Basis of Presentation
	The accompanying condensed unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X. Pursuant to these rules and regulations, certain information and footnote disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The accompanying condensed consolidated balance sheet as of December 31, 2012 is derived from the Company’s audited financial statements as of that date. Because certain information and footnote disclosures have been condensed or omitted, these condensed unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2012 contained in the Company’s most recent Annual Report on Form 10-K. In management’s opinion, all normal and recurring adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows for the periods presented have been included. Certain prior year amounts have been reclassified to conform to the current period presentation. Interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. The Company believes that the disclosures made in these condensed unaudited consolidated financial statements are adequate to make the information not misleading.
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying condensed unaudited consolidated financial statements include MasTec, Inc. and its subsidiaries and include the accounts of all majority-owned subsidiaries over which the Company exercises control and, when applicable, entities in which the Company has a controlling financial interest. Other parties’ interests in companies for which MasTec exercises control and has a controlling financial interest are reported as non-controlling interests within shareholders’ equity. Net income or loss attributable to non-controlling interests is reported as a separate line item below net income. The Company’s investments in entities in which the Company does not have a controlling interest, but has the ability to exert significant influence, are accounted for using the equity method of accounting. Equity method investments are recorded as long-term assets in the condensed unaudited consolidated balance sheets. Income or loss from these investments is recorded within other income or expense, net, in the condensed unaudited consolidated statements of operations. The cost method is used for investments in entities over which the Company does not have the ability to exert significant influence. All significant intercompany balances and transactions have been eliminated in consolidation.
Management Estimates	'
	Management Estimates
	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Key estimates include: the recognition of revenue, in particular, on long-term construction contracts, including estimates of costs to complete projects and provisions for contract losses; allowances for doubtful accounts; accrued self-insured claims; estimated fair values of goodwill and intangible assets, acquisition-related contingent consideration, assets and liabilities classified as held-for-sale, convertible debt obligations, available for sale securities and investments in cost and equity method investees; asset lives used in computing depreciation and amortization, including amortization of intangible assets; accounting for income taxes; and the estimated impact of contingencies and ongoing litigation. While management believes that such estimates are fair when considered in conjunction with the consolidated financial position and results of operations taken as a whole, actual results could differ from those estimates and such differences may be material to the condensed unaudited consolidated financial statements.
Significant Accounting Policies	'
	Significant Accounting Policies
	Except for adoption of the accounting pronouncements discussed below, there have been no material changes to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
New Accounting Pronouncements	'
	New accounting pronouncements
	Recently Issued Accounting Standards, Not Adopted as of September 30, 2013
	In March 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-05, Foreign Currency Matters (Topic 830): Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-05”).  The objective of ASU 2013-05 is to resolve diversity in practice regarding the release of the cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. ASU 2013-05 is effective prospectively for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements.
	In February 2013, the FASB issued ASU 2013-04, Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-04”). ASU 2013-04 provides guidance related to the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. The guidance requires an entity to measure those obligations as the sum of the amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and any additional amount the reporting entity expects to pay on behalf of its co-obligors. The guidance in ASU 2013-04 also requires an entity to disclose the nature and amount of the obligation.  ASU 2013-05 is effective for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. Retrospective application is required for all periods presented. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements.
	In July 2013, the FASB issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force) (“ASU 2013-11”).  ASU 2013-11 provides guidance on the presentation in the financial statements of an unrecognized tax benefit, or a portion of an unrecognized tax benefit, and explains that unrecognized tax benefits should be presented as a reduction to deferred tax assets for net operating loss carryforwards, similar tax losses or tax credit carryforwards. To the extent a net operating loss carryforward, similar tax loss or tax credit carryforward is not available as of the reporting date under the tax law of the applicable jurisdiction, or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. ASU 2013-11 applies to all entities that have unrecognized tax benefits when a net operating loss carryforward, similar tax loss, or tax credit carryforward exists as of the reporting date. ASU 2013-11 is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013. Retrospective application is permitted. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements.
	Recently Adopted Accounting Pronouncements
	In February 2013, the FASB issued ASU No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (“ASU 2013-02”).  The amendment requires disclosure of information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, disclosure is required, either on the face of the statement where net income is presented, or in the notes, of significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. The new requirements are effective for public companies in interim and annual reporting periods beginning after December 15, 2012. The Company adopted ASU 2013-02 as of January 1, 2013. See Note 14 - Shareholders' Equity for related disclosures.
Business Combinations Policy	'
	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. In the second and third quarters of 2013 and in December 2012, the Company acquired certain businesses, as discussed below and in Note 3 - Acquisitions and Other Investments of the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2012. As of September 30, 2013, the allocations of purchase prices 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 these acquisitions, are provisional and remain preliminary as 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.
	During the three and nine month periods ended September 30, 2013, the Company revised its preliminary allocations for certain of the 2013 and 2012 acquisitions based on new information about the facts and circumstances existing as of the respective dates of such acquisitions, or, for purchase price adjustments, based on the final net assets and net working capital of the businesses acquired, as prescribed in the relevant purchase agreements. These adjustments resulted in the recognition of, or adjusted the fair values of, certain acquired assets and assumed liabilities, which, for the 2012 acquisitions, resulted in the revision of comparative prior period financial information. Such measurement period adjustments are presented as if the adjustments had been taken into account as of the dates of the respective acquisitions. All changes that do not qualify as measurement period adjustments are included in current period earnings.
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, auction rate securities, 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:
	Level 1 - Quoted market prices in active markets for identical assets or liabilities.
	Level 2 - Observable market based inputs or other observable inputs.
	Level 3 - Significant unobservable inputs that cannot be corroborated by observable market data. These values are generally determined using valuation models incorporating management’s estimates of market participant assumptions.

Acquisitions_Accounting_Policy

Acquisitions (Accounting Policy)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Business Combinations Policy	'
	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. In the second and third quarters of 2013 and in December 2012, the Company acquired certain businesses, as discussed below and in Note 3 - Acquisitions and Other Investments of the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2012. As of September 30, 2013, the allocations of purchase prices 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 these acquisitions, are provisional and remain preliminary as 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.
	During the three and nine month periods ended September 30, 2013, the Company revised its preliminary allocations for certain of the 2013 and 2012 acquisitions based on new information about the facts and circumstances existing as of the respective dates of such acquisitions, or, for purchase price adjustments, based on the final net assets and net working capital of the businesses acquired, as prescribed in the relevant purchase agreements. These adjustments resulted in the recognition of, or adjusted the fair values of, certain acquired assets and assumed liabilities, which, for the 2012 acquisitions, resulted in the revision of comparative prior period financial information. Such measurement period adjustments are presented as if the adjustments had been taken into account as of the dates of the respective acquisitions. All changes that do not qualify as measurement period adjustments are included in current period earnings.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Line Items]	'
Schedule of Earnings Per Share Details	'
	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,
		2013			2012			2013			2012
	Net income attributable to MasTec:
	Basic net income from continuing operations (1)	$	49,960		$	36,098		$	104,702		$	78,957
	Interest expense, net of tax, 2009 Convertible Notes	79			78			235			234
	Diluted net income from continuing operations	$	50,039		$	36,176		$	104,937		$	79,191
	Net loss from discontinued operations (1)	(3,822		)	(9,277		)	(5,252		)	(7,872		)
	Diluted net income attributable to MasTec	$	46,217		$	26,899		$	99,685		$	71,319
	Weighted average shares outstanding:
	Basic weighted average shares outstanding	77,093			76,194			76,816			79,009
	Dilutive common stock equivalents	775			887			774			842
	Dilutive premium shares, 2011 Convertible Notes	6,790			1,639			6,337			1,325
	Dilutive shares, 2009 Convertible Notes	806			806			806			806
	Diluted weighted average shares outstanding	85,464			79,526			84,733			81,982
	(1) Calculated as total net income less amounts attributable to non-controlling interests.
2011 Senior 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 Ended September 30,												As of and for the Nine Months Ended September 30,
		2013						2012						2013				2012
		2011 4.0%			2011 4.25%			2011 4.0%			2011 4.25%			2011 4.0%		2011 4.25%		2011 4.0%		2011 4.25%
		Notes			Notes			Notes			Notes			Notes		Notes		Notes		Notes
	Number of conversion shares, principal amount	6,683			6,268			6,683			6,268			6,683		6,268		6,683		6,268
	Weighted average actual per share price	$	32.84		$	32.84		$	17.89		$	17.89		$	30.59	$	30.59	$	17.4	$	17.4
	Weighted average premium value	$	114,176		$	108,864		$	14,208		$	15,106		$	99,104	$	94,728	$	10,975	$	12,073
	Weighted average equivalent premium shares	3,476			3,314			794			845			3,240		3,097		631		694

Acquisitions_Tables

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2013
Business Acquisition [Line Items]	'
Schedule of Business Combination Measurement Period Adjustments	'
	Measurement period adjustments associated with the Company's 2012 acquisitions have been reflected in the Company's December 31, 2012 consolidated balance sheet as follows (in millions):
	As of December 31, 2012		As Previously Reported			Measurement Period Adjustments/Reclassifications				As Revised
	Current assets		$	1,047.10		$	2.5			$	1,049.60
	Property and equipment, net		$	350.4		$	(0.2	)		$	350.2
	Goodwill		$	820.3		$	4.7			$	825
	Other long-term assets, including discontinued operations		$	53.1		$	1.1			$	54.2
	Current liabilities		$	705.7		$	8.1			$	713.8
Big Country [Member]	'
Business Acquisition [Line Items]	'
Schedule of Business Acquisitions, Consideration Paid and Identifiable Net Assets Acquired	'
	The following table summarizes the preliminary estimated fair value of consideration paid and the identifiable assets acquired and liabilities assumed, as adjusted, as of the date of acquisition (in millions):
	Purchase price consideration:	1-May-13
	Cash	$	103.5
	Fair value of contingent consideration (earn-out liability)	22.8
	Total consideration transferred	$	126.3
	Identifiable assets acquired and liabilities assumed:
	Current assets	$	69
	Property and equipment	44
	Pre-qualifications	29.6
	Finite-lived intangible assets	10.7
	Current liabilities	(21.7		)
	Long-term debt	(24.4		)
	Deferred income taxes	(13.1		)
	Total identifiable net assets	$	94.1
	Goodwill	$	32.2
	Total net assets acquired, including goodwill	$	126.3
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	'
	The fair values and weighted average useful lives of Big Country's acquired finite-lived intangible assets, as adjusted, as of the date of acquisition were assigned as follows:
		Fair Value			Weighted Average Useful Life
		(in millions)			(in years)
	Backlog	$	1.9		1
	Non-compete agreements	1.8			8
	Customer relationships	7			6
	Total acquired amortizing intangibles	$	10.7		5
2013 Acquisitions [Member]	'
Business Acquisition [Line Items]	'
Business Acquisition, Pro Forma Information	'
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2013			2012				2013			2012
		(unaudited, in millions)							(unaudited, in millions)
	Revenue	$	1,273.60		$	1,158.70			$	3,284.90		$	3,026.20
	Net income from continuing operations	$	50		$	42.7			$	113.4		$	88.9
	Results of Businesses Acquired in 2013
	Revenues and net income from the Company's 2013 acquisitions for the periods indicated are as follows (in millions):
		For the Three Months Ended September 30, 2013			For the Nine Months Ended September 30, 2013
	Revenue	$	101.8		$	141.4
	Net income	$	6.2		$	7.7
2012 Acquisitions [Member]	'
Business Acquisition [Line Items]	'
Business Acquisition, Pro Forma Information	'
	Revenues and net income from the Company's 2012 acquisitions for the periods indicated are as follows (in millions):
		For the Three Months Ended September 30, 2013			For the Nine Months Ended September 30, 2013
	Revenue	$	39.9		$	129
	Net income	$	1.4		$	5.2

Discontinued_Operations_Tables

Discontinued Operations (Tables) (Globetec [Member])	9 Months Ended
	Sep. 30, 2013
Globetec [Member]	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'
Summary of Assets, Liabilities and Results of Operations from Discontinued Operations	'
	The following table contains a summary of assets and liabilities associated with Globetec as of December 31, 2012, and, as of September 30, 2013, a summary of the contingent assets and liabilities, as described above, that were retained by the Company (in millions):
		September 30,			December 31,
		2013			2012
	Assets:
	Current assets	$	3.1		$	18.6
	Long-term assets	11.3			7.7
	Assets of discontinued operations	$	14.4		$	26.3
	Liabilities:
	Current liabilities of discontinued operations	$	1.3		$	10.7
	The following table presents results from discontinued operations associated with the Globetec operation for the periods indicated (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Revenue	$	4.8		$	4.8		$	18		$	13.5
	Loss from operations, before tax	(0.5		)	(2.6		)	(2.7		)	(5.8		)
	Loss on disposal and impairment charges, before tax	(5.7		)	(12.7		)	(6.0		)	(12.7		)
	Benefit from income taxes	2.5			6			3.5			6.9
	Net loss from discontinued operations	$	(3.7	)	$	(9.3	)	$	(5.2	)	$	(11.6	)

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2013
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, 2012	$	305.8		$	272.1			$	129.5			$	117.6			$	825
	Additions from new business combinations	10			32.3				19.2				—				61.5
	Accruals of acquisition-related contingent consideration (1)	6.5			—				—				—				6.5
	Currency translation adjustments	—			(1.7		)		—				—				(1.7		)
	Balance as of September 30, 2013	$	322.3		$	302.7			$	148.7			$	117.6			$	891.3
	(1) Represents contingent consideration for acquisitions prior to January 1, 2009, which is only 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, net (in millions):
			Other Intangible Assets
			Non-amortizing							Amortizing
			Trade Names			Pre-Qualifications				Customer Relationships and Backlog				Other (1)				Total
	Other intangible assets, gross carrying amount as of December 31, 2012		$	34.8		$	31.3			$	109.6			$	19.8			$	195.5
	Accumulated amortization									$	(48.2	)		$	(10.3	)		$	(58.5	)
	Other intangible assets, net, as of December 31, 2012		$	34.8		$	31.3			$	61.4			$	9.5			$	137
	Additions from new business combinations		—			29.6				19.9				2.5				52
	Amortization expense									(14.4		)		(0.8		)		(15.2		)
	Currency translation adjustments		—			(0.7		)		(0.3		)		—				(1.0		)
	Other intangible assets, net, as of September 30, 2013		$	34.8		$	60.2			$	66.6			$	11.2			$	172.8
	(1) Consists principally of trade names and non-compete agreements.

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule Of Fair Values Of Financial Assets And Liabilities Measured On A Recurring Basis	'
	The fair values of financial assets and liabilities measured on a recurring basis were determined using the following inputs as of the dates indicated (in millions):
				Fair Value Measurements
				Using Inputs Considered as Significant
		Fair Value as of		Level 1		Level 2		Level 3
		30-Sep-13
	Assets
	Life insurance surrender values	$	5	$	5
	Auction rate securities (See Note 7)	$	9.2					$	9.2
	Liabilities
	Acquisition-related contingent consideration (1)	$	169.8					$	169.8
				Fair Value Measurements
				Using Inputs Considered as Significant
		Fair Value as of		Level 1		Level 2		Level 3
		31-Dec-12
	Assets
	Life insurance surrender values	$	11.9	$	11.9
	Auction rate securities (See Note 7)	$	14.4					$	14.4
	Liabilities
	Acquisition-related contingent consideration (1)	$	143.6					$	143.6
	(1) For acquisitions that closed after January 1, 2009.
Schedule of Fair Values of Financial Assets And Liabilities Measured On A Nonrecurring 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, 2013				December 31, 2012
		Carrying		Fair		Carrying				Fair
		Amount		Value		Amount				Value
	4.875% senior notes	$	400	$	378	$	—			$	—
	7.625% senior notes	$	—	$	—	$	150			$	154.9
	2009 Convertible Notes	$	12.6	$	24.7	$	12.7			$	21
	2011 Convertible Notes	$	197	$	397.8	$	193			$	338.3

Accounts_Receivable_Net_of_All1

Accounts Receivable, Net of Allowance (Tables)	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Schedule Of Accounts Receivable, Net of Allowance	'
	The following table provides details of accounts receivable, net of allowance, for our continuing operations as of the dates indicated (in millions):
		September 30,			December 31,
		2013			2012
	Contract billings	$	711.4		$	522
	Retainage	134.7			113.5
	Costs and earnings in excess of billings	393.9			253
	Accounts receivable, gross	$	1,240.00		$	888.5
	Less allowance for doubtful accounts	(14.9		)	(11.3		)
	Accounts receivable, net	$	1,225.10		$	877.2

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Long-term Debt, Unclassified [Abstract]	'
Schedule of Long Term Debt Instruments	'
	The following table provides details of the carrying value of debt as of the dates indicated (in millions):
	Description		Maturity Date	September 30,				December 31,
				2013				2012
	Credit facility		August 22, 2016	$	36.4			$	134
	4.875% senior notes		March 15, 2023	400				—
	7.625% senior notes		February 1, 2017	—				150
	2011 4.0% senior convertible notes		June 15, 2014	103.1				100.9
	2011 4.25% senior convertible notes		December 15, 2014	93.9				92.1
	2009 4.0% senior convertible notes		June 15, 2014	9.6				9.7
	2009 4.25% senior convertible notes		December 15, 2014	3				3
	Capital lease obligations, weighted average interest rate of 2.8%		In installments through March 2020	133.3				79
	Notes payable for equipment and other debt, weighted average interest rate of 3.5%		In installments through May 2018	53.9				30.2
	Total debt			$	833.2			$	598.9
	Less current maturities			(53.3		)		(52.6		)
	Long-term debt			$	779.9			$	546.3
Schedule of Interest Expense, Net	'
	The following table provides details of interest expense, net, classified within continuing operations for the periods indicated (in millions):
		For the Three Months Ended September 30,							For the Nine Months Ended September 30,
		2013			2012				2013			2012
	Interest expense:
	Contractual and other interest expense	$	10.4		$	7.4			$	27.9		$	21.8
	Accretion of senior convertible note discount	1.3			1.2				3.9			3.7
	Amortization of deferred financing costs	1			0.9				3			2.7
	Total interest expense	$	12.7		$	9.5			$	34.8		$	28.2
	Interest income	—			(0.1		)		(0.3		)	(0.3		)
	Interest expense, net	$	12.7		$	9.4			$	34.5		$	27.9

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2013
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, for our continuing operations as of the dates indicated (in millions):
		September 30,			December 31,
		2013			2012
	Land	$	4.8		$	4.8
	Buildings and leasehold improvements	18.1			15.4
	Machinery and equipment	728.7			521.5
	Office furniture and equipment	105.4			89.4
	Total property and equipment	$	857		$	631.1
	Less accumulated depreciation and amortization	(352.7		)	(280.9		)
	Property and equipment, net	$	504.3		$	350.2

StockBased_Compensation_and_Ot1

Stock-Based Compensation and Other Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Share-based Compensation [Abstract]	'
Summary of Restricted Share Award Activity	'
	Activity, restricted share awards:	Restricted		Per Share Weighted Average Grant Date
		Shares		Fair Value
	Non-vested restricted shares, as of December 31, 2012	782,281		$	19.1
	Granted	428,262		31.04
	Vested	(64,288	)	18.22
	Canceled/forfeited	(15,187	)	15.35
	Non-vested restricted shares, as of September 30, 2013	1,131,068		$	23.72
Summary of Stock Option Activity	'
	Activity, stock options:	Stock		Per Share Weighted Average			Weighted Average		Aggregate Intrinsic
		Options		Exercise Price			Remaining		Value (1)
							Contractual Life (years)		(in millions)
	Options outstanding as of December 31, 2012	1,043,825		$	10.5		2.33		$	15.1
	Exercised	(498,123	)	9.91
	Canceled/forfeited	(35,000	)	7.74
	Options outstanding as of September 30, 2013	510,702		$	11.27		2.19		$	9.7
	Options exercisable as of September 30, 2013	510,702		$	11.27		2.19		$	9.7
	-1	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 Employee Stock Purchase Plan Activity	'
		Nine Months Ended September 30,
	Activity, employee stock purchase plan:	2013			2012
	Cash proceeds (in millions)	$	6		$	0.9
	Number of common shares	436,925			67,073
	Weighted average price per share	$	13.69		$	13.43
	Weighted average grant date fair value per share	$	5.55		$	3.96
Summary of Tax Benefits from Stock-Based Compensation	'
	Details of stock based compensation expense and related tax benefits for the periods indicated are as follows (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Stock based compensation expense	$	3		$	1.2		$	9.6		$	3.4
	Income tax benefit from stock based compensation	4.5			0.7			7.7			1.6
	Excess tax benefit from stock based compensation (1)	$	3		$	0.2		$	4.4		$	0.3
	-1	Excess tax benefits, which represent cash flows from tax deductions in excess of the 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_PlansTables

Other Retirement Plans(Tables)	9 Months Ended
	Sep. 30, 2013
Multiemployer Plans [Abstract]	'
Schedule of Multiemployer Plan Contributions and Covered Employees	'
	Total contributions to multi-employer pension plans, and the related number of employees covered by these plans, for the periods indicated ranged as follows (dollars in millions):
		Number of Employees		Contributions (in millions)
	For the Three Months Ended September 30,	Low	High	Pension		Post-Retirement Benefit		Total
	2013	2,392	2,734	$	14.8	$	1	$	15.8
	2012	1,575	2,509	$	8.7	$	0.3	$	9
	For the Nine Months Ended September 30,	Low	High	Pension		Post-Retirement Benefit		Total
	2013	778	2,734	$	29.6	$	2.9	$	32.5
	2012	308	2,509	$	21.1	$	0.8	$	21.9

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss)	'
	Changes in accumulated other comprehensive (loss) income by component during the periods indicated are as follows (in thousands):
			For the Nine Months Ended September 30,
			2013										2012
			Unrealized (Losses) Gains										Unrealized (Losses) Gains
			Available-for-Sale Securities				Foreign Currency Items			Total			Available-for-Sale Securities			Foreign Currency Items			Total
	Balance as of January 1		$	(5,395	)		$	(106	)	$	(5,501	)	$	(5,917	)	$	(2,029	)	$	(7,946	)
	Activity before reclassifications, net of tax		(118		)		(3,839		)	(3,957		)	339			2,304			2,643
	Reclassifications, net of tax		(440		)	(1)	—			(440		)	—			—			—
	Activity, net of tax		(558		)		(3,839		)	(4,397		)	339			2,304			2,643
	Balance as of September 30		$	(5,953	)		$	(3,945	)	$	(9,898	)	$	(5,578	)	$	275		$	(5,303	)
	(1) Represents the reclassification adjustment for gains on securities sold, which was recognized as a component of other income. See Note 7 - Auction Rate Securities.
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]	'
Schedule of Share Activity	'
	Treasury Stock and Share Activity (in thousands):
		Common Shares			Treasury
		Outstanding			Shares
	Balance as of December 31, 2012	76,448			9,467
	Shares issued for stock option exercises	498
	Shares issued for restricted stock awards	64
	Other shares issued, net	409
	Shares contributed by shareholder, former owner of acquired business  (1)	(200	)
	Balance as of September 30, 2013	77,219			9,467
	(1) See Note 12 - Stock-Based Compensation and Other Employee Benefit Plans for contributed share details.

Segments_and_Operations_by_Geo1

Segments and Operations by Geographic Area (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Schedule of Segment Reporting Information, by 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).
	As of and for the three month period ended September 30, 2013:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	543		$	519.1		$	118.8		$	85.1		$	3.5	$	—		$	(0.1	)	$	1,269.40
	EBITDA	$	71.8		$	68.1		$	12.1		$	(6.4	)	$	0.1	$	(13.6	)	$	—		$	132.1
	Depreciation	$	8		$	19.3		$	2.6		$	1.2		$	—	$	0.9		$	—		$	32
	Amortization	$	1.5		$	3.2		$	0.6		$	0.5		$	—	$	—		$	—		$	5.8
	As of and for the three month period ended September 30, 2012:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	490		$	284		$	74.8		$	211.7		$	7.5	$	—		$	(0.7	)	$	1,067.30
	EBITDA	$	59.5		$	29		$	10.5		$	9.9		$	1.2	$	(18.4	)	$	—		$	91.7
	Depreciation	$	6.9		$	9.5		$	1.6		$	1		$	—	$	0.8		$	—		$	19.8
	Amortization	$	0.4		$	0.5		$	1.2		$	0.7		$	—	$	—		$	—		$	2.8
	As of and for the nine month period ended September 30, 2013:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	1,464.50		$	1,134.80		$	321.9		$	237.3		$	9.2	$	—		$	(2.0	)	$	3,165.70
	EBITDA	$	181.6		$	161.7		$	27		$	(14.6	)	$	0.5	$	(47.9	)	$	—		$	308.3
	Depreciation	$	22.8		$	51.8		$	7.1		$	3.6		$	—	$	2.6		$	—		$	87.9
	Amortization	$	4		$	8.4		$	1.3		$	1.5		$	—	$	—		$	—		$	15.2
	As of and for the nine month period ended September 30, 2012:
		Communications			Oil and Gas			Electrical			Power			Other		Corporate			Eliminations			Continuing Operations
								Transmission			Generation and Industrial											Consolidated
	Revenue	$	1,311.10		$	715.3		$	228.2		$	527.4		$	14.1	$	—		$	(1.7	)	$	2,794.40
	EBITDA	$	139.4		$	57.3		$	31.1		$	28.2		$	1.7	$	(34.5	)	$	—		$	223.2
	Depreciation	$	19.9		$	27.2		$	4.3		$	3		$	—	$	2.2		$	—		$	56.6
	Amortization	$	1.3		$	1.4		$	3.8		$	2		$	—	$	—		$	—		$	8.5
Reconciliation of EBITDA to Income from Continuing Operations	'
	The following table presents a reconciliation of EBITDA for our continuing operations to consolidated income from continuing operations before provision for income taxes (in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	EBITDA	$	132.1		$	91.7		$	308.3		$	223.2
	Less:
	Interest expense, net	(12.7		)	(9.4		)	(34.5		)	(27.9		)
	Depreciation	(32.0		)	(19.8		)	(87.9		)	(56.6		)
	Amortization	(5.8		)	(2.8		)	(15.2		)	(8.5		)
	Income from continuing operations before provision for income taxes	$	81.6		$	59.6		$	170.6		$	130.2
Schedule of Revenue and Long-Lived Assets by Geographical Area	'
	The following table presents revenue by geographic area for the periods indicated (dollar amounts in millions):
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
		2013			2012			2013			2012
	Continuing operations:
	Derived from foreign operations	$	90.9		$	33.7		$	172		$	133.7
	Derived in the United States	1,178.50			1,033.60			2,993.70			2,660.70
	Revenue from continuing operations	$	1,269.40		$	1,067.30		$	3,165.70		$	2,794.40
	Discontinued operations:
	Derived from foreign operations	$	2.3		$	1.9		$	7		$	4.6
	Derived in the United States	2.5			2.9			11			69.1
	Revenue from discontinued operations	$	4.8		$	4.8		$	18		$	73.7
	The following table presents long-lived assets held in foreign countries for our continuing operations as of the dates indicated (in millions):
		September 30,			December 31,
		2013			2012
	Property and equipment, net	$	48.8		$	11.4
	Goodwill and other intangible assets, net	$	94		$	30.5
Schedule of Significant Customers	'
	Revenue concentration information for significant customers, as a percent of total consolidated revenue from continuing operations, is as follows:
		For the Three Months Ended September 30,			For the Nine Months Ended September 30,
		2013		2012	2013		2012
	Customer:
	AT&T	16%		17%	18%		17%
	DIRECTV®	13%		16%	15%		17%
	Enbridge, Inc.	20%		3%	14%		1%
	The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for both AT&T's wireless and wireline infrastructure businesses. Revenue from AT&T is included in the Communications segment.
	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.
	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.

Concentrations_of_Risk_Tables

Concentrations of Risk (Tables)	9 Months Ended
	Sep. 30, 2013
Concentration Risk [Line Items]	'
Schedule of Major Customer Revenue Concentration	'
	Revenue concentration information for significant customers, as a percent of total consolidated revenue from continuing operations, is as follows:
		For the Three Months Ended September 30,		For the Nine Months Ended September 30,
		2013	2012	2013	2012
	Customer:
	AT&T	16%	17%	18%	17%
	DIRECTV®	13%	16%	15%	17%
	Enbridge, Inc.	20%	3%	14%	1%
	The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for both AT&T's wireless and wireline infrastructure businesses. Revenue from AT&T is included in the Communications segment.
	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.
	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.
Ten Largest Customers [Member]	'
Concentration Risk [Line Items]	'
Schedule of Major Customer Revenue Concentration	'
	Revenue concentration information for the Company's top ten customers, as a percent of total consolidated revenue from continuing operations, is as follows:
		For the Three Months Ended September 30,		For the Nine Months Ended September 30,
		2013	2012	2013	2012
	Revenue from top ten customers	73%	67%	69%	66%

Supplemental_Guarantor_Financi1

Supplemental Guarantor Financial Information (Tables)	9 Months Ended
	Sep. 30, 2013
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
	For the Three Months Ended September 30, 2013 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,086,063		$	187,689		$	(4,367	)	$	1,269,385
	Costs of revenue, excluding depreciation and amortization	—			927,295			158,204			(4,367		)	1,081,132
	Depreciation and amortization	1			30,637			7,118			—			37,756
	General and administrative expenses	457			47,967			10,552			—			58,976
	Interest expense, net	—			11,951			715			—			12,666
	Other income, net	—			(2,309		)	(469		)	—			(2,778		)
	(Loss) income from continuing operations before provision for income taxes	$	(458	)	$	70,522		$	11,569		$	—		$	81,633
	Benefit from (provision for) income taxes	174			(28,840		)	(3,032		)	—			(31,698		)
	Net (loss) income from continuing operations before non-controlling interests	$	(284	)	$	41,682		$	8,537		$	—		$	49,935
	Loss from discontinued operations, net of tax	—			(3,566		)	(169		)	—			(3,735		)
	Equity in income from subsidiaries, net of tax	46,484			—			—			(46,484		)	—
	Net income (loss)	$	46,200		$	38,116		$	8,368		$	(46,484	)	$	46,200
	Net income (loss) attributable to non-controlling interests	—			87			(25		)	—			62
	Net income (loss) attributable to MasTec, Inc.	$	46,200		$	38,029		$	8,393		$	(46,484	)	$	46,138
	Comprehensive income (loss)	$	46,200		$	38,024		$	11,304		$	(46,484	)	$	49,044
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME
	For the Three Months Ended September 30, 2012 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	1,028,091		$	40,222		$	(1,013	)	$	1,067,300
	Costs of revenue, excluding depreciation and amortization	—			886,198			39,119			(1,013		)	924,304
	Depreciation and amortization	—			22,065			580			—			22,645
	General and administrative expenses	303			39,251			2,960			—			42,514
	Interest expense, net	—			9,435			11			—			9,446
	Other expense, net	—			8,696			119			—			8,815
	(Loss) income from continuing operations before provision for income taxes	$	(303	)	$	62,446		$	(2,567	)	$	—		$	59,576
	Benefit from (provision for) income taxes	114			(24,564		)	972			—			(23,478		)
	Net (loss) income from continuing operations before non-controlling interests	$	(189	)	$	37,882		$	(1,595	)	$	—		$	36,098
	Loss from discontinued operations, net of tax	—			(8,852		)	(429		)	—			(9,281		)
	Equity in income from subsidiaries, net of tax	27,006			—			—			(27,006		)	—
	Net income (loss)	$	26,817		$	29,030		$	(2,024	)	$	(27,006	)	$	26,817
	Net loss attributable to non-controlling interests	—			—			(4		)	—			(4		)
	Net income (loss) attributable to MasTec, Inc.	$	26,817		$	29,030		$	(2,020	)	$	(27,006	)	$	26,821
	Comprehensive income (loss)	$	26,817		$	29,418		$	152		$	(27,006	)	$	29,381
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME
	For the Nine Months Ended September 30, 2013 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	2,751,408		$	424,616		$	(10,367	)	$	3,165,657
	Costs of revenue, excluding depreciation and amortization	—			2,348,835			356,819			(10,367		)	2,695,287
	Depreciation and amortization	2			87,426			15,683			—			103,111
	General and administrative expenses	1,443			134,460			23,858			—			159,761
	Interest expense, net	—			33,583			966			—			34,549
	Loss on extinguishment of debt	—			5,624			—			—			5,624
	Other income, net	—			(2,526		)	(757		)	—			(3,283		)
	(Loss) income from continuing operations before provision for income taxes	$	(1,445	)	$	144,006		$	28,047		$	—		$	170,608
	Benefit from (provision for) income taxes	572			(56,782		)	(9,612		)	—			(65,822		)
	Net (loss) income from continuing operations before non-controlling interests	$	(873	)	$	87,224		$	18,435		$	—		$	104,786
	Loss from discontinued operations, net of tax	—			(4,178		)	(987		)	—			(5,165		)
	Equity in income from subsidiaries, net of tax	100,494			—			—			(100,494		)	—
	Net income (loss)	$	99,621		$	83,046		$	17,448		$	(100,494	)	$	99,621
	Net income attributable to non-controlling interests	—			87			85			—			172
	Net income (loss) attributable to MasTec, Inc.	$	99,621		$	82,959		$	17,363		$	(100,494	)	$	99,449
	Comprehensive income (loss)	$	99,621		$	82,489		$	13,608		$	(100,494	)	$	95,224
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME
	For the Nine Months Ended September 30, 2012 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Revenue	$	—		$	2,644,197		$	152,267		$	(2,033	)	$	2,794,431
Costs of revenue, excluding depreciation and amortization	—			2,312,564			134,525			(2,033		)	2,445,056
Depreciation and amortization	1			63,403			1,721			—			65,125
General and administrative expenses	1,052			109,366			7,774			—			118,192
Interest expense, net	—			27,880			3			—			27,883
Other expense, net	—			7,655			334			—			7,989
(Loss) income from continuing operations before provision for income taxes	$	(1,053	)	$	123,329		$	7,910		$	—		$	130,186
Benefit from (provision for) income taxes	423			(49,766		)	(1,886		)	—			(51,229		)
Net (loss) income from continuing operations before non-controlling interests	$	(630	)	$	73,563		$	6,024		$	—		$	78,957
Loss from discontinued operations, net of tax	—			(6,099		)	(1,782		)	—			(7,881		)
Equity in income from subsidiaries, net of tax	71,706			—			—			(71,706		)	—
Net income (loss)	$	71,076		$	67,464		$	4,242		$	(71,706	)	$	71,076
Net loss attributable to non-controlling interests	—			—			(9		)	—			(9		)
Net income (loss) attributable to MasTec, Inc.	$	71,076		$	67,464		$	4,251		$	(71,706	)	$	71,085
Comprehensive income (loss)	$	71,076		$	67,803		$	6,546		$	(71,706	)	$	73,719
Condensed Unaudited Consolidating Balance Sheets	'
	CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS
	As of September 30, 2013 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Assets
	Current assets, including discontinued operations	$	—		$	1,120,527		$	211,789		$	—		$	1,332,316
	Property and equipment, net	—			431,899			72,414			—			504,313
	Goodwill and other intangible assets, net	—			890,683			173,416			—			1,064,099
	Net investments in and advances to (from) consolidated affiliates	974,904			147,960			(312		)	(1,122,552		)	—
	Other long-term assets, including discontinued operations	9,216			42,899			1,495			—			53,610
	Total assets	$	984,120		$	2,633,968		$	458,802		$	(1,122,552	)	$	2,954,338
	Liabilities and Shareholders’ Equity
	Total current liabilities	$	8		$	799,374		$	82,847		$	—		$	882,229
	Long-term debt	—			750,841			29,079			—			779,920
	Other liabilities	—			226,184			86,918			—			313,102
	Total liabilities	$	8		$	1,776,399		$	198,844		$	—		$	1,975,251
	Total shareholders’ equity	$	984,112		$	857,569		$	259,958		$	(1,122,552	)	$	979,087
	Total liabilities and shareholders’ equity	$	984,120		$	2,633,968		$	458,802		$	(1,122,552	)	$	2,954,338
	CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS
	As of December 31, 2012 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Assets
	Current assets, including discontinued operations	$	—		$	960,523		$	89,118		$	—		$	1,049,641
	Property and equipment, net	—			326,588			23,604			—			350,192
	Goodwill and other intangible assets, net	—			890,323			71,650			—			961,973
	Net investments in and advances to (from) consolidated affiliates	854,992			172,150			(21,394		)	(1,005,748		)	—
	Other long-term assets, including discontinued operations	7,701			43,442			3,017			—			54,160
	Total assets	$	862,693		$	2,393,026		$	165,995		$	(1,005,748	)	$	2,415,966
	Liabilities and Shareholders’ Equity
	Total current liabilities	$	20		$	675,966		$	37,807		$	—		$	713,793
	Long-term debt	—			546,262			61			—			546,323
	Other liabilities	—			262,099			31,876			—			293,975
	Total liabilities	$	20		$	1,484,327		$	69,744		$	—		$	1,554,091
	Total shareholders’ equity	$	862,673		$	908,699		$	96,251		$	(1,005,748	)	$	861,875
	Total liabilities and shareholders’ equity	$	862,693		$	2,393,026		$	165,995		$	(1,005,748	)	$	2,415,966
Condensed Unaudited Consolidating Statements Of Cash Flows	'
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS
	For the Nine Months Ended September 30, 2013 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Net cash (used in) provided by operating activities	$	(2,401	)	$	116,783		$	10,609		$	—		$	124,991
	Cash flows (used in) provided by investing activities:
	Cash paid for acquisitions, net, including contingent consideration	$	—		$	(55,453	)	$	(103,993	)	$	—		$	(159,446	)
	Capital expenditures	—			(97,602		)	(3,809		)	—			(101,411		)
	Proceeds from sale of property and equipment	—			7,629			659			—			8,288
	Proceeds from disposal of business, net of cash divested	—			(4,332		)	—			—			(4,332		)
	Proceeds from sale or redemption of investments	—			5,025			—			—			5,025
	Payments for other investments, net	—			(1,174		)	—			—			(1,174		)
	Net cash used in investing activities	$	—		$	(145,907	)	$	(107,143	)	$	—		$	(253,050	)
	Cash flows provided by (used in) financing activities:
	Proceeds from issuance of 4.875% senior notes	$	—		$	400,000		$	—		$	—		$	400,000
	Repayment of 7.625% senior notes	—			(150,000		)	—			—			(150,000		)
	Proceeds from credit facility	—			664,979			101,175			—			766,154
	Repayments of credit facility	—			(753,960		)	(106,110		)	—			(860,070		)
	Repayments of other borrowings	—			(24,246		)	—			—			(24,246		)
	Proceeds from book overdrafts	—			2,791			—			—			2,791
	Payments of capital lease obligations	—			(31,249		)	(965		)	—			(32,214		)
	Proceeds from stock option exercises and other share-based awards	9,231			—			—			—			9,231
	Excess tax benefit from non-cash stock-based compensation	—			4,446			—			—			4,446
	Payments for debt extinguishment, call premiums	—			(4,116		)	—			—			(4,116		)
	Payments of financing costs	—			(7,718		)	—			—			(7,718		)
	Net financing activities and advances (to) from consolidated affiliates	(6,830		)	(81,999		)	88,829			—			—
	Net cash provided (used in) by financing activities	$	2,401		$	18,928		$	82,929		$	—		$	104,258
	Net decrease in cash and cash equivalents	—			(10,196		)	(13,605		)	—			(23,801		)
	Net effect of currency translation on cash	—			—			(118		)	—			(118		)
	Cash and cash equivalents - beginning of period	—			12,969			13,798			—			26,767
	Cash and cash equivalents - end of period	$	—		$	2,773		$	75		$	—		$	2,848
	Cash and cash equivalents of discontinued operations	$	—		$	—		$	—		$	—		$	—
	Cash and cash equivalents of continuing operations	$	—		$	2,773		$	75		$	—		$	2,848
	CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS
	For the Nine Months Ended September 30, 2012 (in thousands)
		MasTec, Inc.			Guarantor			Non-Guarantor			Eliminations			Consolidated
					Subsidiaries			Subsidiaries						MasTec, Inc.
	Net cash (used in) provided by operating activities	$	(891	)	$	96,464		$	19,097		$	—		$	114,670
	Cash flows (used in) provided by investing activities:
	Cash paid for acquisitions, net, including contingent consideration	$	—		$	(16,094	)	$	(1,402	)	$	—		$	(17,496	)
	Capital expenditures	—			(49,109		)	(1,222		)	—			(50,331		)
	Proceeds from sale of property and equipment	—			5,808			—			—			5,808
	Proceeds from disposal of business, net of cash divested	—			97,728			—			—			97,728
	Payments for other investments, net	(284		)	—			—			—			(284		)
	Net cash (used in) provided by investing activities	$	(284	)	$	38,333		$	(2,624	)	$	—		$	35,425
	Cash flows provided by (used in) financing activities:
	Proceeds from credit facility	$	—		$	631,815		$	—		$	—		$	631,815
	Repayments of credit facility	—			(681,815		)	—			—			(681,815		)
	Repayments of other borrowings	—			(15,510		)	—			—			(15,510		)
	Repayments of book overdrafts	—			(5,645		)	—			—			(5,645		)
	Payments of capital lease obligations	—			(14,790		)	(16		)	—			(14,806		)
	Proceeds from stock option exercises and other share-based awards	1,445			—			—			—			1,445
	Excess tax benefit from non-cash stock-based compensation	—			302			—			—			302
	Purchases of treasury stock	(75,000		)	—			—			—			(75,000		)
	Payments of financing costs	—			(113		)	—			—			(113		)
	Net financing activities and advances (to) from consolidated affiliates	74,730			(58,405		)	(16,325		)	—			—
	Net cash provided by (used in) financing activities	$	1,175		$	(144,161	)	$	(16,341	)	$	—		$	(159,327	)
	Net (decrease) increase in cash and cash equivalents	—			(9,364		)	132			—			(9,232		)
	Net effect of currency translation on cash	—			20			115			—			135
	Cash and cash equivalents - beginning of period	—			16,241			4,038			—			20,279
	Cash and cash equivalents - end of period	$	—		$	6,897		$	4,285		$	—		$	11,182
	Cash and cash equivalents of discontinued operations	$	—		$	684		$	26		$	—		$	710
	Cash and cash equivalents of continuing operations	$	—		$	6,213		$	4,259		$	—		$	10,472

Business_Basis_of_Presentation2

Business, Basis of Presentation and Significant Accounting Policies (Narrative) (Detail)	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recently Issued Accounting Standards, Not Adopted as of September 30, 2013	'Recently Issued Accounting Standards, Not Adopted as of SeptemberB 30, 2013. In March 2013, the Financial Accounting Standards Board (bFASBb) issued Accounting Standards Update (bASUb) 2013-05, Foreign Currency Matters (Topic 830): Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (a consensus of the FASB Emerging Issues Task Force) (bASU 2013-05b).B The objective of ASU 2013-05 is to resolve diversity in practice regarding the release of the cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. ASU 2013-05 is effective prospectively for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements. In February 2013, the FASB issued ASU 2013-04, Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date (a consensus of the FASB Emerging Issues Task Force) (bASU 2013-04b). ASU 2013-04 provides guidance related to the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. The guidance requires an entity to measure those obligations as the sum of the amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and any additional amount the reporting entity expects to pay on behalf of its co-obligors. The guidance in ASU 2013-04 also requires an entity to disclose the nature and amount of the obligation.B ASU 2013-05 is effective for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013. Retrospective application is required for all periods presented. The Company is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements. In July 2013, the FASB issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force) (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 is currently evaluating the potential impact of this ASU on its condensed unaudited consolidated financial statements.
Recently Adopted Accounting Pronouncements	'Recently Adopted Accounting Pronouncements. In February 2013, the FASB issued ASU No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (bASU 2013-02b).B The amendment requires disclosure of information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, disclosure is required, either on the face of the statement where net income is presented, or in the notes, of significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. The new requirements are effective for public companies in interim and annual reporting periods beginning after December 15, 2012. The Company adopted ASU 2013-02 as of January 1, 2013. See Note 14 - Shareholders' Equity for related disclosures.

Earnings_Per_Share_Narrative_D

Earnings Per Share (Narrative) (Detail) (USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
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.	'
Treasury stock acquired, shares	'	4.9
Treasury stock acquired, value	'	$75
Unsecured Debt [Member] | Convertible Debt [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. As the Companybs weighted average stock price for the three and nine month periods ended SeptemberB 30, 2013 and 2012 exceeded the conversion prices of the 2011 Convertible Notes, dilutive shares associated with the 2011 Convertible Notes, which are attributable to the weighted average premium value, in shares, of the conversion shares underlying the 2011 Convertible Notes in excess of the respective principal amounts thereof, have been included in the Company's share count for the corresponding periods.	'
Unsecured Debt [Member] | Convertible Debt [Member] | Total Convertible Debt [Member]	'	'
Earnings Per Share [Line Items]	'	'
Principal amount	215	'
Unsecured Debt [Member] | Convertible Debt [Member] | 2011 Senior Convertible Notes [Member]	'	'
Earnings Per Share [Line Items]	'	'
Principal amount	202.3	'
Unsecured Debt [Member] | Convertible Debt [Member] | 2009 Senior Convertible Notes [Member]	'	'
Earnings Per Share [Line Items]	'	'
Principal amount	12.6	'
Unsecured Debt [Member] | Convertible Debt [Member] | 2011 4.0% Notes [Member]	'	'
Earnings Per Share [Line Items]	'	'
Principal amount	105.3	'
Debt instrument, interest rate	4.00%	'
Conversion price per share	15.76	'
Unsecured Debt [Member] | Convertible Debt [Member] | 2011 4.25% Notes [Member]	'	'
Earnings Per Share [Line Items]	'	'
Principal amount	97	'
Debt instrument, interest rate	4.25%	'
Conversion price per share	15.48	'

Earnings_Per_Share_Schedule_Of

Earnings Per Share (Schedule Of Earnings Per Share, Basic and Diluted) (Detail) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Diluted Net Income Attributable to MasTec	'		'		'		'
Basic net income from continuing operations	$49,960	[1]	$36,098	[1]	$104,702	[1]	$78,957	[1]
Net loss from discontinued operations	-3,822	[1]	-9,277	[1]	-5,252	[1]	-7,872	[1]
Diluted net income attributable to MasTec	46,217		26,899		99,685		71,319
Weighted Average Number of Shares Outstanding, Diluted	'		'		'		'
Basic weighted average shares outstanding	77,093		76,194		76,816		79,009
Dilutive common stock equivalents	775		887		774		842
Diluted weighted average shares outstanding	85,464		79,526		84,733		81,982
Continuing Operations [Member]	'		'		'		'
Diluted Net Income Attributable to MasTec	'		'		'		'
Diluted net income attributable to MasTec	50,039		36,176		104,937		79,191
Unsecured Debt [Member] | Convertible Debt [Member] | 2009 Senior Convertible Notes [Member]	'		'		'		'
Diluted Net Income Attributable to MasTec	'		'		'		'
Interest expense, net of tax, 2009 Convertible Notes	$79		$78		$235		$234
Weighted Average Number of Shares Outstanding, Diluted	'		'		'		'
Dilutive shares, 2009 Convertible Notes	806		806		806		806
Unsecured Debt [Member] | Convertible Debt [Member] | 2011 Senior Convertible Notes [Member]	'		'		'		'
Weighted Average Number of Shares Outstanding, Diluted	'		'		'		'
Dilutive premium shares, 2011 Convertible Notes	6,790		1,639		6,337		1,325
[1]	Calculated as total net income less amounts attributable to non-controlling interests.

Earnings_Per_Share_Schedule_Of1

Earnings Per Share (Schedule Of Convertible Note Premium Share Information) (Detail) (Unsecured Debt [Member], Convertible Debt [Member], USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
2011 4.0% Notes [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Number of conversion shares, principal amount	6,683	6,683	6,683	6,683
Weighted average equivalent premium shares	3,476	794	3,240	631
2011 4.25% Notes [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Number of conversion shares, principal amount	6,268	6,268	6,268	6,268
Weighted average equivalent premium shares	3,314	845	3,097	694
Weighted Average [Member] | 2011 4.0% Notes [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Weighted average actual per share price	32.84	17.89	30.59	17.4
Weighted average premium value	114,176	14,208	99,104	10,975
Weighted Average [Member] | 2011 4.25% Notes [Member]	'	'	'	'
Earnings Per Share [Line Items]	'	'	'	'
Weighted average actual per share price	32.84	17.89	30.59	17.4
Weighted average premium value	108,864	15,106	94,728	12,073

Acquisitions_Narrative_Details

Acquisitions (Narrative) (Details)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Business combination, provisional information, initial accounting incomplete, items	' As of SeptemberB 30, 2013, the allocations of purchase prices 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 these acquisitions, are provisional and remain preliminary as 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 combination, provisional information, initial accounting incomplete, nature of adjustments	'During the three and nine month periods ended SeptemberB 30, 2013, the Company revised its preliminary allocations for certain of the 2013 and 2012 acquisitions based on new information about the facts and circumstances existing as of the respective dates of such acquisitions, or, for purchase price adjustments, based on the final net assets and net working capital of the businesses acquired, as prescribed in the relevant purchase agreements. These adjustments resulted in the recognition of, or adjusted the fair values of, certain acquired assets and assumed liabilities, which, for the 2012 acquisitions, resulted in the revision of comparative prior period financial information. Such measurement period adjustments are presented as if the adjustments had been taken into account as of the dates of the respective acquisitions. All changes that do not qualify as measurement period adjustments are included in current period earnings.

Acquisitions_2013_Acquisitions

Acquisitions - 2013 Acquisitions (Narrative) (Details) (USD $)	9 Months Ended		9 Months Ended		9 Months Ended	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	2-May-13	Sep. 30, 2013	2-May-13	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	Big Country [Member]	Big Country [Member]	Big Country [Member]	Big Country [Member]	Other 2013 Acquisitions [Member]	2013 Acquisitions [Member]	2013 Acquisitions [Member]
			Earn-out Arrangements [Member]	Earn-out Arrangements [Member]
Business Acquisition [Line Items]	'	'	'	'	'	'	'
Effective date of acquisition	1-May-13	'	'	'	'	'	'
Business combination, percentage of voting interests acquired	'	100.00%	'	'	'	'	'
Business combination, name of acquired entity	'Big Country Energy Services, Inc.	'	'	'	'	'	'
Business combination, description of acquired entity	'Big Country is a North American oil and gas pipeline and facility construction services company, headquartered in Calgary, Alberta, Canada.B Big Country also has construction offices in Alberta, British Columbia and Saskatchewan, as well as in Wyoming and North Dakota. Big Country's services include oil, natural gas and natural gas liquids gathering systems and pipeline construction; pipeline modification and replacement services; compressor and pumping station construction; and other related services supporting the oil and gas production, processing and transportation industries.	'	'	'	'Effective AprilB 1, 2013, MasTec acquired a former subcontractor to its wireless business, which will provide self-perform communications tower construction, installation, maintenance and other services in support of telecommunications infrastructure construction in the Company's communications segment. In addition, effective AugustB 1, 2013, MasTec acquired an electrical transmission services company, which focuses primarily on substation construction activities within the Company's electrical transmission segment.	'	'
Business combination, goodwill recognized, description	'Goodwill arising from the acquisition represents the estimated value of Big Country'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 Big Country and MasTec.	'	'	'	'	'	'
Business combination, goodwill, tax deductible amount	'	$4	'	'	'	'	'
Business combination, contingent consideration arrangements, basis for amount	'	'	'The contingent earn-out obligation is equal to 25% of the excess, if any, of Big Countrybs annual earnings 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 cash.	'	'	'	'
Earn-out period	'	'	'	'5 years	'	'	'
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 combination, contingent consideration arrangements, range of outcomes, value, low	'	'	'	1	'	'	'
Business combination, contingent consideration arrangements, range of outcomes, value, high	'	'	'	110	'	'	'
Business combination, contingent consideration arrangements, range of outcomes, maximum unlimited	'	'	'there is no maximum earn-out payment amount.	'	'	'	'
Acquisition costs	'	'	'	'	'	$0.30	$1.50

Acquisitions_2012_Acquisitions

Acquisitions - 2012 Acquisitions (Narrative) (Detail) (USD $)	0 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Dec. 01, 2012	Sep. 30, 2013	Dec. 02, 2012
Bottom Line Services [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Effective date of acquisition	'	1-Dec-12	'
Business combination, name of acquired entity	'	'Bottom Line Services, LLC	'
Business combination, percentage of voting interests acquired	'	'	100.00%
Acquisition payments in cash	$67.60	'	'
Business combination, description of acquired entity	'	'BLS's services include pipeline and facilities construction, painting and maintenance services, primarily in eastern Texas.	'
Bottom Line Services [Member] | Earn-out Arrangements [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Earn-out period	'	'	'5 years
Fair value of contingent consideration (earn-out liability)	$11.10	'	'
Other 2012 Acquisitions [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Effective date of acquisition	'	1-Dec-12	'
Business combination, description of acquired entity	'	'MasTec acquired a former subcontractor to MasTec's oil and gas business, which provides self-perform clearing and trenching services for natural gas and petroleum pipeline infrastructure construction, and also acquired a former subcontractor to MasTec's wireless business, which provides self-perform communications tower construction, installation, maintenance and other services in support of telecommunications infrastructure construction.	'

Acquisitions_Schedule_of_Busin

Acquisitions (Schedule of Business Acquisitions, Consideration Paid and Identifiable Net Assets Acquired) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	1-May-13	2-May-13	2-May-13	2-May-13	2-May-13	2-May-13	2-May-13	1-May-13
			Big Country [Member]	Big Country [Member]	Big Country [Member]	Big Country [Member]	Big Country [Member]	Big Country [Member]	Big Country [Member]	Big Country [Member]
					Pre-Qualifications [Member]	Current Assets [Member]	Current Liabilities [Member]	Long-term Debt [Member]	Deferred Income Taxes [Member]	Earn-out Arrangements [Member]
Purchase price consideration:	'	'	'	'	'	'	'	'	'	'
Cash	'	'	$103,500,000	'	'	'	'	'	'	'
Fair value of contingent consideration (earn-out liability)	'	'	'	'	'	'	'	'	'	22,800,000
Total consideration transferred	'	'	126,300,000	'	'	'	'	'	'	'
Identifiable assets acquired and liabilities assumed:	'	'	'	'	'	'	'	'	'	'
Assets	'	'	'	'	'	69,000,000	'	'	'	'
Property and equipment	'	'	'	44,000,000	'	'	'	'	'	'
Pre-qualifications	'	'	'	'	29,600,000	'	'	'	'	'
Finite-lived intangible assets	'	'	'	10,700,000	'	'	'	'	'	'
Liabilities	'	'	'	'	'	'	-21,700,000	-24,400,000	-13,100,000	'
Total identifiable net assets	'	'	'	94,100,000	'	'	'	'	'	'
Goodwill	891,266,000	824,953,000	'	32,200,000	'	'	'	'	'	'
Total net assets acquired, including goodwill	'	'	'	$126,300,000	'	'	'	'	'	'

Acquisition_Schedule_of_Acquir

Acquisition (Schedule of Acquired Finite Lived Intangibles) (Details) (Big Country [Member], USD $)	0 Months Ended
In Millions, unless otherwise specified	1-May-13	2-May-13
Acquired Finite-Lived Intangible Assets [Line Items]	'	'
Finite-lived intangible assets	'	$10.70
Finite-lived intangible assets, weighted average useful life	'5 years	'
Backlog [Member]	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'
Finite-lived intangible assets	'	1.9
Finite-lived intangible assets, weighted average useful life	'1 year	'
Noncompete Agreements [Member]	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'
Finite-lived intangible assets	'	1.8
Finite-lived intangible assets, weighted average useful life	'8 years	'
Customer Relationships [Member]	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'
Finite-lived intangible assets	'	$7
Finite-lived intangible assets, weighted average useful life	'6 years	'

Acquisitions_Schedule_of_Busin1

Acquisitions (Schedule of Business Acquisition Pro Forma Information) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
2013 Acquisitions [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Pro forma information, description	'	'	'The unaudited pro forma combined results of operations presented below for three and nine month periods ended September 30, 2013 and 2012, respectively, have been prepared by adjusting the historical results of MasTec to include the historical results of the acquisitions described above as if they occurred on JanuaryB 1, 2012. The unaudited pro forma combined historical results were then adjusted (i) to remove one-time acquisition costs; (ii) to increase amortization expense resulting from 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 pro forma results of operations do 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 pro forma results of operations do 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 company in the future.	'
Pro forma revenue	$1,273.60	$1,158.70	$3,284.90	$3,026.20
Pro forma net income from continuing operations	50	42.7	113.4	88.9
Aquiree revenue since acquisition date	101.8	'	141.4	'
Acquiree net income since acquisition date	6.2	'	7.7	'
2012 Acquisitions [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Aquiree revenue since acquisition date	39.9	'	129	'
Acquiree net income since acquisition date	$1.40	'	$5.20	'

Acquisitions_Schedule_of_Measu

Acquisitions (Schedule of Measurement Period Adjustments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Measurement Period Adjustments [Line Items]	'	'
Current assets	$1,332,316	$1,049,641
Property and equipment, net	504,313	350,192
Goodwill	891,266	824,953
Other long-term assets, including disontinued operations	53,610	54,160
Current liabilties	882,229	713,793
Scenario, Previously Reported [Member]	'	'
Measurement Period Adjustments [Line Items]	'	'
Current assets	'	1,047,100
Property and equipment, net	'	350,400
Goodwill	'	820,300
Other long-term assets, including disontinued operations	'	53,100
Current liabilties	'	705,700
Scenario, Adjustment [Member] | 2012 Acquisitions [Member] | Purchase Price Allocation Adjustments [Member]	'	'
Measurement Period Adjustments [Line Items]	'	'
Current assets	'	2,500
Property and equipment, net	'	-200
Goodwill	'	4,700
Other long-term assets, including disontinued operations	'	1,100
Current liabilties	'	$8,100

Discontinued_Operations_Narrat

Discontinued Operations (Narrative) (Detail) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Jun. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Globetec [Member]

Globetec [Member]

Globetec [Member]

Globetec [Member]

Globetec [Member]

Globetec [Member]

Globetec [Member]

Globetec [Member]

Globetec [Member]

DirectStar [Member]

DirectStar [Member]

DirectStar [Member]

DirectStar [Member]

Variable Interest Entity, Not Primary Beneficiary [Member]

Variable Interest Entity, Not Primary Beneficiary [Member]

Variable Interest Entity, Not Primary Beneficiary [Member]

Variable Interest Entity, Not Primary Beneficiary [Member]

Variable Interest Entity, Not Primary Beneficiary [Member]

Surety Bond [Member]

Prepaid Expenses and Other Current Assets [Member]

Prepaid Expenses and Other Current Assets [Member]

Other Noncurrent Assets [Member]

Maximum [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Discontinued operations description

'

'

'

'

'

'

'In September 2012, the Company's board of directors approved a plan of sale for its Globetec business. Accordingly, Globetec's projects and assets are reflected as assets and liabilities of discontinued operations in the condensed unaudited consolidated balance sheets for all periods presented, and Globetec's results of operations are presented as discontinued operations in the condensed unaudited consolidated statements of operations for all periods presented. Effective AugustB 31, 2013, the Company sold all of its membership interests in Globetec Construction, LLC ("Globetec") for nominal consideration amount and retained certain assets, including two pre-closing, intercompany loans of $2.0 million and $5.6 million.

'

'

'

'

'

'

'

'

'In May 2012, Red Ventures exercised its option to acquire from the Company the equity interests in DirectStar, which provides marketing and sales services on behalf of DIRECTVB.. The Company consummated the sale of DirectStar to Red Ventures in June 2012 for a net sale price of $98.9 million in cash. DirectStar is presented as a discontinued operation in the Companybs condensed unaudited consolidated financial statements for all periods presented.

'

Disposal date

'

'

'

'

'

'

31-Aug-13

'

'

'

'

'

'

'

'

30-Jun-12

'

Variable interest entity, nonconsolidated, carrying amount, loan to entity

'

'

'

'

'

'

'

'

'

'

$2,000,000

'

$5,600,000

'

'

'

'

Loan, variable interest entity, nonconsolidated, interest rate

'

'

'

'

'

'

'

'

'

'

0.25%

'

'

'

'

'

'

Loan, variable interest entity, unconsolidated, interest rate, minimum

'

'

'

'

'

'

'

'

'

'

'

'

5.00%

'

'

'

'

Loan, variable interest entity, maturity date

'

'

'

'

'

'

'

'

'

'

'

3-Oct-14

3-Oct-14

'

'

'

'

Loan, variable interest entity, unconsolidated, interest rate, maximum

'

'

'

'

'

'

'

'

'

'

'

'

10.00%

'

'

'

'

Discontinued operations, status at latest balance sheet date

'

'

'

'

'

'

' The sale agreement provides that the Company would retain certain contingent assets and liabilities of the Globetec business, which are reported in discontinued operations

'

'

'

'

'

'

'

'

'

'

Variable interest entity, ownership percentage

'

'

'

'

'

'

'

'

0.00%

'

'

'

'

'

'

'

'

Outstanding bonds, amount

'

'

'

'

'

'

'

'

'

41,800,000

'

'

'

'

'

'

'

Net sale price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

98,900,000

'

'

Income from discontinued operations, net of tax

($3,735,000)

($9,281,000)

($5,165,000)

($7,881,000)

($3,700,000)

($9,300,000)

($5,200,000)

($11,600,000)

'

'

'

'

'

$0

'

'

$3,700,000

Discontinued_Operations_Summar

Discontinued Operations (Summary of Assets and Liabilities) (Detail) (Globetec [Member], USD $)	Dec. 31, 2012	Sep. 30, 2013
In Millions, unless otherwise specified		Variable Interest Entity, Not Primary Beneficiary [Member]
Assets	'	'
Current assets	$18.60	$3.10
Long-term assets	7.7	11.3
Assets of discontinued operations	26.3	14.4
Liabilities	'	'
Current liabilities of discontinued operations	$10.70	$1.30

Discontinued_Operations_Result

Discontinued Operations (Results of Operations from Discontinued Operations) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Loss on disposal and impairment charges, before tax	'	'	($6,036,000)	($12,922,000)
Net loss from discontinued operations	-3,735,000	-9,281,000	-5,165,000	-7,881,000
Globetec [Member]	'	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Revenue	4,800,000	4,800,000	18,000,000	13,500,000
Loss from operations, before tax	-500,000	-2,600,000	-2,700,000	-5,800,000
Loss on disposal and impairment charges, before tax	-5,700,000	-12,700,000	-6,000,000	-12,700,000
Benefit from income taxes	2,500,000	6,000,000	3,500,000	6,900,000
Net loss from discontinued operations	($3,700,000)	($9,300,000)	($5,200,000)	($11,600,000)

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Goodwill by Segment Rollforward) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
Goodwill [Roll Forward]	'
Goodwill, beginning balance	$824,953,000
Additions from new business combinations, goodwill	61,500,000
Currency translation adjustments, goodwill	-1,700,000
Goodwill, ending balance	891,266,000
Earn-out Arrangements [Member]	'
Goodwill [Roll Forward]	'
Accruals of acquisition-related contingent consideration	6,500,000	[1]
Reportable Segments [Member] | Communications [Member]	'
Goodwill [Roll Forward]	'
Goodwill, beginning balance	305,800,000
Additions from new business combinations, goodwill	10,000,000
Currency translation adjustments, goodwill	0
Goodwill, ending balance	322,300,000
Reportable Segments [Member] | Communications [Member] | Earn-out Arrangements [Member]	'
Goodwill [Roll Forward]	'
Accruals of acquisition-related contingent consideration	6,500,000	[1]
Reportable Segments [Member] | Oil and Gas [Member]	'
Goodwill [Roll Forward]	'
Goodwill, beginning balance	272,100,000
Additions from new business combinations, goodwill	32,300,000
Currency translation adjustments, goodwill	-1,700,000
Goodwill, ending balance	302,700,000
Reportable Segments [Member] | Oil and Gas [Member] | Earn-out Arrangements [Member]	'
Goodwill [Roll Forward]	'
Accruals of acquisition-related contingent consideration	0	[1]
Reportable Segments [Member] | Electrical Transmission [Member]	'
Goodwill [Roll Forward]	'
Goodwill, beginning balance	129,500,000
Additions from new business combinations, goodwill	19,200,000
Currency translation adjustments, goodwill	0
Goodwill, ending balance	148,700,000
Reportable Segments [Member] | Electrical Transmission [Member] | Earn-out Arrangements [Member]	'
Goodwill [Roll Forward]	'
Accruals of acquisition-related contingent consideration	0	[1]
Reportable Segments [Member] | Power Generation and Industrial [Member]	'
Goodwill [Roll Forward]	'
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] | Power Generation and Industrial [Member] | Earn-out Arrangements [Member]	'
Goodwill [Roll Forward]	'
Accruals of acquisition-related contingent consideration	$0	[1]
[1]	Represents contingent consideration for acquisitions prior to January 1, 2009, which is only accrued as earned, in accordance with U.S. GAAP.

Recovered_Sheet1

Goodwill And Other Intangible Assets (Rollforward of Other Intangible Assets) (Detail) (USD $)

9 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Accumulated Translation Adjustment [Member]

Continuing Operations [Member]

Continuing Operations [Member]

Continuing Operations [Member]

Continuing Operations [Member]

Customer Relationships and Backlog [Member]

Customer Relationships and Backlog [Member]

Customer Relationships and Backlog [Member]

Other Finite-Lived Intangible Assets [Member]

Other Finite-Lived Intangible Assets [Member]

Other Finite-Lived Intangible Assets [Member]

Trade Names [Member]

Pre-Qualifications [Member]

Intangible Assets Excluding Goodwill [Member]

Continuing Operations [Member]

Continuing Operations [Member]

Intangible Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other intangible assets, non-amortizing

'

'

'

'

'

'

'

'

'

'

'

'

'

$34,800,000

$60,200,000

Gross carrying amount, amortizing intangible assets

'

'

'

'

'

'

'

'

109,600,000

'

'

19,800,000

[1]

'

'

'

Gross carrying amount, other intangible assets

'

195,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated amortization, amortizing intangible assets

'

-58,500,000

'

'

'

'

'

'

-48,200,000

'

'

-10,300,000

[1]

'

'

'

Other Intangible Assets [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other intangible assets, non-amortizing, beginning balance

'

'

'

'

'

'

'

'

'

'

'

'

'

34,800,000

31,300,000

Additions from new business combinations, other non-amortizing intangible assets

'

'

'

'

'

'

'

'

'

'

'

'

'

0

29,600,000

Currency translation adjustments, other non-amortizing intangible assets

'

'

'

'

'

'

'

'

'

'

'

'

'

0

-700,000

Other intangible assets, non-amortizing,ending balance

'

'

'

'

'

'

'

'

'

'

'

'

'

34,800,000

60,200,000

Other intangible assets, amortizing, net, beginning balance

'

'

'

'

'

'

'

61,400,000

'

'

9,500,000

[1]

'

'

'

'

Additions from new business combinations, amortizing intangible assets

'

'

'

'

'

'

'

19,900,000

'

'

2,500,000

[1]

'

'

'

'

Amortization of intangible assets

'

'

'

-5,800,000

-2,800,000

-15,200,000

-8,500,000

'

'

-14,400,000

'

'

-800,000

[1]

'

'

Currency translation adjustments, amortizing intangible assets

'

'

'

'

'

'

'

-300,000

'

'

0

[1]

'

'

'

'

Other intangible assets, amortizing, net, ending balance

'

'

'

'

'

'

'

66,600,000

'

'

11,200,000

[1]

'

'

'

'

Other intangible assets, net, beginning balance

137,020,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additions from new business combinations, other intangible assets

52,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Currency translation adjustments, other intangible assets

'

'

-1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Other intangible assets, net, ending balance

$172,833,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Consists principally of trade names and non-compete agreements.

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets (Narrative) (Details) (Continuing Operations [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Continuing Operations [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization of intangible assets	$5.80	$2.80	$15.20	$8.50

Recovered_Sheet2

Fair Value Of Financial Instruments (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
					Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	Earn-out Arrangements [Member]	Earn-out Arrangements [Member]	Earn-out Arrangements [Member]
					Unsecured Debt [Member]	Unsecured Debt [Member]	Unsecured Debt [Member]		2013 Acquisitions [Member]	Accumulated Translation Adjustment [Member]
					Total Senior And Senior Convertible Notes [Member]	7.625% Senior Notes [Member]	7.625% Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'	'	'	'	'	'
Payments of contingent consideration	'	'	'	'	'	'	'	$2,700,000	'	'
Currency translation gains included in other comprehensive income, contingent consideration	'	'	'	'	'	'	'	'	'	1,100,000
Additions from new business combinations, contingent consideration	'	'	'	'	'	'	'	'	30,000,000	'
Fair value measurements, valuation techniques	'	'	'	'	'The estimated fair values of the Companybs 4.875% senior notes, 7.625% senior notes, 2009 Convertible Notes and 2011 Convertible Notes are based on quoted market prices, a Level 1 input.	'	'	'	'	'
Loss on extinguishment of debt	$0	$0	$5,624,000	$0	'	$5,600,000	$5,600,000	'	'	'

Recovered_Sheet3

Fair Value Of Financial Instruments (Schedule Of Fair Values Of Financial Assets And Liabilities Measured On A Recurring Basis) (Detail) (Fair Value [Member], USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Carrying amount, life insurance policies	$5		$11.90
Earn-out Arrangements [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Acquisition-related contingent consideration	169.8	[1]	143.6	[1]
Auction Rate Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Auction rate securities (See Note 7)	9.2		14.4
Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Carrying amount, life insurance policies	5		11.9
Level 3 [Member] | Earn-out Arrangements [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Acquisition-related contingent consideration	169.8	[1]	143.6	[1]
Level 3 [Member] | Auction Rate Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Auction rate securities (See Note 7)	$9.20		$14.40
[1]	For acquisitions that closed after January 1, 2009.

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Schedule of Fair Values of Financial Assets and Liabilities Measured On A Nonrecurring Basis) (Details) (Unsecured Debt [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Carrying Amount [Member] | Senior Notes [Member] | 4.875% Senior Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior notes	$400	$0
Carrying Amount [Member] | Senior Notes [Member] | 7.625% Senior Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior notes	0	150
Carrying Amount [Member] | Convertible Debt [Member] | 2009 Senior Convertible Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior convertible notes	12.6	12.7
Carrying Amount [Member] | Convertible Debt [Member] | 2011 Senior Convertible Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior convertible notes	197	193
Fair Value [Member] | Senior Notes [Member] | 4.875% Senior Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior notes	378	0
Fair Value [Member] | Senior Notes [Member] | 7.625% Senior Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior notes	0	154.9
Fair Value [Member] | Convertible Debt [Member] | 2009 Senior Convertible Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior convertible notes	24.7	21
Fair Value [Member] | Convertible Debt [Member] | 2011 Senior Convertible Notes [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Senior convertible notes	$397.80	$338.30

Auction_Rate_Securities_Narrat

Auction Rate Securities (Narrative) (Detail) (USD $)

9 Months Ended

9 Months Ended

3 Months Ended

3 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

31-May-13

31-May-13

Jun. 30, 2013

31-May-13

31-May-13

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Auction Rate Securities [Member]

Fair Value [Member]

Fair Value [Member]

Asset-backed Securities [Member]

Asset-backed Securities [Member]

Asset-backed Securities [Member]

Asset-backed Securities [Member]

Securities Redeemed or Sold [Member]

Securities Redeemed or Sold [Member]

Securities Redeemed or Sold [Member]

Securities Redeemed or Sold [Member]

Securities Redeemed or Sold [Member]

Securities Redeemed or Sold [Member]

Minimum [Member]

Maximum [Member]

Fair Value [Member]

Asset-backed Securities [Member]

Asset-backed Securities [Member]

Asset-backed Securities [Member]

Collateralized Debt Obligations [Member]

Collateralized Debt Obligations [Member]

Collateralized Debt Obligations [Member]

Fair Value [Member]

Fair Value [Member]

Auction Rate Securities [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Auction rate securities, par value

'

'

'

'

'

'

'

'

'

'

'

$2,600,000

'

'

$5,000,000

'

Auction rate securities, redeemed at par, proceeds

'

'

'

'

'

'

'

'

'

'

2,600,000

'

'

'

'

'

Aucition rate securities, proceeds from sale

5,025,000

0

'

'

'

'

'

'

'

'

'

'

'

2,400,000

'

'

Auction rate securities, fair value

'

'

'

'

9,200,000

14,400,000

'

'

'

9,200,000

'

'

2,600,000

'

'

2,400,000

Adjusted cost basis

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,700,000

'

Auction rate securities, realized gain

'

'

'

'

'

'

'

'

'

'

'

'

'

700,000

'

'

Auction rate securities, gross unrealized net losses

'

'

'

$200,000

'

'

$1,100,000

'

'

'

'

'

'

'

'

'

Fair value measurements, valuation techniques

'

'

'Fair values of the Company's auction rate securities are estimated by an independent valuation firm, Houlihan Capital Advisors, LLC, using a probability weighted discounted cash flow model.

'

'

'

'

'

'

'

'

'

'

'

'

'

Contractual maturities of securities

'

'

'

'

'

'

'

27-Mar-28

28-Oct-47

'

'

'

'

'

'

'

Recovered_Sheet4

Accounts Receivable, Net Of Allowance (Schedule Of Accounts Receivable) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Receivables [Abstract]	'	'
Contract billings	$711,400,000	$522,000,000
Retainage	134,700,000	113,500,000
Costs and earnings in excess of billings	393,900,000	253,000,000
Accounts receivable, gross	1,240,000,000	888,500,000
Less allowance for doubtful accounts	-14,900,000	-11,300,000
Accounts receivable, net	$1,225,122,000	$877,214,000

Debt_Long_Term_Debt_Instrument

Debt (Long Term Debt Instruments) (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
Total debt	$833,200,000	$598,900,000
Less current maturities	-53,343,000	-52,596,000
Long-term debt	779,920,000	546,323,000
Senior Notes [Member] | 4.875% Senior Notes [Member] | Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Debt instrument, maturity date	15-Mar-23	'
Carrying value of debt	400,000,000	0
Senior Notes [Member] | 7.625% Senior Notes [Member] | Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Debt instrument, maturity date	1-Feb-17	'
Carrying value of debt	0	150,000,000
Convertible Debt [Member] | 2011 4.0% Notes [Member] | Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Debt instrument, maturity date	15-Jun-14	'
Carrying value of debt	103,100,000	100,900,000
Convertible Debt [Member] | 2011 4.25% Notes [Member] | Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Debt instrument, maturity date	15-Dec-14	'
Carrying value of debt	93,900,000	92,100,000
Convertible Debt [Member] | 2009 4.0% Notes [Member] | Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Debt instrument, maturity date	15-Jun-14	'
Carrying value of debt	9,600,000	9,700,000
Convertible Debt [Member] | 2009 4.25% Notes [Member] | Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Debt instrument, maturity date	15-Dec-14	'
Carrying value of debt	3,000,000	3,000,000
Capital Lease Obligations [Member]	'	'
Debt Instrument [Line Items]	'	'
Capital lease obligations	133,300,000	79,000,000
Capital Lease Obligations [Member] | Maximum [Member]	'	'
Debt Instrument [Line Items]	'	'
Lease expiration date	31-Mar-20	'
Loans Payable [Member]	'	'
Debt Instrument [Line Items]	'	'
Carrying value of debt	53,900,000	30,200,000
Loans Payable [Member] | Maximum [Member]	'	'
Debt Instrument [Line Items]	'	'
Debt instrument, maturity date	31-May-18	'
Revolving Credit Facility [Member]	'	'
Debt Instrument [Line Items]	'	'
Line of credit facility, expiration date	22-Aug-16	'
Revolving Credit Facility [Member] | Line of Credit [Member]	'	'
Debt Instrument [Line Items]	'	'
Line of credit facility, expiration date	22-Aug-16	'
Credit facility, amount outstanding	$36,400,000	$134,000,000

Property_And_Equipment_Net_Sch

Property And Equipment, Net (Schedule Of Property And Equipment, Net) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Property and Equipment [Line Items]	'	'
Property and equipment	$857,000,000	$631,100,000
Less accumulated depreciation and amortization	-352,700,000	-280,900,000
Property and equipment, net	504,313,000	350,192,000
Land [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	4,800,000	4,800,000
Building and Leasehold Improvements [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	18,100,000	15,400,000
Machinery and Equipment [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	728,700,000	521,500,000
Office Furniture and Equipment [Member]	'	'
Property and Equipment [Line Items]	'	'
Property and equipment	$105,400,000	$89,400,000

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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Receivables [Abstract]	'	'	'	'
Provision for doubtful accounts	$1.90	$1.20	$4.40	$2.50

Debt_Long_Term_Debt_Instrument1

Debt (Long Term Debt Instruments) (Parenthetical) (Detail)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	Senior Notes [Member]	Senior Notes [Member]	Convertible Debt [Member]	Convertible Debt [Member]	Convertible Debt [Member]	Convertible Debt [Member]	Capital Lease Obligations [Member]	Loans Payable [Member]
	4.875% Senior Notes [Member]	7.625% Senior Notes [Member]	2011 4.0% Notes [Member]	2011 4.25% Notes [Member]	2009 4.0% Notes [Member]	2009 4.25% Notes [Member]
	Unsecured Debt [Member]	Unsecured Debt [Member]	Unsecured Debt [Member]	Unsecured Debt [Member]	Unsecured Debt [Member]	Unsecured Debt [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'
Debt instrument, interest rate	4.88%	7.63%	4.00%	4.25%	4.00%	4.25%	'	'
Debt instrument, weighted average interest rate	'	'	'	'	'	'	2.80%	3.50%

Property_And_Equipment_Net_Nar

Property And Equipment, Net (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Property and Equipment [Line Items]	'	'	'	'
Depreciation and amortization	'	'	$103,111	$65,767
Continuing Operations [Member]	'	'	'	'
Property and Equipment [Line Items]	'	'	'	'
Depreciation and amortization	37,756	22,645	103,111	65,125
Property and Equipment [Member] | Continuing Operations [Member]	'	'	'	'
Property and Equipment [Line Items]	'	'	'	'
Depreciation and amortization	$32,000	$19,800	$87,900	$56,600

Debt_Senior_Notes_Narrative_De

Debt - Senior Notes (Narrative) (Detail) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Debt Repurchased [Member]

Debt Redeemed [Member]

Non-Call Redemption [Member]

Equity Claw Redemption [Member]

Maximum [Member]

Maximum [Member]

Minimum [Member]

4.875% Senior Notes [Member]

7.625% Senior Notes [Member]

7.625% Senior Notes [Member]

7.625% Senior Notes [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Non-Call Redemption [Member]

Equity Claw Redemption [Member]

Non-Call Redemption [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

7.625% Senior Notes [Member]

7.625% Senior Notes [Member]

4.875% Senior Notes [Member]

4.875% Senior Notes [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

4.875% Senior Notes [Member]

4.875% Senior Notes [Member]

4.875% Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, issuance date

'

'

'

'

18-Mar-13

'

'

'

'

'

'

'

'

'

'

Principal amount

'

'

'

'

$400,000,000

'

'

$150,000,000

'

'

'

'

'

'

'

Debt instrument, interest rate

'

'

'

'

4.88%

'

'

7.63%

'

'

'

'

'

'

'

Debt instrument, maturity date

'

'

'

'

15-Mar-23

'

1-Feb-17

'

'

'

'

'

'

'

'

Debt instrument, payment terms

'

'

'

'

'The 4.875% Senior Notes bear interest at a rate of 4.875% per annum, payable on March 15 and September 15 of each year. Interest payments commenced on September 15, 2013.

'

'

'

'

'

'

'

'

'

'

Debt instrument, date of first required payment

'

'

'

'

15-Sep-13

'

'

'

'

'

'

'

'

'

'

Debt instrument, guarantees

'

'

'

'

'The 4.875% Senior Notes are guaranteed on an unsecured unsubordinated basis by MasTec's direct and indirect 100%-owned domestic subsidiaries that guarantee the Company's credit facility.

'

'

'

'

'

'

'

'

'

'

Debt instrument, call feature description

'

'

'

'

'The Company has the option to redeem all or a portion of the 4.875% Senior Notes at any time on or after March 15, 2018 at the redemption prices set forth in the indenture that governs the 4.875% Senior Notes (the b4.875% Senior Notes Indentureb) plus accrued and unpaid interest, if any, to the redemption date.

'

'

'

'

'

'

'

'

'

'

Debt instrument, earliest call date

'

'

'

'

15-Mar-18

'

'

'

'

'

'

'

'

'

'

Debt instrument, redemption description

'

'

'

'

'

'

'In connection with the issuance of the 4.875% Senior Notes, the Company repurchased approximately $121.1 million of its 7.625% Senior Notes on March 18, 2013 in a tender offer at a price of 102.792% of the principal amount, which included an early tender payment of $30.00 per $1,000 principal amount of notes tendered. The holders of the tendered 7.625% Senior Notes also received accrued interest from the most recent interest payment date to, but not including, the date of repurchase. In addition, on March 29, 2013, the Company redeemed the remaining outstanding $28.9 million aggregate principal amount of the 7.625% Senior Notes in accordance with their terms at a price of 102.542% of the principal amount plus accrued interest from the most recent interest payment date to, but not including, the date of redemption.

'

'

'

'At any time prior to March 15, 2018, the Company may redeem all or a part of the 4.875% Senior Notes at a redemption price equal to 100% of the principal amount of 4.875% Senior Notes redeemed plus an applicable premium, as defined in the 4.875% Senior Notes Indenture, together with accrued and unpaid interest, if any, to the redemption date.

'In addition, at any time prior to March 15, 2016, the Company may redeem up to 35% of the principal amount of the 4.875% Senior Notes using the net cash proceeds of one or more sales of the Company's capital stock, as defined in the 4.875% Senior Notes Indenture, at a redemption price of 104.875% of the principal amount, plus accrued and unpaid interest to the redemption date.

'

'

'

Repurchase and redemption of notes, amount

'

'

150,000,000

0

'

'

'

'

121,100,000

28,900,000

'

'

'

'

'

Debt instrument, redemption period end date

'

'

'

'

'

'

'

'

'

'

15-Mar-18

15-Mar-16

'

'

'

Debt instrument, redemption price percentage of principal amount

'

'

'

'

'

'

'

'

102.79%

102.54%

'

104.88%

'

'

100.00%

Debt instrument, redemption using proceeds from equity issuance, percentage of principal amount available for redemption

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

35.00%

'

Debt instrument, restrictive covenants

'

'

'

'

'The 4.875% Senior Notes Indenture, among other things, generally limits the ability of the Company and certain of its subsidiaries, subject to certain exceptions, to (i)B incur additional debt and issue preferred stock, (ii)B create liens, (iii)B pay dividends, acquire shares of capital stock, make payments on subordinated debt or make investments, (iv)B place limitations on distributions from certain subsidiaries, (v)B issue guarantees, (vi)B issue or sell the capital stock of certain subsidiaries, (vii)B sell assets, (viii)B enter into transactions with affiliates and (ix)B effect mergers. The 4.875% Senior Notes Indenture provides for customary events of default, as well as customary remedies upon an event of default, as defined in the 4.875% Senior Notes Indenture, including acceleration of repayment of outstanding amounts.

'

'

'

'

'

'

'

'

'

'

Deferred financing costs

'

'

'

'

7,700,000

'

'

'

'

'

'

'

'

'

'

Loss on extinguishment of debt

0

0

5,624,000

0

'

5,600,000

5,600,000

'

'

'

'

'

'

'

'

Payments for debt extinguishment, call premiums

'

'

4,116,000

0

'

'

4,100,000

'

'

'

'

'

'

'

'

Write-off of unamortized financing costs on redeemed debt

'

'

$1,508,000

$0

'

'

$1,500,000

'

'

'

'

'

'

'

'

Debt_Credit_Facility_Narrative

Debt - Credit Facility (Narrative) (Details) (Revolving Credit Facility [Member], USD $)	0 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
Line of credit facility, remaining borrowing capacity	$425.20	$345.20
Unused credit facility fee	0.40%	0.35%
Line of Credit [Member]	'	'
Debt Instrument [Line Items]	'	'
Credit facility, amount outstanding	36.4	134
Weighted Average [Member] | Line of Credit [Member]	'	'
Debt Instrument [Line Items]	'	'
Line of credit interest rate	3.93%	3.95%
Letter of Credit [Member]	'	'
Debt Instrument [Line Items]	'	'
Letters of credit issued	138.5	120.8
Line of credit facility, capacity available for issuance of letters of credit	$211.50	$229.20
Letter of Credit [Member] | Minimum [Member]	'	'
Debt Instrument [Line Items]	'	'
Line of credit interest rate	1.13%	1.00%
Letter of Credit [Member] | Maximum [Member]	'	'
Debt Instrument [Line Items]	'	'
Line of credit interest rate	2.25%	2.00%

Debt_2011_Convertible_Notes_Na

Debt - 2011 Convertible Notes (Narrative) (Details) (Convertible Debt [Member], Unsecured Debt [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013
In Millions, unless otherwise specified	2011 Senior Convertible Notes [Member]	2011 Senior Convertible Notes [Member]	2011 4.0% Notes [Member]
Debt Instrument [Line Items]	'	'	'
Unamortized debt discount and financing costs	$5.30	$9.30	'
Debt instrument, maturity date	'	'	15-Jun-14
Principal amount	$202.30	'	$105.30

Debt_Guarantees_and_Covenants_

Debt - Guarantees and Covenants (Narrative) (Details)	9 Months Ended
	Sep. 30, 2013
Debt Instrument [Line Items]	'
Debt instrument, covenant compliance	'MasTec was in compliance with all provisions and covenants pertaining to its outstanding debt instruments as of September 30, 2013 and December 31, 2012.
Total Senior And Senior Convertible Notes [Member] | Senior Notes [Member] | Unsecured Debt [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, guarantees	'The Companybs 2011 Convertible Notes and 2009 Convertible Notes are, and, through March 29, 2013, the Company's 7.625% Senior Notes were, 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 Company's Credit Facility or other outstanding indebtedness. The Company's 4.875% Senior Notes are guaranteed on an unsecured, unsubordinated, joint and several basis by the Company's 100%-owned domestic subsidiaries that guarantee the Credit Facility.

Debt_Schedule_Of_Interest_Expe

Debt (Schedule Of Interest Expense, Net) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Debt Instrument [Line Items]	'	'	'	'
Interest expense, net	$12,666,000	$9,446,000	$34,549,000	$27,883,000
Continuing Operations [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Contractual and other interest expense	10,400,000	7,400,000	27,900,000	21,800,000
Accretion of senior convertible note discount	1,300,000	1,200,000	3,900,000	3,700,000
Amortization of deferred financing costs	1,000,000	900,000	3,000,000	2,700,000
Total interest expense	12,700,000	9,500,000	34,800,000	28,200,000
Interest income	0	-100,000	-300,000	-300,000
Interest expense, net	$12,700,000	$9,400,000	$34,500,000	$27,900,000

Capital_Lease_Obligations_Narr

Capital Lease Obligations (Narrative) (Details) (Machinery and Equipment [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Machinery and Equipment [Member]	'	'
Capital Leases [Line Items]	'	'
Assets held under capital lease, net	$142.20	$102.20

Operating_Lease_Obligations_Na

Operating Lease Obligations (Narrative) (Details) (Continuing Operations [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Continuing Operations [Member]	'	'	'	'
Operating Leases [Line Items]	'	'	'	'
Operating leases, rent expense	$75.60	$69.40	$176	$168.20

StockBased_Compensation_and_Ot2

Stock-Based Compensation and Other Employee Benefit Plans (Narrative) (Detail) (USD $)

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Millions, except Share data, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

2013 Incentive Plan [Member]

2013 Bargaining Units ESPP [Member]

2011 ESPP [Member]

EC Source Share Award [Member]

EC Source Share Award [Member]

ESPPs [Member]

Investor [Member]

Restricted Stock [Member]

Employee Stock Purchase [Member]

Employee Stock Purchase [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Employee Stock Purchase [Member]

EC Source Share Award [Member]

Restricted Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation plan, description

'

'

'

'

'

'

'

'

'

'the MasTec, Inc. 2013 Incentive Plan (the "2013 Incentive Plan"), which became effective in May 2013. As of September 30, 2013, the 2013 Incentive Plan had 4,926,681 shares available for issuance.

' In March 2013, the Company authorized the issuance of up to 1,000,000 new shares of MasTec, Inc. common stock to eligible employees under the MasTec, Inc. Bargaining Units Employee Stock Purchase Plan (the "2013 Bargaining Units ESPP"). The 2013 Bargaining Units ESPP became effective on July 1, 2013.

' The MasTec, Inc. 2011 Employee Stock Purchase Plan (the b2011 ESPP" and, together with the 2013 Bargaining Units ESPP, the "ESPPs") also provides for the issuance of up to 1,000,000 shares of MasTec, Inc. common stock for eligible employees.

'

'

'The Company's ESPPs allow qualified employees to purchase MasTec, Inc. common stock at 85% of the fair market value of the common stock 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 document. Through June 30, 2013, the offering period was an annual period, composed of four interim exercise periods. Effective July 1, 2013, the offering period became quarterly.

'During the second quarter of 2013, the Company entered into an agreement with the previous owners of EC Source to establish an incentive program for its employees and granted 350,000 restricted share awards (the bEC Source Share Awardb).

Shares available for grant

6,383,118

'

6,383,118

'

'

'

'

'

'

4,926,681

'

'

'

'

'

'

Number of shares authorized under plan

'

'

'

'

'

'

'

'

'

'

1,000,000

1,000,000

'

'

'

'

Unearned compensation

'

'

'

'

$17.40

$17.40

'

$17.40

'

'

'

'

'

'

'

'

Unearned compensation, weighted average expected recognition period

'

'

'

'

'1 year 4 months 24 days

'

'

'

'

'

'

'

'

'

'

'

Total intrinsic value of vested awards

'

'

'

'

'

0.9

0.7

2

2.9

'

'

'

'

'

'

'

Restricted shares - granted

'

'

'

'

'

'

'

428,262

'

'

'

'

350,000

'

'

'

Share-based compensation, terms of award

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'In the event that shares granted under the EC Source Share Award are forfeited prior to vesting, the former owners of EC Source will be re-issued the pro-rata percentage of the former owners' contributed shares to total shares awarded under the EC Source share grant.

Share-based compensation, fair value measurement, significant assumptions

'

'

'

'

'

'

'

'

'

'

'

'

'

' As of September 30, 2013, the Company did not anticipate the occurrence of any such forfeitures.

'

'

Intrinsic value of stock options exercised

4.6

0.4

10.4

0.7

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from stock option exercises

0.4

0.3

3.8

0.6

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation, purchase price of common stock, percent of fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

85.00%

'

Share-based compensation, fair value assumptions, method used

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'The fair value of purchases under the Company's ESPP is estimated using the Black-Scholes option-pricing valuation model.

'

Adjustments related to tax withholding, share based compensation

'

'

$2.40

'

'

'

'

'

'

'

'

'

'

'

'

'

StockBased_Compensation_and_Ot3

Stock-Based Compensation and Other Employee Benefit Plans (Summary of Restricted Share Awards) (Details) (Restricted Stock [Member], USD $)	9 Months Ended
	Sep. 30, 2013
Restricted Stock [Member]	'
Restricted Share Award Activity, Number of Shares [Roll Forward]	'
Non-vested restricted shares, beginning balance	782,281
Granted	428,262
Vested	-64,288
Canceled/forfeited	-15,187
Non-vested restricted shares, ending balance	1,131,068
Restricted Share Award Activity, Weighted Average Grant Date Fair Value [Roll Forward]	'
Weighted average grant date fair value, beginning balance	$19.10
Granted	$31.04
Vested	$18.22
Canceled/forfeited	$15.35
Weighted average grant date fair value, ending balance	$23.72

StockBased_Compensation_and_Ot4

Stock-Based Compensation and Other Employee Benefit Plans (Summary of Stock Options) (Details) (USD $)	0 Months Ended				9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012		Sep. 30, 2013
Outstanding Stock Options, Activity [Roll Forward]	'		'		'
Options outstanding, vested, beginning balance	'		'		1,043,825
Exercised	'		'		-498,123
Canceled/forfeited	'		'		-35,000
Options outstanding, vested, ending balance	510,702		1,043,825		510,702
Outstanding Stock Options, Weighted Average Exercise Price [Roll Forward]	'		'		'
Weighted average exercise price, vested, beginning balance	'		'		$10.50
Canceled/forfeited	'		'		$7.74
Weighted average exercise price, vested, ending balance	$11.27		$10.50		$11.27
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]	'		'		'
Options exercisable	510,702		'		510,702
Options exercisable, weighted average exercise price	$11.27		'		$11.27
Options outstanding, vested, weighted average remaining contractual life	'2 years 2 months 9 days		'2 years 3 months 29 days		'
Options exercisable, weighted average remaining contractual life	'2 years 2 months 9 days		'		'
Options outstanding, aggregate intrinsic value, vested	$9.70	[1]	$15.10	[1]	$9.70	[1]
Options exercisable, aggregate intrinsic value, vested	$9.70	[1]	'		$9.70	[1]
Employee Stock Option [Member]	'		'		'
Outstanding Stock Options, Activity [Roll Forward]	'		'		'
Exercised	'		'		-498,123
Outstanding Stock Options, Weighted Average Exercise Price [Roll Forward]	'		'		'
Exercised	'		'		$9.91
[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 Employee Stock Purchase Plan Activity) (Details) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of common shares	498,123	'
ESPPs [Member] | Employee Stock Purchase [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Cash proceeds (in millions)	$6	$0.90
Number of common shares	436,925	67,073
Weighted average price per share	$13.69	$13.43
Weighted average grant date fair value per share	$5.55	$3.96

StockBased_Compensation_and_Ot6

Stock-Based Compensation and Other Employee Benefit Plans (Summary of Tax Benefits from Stock-Based Compensation) (Detail) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Share-based Compensation [Abstract]	'		'		'		'
Stock-based compensation expense	$3,000,000		$1,200,000		$9,647,000		$3,351,000
Income tax benefit from stock-based compensation	4,500,000		700,000		7,700,000		1,600,000
Excess tax benefit from stock-based compensation	$3,000,000	[1]	$200,000	[1]	$4,446,000	[1]	$302,000	[1]
[1]	Excess tax benefits, which represent cash flows from tax deductions in excess of the 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_Schedul

Other Retirement Plans (Schedule of Multiemployer Plan Contributions and Covered Employees) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Multiemployer Plans [Line Items]	'	'	'	'
Multiemployer plan, period contributions	$15.80	$9	$32.50	$21.90
Multiemployer Plans, Pension [Member]	'	'	'	'
Multiemployer Plans [Line Items]	'	'	'	'
Multiemployer plan, period contributions	14.8	8.7	29.6	21.1
Multiemployer Plans, Postretirement Benefit [Member]	'	'	'	'
Multiemployer Plans [Line Items]	'	'	'	'
Multiemployer plan, period contributions	$1	$0.30	$2.90	$0.80
Workforce Subject to Collective Bargaining Arrangements [Member] | Minimum [Member]	'	'	'	'
Multiemployer Plans [Line Items]	'	'	'	'
Entity number of employees during period	2,392	1,575	778	308
Workforce Subject to Collective Bargaining Arrangements [Member] | Maximum [Member]	'	'	'	'
Multiemployer Plans [Line Items]	'	'	'	'
Entity number of employees during period	2,734	2,509	2,734	2,509

Shareholders_Equity_Summary_of

Shareholders' Equity (Summary of Share Activity) (Details)	9 Months Ended
	Sep. 30, 2013
Rollforward of Share Activity, Common and Treasury Shares	'
Common shares outstanding, beginning balance	76,448,000
Shares issued for stock option exercises	498,123
Shares issued for restricted stock awards	64,288
Other shares issued, net	409,000
Common shares outstanding, ending balance	77,219,000
Treasury shares, beginning balance	9,467,286
Treasury shares, ending balance	9,467,286
Investor [Member] | Common Stock Outstanding [Member]	'
Rollforward of Share Activity, Common and Treasury Shares	'
Shares contributed by shareholder, former owner of acquired business	-200,000	[1]
[1]	See Note 12 - Stock-Based Compensation and Other Employee Benefit Plans for contributed share details.

Shareholders_Equity_Changes_in

Shareholders' Equity (Changes in Other Comprehensive (Income) Loss (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'		'
Accumulated other comprehensive loss, beginning balance	'	'	($5,501)		($7,946)
Activity before reclassifications, net of tax	'	'	-3,957		2,643
Reclassifications, net of tax	'	'	-440		0
Activity, net of tax	'	'	-4,397		2,643
Accumulated other comprehensive loss, ending balance	-9,898	-5,303	-9,898		-5,303
Accumulated Net Unrealized Investment Gain (Loss) [Member]	'	'	'		'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'		'
Accumulated other comprehensive loss, beginning balance	'	'	-5,395		-5,917
Activity before reclassifications, net of tax	'	'	-118		339
Reclassifications, net of tax	'	'	-440	[1]	0
Activity, net of tax	-92	388	-558		339
Accumulated other comprehensive loss, ending balance	-5,953	-5,578	-5,953		-5,578
Accumulated Translation Adjustment [Member]	'	'	'		'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'		'
Accumulated other comprehensive loss, beginning balance	'	'	-106		-2,029
Activity before reclassifications, net of tax	'	'	-3,839		2,304
Reclassifications, net of tax	'	'	0		0
Activity, net of tax	2,936	2,176	-3,839		2,304
Accumulated other comprehensive loss, ending balance	($3,945)	$275	($3,945)		$275
[1]	Represents the reclassification adjustment for gains on securities sold, which was recognized as a component of other income. See Note 7 - Auction Rate Securities.

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Effective income tax rate, continuing operations	38.80%	39.40%	38.60%	39.40%
Quarterly financial information, income taxes	'	'	'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.	'

Segments_and_Operations_by_Geo2

Segments and Operations by Geographic Area (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Number of reportable segments	'	'	5	'
Segment reporting, factors used to identify entity's reportable segments	'	'	'MasTec presents its continuing operations under 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 and has been determined in accordance with the criteria in Accounting Standards Codification ("ASC") 280, Segment Reporting.	'
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.	'
Continuing Operations [Member] | Communications [Member] | Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member] | Utilities [Member] | Reportable Segments [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Entity-wide revenue, major customer, percentage	6.90%	11.60%	7.20%	11.20%

Segments_and_Operations_by_Geo3

Segments and Operations by Geographic Area (Schedule of Segment Reporting Information, by Segment) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	$1,269,385,000	$1,067,300,000	$3,165,657,000	$2,794,431,000
Depreciation	'	'	103,111,000	65,767,000
Continuing Operations [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	1,269,400,000	1,067,300,000	3,165,700,000	2,794,400,000
EBITDA	132,100,000	91,700,000	308,300,000	223,200,000
Depreciation	37,756,000	22,645,000	103,111,000	65,125,000
Amortization	5,800,000	2,800,000	15,200,000	8,500,000
Continuing Operations [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	32,000,000	19,800,000	87,900,000	56,600,000
Continuing Operations [Member] | Corporate, Non-Segment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	0	0	0	0
EBITDA	-13,600,000	-18,400,000	-47,900,000	-34,500,000
Amortization	0	0	0	0
Continuing Operations [Member] | Corporate, Non-Segment [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	900,000	800,000	2,600,000	2,200,000
Continuing Operations [Member] | Intersegment Elimination [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	-100,000	-700,000	-2,000,000	-1,700,000
EBITDA	0	0	0	0
Amortization	0	0	0	0
Continuing Operations [Member] | Intersegment Elimination [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	0	0	0	0
Continuing Operations [Member] | Communications [Member] | Reportable Segments [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	543,000,000	490,000,000	1,464,500,000	1,311,100,000
EBITDA	71,800,000	59,500,000	181,600,000	139,400,000
Amortization	1,500,000	400,000	4,000,000	1,300,000
Continuing Operations [Member] | Communications [Member] | Reportable Segments [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	8,000,000	6,900,000	22,800,000	19,900,000
Continuing Operations [Member] | Oil and Gas [Member] | Reportable Segments [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	519,100,000	284,000,000	1,134,800,000	715,300,000
EBITDA	68,100,000	29,000,000	161,700,000	57,300,000
Amortization	3,200,000	500,000	8,400,000	1,400,000
Continuing Operations [Member] | Oil and Gas [Member] | Reportable Segments [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	19,300,000	9,500,000	51,800,000	27,200,000
Continuing Operations [Member] | Electrical Transmission [Member] | Reportable Segments [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	118,800,000	74,800,000	321,900,000	228,200,000
EBITDA	12,100,000	10,500,000	27,000,000	31,100,000
Amortization	600,000	1,200,000	1,300,000	3,800,000
Continuing Operations [Member] | Electrical Transmission [Member] | Reportable Segments [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	2,600,000	1,600,000	7,100,000	4,300,000
Continuing Operations [Member] | Power Generation and Industrial [Member] | Reportable Segments [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	85,100,000	211,700,000	237,300,000	527,400,000
EBITDA	-6,400,000	9,900,000	-14,600,000	28,200,000
Amortization	500,000	700,000	1,500,000	2,000,000
Continuing Operations [Member] | Power Generation and Industrial [Member] | Reportable Segments [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	1,200,000	1,000,000	3,600,000	3,000,000
Continuing Operations [Member] | All Other Segments [Member] | Reportable Segments [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	3,500,000	7,500,000	9,200,000	14,100,000
EBITDA	100,000	1,200,000	500,000	1,700,000
Amortization	0	0	0	0
Continuing Operations [Member] | All Other Segments [Member] | Reportable Segments [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Depreciation	$0	$0	$0	$0

Segments_and_Operations_by_Geo4

Segments and Operations by Geographic Area (Reconciliation of EBITDA to Income from Continuing Operations) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting, Reconciling Item [Line Items]	'	'	'	'
Interest expense, net	($12,666,000)	($9,446,000)	($34,549,000)	($27,883,000)
Depreciation	'	'	-103,111,000	-65,767,000
Income from continuing operations before provision for income taxes	81,633,000	59,576,000	170,608,000	130,186,000
Continuing Operations [Member]	'	'	'	'
Segment Reporting, Reconciling Item [Line Items]	'	'	'	'
EBITDA	132,100,000	91,700,000	308,300,000	223,200,000
Interest expense, net	-12,700,000	-9,400,000	-34,500,000	-27,900,000
Depreciation	-37,756,000	-22,645,000	-103,111,000	-65,125,000
Amortization	-5,800,000	-2,800,000	-15,200,000	-8,500,000
Continuing Operations [Member] | Property and Equipment [Member]	'	'	'	'
Segment Reporting, Reconciling Item [Line Items]	'	'	'	'
Depreciation	($32,000,000)	($19,800,000)	($87,900,000)	($56,600,000)

Segments_and_Operations_by_Geo5

Segments and Operations by Geographic Area (Foreign Operations) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	$1,269,385	$1,067,300	$3,165,657	$2,794,431	'
Property and equipment, net	504,313	'	504,313	'	350,192
Goodwill and other intangible assets, net	1,064,099	'	1,064,099	'	961,973
Continuing Operations [Member]	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	1,269,400	1,067,300	3,165,700	2,794,400	'
Discontinued Operations [Member]	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	4,800	4,800	18,000	73,700	'
Reportable Geographical Components [Member] | Foreign Operations [Member] | Continuing Operations [Member]	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	90,900	33,700	172,000	133,700	'
Property and equipment, net	48,800	'	48,800	'	11,400
Goodwill and other intangible assets, net	94,000	'	94,000	'	30,500
Reportable Geographical Components [Member] | Foreign Operations [Member] | Discontinued Operations [Member]	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	2,300	1,900	7,000	4,600	'
Reportable Geographical Components [Member] | UNITED STATES | Continuing Operations [Member]	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	1,178,500	1,033,600	2,993,700	2,660,700	'
Reportable Geographical Components [Member] | UNITED STATES | Discontinued Operations [Member]	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	$2,500	$2,900	$11,000	$69,100	'

Segments_and_Operations_by_Geo6

Segments and Operations by Geographic Area (Schedule of Significant Customers, Revenue Concentration) (Details) (Reportable Segments [Member])	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Communications [Member] | AT&T [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Segment reporting, disclosure of major customers	'	'	'The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for both AT&T's wireless and wireline infrastructure businesses. Revenue from AT&T is included in the Communications segment.	'
Communications [Member] | DIRECTV[Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Segment reporting, disclosure of major 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.	'
Oil and Gas [Member] | Enbridge [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Segment reporting, disclosure of major 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.	'
Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member] | Continuing Operations [Member] | Communications [Member] | AT&T [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Entity-wide revenue, major customer, percentage	16.00%	17.00%	18.00%	17.00%
Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member] | Continuing Operations [Member] | Communications [Member] | DIRECTV[Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Entity-wide revenue, major customer, percentage	13.00%	16.00%	15.00%	17.00%
Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member] | Continuing Operations [Member] | Oil and Gas [Member] | Enbridge [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Entity-wide revenue, major customer, percentage	20.00%	3.00%	14.00%	1.00%

Commitments_and_Contingencies_

Commitments and Contingencies - Litigation (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	Resolved Litigation [Member]	Resolved Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]
	Sintel [Member]	Sintel [Member]	Sintel [Member]	Sunlight Entities Somerset [Member]	Sunlight Entities Morris [Member]	Sunlight Entities Sussex [Member]	City Of Marathon [Member]	City Of Marathon [Member]
								Minimum [Member]
Commitments and Contingencies [Line Items]	'	'	'	'	'	'	'	'
Legal proceeding, plaintiff	'	'The labor union representing the workers of Sistemas e Instalaciones de Telecomunicacion S.A. (bSintelb)	'	'	'	'	'The Company	'
Litigation, settlement agreement, terms	'	'On June 17, 2013, MasTec, the workers and the prosecutor resolved the matter, resulting in the dismissal all of the charges and claims brought against MasTec and the MasTec defendants. The workers provided MasTec and MasTec defendants with a release and an acknowledgment that MasTec and MasTec defendants acted in good faith and did not cause Sintel's bankruptcy. On June 20, 2013, the Audiencia Nacional issued an order dismissing the charges and claims against MasTec and the MasTec defendants and finding another party guilty and liable of certain charges.	'	'	'	'	'	'
Litigation, date of dismissal	'	20-Jun-13	'	'	'	'	'	'
Pending or threatened litigation, loss in period	$2.80	'	$9.60	'	'	'	'	'
Contract price, pending litigation	'	'	'	29	36	26	'	'
Damages sought	'	'	'	'	'	'	'	$6

Commitments_and_Contingencies_1

Commitments and Contingencies - Other (Narrative) (Detail) (USD $)

9 Months Ended

0 Months Ended

0 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Standby Letters of Credit [Member]

Standby Letters of Credit [Member]

Guarantee Obligations [Member]

Guarantee Obligations [Member]

Performance Guarantee [Member]

Performance Guarantee [Member]

Performance Guarantee [Member]

Performance Guarantee [Member]

Surety Bond [Member]

Surety Bond [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Workers Compensation Policy [Member]

General Liability Policy [Member]

Automobile Liability Policy [Member]

Umbrella Policy [Member]

Workers Compensation, General And Automobile Policies [Member]

Workers Compensation, General And Automobile Policies [Member]

Employee Group Health Claims Policy [Member]

Employee Group Health Claims Policy [Member]

Employee Group Health Claims Policy [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Letter of Credit [Member]

Letter of Credit [Member]

Estimate [Member]

Estimate [Member]

Uninsured Risk [Member]

Uninsured Risk [Member]

Per Employee [Member]

Commitments and Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Letters of credit, outstanding amount

'

'

'

'

'

'

'

'

'

'

'

'

$52.20

$53.20

$138.50

$120.80

'

'

'

'

'

'

Outstanding bonds, amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,400

1,100

'

'

10.9

9

Estimated cost to complete bonded projects

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

383.8

284.5

'

'

Per claim deductible, insurance policies

'

'

'

1

2

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum coverage, per claim and aggregate

'

'

'

'

'

'

100

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Self insurance reserve

'

'

'

'

'

'

'

53.1

48.1

1

1.1

'

'

'

'

'

'

'

'

'

'

'

Self insurance reserve, noncurrent

'

'

'

'

'

'

'

32.6

28.5

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum loss

'

'

'

'

'

'

'

'

'

'

'

0.4

'

'

'

'

'

'

'

'

'

'

Cash collateral held by insurance carriers

'

$1.50

$2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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_2

Commitments and Contingencies - Collective Bargaining Agreements and Multi-Employer Pension Plans (Narrative) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Nov. 15, 2011
Commitments and Contingencies [Line Items]	'	'
Multiemployer plans, collective bargaining arrangement, 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 multi-employer pension plan contribution rates are determined annually and assessed on a bpay-as-you-gob basis based on union employee payrolls. 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.	'
Multiemployer Plans, Pension [Member] | Withdrawal from Multiemployer Defined Benefit Plan [Member] | Central States Southeast And Southwest Areas Pension Fund [Member]	'	'
Commitments and Contingencies [Line Items]	'	'
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 $5.7 million was outstanding as of September 30, 2013. 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 made a demand on the Company for the sum of $10.8 million in withdrawal liability, which sum included 2011 contribution amounts. The Company is vigorously opposing this demand because it believes that it legally and effectively withdrew from Central States on November 15, 2011. If Central States were to prevail in its assertion that the Company, in fact, withdrew after that date, then the amount of the Companybs withdrawal liability would increase to approximately $10.8 million.	'
Multiemployer plans, withdrawal liability	$5.70	$6.40
Maximum loss	$10.80	'

Concentrations_Of_Risk_Narrati

Concentrations Of Risk (Narrative) (Details)	9 Months Ended
	Sep. 30, 2013
	customer
Risks and Uncertainties [Abstract]	'
Number Of Customers	460

Concentrations_Of_Risk_Schedul

Concentrations Of Risk (Schedule Of Major Customers, By Revenue Concentration) (Detail) (Customer Concentration Risk [Member], Continuing Operations [Member], Sales Revenue, Services, Net [Member], Ten Largest Customers [Member])	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Customer Concentration Risk [Member] | Continuing Operations [Member] | Sales Revenue, Services, Net [Member] | Ten Largest Customers [Member]	'	'	'	'
Concentration Risk [Line Items]	'	'	'	'
Revenues as a percent of total	73.00%	67.00%	69.00%	66.00%

Related_Party_Transactions_Det

Related Party Transactions (Detail) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Oct. 16, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Management [Member]

Management [Member]

Management [Member]

Management [Member]

Management [Member]

Management [Member]

Management [Member]

Board of Directors Chairman [Member]

Board of Directors Chairman [Member]

Board of Directors Chairman [Member]

Board of Directors Chairman [Member]

Board of Directors Chairman [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Related Customer [Member]

Related Customer [Member]

Related Customer [Member]

Related Customer [Member]

Related Customer [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Life Insurance [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member]

Scenario, Forecast [Member]

Subsequent Event [Member]

Maximum [Member]

Related Party Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Charges to related party

$135,000

$123,000

$422,000

$382,000

'

'

'

'

'

'

'

'

'

'

'

'

Due from related party

45,000

'

45,000

'

907,000

'

'

'

'

'

'

'

'

'

'

'

Revenue, related party

350,000

318,000

951,000

924,000

'

'

'

'

'

'

'

'

'

'

'

'

Accounts receivable, related party

414,000

'

414,000

'

1,232,000

'

'

'

'

'

'

'

'

'

'

'

Life insurance, face amount

'

'

'

'

'

'

'

'

'

'

'

200,000,000

'

'

'

'

Payments for life insurance policies

'

'

'

'

'

'

'

1,100,000

0

1,200,000

300,000

'

0

0

0

0

Carrying amount, life insurance policies

'

'

'

'

'

$10,100,000

$8,700,000

'

'

'

'

'

'

'

'

'

Supplemental_Guarantor_Financi2

Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements Of Operations And Comprehensive Income) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Revenue	$1,269,385,000	$1,067,300,000	$3,165,657,000	$2,794,431,000
Costs of revenue, excluding depreciation and amortization	1,081,132,000	924,304,000	2,695,287,000	2,445,056,000
Depreciation and amortization	'	'	103,111,000	65,767,000
General and administrative expenses	58,976,000	42,514,000	159,761,000	118,192,000
Interest expense, net	12,666,000	9,446,000	34,549,000	27,883,000
Loss on extinguishment of debt	0	0	5,624,000	0
Other (income) expense, net	-2,778,000	8,815,000	-3,283,000	7,989,000
Income from continuing operations before provision for income taxes	81,633,000	59,576,000	170,608,000	130,186,000
(Benefit from) provision for income taxes	-31,698,000	-23,478,000	-65,822,000	-51,229,000
Net income from continuing operations before non-controlling interests	49,935,000	36,098,000	104,786,000	78,957,000
Loss from discontinued operations, net of tax	-3,735,000	-9,281,000	-5,165,000	-7,881,000
Equity in income from subsidiaries, net of tax	0	0	0	0
Net income	46,200,000	26,817,000	99,621,000	71,076,000
Net income (loss) attributable to non-controlling interests	62,000	-4,000	172,000	-9,000
Net income attributable to MasTec, Inc.	46,138,000	26,821,000	99,449,000	71,085,000
Comprehensive income (loss)	49,044,000	29,381,000	95,224,000	73,719,000
Continuing Operations [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Revenue	1,269,400,000	1,067,300,000	3,165,700,000	2,794,400,000
Depreciation and amortization	37,756,000	22,645,000	103,111,000	65,125,000
Interest expense, net	12,700,000	9,400,000	34,500,000	27,900,000
Consolidation, Eliminations [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Revenue	-4,367,000	-1,013,000	-10,367,000	-2,033,000
Costs of revenue, excluding depreciation and amortization	-4,367,000	-1,013,000	-10,367,000	-2,033,000
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 provision for income taxes	0	0	0	0
(Benefit from) provision for income taxes	0	0	0	0
Net income from continuing operations before non-controlling interests	0	0	0	0
Loss from discontinued operations, net of tax	0	0	0	0
Equity in income from subsidiaries, net of tax	-46,484,000	-27,006,000	-100,494,000	-71,706,000
Net income	-46,484,000	-27,006,000	-100,494,000	-71,706,000
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to MasTec, Inc.	-46,484,000	-27,006,000	-100,494,000	-71,706,000
Comprehensive income (loss)	-46,484,000	-27,006,000	-100,494,000	-71,706,000
Consolidation, Eliminations [Member] | Continuing Operations [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Depreciation and amortization	0	0	0	0
MasTec, Inc. [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Revenue	0	0	0	0
Costs of revenue, excluding depreciation and amortization	0	0	0	0
General and administrative expenses	457,000	303,000	1,443,000	1,052,000
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 provision for income taxes	-458,000	-303,000	-1,445,000	-1,053,000
(Benefit from) provision for income taxes	174,000	114,000	572,000	423,000
Net income from continuing operations before non-controlling interests	-284,000	-189,000	-873,000	-630,000
Loss from discontinued operations, net of tax	0	0	0	0
Equity in income from subsidiaries, net of tax	46,484,000	27,006,000	100,494,000	71,706,000
Net income	46,200,000	26,817,000	99,621,000	71,076,000
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to MasTec, Inc.	46,200,000	26,817,000	99,621,000	71,076,000
Comprehensive income (loss)	46,200,000	26,817,000	99,621,000	71,076,000
MasTec, Inc. [Member] | Continuing Operations [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Depreciation and amortization	1,000	0	2,000	1,000
Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Revenue	1,086,063,000	1,028,091,000	2,751,408,000	2,644,197,000
Costs of revenue, excluding depreciation and amortization	927,295,000	886,198,000	2,348,835,000	2,312,564,000
General and administrative expenses	47,967,000	39,251,000	134,460,000	109,366,000
Interest expense, net	11,951,000	9,435,000	33,583,000	27,880,000
Loss on extinguishment of debt	'	'	5,624,000	'
Other (income) expense, net	-2,309,000	8,696,000	-2,526,000	7,655,000
Income from continuing operations before provision for income taxes	70,522,000	62,446,000	144,006,000	123,329,000
(Benefit from) provision for income taxes	-28,840,000	-24,564,000	-56,782,000	-49,766,000
Net income from continuing operations before non-controlling interests	41,682,000	37,882,000	87,224,000	73,563,000
Loss from discontinued operations, net of tax	-3,566,000	-8,852,000	-4,178,000	-6,099,000
Equity in income from subsidiaries, net of tax	0	0	0	0
Net income	38,116,000	29,030,000	83,046,000	67,464,000
Net income (loss) attributable to non-controlling interests	87,000	0	87,000	0
Net income attributable to MasTec, Inc.	38,029,000	29,030,000	82,959,000	67,464,000
Comprehensive income (loss)	38,024,000	29,418,000	82,489,000	67,803,000
Guarantor Subsidiaries [Member] | Continuing Operations [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Depreciation and amortization	30,637,000	22,065,000	87,426,000	63,403,000
Non-Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Revenue	187,689,000	40,222,000	424,616,000	152,267,000
Costs of revenue, excluding depreciation and amortization	158,204,000	39,119,000	356,819,000	134,525,000
General and administrative expenses	10,552,000	2,960,000	23,858,000	7,774,000
Interest expense, net	715,000	11,000	966,000	3,000
Loss on extinguishment of debt	'	'	0	'
Other (income) expense, net	-469,000	119,000	-757,000	334,000
Income from continuing operations before provision for income taxes	11,569,000	-2,567,000	28,047,000	7,910,000
(Benefit from) provision for income taxes	-3,032,000	972,000	-9,612,000	-1,886,000
Net income from continuing operations before non-controlling interests	8,537,000	-1,595,000	18,435,000	6,024,000
Loss from discontinued operations, net of tax	-169,000	-429,000	-987,000	-1,782,000
Equity in income from subsidiaries, net of tax	0	0	0	0
Net income	8,368,000	-2,024,000	17,448,000	4,242,000
Net income (loss) attributable to non-controlling interests	-25,000	-4,000	85,000	-9,000
Net income attributable to MasTec, Inc.	8,393,000	-2,020,000	17,363,000	4,251,000
Comprehensive income (loss)	11,304,000	152,000	13,608,000	6,546,000
Non-Guarantor Subsidiaries [Member] | Continuing Operations [Member]	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'
Depreciation and amortization	$7,118,000	$580,000	$15,683,000	$1,721,000

Supplemental_Guarantor_Financi3

Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Balance Sheets) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Current assets, including discontinued operations	$1,332,316	$1,049,641
Property and equipment, net	504,313	350,192
Goodwill and other intangible assets, net	1,064,099	961,973
Net investments in and advances to (from) consolidated affilliates	0	0
Other long-term assets, including disontinued operations	53,610	54,160
Total assets	2,954,338	2,415,966
Liabilities and Shareholders' Equity	'	'
Total current liabilities	882,229	713,793
Long-term debt	779,920	546,323
Other liabilities	313,102	293,975
Total liabilities	1,975,251	1,554,091
Total shareholders' equity	979,087	861,875
Total liabilities and shareholders' equity	2,954,338	2,415,966
Consolidation, Eliminations [Member]	'	'
Assets	'	'
Current assets, including discontinued operations	0	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Net investments in and advances to (from) consolidated affilliates	-1,122,552	-1,005,748
Other long-term assets, including disontinued operations	0	0
Total assets	-1,122,552	-1,005,748
Liabilities and Shareholders' Equity	'	'
Total current liabilities	0	0
Long-term debt	0	0
Other liabilities	0	0
Total liabilities	0	0
Total shareholders' equity	-1,122,552	-1,005,748
Total liabilities and shareholders' equity	-1,122,552	-1,005,748
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
Net investments in and advances to (from) consolidated affilliates	974,904	854,992
Other long-term assets, including disontinued operations	9,216	7,701
Total assets	984,120	862,693
Liabilities and Shareholders' Equity	'	'
Total current liabilities	8	20
Long-term debt	0	0
Other liabilities	0	0
Total liabilities	8	20
Total shareholders' equity	984,112	862,673
Total liabilities and shareholders' equity	984,120	862,693
Guarantor Subsidiaries [Member]	'	'
Assets	'	'
Current assets, including discontinued operations	1,120,527	960,523
Property and equipment, net	431,899	326,588
Goodwill and other intangible assets, net	890,683	890,323
Net investments in and advances to (from) consolidated affilliates	147,960	172,150
Other long-term assets, including disontinued operations	42,899	43,442
Total assets	2,633,968	2,393,026
Liabilities and Shareholders' Equity	'	'
Total current liabilities	799,374	675,966
Long-term debt	750,841	546,262
Other liabilities	226,184	262,099
Total liabilities	1,776,399	1,484,327
Total shareholders' equity	857,569	908,699
Total liabilities and shareholders' equity	2,633,968	2,393,026
Non-Guarantor Subsidiaries [Member]	'	'
Assets	'	'
Current assets, including discontinued operations	211,789	89,118
Property and equipment, net	72,414	23,604
Goodwill and other intangible assets, net	173,416	71,650
Net investments in and advances to (from) consolidated affilliates	-312	-21,394
Other long-term assets, including disontinued operations	1,495	3,017
Total assets	458,802	165,995
Liabilities and Shareholders' Equity	'	'
Total current liabilities	82,847	37,807
Long-term debt	29,079	61
Other liabilities	86,918	31,876
Total liabilities	198,844	69,744
Total shareholders' equity	259,958	96,251
Total liabilities and shareholders' equity	$458,802	$165,995

Supplemental_Guarantor_Financi4

Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements Of Cash Flows) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Condensed Cash Flow Statements, Captions [Line Items]	'	'
Net cash (used in) provided by operating activities	$124,991	$114,670
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net, including contingent consideration	-159,446	-17,496
Capital expenditures	-101,411	-50,331
Proceeds from sale of property and equipment	8,288	5,808
Proceeds from disposal of business, net of cash divested	-4,332	97,728
Proceeds from sale or redemption of investments	5,025	0
Payments for other investments, net	-1,174	-284
Net cash (used in) provided by investing activities	-253,050	35,425
Cash flows provided by (used in) financing activities:	'	'
Proceeds from issuance of 4.875% senior notes	400,000	0
Repayment of 7.625% senior notes	-150,000	0
Proceeds from credit facility	766,154	631,815
Repayments of credit facility	-860,070	-681,815
Repayments of other borrowings	-24,246	-15,510
(Repayments of) proceeds from book overdrafts	2,791	-5,645
Payments of capital lease obligations	-32,214	-14,806
Proceeds from stock option exercises and other share-based awards	9,231	1,445
Excess tax benefit from non-cash stock-based compensation	4,446	302
Purchases of treasury stock	0	-75,000
Payments for debt extinguishment, call premiums	-4,116	0
Payments of financing costs	-7,718	-113
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash provided by (used in) financing activities	104,258	-159,327
Net decrease in cash and cash equivalents	-23,801	-9,232
Net effect of currency translation on cash	-118	135
Cash and cash equivalents - beginning of period	26,767	20,279
Cash and cash equivalents - end of period	2,848	11,182
Cash and cash equivalents of discontinued operations	0	710
Cash and cash equivalents of continuing operations	2,848	10,472
Consolidation, Eliminations [Member]	'	'
Condensed Cash Flow Statements, Captions [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, including contingent consideration	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	0
Proceeds from sale or redemption of investments	0	'
Payments for other investments, net	0	0
Net cash (used in) provided by investing activities	0	0
Cash flows provided by (used in) financing activities:	'	'
Proceeds from issuance of 4.875% senior notes	0	'
Repayment of 7.625% senior notes	0	'
Proceeds from credit facility	0	0
Repayments of credit facility	0	0
Repayments of other borrowings	0	0
(Repayments of) proceeds from book overdrafts	0	0
Payments of capital lease obligations	0	0
Proceeds from stock option exercises and other share-based awards	0	0
Excess tax benefit from non-cash stock-based compensation	0	0
Purchases of treasury stock	'	0
Payments for debt extinguishment, call premiums	0	'
Payments of financing costs	0	0
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash provided by (used in) financing activities	0	0
Net decrease in cash and cash equivalents	0	0
Net effect of currency translation on cash	0	0
Cash and cash equivalents - beginning of period	0	0
Cash and cash equivalents - end of period	0	0
Cash and cash equivalents of discontinued operations	0	0
Cash and cash equivalents of continuing operations	0	0
MasTec, Inc. [Member]	'	'
Condensed Cash Flow Statements, Captions [Line Items]	'	'
Net cash (used in) provided by operating activities	-2,401	-891
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net, including contingent consideration	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	0
Proceeds from sale or redemption of investments	0	'
Payments for other investments, net	0	-284
Net cash (used in) provided by investing activities	0	-284
Cash flows provided by (used in) financing activities:	'	'
Proceeds from issuance of 4.875% senior notes	0	'
Repayment of 7.625% senior notes	0	'
Proceeds from credit facility	0	0
Repayments of credit facility	0	0
Repayments of other borrowings	0	0
(Repayments of) proceeds from book overdrafts	0	0
Payments of capital lease obligations	0	0
Proceeds from stock option exercises and other share-based awards	9,231	1,445
Excess tax benefit from non-cash stock-based compensation	0	0
Purchases of treasury stock	'	-75,000
Payments for debt extinguishment, call premiums	0	'
Payments of financing costs	0	0
Net financing activities and advances (to) from consolidated affiliates	-6,830	74,730
Net cash provided by (used in) financing activities	2,401	1,175
Net decrease in cash and cash equivalents	0	0
Net effect of currency translation on cash	0	0
Cash and cash equivalents - beginning of period	0	0
Cash and cash equivalents - end of period	0	0
Cash and cash equivalents of discontinued operations	0	0
Cash and cash equivalents of continuing operations	0	0
Guarantor Subsidiaries [Member]	'	'
Condensed Cash Flow Statements, Captions [Line Items]	'	'
Net cash (used in) provided by operating activities	116,783	96,464
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net, including contingent consideration	-55,453	-16,094
Capital expenditures	-97,602	-49,109
Proceeds from sale of property and equipment	7,629	5,808
Proceeds from disposal of business, net of cash divested	-4,332	97,728
Proceeds from sale or redemption of investments	5,025	'
Payments for other investments, net	-1,174	0
Net cash (used in) provided by investing activities	-145,907	38,333
Cash flows provided by (used in) financing activities:	'	'
Proceeds from issuance of 4.875% senior notes	400,000	'
Repayment of 7.625% senior notes	-150,000	'
Proceeds from credit facility	664,979	631,815
Repayments of credit facility	-753,960	-681,815
Repayments of other borrowings	-24,246	-15,510
(Repayments of) proceeds from book overdrafts	2,791	-5,645
Payments of capital lease obligations	-31,249	-14,790
Proceeds from stock option exercises and other share-based awards	0	0
Excess tax benefit from non-cash stock-based compensation	4,446	302
Purchases of treasury stock	'	0
Payments for debt extinguishment, call premiums	-4,116	'
Payments of financing costs	-7,718	-113
Net financing activities and advances (to) from consolidated affiliates	-81,999	-58,405
Net cash provided by (used in) financing activities	18,928	-144,161
Net decrease in cash and cash equivalents	-10,196	-9,364
Net effect of currency translation on cash	0	20
Cash and cash equivalents - beginning of period	12,969	16,241
Cash and cash equivalents - end of period	2,773	6,897
Cash and cash equivalents of discontinued operations	0	684
Cash and cash equivalents of continuing operations	2,773	6,213
Non-Guarantor Subsidiaries [Member]	'	'
Condensed Cash Flow Statements, Captions [Line Items]	'	'
Net cash (used in) provided by operating activities	10,609	19,097
Cash flows (used in) provided by investing activities:	'	'
Cash paid for acquisitions, net, including contingent consideration	-103,993	-1,402
Capital expenditures	-3,809	-1,222
Proceeds from sale of property and equipment	659	0
Proceeds from disposal of business, net of cash divested	0	0
Proceeds from sale or redemption of investments	0	'
Payments for other investments, net	0	0
Net cash (used in) provided by investing activities	-107,143	-2,624
Cash flows provided by (used in) financing activities:	'	'
Proceeds from issuance of 4.875% senior notes	0	'
Repayment of 7.625% senior notes	0	'
Proceeds from credit facility	101,175	0
Repayments of credit facility	-106,110	0
Repayments of other borrowings	0	0
(Repayments of) proceeds from book overdrafts	0	0
Payments of capital lease obligations	-965	-16
Proceeds from stock option exercises and other share-based awards	0	0
Excess tax benefit from non-cash stock-based compensation	0	0
Purchases of treasury stock	'	0
Payments for debt extinguishment, call premiums	0	'
Payments of financing costs	0	0
Net financing activities and advances (to) from consolidated affiliates	88,829	-16,325
Net cash provided by (used in) financing activities	82,929	-16,341
Net decrease in cash and cash equivalents	-13,605	132
Net effect of currency translation on cash	-118	115
Cash and cash equivalents - beginning of period	13,798	4,038
Cash and cash equivalents - end of period	75	4,285
Cash and cash equivalents of discontinued operations	0	26
Cash and cash equivalents of continuing operations	$75	$4,259

Subsequent_Events_Narrative_De

Subsequent Events (Narrative) (Details) (Revolving Credit Facility [Member])	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Oct. 29, 2013	Oct. 29, 2013	Sep. 30, 2013	Oct. 29, 2013	Sep. 30, 2013	Oct. 29, 2013
	USD ($)	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Maximum [Member]	Maximum [Member]	Letter of Credit [Member]	Letter of Credit [Member]
			USD ($)	CAD	USD ($)	Subsequent Event [Member]	Maximum [Member]	Maximum [Member]
						USD ($)	USD ($)	Subsequent Event [Member]
								USD ($)
Subsequent Event [Line Items]	'	'	'	'	'	'	'	'
Subsequent event, description	'On October 29, 2013, MasTec entered into an amendment (the bAmendmentb) to its Credit Facility, which, among other things, extended the maturity to October 2018 and increased the revolving commitments available from $600 million to $750 million, of which up to $100 million may be borrowed in Canadian dollars.B Additionally, the Amendment increased the amount available for letters of credit from $350 million to $450 million and the amount available for swing line loans from $50 million to $75 million.B The Amendment also reduced the rates applicable to the commitments, borrowings and letters of credit under the Credit Facility.	'	'	'	'	'	'	'
Line of credit facility, maximum borrowing capacity	$600	'	$750	100	'	'	'	'
Line of credit facility, expiration date	22-Aug-16	31-Oct-18	'	'	'	'	'	'
Line of credit facility, capacity available for issuance of letters of credit	'	'	'	'	'	'	350	450
Line of credit facility, capacity available for swing loans	'	'	'	'	$50	$75	'	'