Debt (Narrative) (Detail) (USD $)	12 Months Ended					12 Months Ended				12 Months Ended					12 Months Ended				12 Months Ended			1 Months Ended	3 Months Ended	12 Months Ended							1 Months Ended	3 Months Ended	12 Months Ended							12 Months Ended						3 Months Ended	12 Months Ended	15 Months Ended	12 Months Ended							12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 7.625% Senior Notes [Member]	Dec. 31, 2011 7.625% Senior Notes [Member]	Dec. 31, 2012 Financial Standby Letter of Credit [Member] Minimum [Member]	Dec. 31, 2012 Financial Standby Letter of Credit [Member] Maximum [Member]	Dec. 31, 2012 Revolving Credit Facility [Member]	Dec. 31, 2011 Revolving Credit Facility [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Previous Line Of Credit [Member]	Aug. 31, 2011 Revolving Credit Facility [Member] Previous Line Of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Line of Credit [Member]	Dec. 31, 2011 Revolving Credit Facility [Member] Line of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Minimum [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Minimum [Member] Letter of Credit [Member]	Dec. 31, 2011 Revolving Credit Facility [Member] Minimum [Member] Letter of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Minimum [Member] Line of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Maximum [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Maximum [Member] Letter of Credit [Member]	Dec. 31, 2011 Revolving Credit Facility [Member] Maximum [Member] Letter of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Maximum [Member] Line of Credit [Member]	Dec. 31, 2012 Letter of Credit [Member] Minimum [Member]	Dec. 31, 2012 Letter of Credit [Member] Maximum [Member]	Jun. 30, 2009 Original 4.0% Notes [Member] Convertible Debt [Member]	Mar. 31, 2011 Original 4.0% Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Original 4.0% Notes [Member] Convertible Debt [Member]		Dec. 31, 2009 Original 4.0% Notes [Member] Convertible Debt [Member]	Dec. 31, 2011 Original 4.0% Notes [Member] Convertible Debt [Member]		Dec. 31, 2010 Original 4.0% Notes [Member] Convertible Debt [Member]		Nov. 30, 2009 Original 4.25% Notes [Member] Convertible Debt [Member]	Mar. 31, 2011 Original 4.25% Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Original 4.25% Notes [Member] Convertible Debt [Member]		Dec. 31, 2009 Original 4.25% Notes [Member] Convertible Debt [Member]	Dec. 31, 2011 Original 4.25% Notes [Member] Convertible Debt [Member]		Dec. 31, 2010 Original 4.25% Notes [Member] Convertible Debt [Member]		Dec. 31, 2012 Convertible Debt [Member] Total New Senior Convertible Notes [Member]	Dec. 31, 2012 Convertible Debt [Member] Original 4.0% Notes [Member]	Dec. 31, 2012 Convertible Debt [Member] Original 4.25% Notes [Member]	Dec. 31, 2012 Total Exchanged Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2011 Total Exchanged Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2010 Total Exchanged Senior Convertible Notes [Member] Convertible Debt [Member]	Mar. 31, 2011 Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Mar. 31, 2011 Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Total New Senior Convertible Notes [Member] Weighted Average [Member] Convertible Debt [Member]	Dec. 31, 2012 Total Remaining Original Convertible Notes [Member] Convertible Debt [Member]	Mar. 31, 2011 Aggregate Principal [Member] Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Eurocurrency Rate [Member] Revolving Credit Facility [Member] Minimum [Member] Line of Credit [Member]	Dec. 31, 2012 Eurocurrency Rate [Member] Revolving Credit Facility [Member] Maximum [Member] Line of Credit [Member]	Dec. 31, 2012 Base Rate [Member] Revolving Credit Facility [Member] Minimum [Member] Line of Credit [Member]	Dec. 31, 2012 Base Rate [Member] Revolving Credit Facility [Member] Maximum [Member] Line of Credit [Member]	Dec. 31, 2012 Convertible Term 1 [Member] Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Convertible Term 2 [Member] Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Convertible Term 3 [Member] Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Dec. 31, 2012 Long-term Debt [Member]	Dec. 31, 2011 Long-term Debt [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity									$ 260,000,000	$ 600,000,000
Line of credit facility, expiration date								May 31, 2013		Aug. 22, 2016
Line of credit facility, capacity available for issuance of letters of credit																	350,000,000				229,200,000
Line of credit facility, borrowing capacity description						Subject to certain terms in the Credit Facility, the Company has the option to increase its revolving commitments and/or establish term loans of up to $200 million in total. Borrowings under the Credit Facility will be used to refinance existing indebtedness and for working capital, capital expenditures and other corporate purposes, including the repurchase or prepayment of indebtedness; however, the Credit Facility restricts the repurchase or prepayment of certain unsecured indebtedness, including the Company’s senior notes due 2017 and senior convertible notes due 2014, unless the Company has at least $50 million of remaining liquidity (as defined in the Credit Facility) after any such repurchase or prepayment.
Line of credit facility, covenant terms						The Credit Facility requires that the Company maintain a consolidated leverage ratio (as defined in the Credit Facility) at or below 3.50 to 1.00 and a consolidated interest coverage ratio (as defined in the Credit Facility) at or above 3.00 to 1.00. Subject to customary exceptions, the Credit Facility also limits the Company’s ability to engage in certain activities, including acquisitions, mergers and consolidations, debt incurrence, investments, capital expenditures, asset sales, debt prepayments, lien incurrence and the making of distributions on or repurchases of capital stock.
Line of credit facility, leverage ratio												1.00				3.50
Line of credit facility, interest coverage ratio												1.00				3.00
Line of credit facility, interest rate description						Amounts borrowed under the Credit Facility will bear interest, at the Company’s option, at a rate equal to either (a) the eurocurrency rate (as defined in the Credit Facility), plus a margin of 1.50% to 2.50%, as determined based on the Company’s consolidated leverage ratio (as defined in the Credit Facility) as of the most recent fiscal quarter, or (b) the base rate, which is equal to the highest of (i) the federal funds rate (as defined in the Credit Facility) plus 0.5%, (ii) Bank of America’s prime rate and (iii) the eurocurrency rate plus 1.00%, plus a margin of 0.50% to 1.50%, as determined based on the Company’s consolidated leverage ratio as of the most recent fiscal quarter. Financial standby letters of credit and commercial letters of credit issued under the Credit Facility are subject to a letter of credit fee of 1.50% to 2.50% and performance standby letters of credit are subject to a letter of credit fee of 0.75% to 1.25% in each case, based on the Company’s consolidated leverage ratio as of the most recent fiscal quarter.
Debt instrument, basis spread, variable interest or fee																																																			0.50%	1.50%	2.50%	0.50%	1.50%
Line of credit facility, commitment fee description						The Company must also pay a commitment fee to the lenders on any unused availability under the Credit Facility, which is equal to 0.25% to 0.45%, based on the Company’s consolidated leverage ratio as of the then most recent fiscal quarter.
Credit facility, amount outstanding										134,000,000	60,000,000
Letters of credit issued						120,800,000	90,000,000
Line of credit facility, remaining borrowing capacity						345,200,000
Line of credit interest rate				0.80%	1.30%	3.95%	2.94%						1.00%	1.00%			2.00%	2.00%		1.50%	2.50%
Unused credit facility fee						0.35%	0.35%								0.25%				0.45%
Line of credit facility, collateral						The Credit Facility is guaranteed by certain of the Company’s 100%-owned direct and indirect domestic subsidiaries. It is collateralized by a first priority security interest in substantially all of the Company’s assets and the assets of its wholly-owned subsidiaries, as well as a pledge of the outstanding equity interests in certain of the Company’s operating subsidiaries.
Debt instrument exchange fee																																														During the first quarter of 2011, the Company exchanged $105.3 million of its Original 4.0% Notes and $97.0 million of its Original 4.25% Notes for identical principal amounts of New 4.0% Notes and New 4.25% Notes, respectively, for an exchange fee of approximately 50 basis points, or 0.5%, of the aggregate principal amount of the notes exchanged.
Debt instrument, exchanged amount																							105,300,000									97,000,000											0	202,322,000	0
Exchange fee incurred for debt conversion																																															1,000,000	700,000
Debt issuance cost																										5,400,000									3,700,000
Convertible notes, 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 contractors’ licenses.																																							The 4.25% and 4.0% senior convertible notes are guaranteed by certain of the Company's 100%-owned direct and indirect domestic operating subsidiaries
Debt instrument, terms of conversion feature																																																								if the last reported sale price of the Company’s common stock is greater than or equal to 130% of the applicable conversion price of the New Convertible Notes during at least 20 of the last 30 consecutive trading days ending on and including the last trading day of a calendar quarter, then the applicable New Convertible Notes may be converted during the immediately following calendar quarter (and only during such calendar quarter);	if after any five consecutive trading-day period in which the trading price per $1,000 principal amount of New Convertible Notes for each trading day during such period was less than 98% of the product of the last reported sale price of the Company’s common stock and the applicable conversion rate, then the applicable New Convertible Notes may be converted during the immediately following five business day period; or	if the Company effects certain distributions to its shareholders or if the Company is party to a consolidation, merger, binding share exchange, or a sale, transfer, lease or other conveyance of all or substantially all of its assets, pursuant to which the Company’s common stock would be converted into or exchanged for, or would constitute solely the right to receive, cash, securities or other assets, or in the case of certain other fundamental changes, then the New Convertible Notes may be converted during the period that is 45 trading days prior to the ex-dividend date or the initial anticipated effective date of the transaction, as applicable.
Unamortized debt discount and financing costs																																														17,400,000		17,400,000
Debt instrument, effective interest rate																																															6.73%
Debt instrument, remaining discount amortization period																																																	2 years
Debt instrument, issuance date																						Jun. 30, 2009									Nov. 30, 2009
Convertible debt, outstanding principal amount																						115,000,000		9,700,000	[1]		9,700,000	[1]	115,000,000	[1]	100,000,000		3,000,000	[1]		3,000,000	[1]	100,000,000	[1]											12,700,000
Debt instrument, payment terms																								The Original 4.0% Notes bear interest at a rate of 4.0% per year, payable semi-annually in arrears, on June 15 and December 15 of each year.									The Original 4.25% Notes bear interest at a rate of 4.25% per year, payable semi-annually in arrears, on June 15 and December 15 of each year.
Debt Instrument, convertible, latest date																																									Jun. 13, 2014	Dec. 12, 2014
Debt instrument, convertible, conversion ratio																								63.4417									64.6162
Debt instrument, convertible, conversion price per share																								$ 15.76									$ 15.48
Debt instrument, restrictive covenants		The indenture that governs the Senior Notes allows the Company to incur additional indebtedness to the extent that the Company’s fixed charge coverage ratio, as therein defined, is at least 2:1. The fixed charge coverage ratio is calculated as consolidated EBITDA for the most recent four fiscal quarters for which internal financial statements are available, divided by fixed charges for such four quarter period, as such terms are defined in the indenture. If the fixed charge coverage ratio is less than 2:1, the Company is still permitted to incur the following additional indebtedness, among others: credit facilities under a defined threshold, renewals to existing debt permitted under the indenture, capital lease obligations up to 5% of the Company’s consolidated net assets, plus an additional $50 million of indebtedness at any time the Senior Notes remain outstanding. The Senior Notes are guaranteed by certain of the Company’s operating subsidiaries.																																						There are no financial covenants on these notes, however, there are certain nonfinancial provisions and covenants associated with these notes.
Business combination, assumed debt																																																											20,600,000	29,900,000
Carrying value of debt		$ 150,000,000	$ 150,000,000																					$ 9,700,000			$ 9,700,000						$ 3,000,000			$ 3,000,000
Debt instrument, maturity date		Feb. 01, 2017																						Jun. 15, 2014									Dec. 15, 2014
Debt instrument, guarantees	The Company’s Senior Notes, New Convertible Notes and Original Convertible Notes are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company's existing and future 100%-owned direct and indirect domestic subsidiaries that are guarantors of the Company's Credit Facility or other outstanding indebtedness.
Debt instrument, covenant compliance	MasTec was in compliance with all provisions and covenants pertaining to its outstanding debt instruments as of December 31, 2012 and 2011.

[1] Dilutive shares associated with the Original Notes are attributable to the underlying principal amounts.