Debt (Narrative) (Detail) (USD $)	3 Months Ended		0 Months Ended					3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended		3 Months Ended									3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Revolving Credit Facility [Member]	Dec. 31, 2012 Revolving Credit Facility [Member]	Mar. 31, 2013 Revolving Credit Facility [Member] Line of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Line of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Weighted Average [Member] Line of Credit [Member]	Mar. 31, 2013 New 4.0% Notes [Member] Convertible Debt [Member]		Mar. 31, 2012 New 4.0% Notes [Member] Convertible Debt [Member]		Mar. 31, 2013 New 4.25% Notes [Member] Convertible Debt [Member]		Mar. 31, 2012 New 4.25% Notes [Member] Convertible Debt [Member]		Mar. 31, 2013 Original 4.0% Notes [Member] Convertible Debt [Member]		Mar. 31, 2012 Original 4.0% Notes [Member] Convertible Debt [Member]		Mar. 31, 2013 Original 4.25% Notes [Member] Convertible Debt [Member]		Mar. 31, 2012 Original 4.25% Notes [Member] Convertible Debt [Member]		Mar. 31, 2013 Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Mar. 31, 2011 Total New Senior Convertible Notes [Member] Convertible Debt [Member]	Mar. 31, 2013 Total New Senior Convertible Notes [Member] Weighted Average [Member] Convertible Debt [Member]	Mar. 31, 2013 Unsecured Debt [Member] 4.875% Senior Notes [Member] Senior Notes [Member]	Mar. 31, 2013 Unsecured Debt [Member] 7.625% Senior Notes [Member] Senior Notes [Member]	Mar. 31, 2013 Letter of Credit [Member] Revolving Credit Facility [Member]	Dec. 31, 2012 Letter of Credit [Member] Revolving Credit Facility [Member]	Mar. 31, 2013 Letter of Credit [Member] Revolving Credit Facility [Member] Minimum [Member]	Dec. 31, 2012 Letter of Credit [Member] Revolving Credit Facility [Member] Minimum [Member]	Mar. 31, 2013 Letter of Credit [Member] Revolving Credit Facility [Member] Maximum [Member]	Dec. 31, 2012 Letter of Credit [Member] Revolving Credit Facility [Member] Maximum [Member]	Mar. 31, 2013 Debt Repurchased [Member] Unsecured Debt [Member] 7.625% Senior Notes [Member] Senior Notes [Member]	Mar. 31, 2013 Debt Redeemed [Member] Unsecured Debt [Member] 7.625% Senior Notes [Member] Senior Notes [Member]	Mar. 31, 2013 Call Period Redemption [Member] Unsecured Debt [Member] 4.875% Senior Notes [Member] Senior Notes [Member]	Mar. 31, 2013 Non-Call Redemption [Member] Unsecured Debt [Member] 4.875% Senior Notes [Member] Senior Notes [Member]	Mar. 31, 2013 Equity Claw Redemption [Member] Unsecured Debt [Member] 4.875% Senior Notes [Member] Senior Notes [Member]	Mar. 31, 2013 Equity Claw Redemption [Member] Unsecured Debt [Member] 4.875% Senior Notes [Member] Maximum [Member] Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, issuance date																											Mar. 18, 2013
Principal amount								$ 105,322,000	[1]	$ 105,322,000	[1]	$ 97,000,000	[1]	$ 97,000,000	[1]	$ 9,600,000	[2]	$ 9,700,000	[2]	$ 3,000,000	[2]	$ 3,000,000	[2]				$ 400,000,000	$ 150,000,000
Debt instrument, interest rate								4.00%				4.25%				4.00%				4.25%							4.875%	7.625%
Debt instrument, maturity date								Jun. 15, 2014				Dec. 15, 2014				Jun. 15, 2014				Dec. 15, 2014							Mar. 15, 2023	Feb. 01, 2017
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, commencing on September 15, 2013.
Debt instrument, date of first required payment																											Sep. 15, 2013
Debt instrument, guarantees	The Company’s New Convertible Notes and Original 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 subordinated basis by the Company's 100%-owned domestic subsidiaries that guarantee the Credit Facility.																										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 “4.875% Senior Notes Indenture”) plus accrued and unpaid interest, if any, to the redemption date.
Debt instrument, redemption description																												On March 18, 2013, the Company repurchased approximately $121.1 million of its 7.625% Senior Notes 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 the date of repurchase. In addition, the remaining outstanding $28.9 million aggregate principal balance of the 7.625% Senior Notes was effectively redeemed in accordance with their terms on March 29, 2013 at a price of 102.542% of the principal amount, plus accrued interest from the most recent interest payment date to 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, and 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.
Debt instrument, redemption period start date																																					Mar. 15, 2018
Debt instrument, redemption period end date																																						Mar. 15, 2018	Mar. 15, 2016
Debt instrument, redemption price percentage																																			102.792%	102.542%		100.00%	104.875%
Debt instrument, redemption using proceeds from equity issuance, percentage of principal amount																																								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) 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.
Deferred financing costs																											7,000,000
Repurchase and redemption of notes	150,000,000	0																																	121,100,000	28,900,000
Loss on extinguishment of debt	5,624,000	0																										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
Credit facility, amount outstanding					0	134,000,000
Line of credit interest rate							3.95%																								1.00%	1.00%	2.00%	2.00%
Letters of credit issued																													119,300,000	120,800,000
Line of credit facility, remaining borrowing capacity			480,700,000	345,200,000
Line of credit facility, capacity available for issuance of letters of credit																													230,700,000	229,200,000
Unused credit facility fee			0.35%	0.35%
Unamortized debt discount and financing costs								$ 3,700,000				$ 4,300,000													$ 17,400,000
Debt instrument, effective interest rate																								6.73%
Debt instrument, remaining discount amortization period																										1 year 6 months
Debt instrument, covenant compliance	MasTec was in compliance with all provisions and covenants pertaining to its outstanding debt instruments as of March 31, 2013 and December 31, 2012.

[1] Dilutive shares associated with the New Convertible Notes are attributable to the premium over the respective conversion prices.

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