Stock-Based Compensation and Other Employee Benefit Plans (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2014	May. 31, 2013
Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation, number of shares available for grant or issuance	5,513,000
Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plan, description	The Company has certain employee stock purchase plans under which shares of the Company’s common stock are available for purchase by eligible employees. These plans allow qualified employees to purchase MasTec, Inc. common stock at 85% of its fair market value at the lower of (i) the date of commencement of the offering period or (ii) the last day of the exercise period, as defined in the plan documents. 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.
2013 Incentive Plan [Member] | Restricted Shares [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plan, description	The MasTec, Inc. 2013 Incentive Plan (the “2013 Incentive Plan”), which became effective in May 2013, permits a total of approximately 7,391,000 shares of the Company’s common stock to be issued, including approximately 5,291,000 shares that remained available under prior plans that terminated upon adoption of the 2013 Incentive Plan.
2013 Incentive Plan [Member] | Restricted Shares [Member] | Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plan, number of shares authorized	7,391,000
Prior Incentive Plans [Member] | Restricted Shares [Member] | Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation, number of shares available for grant or issuance		5,291,000
2013 Bargaining Units ESPP [Member] | Employee Stock Purchase Plans [Member] | Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plan, number of shares authorized	1,000,000
Employee Stock Plans [Member] | Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plan, description	The MasTec, Inc. Bargaining Units Employee Stock Purchase Plan (the “2013 Bargaining Units ESPP”), which became effective on July 1, 2013, permits the issuance of up to 1,000,000 new shares of MasTec, Inc. common stock to eligible employees. 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.
2011 ESPP [Member] | Employee Stock Purchase Plans [Member] | Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plan, number of shares authorized	1,000,000