Equity	9 Months Ended
Sep. 30, 2018
Equity [Abstract]
Equity	Note 11 – Equity Share Activity The Company’s share repurchase programs provide for the repurchase of shares of MasTec common stock from time to time in open market transactions or in privately-negotiated transactions in accordance with applicable securities laws. The timing and the amount of any repurchases is determined based on market conditions, legal requirements, cash flow and liquidity needs and other factors. The Company’s share repurchase programs do not have an expiration date and may be modified or suspended at any time at the Company’s discretion. Share repurchases, which are recorded at cost and are held in the Company’s treasury, are funded with available cash or with availability under the Credit Facility. During the three and nine month periods ended September 30, 2018, the Company repurchased approximately 1.6 million and 4.3 million shares of its common stock, respectively, for an aggregate purchase price of $70.1 million and $198.4 million, respectively. Of the total repurchased shares, 2.0 million were repurchased in the first quarter of 2018 for $98.4 million under a now completed $100 million share repurchase program that was established in 2016. The additional 2.3 million shares were repurchased under a separate $100 million share repurchase program that was authorized in March 2018 and completed in the third quarter. In September 2018, a new $150 million share repurchase program was authorized, all of which remains available as of September 30, 2018. Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is composed of unrealized foreign currency gains and losses from fluctuations in foreign currency exchange rates of the Company’s foreign subsidiaries with a functional currency other than the U.S. dollar, as well as unrealized gains and losses from certain investment activities. Unrealized foreign currency activity for each of the three and nine month periods ended September 30, 2018 and 2017 is primarily related to translation gains and losses resulting from the Company’s Canadian operations, and unrealized investment activity for each of the three and nine month periods ended September 30, 2018 and 2017 relates to unrealized gains and losses on interest rate swaps associated with the Waha JVs.

Note 11 – Equity

Share Activity

The Company’s share repurchase programs provide for the repurchase of shares of MasTec common stock from time to time in open market transactions or in privately-negotiated transactions in accordance with applicable securities laws. The timing and the amount of any repurchases is determined based on market conditions, legal requirements, cash flow and liquidity needs and other factors. The Company’s share repurchase programs do not have an expiration date and may be modified or suspended at any time at the Company’s discretion. Share repurchases, which are recorded at cost and are held in the Company’s treasury, are funded with available cash or with availability under the Credit Facility.

During the three and nine month periods ended September 30, 2018, the Company repurchased approximately 1.6 million and 4.3 million shares of its common stock, respectively, for an aggregate purchase price of $70.1 million and $198.4 million, respectively. Of the total repurchased shares, 2.0 million were repurchased in the first quarter of 2018 for $98.4 million under a now completed $100 million share repurchase program that was established in 2016. The additional 2.3 million shares were repurchased under a separate $100 million share repurchase program that was authorized in March 2018 and completed in the third quarter. In September 2018, a new $150 million share repurchase program was authorized, all of which remains available as of September 30, 2018.

Accumulated Other Comprehensive Loss

Accumulated other comprehensive loss is composed of unrealized foreign currency gains and losses from fluctuations in foreign currency exchange rates of the Company’s foreign subsidiaries with a functional currency other than the U.S. dollar, as well as unrealized gains and losses from certain investment activities. Unrealized foreign currency activity for each of the three and nine month periods ended September 30, 2018 and 2017 is primarily related to translation gains and losses resulting from the Company’s Canadian operations, and unrealized investment activity for each of the three and nine month periods ended September 30, 2018 and 2017 relates to unrealized gains and losses on interest rate swaps associated with the Waha JVs.