Basis of Presentation	9 Months Ended
Sep. 30, 2018
Basis of Presentation
Basis of Presentation	Note 2—Basis of Presentation Interim condensed consolidated financial statements — The interim condensed consolidated financial statements for the three and nine month periods ended September 30, 2018 and 2017 have been prepared in accordance with Rule 10-01 of Regulation S-X of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). As such, certain disclosures, which would substantially duplicate the disclosures contained in our Annual Report on Form 10-K, filed on February 26, 2018, which contains our audited consolidated financial statements for the year ended December 31, 2017, have been omitted. This Third Quarter 2018 Report on Form 10-Q should be read in concert with our most recent Annual Report on Form 10-K. The interim financial information is unaudited. In the opinion of management, the interim information includes all adjustments (consisting of normal recurring adjustments) necessary for the fair presentation of the interim financial information. Reclassification — Certain previously reported amounts have been reclassified to conform to the current period presentation. Customer concentration — We operate in multiple industry segments encompassing the construction of commercial, industrial and public works infrastructure assets primarily throughout the United States. Typically, the top ten customers in any one calendar year generate revenue in excess of 50% of total revenue; however, the group that comprises the top ten customers varies from year to year. During the three and nine months ended September 30, 2018, revenue generated by the top ten customers were approximately $483.0 million and $1,045.9 million, respectively, which represented 53.1% and 50.7%, respectively, of total revenue during the applicable period. During the three and nine months ended September 30, 2018, a Midwest utility customer represented 7.9% and 8.4% of total revenue, respectively, and a California utility customer represented 8.2% and 8.6% of total revenue, respectively. During the three and nine months ended September 30, 2017, revenues generated by the top ten customers were approximately $317.2 million and $1,058.5 million, respectively, which represented 52.2% and 58.8%, respectively, of total revenues during the applicable period. During the three and nine months ended September 30, 2017, a California utility project represented 10.6% and 8.8% of total revenues, respectively, and a state department of transportation customer represented 8.4% and 9.8% of total revenues, respectively. At September 30, 2018, approximately 10.2% of our accounts receivable were due from one customer, and that customer provided 8.4% of our revenue for the nine months ended September 30, 2018. In addition, of total accounts receivable, approximately 4.4% are from one customer with whom we are currently engaged in a dispute resolution. See Note 17 – “Commitments and Contingencies”. At September 30, 2017, approximately 10.8% of our accounts receivable were due from one customer, and that customer provided 7.9% of our revenue for the nine months ended September 30, 2017. In addition, approximately 11.2% of total accounts receivable at September 30, 2017 were from one customer with whom we are currently engaged in a dispute resolution. Multiemployer plans — Various of our subsidiaries are signatories to collective bargaining agreements. These agreements require that we participate in and contribute to a number of multiemployer benefit plans for our union employees at rates determined by the agreements. The trustees for each multiemployer plan determine the eligibility and allocations of contributions and benefit amounts, determine the types of benefits, and administer the plan. To the extent that any plans are underfunded, the Employee Retirement Income Security Act of 1974, as amended by the Multi-Employer Pension Plan Amendments Act of 1980, requires that if we were to withdraw from an agreement or if a plan is terminated, we may incur a withdrawal obligation. The potential withdrawal obligation may be significant. In accordance with Generally Accepted Accounting Principles (“GAAP”), any withdrawal liability would be recorded when it is probable that a liability exists and can be reasonably estimated. In November 2011, we withdrew from the Central States Southeast and Southwest Areas Pension Fund multiemployer plan, and fully paid off the withdrawal liability in the third quarter of 2018 as discussed in Note 17 — “Commitments and Contingencies”. We have no plans to withdraw from any other agreements. Derivative Instruments and Hedging Activities — We recognize all derivative instruments as either assets or liabilities on the balance sheet at their respective fair values. Our use of derivatives consists of an interest rate swap agreement. The interest rate swap agreement was entered into to improve the predictability of cash flows from interest payments related to variable rate debt for the duration of the term loan. The interest rate swap matures in July 2023 and is not designated as a hedge for accounting purposes. Therefore, the change in the fair value of the derivative asset or liability is reflected in net income in the Condensed Consolidated Statements of Income (mark-to-market accounting). Cash flows from derivatives settled are reported as cash flow from operating activities.

Note 2—Basis of Presentation

Interim condensed consolidated financial statements — The interim condensed consolidated financial statements for the three and nine month periods ended September 30, 2018 and 2017 have been prepared in accordance with Rule 10-01 of Regulation S-X of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). As such, certain disclosures, which would substantially duplicate the disclosures contained in our Annual Report on Form 10-K, filed on February 26, 2018, which contains our audited consolidated financial statements for the year ended December 31, 2017, have been omitted.

This Third Quarter 2018 Report on Form 10-Q should be read in concert with our most recent Annual Report on Form 10-K. The interim financial information is unaudited. In the opinion of management, the interim information includes all adjustments (consisting of normal recurring adjustments) necessary for the fair presentation of the interim financial information.

Reclassification — Certain previously reported amounts have been reclassified to conform to the current period presentation.

Customer concentration — We operate in multiple industry segments encompassing the construction of commercial, industrial and public works infrastructure assets primarily throughout the United States. Typically, the top ten customers in any one calendar year generate revenue in excess of 50% of total revenue; however, the group that comprises the top ten customers varies from year to year.

During the three and nine months ended September 30, 2018, revenue generated by the top ten customers were approximately $483.0 million and $1,045.9 million, respectively, which represented 53.1% and 50.7%, respectively, of total revenue during the applicable period. During the three and nine months ended September 30, 2018, a Midwest utility customer represented 7.9% and 8.4% of total revenue, respectively, and a California utility customer represented 8.2% and 8.6% of total revenue, respectively.

During the three and nine months ended September 30, 2017, revenues generated by the top ten customers were approximately $317.2 million and $1,058.5 million, respectively, which represented 52.2% and 58.8%, respectively, of total revenues during the applicable period. During the three and nine months ended September 30, 2017, a California utility project represented 10.6% and 8.8% of total revenues, respectively, and a state department of transportation customer represented 8.4% and 9.8% of total revenues, respectively.

At September 30, 2018, approximately 10.2% of our accounts receivable were due from one customer, and that customer provided 8.4% of our revenue for the nine months ended September 30, 2018. In addition, of total accounts receivable, approximately 4.4% are from one customer with whom we are currently engaged in a dispute resolution. See Note 17 – “Commitments and Contingencies”.

At September 30, 2017, approximately 10.8% of our accounts receivable were due from one customer, and that customer provided 7.9% of our revenue for the nine months ended September 30, 2017. In addition, approximately 11.2% of total accounts receivable at September 30, 2017 were from one customer with whom we are currently engaged in a dispute resolution.

Multiemployer plans — Various of our subsidiaries are signatories to collective bargaining agreements. These agreements require that we participate in and contribute to a number of multiemployer benefit plans for our union employees at rates determined by the agreements. The trustees for each multiemployer plan determine the eligibility and allocations of contributions and benefit amounts, determine the types of benefits, and administer the plan. To the extent that any plans are underfunded, the Employee Retirement Income Security Act of 1974, as amended by the Multi-Employer Pension Plan Amendments Act of 1980, requires that if we were to withdraw from an agreement or if a plan is terminated, we may incur a withdrawal obligation. The potential withdrawal obligation may be significant. In accordance with Generally Accepted Accounting Principles (“GAAP”), any withdrawal liability would be recorded when it is probable that a liability exists and can be reasonably estimated. In November 2011, we withdrew from the Central States Southeast and Southwest Areas Pension Fund multiemployer plan, and fully paid off the withdrawal liability in the third quarter of 2018 as discussed in Note 17 — “Commitments and Contingencies”. We have no plans to withdraw from any other agreements.

Derivative Instruments and Hedging Activities — We recognize all derivative instruments as either assets or liabilities on the balance sheet at their respective fair values. Our use of derivatives consists of an interest rate swap agreement. The interest rate swap agreement was entered into to improve the predictability of cash flows from interest payments related to variable rate debt for the duration of the term loan. The interest rate swap matures in July 2023 and is not designated as a hedge for accounting purposes. Therefore, the change in the fair value of the derivative asset or liability is reflected in net income in the Condensed Consolidated Statements of Income (mark-to-market accounting). Cash flows from derivatives settled are reported as cash flow from operating activities.