Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2019
Basis of Presentation
Summary of Significant Accounting Policies	Note 2—Summary of Significant Accounting Policies Basis of presentation —The accompanying consolidated financial statements were prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and the financial statement rules and regulations of the Securities and Exchange Commission (“SEC”). References for Financial Accounting Standards Board (“FASB”) standards are made to the FASB Accounting Standards Codification (“ASC”). Principles of consolidation —The accompanying Consolidated Financial Statements include the accounts of Primoris, our wholly-owned subsidiaries and the noncontrolling interests of the Carlsbad and Wilmington joint ventures, which are VIEs for which we are the primary beneficiary as determined under the provisions of ASC 810, “Consolidation”. All intercompany balances and transactions have been eliminated in consolidation. Reclassification —Certain previously reported amounts have been reclassified to conform to the current year presentation. Use of estimates —The preparation of our Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. As a construction contractor, we use estimates for costs to complete construction projects and the contract value of certain construction projects. These estimates have a direct effect on gross profit as reported in these consolidated financial statements. Actual results could materially differ from our estimates. Operating cycle — In the accompanying Consolidated Balance Sheets, assets and liabilities relating to long-term construction contracts (e.g. contract assets and contract liabilities) are considered current assets and current liabilities, since they are expected to be realized or liquidated in the normal course of contract completion, although completion may require more than one calendar year. Consequently, we have significant working capital invested in assets that may have a liquidation period extending beyond one year. We have claims receivable and retention due from various customers and others that are currently in dispute, the realization of which is subject to binding arbitration, final negotiation or litigation, all of which may extend beyond one calendar year. Cash and cash equivalents —We consider all highly liquid investments with an original maturity of three months or less when purchased as cash equivalents. Business combinations—Business combinations are accounted for using the acquisition method of accounting. We use the fair value of the assets acquired and liabilities assumed to account for the purchase price of businesses. The determination of fair value requires estimates and judgments of future cash flow expectations to assign fair values to the identifiable tangible and intangible assets. GAAP provides a “measurement period” of up to one year in which to finalize all fair value estimates associated with the acquisition of a business. Most estimates are preliminary until the end of the measurement period. During the measurement period, any material, newly discovered information that existed at the acquisition date would be reflected as an adjustment to the initial valuations and estimates. After the measurement period, any adjustments would be recorded as a current period income or expense. Contingent Earnout Liabilities—As part of certain acquisitions, we agreed to pay cash to certain sellers upon meeting specific operating performance targets for specified periods subsequent to the acquisition date. Each quarter, we evaluate the fair value of the estimated contingency and record a non-operating charge for the change in the fair value. Upon meeting the target, we reflect the full liability on the balance sheet and record a charge to “Other income (expense), net” for the change in the fair value of the liability from the prior period. See Note 3 — “Fair Value Measurements” for further discussion. Goodwill and other intangible assets—We account for goodwill in accordance with ASC 350, “Intangibles — Goodwill and Other”. Under ASC 350, goodwill is subject to an annual impairment test, which we perform as of the first day of the fourth quarter of each year, with more frequent testing if indicators of potential impairment exist. The impairment review is performed at the reporting unit level for those units with recorded goodwill. For the majority of our reporting units, we perform a qualitative assessment to determine whether it is more likely than not (that is, a likelihood of more than 50 percent) that the fair value of the reporting unit is less than its carrying value, including goodwill. Factors used in our qualitative assessment include, but are not limited to, macroeconomic conditions, industry and market conditions, cost factors, overall financial performance and Company and reporting unit specific events. For all other reporting units, we use the quantitative impairment test outlined in ASC 350, which compares the fair value of a reporting unit with its carrying amount. Fair value for the goodwill impairment test is determined utilizing a discounted cash flow analysis based on our financial plan discounted using our weighted average cost of capital and market indicators of terminal year cash flows. Other valuation methods may be used to corroborate the discounted cash flow method. If the carrying amount of a reporting unit is in excess of its fair value, goodwill is considered impaired and an impairment loss is recognized in an amount equal to that excess, limited to the total amount of goodwill of the reporting unit. Income tax—Current income tax expense is the amount of income taxes expected to be paid for the financial results of the current year. A deferred tax liability or asset is established for the expected future tax consequences resulting from the differences in financial reporting bases and tax bases of assets and liabilities using enacted tax rates in effect for the years in which the differences are expected to reverse. A valuation allowance is provided if it is more likely than not that some or all of the deferred tax assets will not be realized. We provide for uncertain tax positions when such tax positions do not meet the recognition thresholds or measurement standards as set forth in ASC 740, “Income Taxes”. The difference between a tax position taken or expected to be taken on our income tax returns and the benefit recognized in our financial statements is referred to as an unrecognized tax benefit. Amounts for uncertain tax positions are adjusted in periods when new information becomes available or when positions are effectively settled. We recognize accrued interest and penalties related to uncertain tax positions, if any, as a component of income tax expense. As a result of the Tax Cuts and Jobs Act (the “Tax Act”) new taxes were created on certain foreign earnings. Namely, U.S. shareholders are now subject to a current tax on global intangible low-taxed income (“GILTI”) earned by specified foreign subsidiaries. Available guidance related to GILTI provides for an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years, or provide for the tax expense related to GILTI in the year the tax is incurred as a period expense. We have elected to recognize the current tax on GILTI as an expense in the period the tax is incurred. The current tax impacts of GILTI are included in our effective tax rate. Staff Accounting Bulletin (“SAB”) 118 provided guidance on accounting for uncertainties of the effects of the Tax Act. Specifically, SAB 118 allowed companies to record provisional estimates of the impact of the Tax Act during a one year “measurement period” from the December 22, 2017 enactment date, similar to that used when accounting for business combinations. As a result of the Tax Act, we remeasured deferred tax assets and liabilities using the newly enacted tax rates and recorded a one-time net tax benefit of $9.4 million as a provisional estimate under SAB 118 in the year ended December 31, 2017. As of December 31, 2018, our accounting for the Tax Act was complete. The provision for income taxes for the year ended December 31, 2018 included a $1.1 million increase from the completion of our provisional accounting for the effects of the Tax Act under SAB 118. The increase was due to $0.6 million of additional expense associated with foreign tax credits, net of associated valuation allowances, and $0.5 million of additional expense related to the corporate tax rate change impact on return-to-provision adjustments, primarily for depreciation. Comprehensive income—We account for comprehensive income in accordance with ASC 220, “Comprehensive Income”, which specifies the computation, presentation and disclosure requirements for comprehensive income (loss). Comprehensive income (loss) consists of net income (loss) and foreign currency translation adjustments, primarily from fluctuations in foreign currency exchange rates of our foreign subsidiaries with a functional currency other than the U.S. dollar. Functional currencies and foreign currency translation— For foreign operations where substantially all monetary transactions are in the local currency, we use the local currency as our functional currency. The effects of translating financial statements of foreign operations into our reporting currency are recognized as a cumulative translation adjustment, net of tax in “Accumulated other comprehensive income (loss)” in the Consolidated Statements of Stockholders’ Equity. For certain foreign operations where substantially all monetary transactions are made in United States dollars, we use the U.S. dollar as our functional currency, with gains or losses on translation recorded in income in the period in which they are incurred. Gains or losses on foreign currency transactions are recorded in income in the period in which they are incurred. Partnerships and joint ventures — We are periodically a member of a partnership or a joint venture. These partnerships or joint ventures are used primarily for the execution of single contracts or projects. Our ownership can vary from a small noncontrolling ownership to a significant ownership interest. We evaluate each partnership or joint venture to determine whether the entity is considered a VIE as defined in ASC 810, “Consolidation”, and if a VIE, whether we are the primary beneficiary of the VIE, which would require us to consolidate the VIE in our financial statements. When consolidation occurs, we account for the interests of the other parties as a noncontrolling interest and disclose the net income attributable to noncontrolling interests. See Note 11 — “Noncontrolling Interests" for further information. Equity method of accounting— We account for our interest in an investment using the equity method of accounting per ASC 323, “Investments—Equity Method and Joint Ventures” if we are not the primary beneficiary of a VIE or do not have a controlling interest. The investment is recorded at cost and the carrying amount is adjusted periodically to recognize our proportionate share of income or loss, additional contributions made and dividends and capital distributions received. We record the effect of any impairment or an other than temporary decrease in the value of its investment. In the event a partially owned equity affiliate were to incur a loss and our cumulative proportionate share of the loss exceeded the carrying amount of the equity method investment, application of the equity method would be suspended and our proportionate share of further losses would not be recognized unless we committed to provide further financial support to the affiliate. We would resume application of the equity method once the affiliate became profitable and our proportionate share of the affiliate’s earnings equals our cumulative proportionate share of losses that were not recognized during the period the application of the equity method was suspended. Cash concentration—We place our cash in demand deposit accounts and short-term U.S. Treasury bonds. At December 31, 2019 and 2018, we had cash balances of $120.3 million and $151.1 million, respectively. Our cash balances are held in high credit quality financial institutions in order to mitigate the risk of holding funds not backed by the federal government or in excess of federally backed limits. Collective bargaining agreements—Approximately 41.0% of our hourly employees, primarily consisting of field laborers, were covered by collective bargaining agreements in 2019. Upon renegotiation of such agreements, we could be exposed to increases in hourly costs and work stoppages. Of the 53 collective bargaining agreements to which we are a party to, 25 will require renegotiation during 2020. We have not had a significant work stoppage in more than 20 years. Multiemployer plans — Various 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. Federal law requires that if we were to withdraw from an agreement, we would incur a withdrawal obligation. The potential withdrawal obligation may be significant. In accordance with GAAP, any withdrawal liability would be recorded when it is probable that a liability exists and can be reasonably estimated. We have no plans to withdraw from any agreements. Insurance—We self-insure worker’s compensation, general liability, and auto insurance up to $0.5 million per claim. We maintained a self-insurance reserve totaling $39.3 million and $42.8 million at December 31, 2019 and 2018, respectively, with the current portion recorded to “Accrued liabilities” and the long-term portion recorded to “Other long-term liabilities” on the Consolidated Balance Sheets. Claims administration expenses are charged to current operations as incurred. Our accruals are based on judgment and the probability of losses, with the assistance of third-party actuaries. Actual payments that may be made in the future could materially differ from such reserves. 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 currently 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 Consolidated Statements of Income (mark-to-market accounting). Cash flows from derivatives settled are reported as cash flow from operating activities. Accounts receivable—Accounts receivable and contract receivables are primarily with public and private companies and governmental agencies located in the United States and Canada. Credit terms for payment of products and services are extended to customers in the normal course of business. Contract receivables are generally progress billings on projects, and as a result, are short term in nature. Generally, we require no collateral from our customers, but file statutory liens or stop notices on any construction projects when collection problems are anticipated. While a project is underway, we estimate the collectability of contract amounts at the same time that we estimate project costs. As discussed in Note 5 — “Revenue”, realization of the eventual cash collection may be recognized as adjustments to the contract revenue and profitability, otherwise, we use the specific identification method of accounting for losses from uncollectible accounts. Under this method an allowance is recorded based upon historical experience and management’s evaluation of outstanding contract receivables at the end of each year. Receivables are written off in the period deemed uncollectible. The allowance for doubtful accounts at December 31, 2019 and 2018 was $0.4 million and $1.7 million, respectively. Significant revision in contract estimates — We recognize revenue over time for firm fixed-price contracts. Under this method, the costs incurred to date as a percentage of total estimated costs are used to calculate revenue. Total estimated costs, and thus contract revenue and margin, are impacted by many factors, which can cause significant changes in estimates during the life cycle of a project. For projects that were in process at the end of the prior year, there can be a difference in revenue and profit that would have been recognized in the prior year had current year estimates of costs to complete been known at the end of the prior year. During the year ended December 31, 2019, certain contracts had revisions in cost estimates from those projected at December 31, 2018. This change in estimate resulted in a decrease in net income attributable to Primoris of $3.4 million, or $0.07 per share (basic and diluted) for the year ended December 31, 2019. Customer concentration — We operate in multiple industry segments encompassing the construction of commercial, utility, 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 50.0% of total revenue; however, the group that comprises the top ten customers varies from year to year. For the years ended December 31, 2019, 2018 and 2017, approximately 47.2%, 52.2% and 56.4%, respectively, of total revenue was generated from our top ten customers in each year. In each of the years, a different group of customers comprised the top ten customers by revenue, and no one customer accounted for more than 10% of total revenue. On January 29, 2019, one of our California utility customers filed for reorganization under Chapter 11 of the U.S. Bankruptcy Code. For the year ended December 31, 2019, the customer accounted for approximately 7.2% of our total revenue. In the third quarter of 2019, we entered into an agreement with a financial institution to sell, on a non-recourse basis, except in limited circumstances, substantially all of our pre-petition bankruptcy receivables with the customer. We received approximately $48.3 million upon the closing of this transaction in October 2019. During the year ended December 31, 2019, we recorded a loss of approximately $2.9 million in “Other income (expense), net” on the Consolidated Statements of Income related to the sale agreement. Additionally, we are continuing to perform services for the customer while the bankruptcy case is ongoing and the amounts billed for post-petition services continue to be collected in the ordinary course of the customer’s post-petition business. Property and equipment—Property and equipment are recorded at cost and are depreciated using the straight-line method over the estimated useful lives of the related assets, usually ranging from three to thirty years. Maintenance and repairs are charged to expense as incurred. Significant renewals and betterments are capitalized. At the time of retirement or other disposition of property and equipment, the cost and accumulated depreciation are removed from the accounts, and any resulting gain or loss is reflected in operating income. We assess the recoverability of property and equipment whenever events or changes in business circumstances indicate that the carrying amount of the asset may not be fully recoverable. We perform an analysis to determine if an impairment exists. The amount of property and equipment impairment, if any, is measured based on fair value and is charged to operations in the period in which the impairment is determined by management. For the years ended December 31, 2019, 2018 and 2017, our management has not identified any material impairment of its property and equipment. Taxes collected from customers—Sales and use taxes collected from our customers are recorded on a net basis. Share-based payments and stock-based compensation—In May 2013, the shareholders approved and we adopted the Primoris Services Corporation 2013 Long-term Incentive Equity Plan (“Equity Plan”). Detailed discussion of shares issued under the Equity Plan are included in Note 17 — “Deferred Compensation Agreements and Stock-Based Compensation” and in Note 21—“Stockholders’ Equity”. Such share issuances include grants of Restricted Stock Units to executives, issuance of stock to certain senior managers and executives and issuances of stock to non-employee members of the Board of Directors. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)”, with several clarifying updates. ASU 2016-02 requires recognition of operating leases with lease terms of more than twelve months on the balance sheet as both assets for the rights and liabilities for the obligations created by the leases. The ASU also requires disclosures that provide qualitative and quantitative information for the lease assets and liabilities recorded in the financial statements. The standard is effective for fiscal years beginning after December 15, 2018, and requires a modified retrospective transition method where a company applies the new lease standard at (i) the beginning of the earliest period presented in the financial statements, or (ii) the adoption date and recognizes a cumulative effect adjustment to the opening balance of retained earnings. We adopted the new standard as of January 1, 2019 using the modified retrospective transition method and elected to apply the new lease standard at the adoption date. See Note 12 — “Leases” for further details. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which introduced an expected credit loss methodology for the measurement and recognition of credit losses on most financial assets, including trade accounts receivables. The expected credit loss methodology under ASU 2016-13 is based on historical experience, current conditions and reasonable and supportable forecasts, and replaces the probable/incurred loss model for measuring and recognizing expected losses under current GAAP. The ASU also requires disclosure of information regarding how a company developed its allowance, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. The ASU and its related clarifying updates are effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. We adopted the new standard on January 1, 2020, and it did not have a material impact on our estimate of the allowance for uncollectable accounts. In January 2017, the FASB issued ASU 2017-04, "Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment". ASU 2017-04 removes the second step of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. ASU 2017-04 is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted. We adopted the standard on January 1, 2019, and it did not have an impact on our financial position, results of operations, or cash flows. In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement”, which eliminates certain disclosure requirements for recurring and nonrecurring fair value measurements. The ASU eliminates such disclosures as the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, and adds new disclosure requirements for Level 3 measurements. This ASU is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted for any eliminated or modified disclosures. We do not expect the adoption of this ASU to have a material impact on our disclosures. In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”, which removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. Depending on the amendment, adoption may be applied on the retrospective, modified retrospective, or prospective basis. We are currently evaluating the potential effects of adopting the provisions of ASU No. 2019-12. Other new pronouncements issued but not effective until after December 31, 2019 are not expected to have a material impact on our consolidated results of operations, financial position or cash flows.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies

Note 2—Summary of Significant Accounting Policies

Basis of presentation —The accompanying consolidated financial statements were prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and the financial statement rules and regulations of the Securities and Exchange Commission (“SEC”). References for Financial Accounting Standards Board (“FASB”) standards are made to the FASB Accounting Standards Codification (“ASC”).

Principles of consolidation —The accompanying Consolidated Financial Statements include the accounts of Primoris, our wholly-owned subsidiaries and the noncontrolling interests of the Carlsbad and Wilmington joint ventures, which are VIEs for which we are the primary beneficiary as determined under the provisions of ASC 810, “Consolidation”. All intercompany balances and transactions have been eliminated in consolidation.

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

Use of estimates —The preparation of our Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. As a construction contractor, we use estimates for costs to complete construction projects and the contract value of certain construction projects. These estimates have a direct effect on gross profit as reported in these consolidated financial statements. Actual results could materially differ from our estimates.

Operating cycle — In the accompanying Consolidated Balance Sheets, assets and liabilities relating to long-term construction contracts (e.g. contract assets and contract liabilities) are considered current assets and current liabilities, since they are expected to be realized or liquidated in the normal course of contract completion, although completion may require more than one calendar year.

Consequently, we have significant working capital invested in assets that may have a liquidation period extending beyond one year. We have claims receivable and retention due from various customers and others that are currently in dispute, the realization of which is subject to binding arbitration, final negotiation or litigation, all of which may extend beyond one calendar year.

Cash and cash equivalents —We consider all highly liquid investments with an original maturity of three months or less when purchased as cash equivalents.

Business combinations—Business combinations are accounted for using the acquisition method of accounting. We use the fair value of the assets acquired and liabilities assumed to account for the purchase price of businesses. The determination of fair value requires estimates and judgments of future cash flow expectations to assign fair values to the identifiable tangible and intangible assets. GAAP provides a “measurement period” of up to one year in which to finalize all fair value estimates associated with the

acquisition of a business. Most estimates are preliminary until the end of the measurement period. During the measurement period, any material, newly discovered information that existed at the acquisition date would be reflected as an adjustment to the initial valuations and estimates. After the measurement period, any adjustments would be recorded as a current period income or expense.

Contingent Earnout Liabilities—As part of certain acquisitions, we agreed to pay cash to certain sellers upon meeting specific operating performance targets for specified periods subsequent to the acquisition date. Each quarter, we evaluate the fair value of the estimated contingency and record a non-operating charge for the change in the fair value. Upon meeting the target, we reflect the full liability on the balance sheet and record a charge to “Other income (expense), net” for the change in the fair value of the liability from the prior period. See Note 3 — “Fair Value Measurements” for further discussion.

Goodwill and other intangible assets—We account for goodwill in accordance with ASC 350, “Intangibles — Goodwill and Other”. Under ASC 350, goodwill is subject to an annual impairment test, which we perform as of the first day of the fourth quarter of each year, with more frequent testing if indicators of potential impairment exist. The impairment review is performed at the reporting unit level for those units with recorded goodwill. For the majority of our reporting units, we perform a qualitative assessment to determine whether it is more likely than not (that is, a likelihood of more than 50 percent) that the fair value of the reporting unit is less than its carrying value, including goodwill. Factors used in our qualitative assessment include, but are not limited to, macroeconomic conditions, industry and market conditions, cost factors, overall financial performance and Company and reporting unit specific events. For all other reporting units, we use the quantitative impairment test outlined in ASC 350, which compares the fair value of a reporting unit with its carrying amount. Fair value for the goodwill impairment test is determined utilizing a discounted cash flow analysis based on our financial plan discounted using our weighted average cost of capital and market indicators of terminal year cash flows. Other valuation methods may be used to corroborate the discounted cash flow method. If the carrying amount of a reporting unit is in excess of its fair value, goodwill is considered impaired and an impairment loss is recognized in an amount equal to that excess, limited to the total amount of goodwill of the reporting unit.

Income tax—Current income tax expense is the amount of income taxes expected to be paid for the financial results of the current year. A deferred tax liability or asset is established for the expected future tax consequences resulting from the differences in financial reporting bases and tax bases of assets and liabilities using enacted tax rates in effect for the years in which the differences are expected to reverse. A valuation allowance is provided if it is more likely than not that some or all of the deferred tax assets will not be realized. We provide for uncertain tax positions when such tax positions do not meet the recognition thresholds or measurement standards as set forth in ASC 740, “Income Taxes”. The difference between a tax position taken or expected to be taken on our income tax returns and the benefit recognized in our financial statements is referred to as an unrecognized tax benefit. Amounts for uncertain tax positions are adjusted in periods when new information becomes available or when positions are effectively settled. We recognize accrued interest and penalties related to uncertain tax positions, if any, as a component of income tax expense.

As a result of the Tax Cuts and Jobs Act (the “Tax Act”) new taxes were created on certain foreign earnings. Namely, U.S. shareholders are now subject to a current tax on global intangible low-taxed income (“GILTI”) earned by specified foreign subsidiaries. Available guidance related to GILTI provides for an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years, or provide for the tax expense related to GILTI in the year the tax is incurred as a period expense. We have elected to recognize the current tax on GILTI as an expense in the period the tax is incurred. The current tax impacts of GILTI are included in our effective tax rate.

Staff Accounting Bulletin (“SAB”) 118 provided guidance on accounting for uncertainties of the effects of the Tax Act. Specifically, SAB 118 allowed companies to record provisional estimates of the impact of the Tax Act during a one year “measurement period” from the December 22, 2017 enactment date, similar to that used when accounting for business combinations. As a result of the Tax Act, we remeasured deferred tax assets and liabilities using the newly enacted tax rates and recorded a one-time net tax benefit of $9.4 million as a provisional estimate under SAB 118 in the year ended December 31, 2017. As of December 31, 2018, our accounting for the Tax Act was complete. The provision for income taxes for the year ended December 31, 2018 included a $1.1 million increase from the completion of our provisional accounting for the effects of the Tax Act under SAB 118. The increase was due to $0.6 million of additional expense associated with foreign tax credits, net of associated valuation allowances, and $0.5 million of additional expense related to the corporate tax rate change impact on return-to-provision adjustments, primarily for depreciation.

Comprehensive income—We account for comprehensive income in accordance with ASC 220, “Comprehensive Income”, which specifies the computation, presentation and disclosure requirements for comprehensive income (loss). Comprehensive income (loss) consists of net income (loss) and foreign currency translation adjustments, primarily from fluctuations in foreign currency exchange rates of our foreign subsidiaries with a functional currency other than the U.S. dollar.

Functional currencies and foreign currency translation— For foreign operations where substantially all monetary transactions are in the local currency, we use the local currency as our functional currency. The effects of translating financial statements of foreign operations into our reporting currency are recognized as a cumulative translation adjustment, net of tax in “Accumulated other comprehensive income (loss)” in the Consolidated Statements of Stockholders’ Equity. For certain foreign operations where substantially all monetary transactions are made in United States dollars, we use the U.S. dollar as our functional currency, with gains or losses on translation recorded in income in the period in which they are incurred. Gains or losses on foreign currency transactions are recorded in income in the period in which they are incurred.

Partnerships and joint ventures — We are periodically a member of a partnership or a joint venture. These partnerships or joint ventures are used primarily for the execution of single contracts or projects. Our ownership can vary from a small noncontrolling ownership to a significant ownership interest. We evaluate each partnership or joint venture to determine whether the entity is considered a VIE as defined in ASC 810, “Consolidation”, and if a VIE, whether we are the primary beneficiary of the VIE, which would require us to consolidate the VIE in our financial statements. When consolidation occurs, we account for the interests of the other parties as a noncontrolling interest and disclose the net income attributable to noncontrolling interests. See Note 11 — “Noncontrolling Interests" for further information.

Equity method of accounting— We account for our interest in an investment using the equity method of accounting per ASC 323, “Investments—Equity Method and Joint Ventures” if we are not the primary beneficiary of a VIE or do not have a controlling interest. The investment is recorded at cost and the carrying amount is adjusted periodically to recognize our proportionate share of income or loss, additional contributions made and dividends and capital distributions received. We record the effect of any impairment or an other than temporary decrease in the value of its investment.

In the event a partially owned equity affiliate were to incur a loss and our cumulative proportionate share of the loss exceeded the carrying amount of the equity method investment, application of the equity method would be suspended and our proportionate share of further losses would not be recognized unless we committed to provide further financial support to the affiliate. We would resume application of the equity method once the affiliate became profitable and our proportionate share of the affiliate’s earnings equals our cumulative proportionate share of losses that were not recognized during the period the application of the equity method was suspended.

Cash concentration—We place our cash in demand deposit accounts and short-term U.S. Treasury bonds. At December 31, 2019 and 2018, we had cash balances of $120.3 million and $151.1 million, respectively. Our cash balances are held in high credit quality financial institutions in order to mitigate the risk of holding funds not backed by the federal government or in excess of federally backed limits.

Collective bargaining agreements—Approximately 41.0% of our hourly employees, primarily consisting of field laborers, were covered by collective bargaining agreements in 2019. Upon renegotiation of such agreements, we could be exposed to increases in hourly costs and work stoppages. Of the 53 collective bargaining agreements to which we are a party to, 25 will require renegotiation during 2020. We have not had a significant work stoppage in more than 20 years.

Multiemployer plans — Various 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. Federal law requires that if we were to withdraw from an agreement, we would incur a withdrawal obligation. The potential withdrawal obligation may be significant. In accordance with GAAP, any withdrawal liability would be recorded when it is probable that a liability exists and can be reasonably estimated. We have no plans to withdraw from any agreements.

Insurance—We self-insure worker’s compensation, general liability, and auto insurance up to $0.5 million per claim. We maintained a self-insurance reserve totaling $39.3 million and $42.8 million at December 31, 2019 and 2018, respectively, with the current portion recorded to “Accrued liabilities” and the long-term portion recorded to “Other long-term liabilities” on the Consolidated Balance Sheets. Claims administration expenses are charged to current operations as incurred. Our accruals are based on judgment and the probability of losses, with the assistance of third-party actuaries. Actual payments that may be made in the future could materially differ from such reserves.

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 currently 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 Consolidated Statements of Income (mark-to-market accounting). Cash flows from derivatives settled are reported as cash flow from operating activities.

Accounts receivable—Accounts receivable and contract receivables are primarily with public and private companies and governmental agencies located in the United States and Canada. Credit terms for payment of products and services are extended to customers in the normal course of business. Contract receivables are generally progress billings on projects, and as a result, are short term in nature. Generally, we require no collateral from our customers, but file statutory liens or stop notices on any construction projects when collection problems are anticipated. While a project is underway, we estimate the collectability of contract amounts at the same time that we estimate project costs. As discussed in Note 5 — “Revenue”, realization of the eventual cash collection may be recognized as adjustments to the contract revenue and profitability, otherwise, we use the specific identification method of accounting for losses from uncollectible accounts. Under this method an allowance is recorded based upon historical experience and management’s evaluation of outstanding contract receivables at the end of each year. Receivables are written off in the period deemed uncollectible. The allowance for doubtful accounts at December 31, 2019 and 2018 was $0.4 million and $1.7 million, respectively.

Significant revision in contract estimates — We recognize revenue over time for firm fixed-price contracts. Under this method, the costs incurred to date as a percentage of total estimated costs are used to calculate revenue. Total estimated costs, and thus contract revenue and margin, are impacted by many factors, which can cause significant changes in estimates during the life cycle of a project. For projects that were in process at the end of the prior year, there can be a difference in revenue and profit that would have been recognized in the prior year had current year estimates of costs to complete been known at the end of the prior year. During the year ended December 31, 2019, certain contracts had revisions in cost estimates from those projected at December 31, 2018. This change in estimate resulted in a decrease in net income attributable to Primoris of $3.4 million, or $0.07 per share (basic and diluted) for the year ended December 31, 2019.

Customer concentration — We operate in multiple industry segments encompassing the construction of commercial, utility, 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 50.0% of total revenue; however, the group that comprises the top ten customers varies from year to year. For the years ended December 31, 2019, 2018 and 2017, approximately 47.2%, 52.2% and 56.4%, respectively, of total revenue was generated from our top ten customers in each year. In each of the years, a different group of customers comprised the top ten customers by revenue, and no one customer accounted for more than 10% of total revenue.

On January 29, 2019, one of our California utility customers filed for reorganization under Chapter 11 of the U.S. Bankruptcy Code. For the year ended December 31, 2019, the customer accounted for approximately 7.2% of our total revenue. In the third quarter of 2019, we entered into an agreement with a financial institution to sell, on a non-recourse basis, except in limited circumstances, substantially all of our pre-petition bankruptcy receivables with the customer. We received approximately $48.3 million upon the closing of this transaction in October 2019. During the year ended December 31, 2019, we recorded a loss of approximately $2.9 million in “Other income (expense), net” on the Consolidated Statements of Income related to the sale agreement. Additionally, we are continuing to perform services for the customer while the bankruptcy case is ongoing and the amounts billed for post-petition services continue to be collected in the ordinary course of the customer’s post-petition business.

Property and equipment—Property and equipment are recorded at cost and are depreciated using the straight-line method over the estimated useful lives of the related assets, usually ranging from three to thirty years. Maintenance and repairs are charged to expense as incurred. Significant renewals and betterments are capitalized. At the time of retirement or other disposition of property and equipment, the cost and accumulated depreciation are removed from the accounts, and any resulting gain or loss is reflected in operating income.

We assess the recoverability of property and equipment whenever events or changes in business circumstances indicate that the carrying amount of the asset may not be fully recoverable. We perform an analysis to determine if an impairment exists. The amount of property and equipment impairment, if any, is measured based on fair value and is charged to operations in the period in which the impairment is determined by management. For the years ended December 31, 2019, 2018 and 2017, our management has not identified any material impairment of its property and equipment.

Taxes collected from customers—Sales and use taxes collected from our customers are recorded on a net basis.

Share-based payments and stock-based compensation—In May 2013, the shareholders approved and we adopted the Primoris Services Corporation 2013 Long-term Incentive Equity Plan (“Equity Plan”). Detailed discussion of shares issued under the Equity Plan are included in Note 17 — “Deferred Compensation Agreements and Stock-Based Compensation” and in Note 21—“Stockholders’ Equity”. Such share issuances include grants of Restricted Stock Units to executives, issuance of stock to certain senior managers and executives and issuances of stock to non-employee members of the Board of Directors.

Recently Issued Accounting Pronouncements

In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)”, with several clarifying updates. ASU 2016-02 requires recognition of operating leases with lease terms of more than twelve months on the balance sheet as both assets for the rights and liabilities for the obligations created by the leases. The ASU also requires disclosures that provide qualitative and quantitative information for the lease assets and liabilities recorded in the financial statements. The standard is effective for fiscal years beginning after December 15, 2018, and requires a modified retrospective transition method where a company applies the new lease standard at (i) the beginning of the earliest period presented in the financial statements, or (ii) the adoption date and recognizes a cumulative effect adjustment to the opening balance of retained earnings. We adopted the new standard as of January 1, 2019 using the modified retrospective transition method and elected to apply the new lease standard at the adoption date. See Note 12 — “Leases” for further details.

In June 2016, the FASB issued ASU 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which introduced an expected credit loss methodology for the measurement and recognition of credit losses on most financial assets, including trade accounts receivables. The expected credit loss methodology under ASU 2016-13 is based on historical experience, current conditions and reasonable and supportable forecasts, and replaces the probable/incurred loss model for measuring and recognizing expected losses under current GAAP. The ASU also requires disclosure of information regarding how a company developed its allowance, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. The ASU and its related clarifying updates are effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. We adopted the new standard on January 1, 2020, and it did not have a material impact on our estimate of the allowance for uncollectable accounts.

In January 2017, the FASB issued ASU 2017-04, "Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment". ASU 2017-04 removes the second step of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. ASU 2017-04 is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted. We adopted the standard on January 1, 2019, and it did not have an impact on our financial position, results of operations, or cash flows.

In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement”, which eliminates certain disclosure requirements for recurring and nonrecurring fair value measurements. The ASU eliminates such disclosures as the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, and adds new disclosure requirements for Level 3 measurements. This ASU is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted for any eliminated or modified disclosures. We do not expect the adoption of this ASU to have a material impact on our disclosures.

In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”, which removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. Depending on the amendment, adoption may be applied on the retrospective, modified retrospective, or prospective basis. We are currently evaluating the potential effects of adopting the provisions of ASU No. 2019-12.

Other new pronouncements issued but not effective until after December 31, 2019 are not expected to have a material impact on our consolidated results of operations, financial position or cash flows.