Significant Accounting Policies and Estimates (Notes)	12 Months Ended
Jan. 25, 2020
Accounting Policies [Abstract]
Basis of Presentation and Accounting Policies	Significant Accounting Policies and Estimates Use of Estimates. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. These key estimates include: the recognition of revenue under the cost-to-cost method of progress, accrued insurance claims, the allowance for doubtful accounts, accruals for contingencies, stock-based compensation expense for performance-based stock awards, the fair value of reporting units for the goodwill impairment analysis, the assessment of impairment of intangibles and other long lived assets, the purchase price allocations of businesses acquired, and income taxes. These estimates are based on our historical experience and management’s understanding of current facts and circumstances. At the time they are made, we believe that such estimates are fair when considered in conjunction with the Company’s consolidated financial position and results of operations taken as a whole. However, actual results could differ materially from those estimates. Leases. Our leases are accounted for as operating leases, with lease expense recognized on a straight-line basis over the lease term. The lease term may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. For leases with initial terms greater than 12 months, we record operating lease right-of-use assets and corresponding operating lease liabilities. Operating lease right-of-use assets represent our right to use the underlying asset for the lease term and operating lease liabilities represent our obligation to make the related lease payments. These assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. As our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. Leases with an initial term of 12 months or less are not recorded on our consolidated balance sheet. Revenue Recognition. We perform a majority of our services under master service agreements and other contracts that contain customer-specified service requirements. These agreements include discrete pricing for individual tasks including, for example, the placement of underground or aerial fiber, directional boring, and fiber splicing, each based on a specific unit of measure. A contractual agreement exists when each party involved approves and commits to the agreement, the rights of the parties and payment terms are identified, the agreement has commercial substance, and collectability of consideration is probable. Our services are performed for the sole benefit of our customers, whereby the assets being created or maintained are controlled by the customer and the services we perform do not have alternative benefits for us. Revenue is recognized over time as services are performed and customers simultaneously receive and consume the benefits we provide. Output measures such as units delivered are utilized to assess progress against specific contractual performance obligations for the majority of our services. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the services to be provided. For us, the output method using units delivered best represents the measure of progress against the performance obligations incorporated within the contractual agreements. This method captures the amount of units delivered pursuant to contracts and is used only when our performance does not produce significant amounts of work in process prior to complete satisfaction of the performance obligation. For a portion of contract items, units to be completed consist of multiple tasks. For these items, the transaction price is allocated to each task based on relative standalone measurements, such as selling prices for similar tasks, or in the alternative, the cost to perform the tasks. Revenue is recognized as the tasks are completed as a measurement of progress in the satisfaction of the corresponding performance obligation, and represented approximately 15% of contract revenues during fiscal 2020. For certain contracts, representing less than 5% of contract revenues during fiscal 2020, fiscal 2019, the 2018 transition period, and fiscal 2017, we use the cost-to-cost measure of progress. These contracts are generally projects that are completed over a period of less than 12 months and for which payment is received in a lump sum at the end of the project. Under the cost-to-cost measure of progress, the extent of progress toward completion is measured based on the ratio of costs incurred to date to the total estimated costs. Contract costs include direct labor, direct materials, and subcontractor costs, as well as an allocation of indirect costs. Contract revenues are recorded as costs are incurred. We accrue the entire amount of a contract loss, if any, at the time the loss is determined to be probable and can be reasonably estimated. There were no material amounts of unapproved change orders or claims recognized during fiscal 2020, fiscal 2019, the 2018 transition period, or fiscal 2017. Accounts Receivable, Net. We grant credit to our customers, generally without collateral, under normal payment terms (typically 30 to 90 days after invoicing). Generally, invoicing occurs within 45 days after the related services are performed. Accounts receivable represents an unconditional right to consideration arising from our performance under contracts with customers. Accounts receivable include billed accounts receivable, unbilled accounts receivable, and retainage. The carrying value of such receivables, net of the allowance for doubtful accounts, represents their estimated realizable value. Unbilled accounts receivable represent amounts we have an unconditional right to receive payment for although invoicing is subject to the completion of certain processes or other requirements. Such requirements may include the passage of time, completion of other items within a statement of work, or other contractual billing requirements. Certain of our contracts contain retainage provisions whereby a portion of the revenue earned is withheld from payment as a form of security until contractual provisions are satisfied. The collectability of retainage is included in our overall assessment of the collectability of accounts receivable. We expect to collect the outstanding balance of current accounts receivable, net (including trade accounts receivable, unbilled accounts receivable, and retainage) within the next 12 months. As of January 26, 2019, accounts receivable of $24.8 million from Windstream were classified as non-current in other assets and were net of the related allowance for doubtful accounts. On February 25, 2019, Windstream filed a voluntary petition under Chapter 11 of the United States Bankruptcy Code in the U.S. Bankruptcy Court for the Southern District of New York. As of January 25, 2020, all Windstream’s accounts receivable was classified as current. We estimate our allowance for doubtful accounts by evaluating specific accounts receivable balances based on historical collection trends, the age of outstanding receivables, and the credit worthiness of our customers. We have participated in a customer-sponsored vendor payment program for one of our customers since fiscal 2016. All eligible accounts receivable from this customer are included in the program and payment is received pursuant to a non-recourse sale to a bank partner of the customer. This program effectively reduces the time to collect these receivables as compared to that customer’s standard payment terms. We incur a discount fee to the bank on the payments received that is reflected as an expense component in other income, net, in the consolidated statements of operations. The operations of this program have not changed since we began participating. Contract Assets. Contract assets include unbilled amounts typically resulting from arrangements whereby complete satisfaction of a performance obligation and the right to payment are conditioned on completing additional tasks or services. Contract Liabilities. Contract liabilities consist of amounts invoiced to customers in excess of revenue recognized. Our contract assets and liabilities are reported in a net position on a contract by contract basis at the end of each reporting period. As of January 25, 2020 and January 26, 2019, the contract liabilities balance is classified as current based on the timing of when we expect to complete the tasks required for the recognition of revenue. Cash and Equivalents. Cash and equivalents primarily include balances on deposit in banks. We maintain our cash and equivalents at financial institutions we believe to be of high credit quality. To date, we have not experienced any loss or lack of access to cash in our operating accounts. Inventories. Inventories consist of materials and supplies used in the ordinary course of business and are carried at the lower of cost (using the first-in, first-out method) or net realizable value. Inventories also include certain job specific materials that are valued using the specific identification method. For contracts where we are required to supply part or all of the materials on behalf of a customer, the loss of a customer or declines in contract volumes could result in an impairment of the value of materials purchased. Property and Equipment. Property and equipment are stated at cost and depreciated on a straight-line basis over their estimated useful lives (see Note 9, Property and Equipment, for the range of useful lives). Leasehold improvements are depreciated on a straight-line basis over the lesser of the estimated useful life of the asset or the remaining lease term. Maintenance and repairs are expensed as incurred and major improvements are capitalized. When assets are sold or retired, the cost and related accumulated depreciation are removed from the accounts and the resulting gain or loss is included in other income. Capitalized software consists primarily of costs to purchase and develop internal-use software and is amortized over its useful life as a component of depreciation expense. Property and equipment includes internally developed capitalized computer software at net book value of $21.2 million and $28.5 million as of January 25, 2020 and January 26, 2019, respectively. Goodwill and Intangible Assets. Goodwill and other indefinite-lived intangible assets are assessed annually for impairment, or more frequently if events occur that would indicate a potential reduction in the fair value of a reporting unit below its carrying value. We perform our annual impairment review of goodwill at the reporting unit level. Each of our operating segments with goodwill represents a reporting unit for the purpose of assessing impairment. If we determine the fair value of the reporting unit’s goodwill or other indefinite-lived intangible assets is less than their carrying value as a result of an annual or interim test, an impairment loss is recognized and reflected in operating income or loss in the consolidated statements of operations during the period incurred. We complete our annual goodwill impairment assessment as of the first day of the fourth fiscal quarter of each year. As a result of the change in our fiscal year end in fiscal 2018, the annual goodwill impairment assessment date was changed to the first day of the fiscal quarter ending on the last Saturday in January, as this became the first day of our fourth fiscal quarter. The change in the annual goodwill impairment assessment date was deemed a change in accounting principle, which we believe to be preferable as the change was made to better align the annual goodwill impairment test with the change in our annual planning and budgeting process related to the new fiscal year end. This change in accounting principle did not delay, accelerate or avoid a goodwill impairment charge and had no effect on the consolidated financial statements, including any cumulative effect on retained earnings. We review finite-lived intangible assets for impairment whenever an event occurs or circumstances change that indicate that the carrying amount of such assets may not be fully recoverable. Recoverability is determined based on an estimate of undiscounted future cash flows resulting from the use of an asset and its eventual disposition. If an asset is not recoverable, an impairment loss is measured by comparing the fair value of the asset to its carrying value. If we determine the fair value of an asset is less than the carrying value, an impairment loss is recognized in operating income or loss in the consolidated statements of operations during the period incurred. We use judgment in assessing whether goodwill and intangible assets are impaired. Estimates of fair value are based on our projection of revenues, operating costs, and cash flows taking into consideration historical and anticipated future results, general economic and market conditions, as well as the impact of planned business or operational strategies. We determine the fair value of our reporting units using a weighing of fair values derived in equal proportions from the income approach and market approach valuation methodologies. The income approach uses the discounted cash flow method and the market approach uses the guideline company method. Changes in our judgments and projections could result in significantly different estimates of fair value, potentially resulting in impairments of goodwill and other intangible assets. The inputs used for fair value measurements of the reporting units and other related indefinite-lived intangible assets are the lowest level (Level 3) inputs. See Note 10, Goodwill and Intangible Assets, for additional information regarding our annual assessment of goodwill and other indefinite-lived intangible assets. Business Combinations. We account for business combinations under the acquisition method of accounting. The purchase price of each business acquired is allocated to the tangible and intangible assets acquired and the liabilities assumed based on information regarding their respective fair values on the date of acquisition. Any excess of the purchase price over the fair value of the separately identifiable assets acquired and the liabilities assumed is allocated to goodwill. Management determines the fair values used in purchase price allocations for intangible assets based on historical data, estimated discounted future cash flows, expected royalty rates for trademarks and trade names, as well as certain other information. The valuation of assets acquired and liabilities assumed requires a number of judgments and is subject to revision as additional information about the fair value of assets and liabilities becomes available. Additional information, which existed as of the acquisition date but unknown to us at that time, may become known during the remainder of the measurement period. This measurement period may not exceed 12 months from the acquisition date. We will recognize any adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustments are determined. Additionally, in the same period in which adjustments are recognized, we will record the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of any change to the provisional amounts, calculated as if the accounting adjustment had been completed at the acquisition date. Acquisition costs are expensed as incurred. The results of operations of businesses acquired are included in the consolidated financial statements from their dates of acquisition. Long-Lived Tangible Assets. We review long-lived tangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be fully recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of an asset group and its eventual disposition. Measurement of an impairment loss is based on the fair value of the asset compared to its carrying value. Long-lived tangible assets to be disposed of are reported at the lower of their carrying amount or fair value less costs to sell. Accrued Insurance Claims. For claims within our insurance program, we retain the risk of loss, up to certain limits, for matters related to automobile liability, general liability (including damages associated with underground facility locating services), workers’ compensation, and employee group health. We have established reserves that we believes to be adequate based on current evaluations and our experience with these types of claims. A liability for unpaid claims and the associated claim expenses, including incurred but not reported losses, is determined with the assistance of an actuary and reflected in the consolidated financial statements as accrued insurance claims. The effect on our financial statements is generally limited to the amount needed to satisfy our insurance deductibles or retentions. We estimate the liability for claims based on facts, circumstances, and historical experience. Even though they will not be paid until sometime in the future, recorded loss reserves are not discounted. Factors affecting the determination of the expected cost for existing and incurred but not reported claims include, but are not limited to, the magnitude and quantity of future claims, the payment pattern of claims which have been incurred, changes in the medical condition of claimants, and other factors such as inflation, tort reform or other legislative changes, unfavorable jury decisions and court interpretations. Per Share Data. Basic earnings per common share is computed based on the weighted average number of common shares outstanding during the period, excluding unvested restricted share units. Diluted earnings per common share includes the weighted average number of common shares outstanding during the period and dilutive potential common shares arising from our stock-based awards (including unvested restricted share units), convertible senior notes, and warrants if their inclusion is dilutive under the treasury stock method. Common stock equivalents related to stock-based awards, convertible senior notes, and warrants are excluded from diluted earnings per common share calculations if their effect would be anti-dilutive. We adopted the Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”) on a prospective basis effective July 30, 2017, the first day of the 2018 transition period. Under the amended guidance, excess tax benefits and tax deficiencies arising from the vesting and exercise of share-based awards are no longer included in the hypothetical proceeds used to repurchase shares when computing diluted earnings per common share under the treasury stock method. See Note 4, Computation of Earnings Per Share, for additional information related to ASU 2016-09’s impact on per share data. Stock-Based Compensation. We have stock-based compensation plans under which we grant stock-based awards, including stock options, time-based restricted share units (“RSUs”), and performance-based restricted share units (“Performance RSUs”) to attract, retain, and reward talented employees, officers, and directors, and to align stockholder and employee interests. The resulting compensation expense is recognized on a straight-line basis over the vesting period, net of actual forfeitures, and is included in general and administrative expenses in the consolidated statements of operations. This expense fluctuates over time as a result of the vesting periods of the stock-based awards and, for our Performance RSUs, the expected achievement of performance measures. Compensation expense for stock-based awards is based on fair value at the measurement date. The fair value of stock options is estimated on the date of grant using the Black-Scholes option pricing model. This valuation is affected by our stock price as well as other inputs, including the expected common stock price volatility over the expected life of the options, the expected term of the stock option, risk-free interest rates, and expected dividends, if any. Stock options vest ratably over a four- year period and are exercisable over a period of up to ten years. The fair value of RSUs and Performance RSUs is estimated on the date of grant and is equal to the closing market price per share of our common stock on that date. RSUs generally vest ratably over a four-year period. Performance RSUs vest ratably over a three-year period, if certain performance measures are achieved. Each RSU and Performance RSU is settled in one share of the Company’s common stock upon vesting. For Performance RSUs, we evaluate compensation expense quarterly and recognize expense only if we determine it is probable that the performance measures for the awards will be met. The performance measures for target awards are based on our operating earnings (adjusted for certain amounts) as a percentage of contract revenues and our operating cash flow level (adjusted for certain amounts) for the applicable four-quarter performance period. Additionally, certain awards include three-year performance measures that are more difficult to achieve than those required to earn target awards and, if met, result in supplemental shares awarded. The performance measures for supplemental awards are based on three-year cumulative operating earnings (adjusted for certain amounts) as a percentage of contract revenues and three-year cumulative operating cash flow level (adjusted for certain amounts). In a period we determine it is no longer probable that we will achieve certain performance measures for the awards, we reverse the stock-based compensation expense that we had previously recognized and associated with the portion of Performance RSUs that are no longer expected to vest. The amount of the expense ultimately recognized depends on the number of awards that actually vest. Accordingly, stock-based compensation expense may vary from period to period. For additional information on our stock-based compensation plans, stock options, RSUs, and Performance RSUs, see Note 19, Stock-Based Awards. Income Taxes. We account for income taxes under the asset and liability method. This approach requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of assets and liabilities. Our effective income tax rate differs from the statutory rate for the tax jurisdictions where we operate, primarily as the result of the impact of non-deductible and non-taxable items, tax credits recognized in relation to pre-tax results, certain tax impacts from the vesting and exercise of share-based awards, and certain tax impacts from the Tax Cuts and Jobs Act of 2017 (“Tax Reform”). Tax Reform had a substantial impact on our consolidated financial statements for the 2018 transition period. See Note 15, Income Taxes, for further information. Measurement of our tax position is based on the applicable statutes, federal and state case law, and our interpretations of tax regulations. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income during the period that includes the enactment date. We record net deferred tax assets to the extent we believe these assets will more likely than not be realized. In making such determination, we consider all relevant factors, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent financial operations. In the event we determine that we would be able to realize deferred income tax assets in excess of their net recorded amount, we would adjust the valuation allowance, which would reduce the provision for income taxes. We recognize tax benefits in the amount that we deem, more likely than not, will be realized upon ultimate settlement of any tax uncertainty. Tax positions that fail to qualify for recognition are recognized during the period in which the more-likely-than-not standard has been reached, when the tax positions are resolved with the respective taxing authority or when the statute of limitations for tax examination has expired. We recognize applicable interest related to tax amounts in interest expense and penalties within general and administrative expenses. We believe our provision for income taxes is adequate; however, any assessment would affect our results of operations and cash flows. With few exceptions, we are no longer subject to U.S. federal, state and local, or Canadian income tax examinations for fiscal years ended 2015 and prior. Fair Value of Financial Instruments. Our financial instruments primarily consist of cash and equivalents, restricted cash, accounts receivable, income taxes receivable and payable, accounts payable, certain accrued expenses, and long-term debt. The carrying amounts of these items approximate fair value due to their short maturity, except for the fair value of our long-term debt, which is based on observable market-based inputs (Level 2). See Note 14, Debt, for further information regarding the fair value of such financial instruments. Our cash and equivalents are based on quoted market prices in active markets for identical assets (Level 1) as of January 25, 2020 and January 26, 2019. During fiscal 2020, fiscal 2019, the 2018 transition, and fiscal 2017, we had no material nonrecurring fair value measurements of assets or liabilities subsequent to their initial recognition. Taxes Collected from Customers. ASC Topic 606, Taxes Collected from Customers and Remitted to Governmental Authorities, addresses the income statement presentation of any taxes collected from customers and remitted to a government authority and provides that the presentation of taxes on either a gross basis or a net basis is an accounting policy decision that should be disclosed. Our policy is to present contract revenues net of sales taxes.

Use of Estimates. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. These key estimates include: the recognition of revenue under the cost-to-cost method of progress, accrued insurance claims, the allowance for doubtful accounts, accruals for contingencies, stock-based compensation expense for performance-based stock awards, the fair value of reporting units for the goodwill impairment analysis, the assessment of impairment of intangibles and other long lived assets, the purchase price allocations of businesses acquired, and income taxes. These estimates are based on our historical experience and management’s understanding of current facts and circumstances. At the time they are made, we believe that such estimates are fair when considered in conjunction with the Company’s consolidated financial position and results of operations taken as a whole. However, actual results could differ materially from those estimates.

Leases. Our leases are accounted for as operating leases, with lease expense recognized on a straight-line basis over the lease term. The lease term may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. For leases with initial terms greater than 12 months, we record operating lease right-of-use assets and corresponding operating lease liabilities. Operating lease right-of-use assets represent our right to use the underlying asset for the lease term and operating lease liabilities represent our obligation to make the related lease payments. These assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. As our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. Leases with an initial term of 12 months or less are not recorded on our consolidated balance sheet.

measure. A contractual agreement exists when each party involved approves and commits to the agreement, the rights of the parties and payment terms are identified, the agreement has commercial substance, and collectability of consideration is probable. Our services are performed for the sole benefit of our customers, whereby the assets being created or maintained are controlled by the customer and the services we perform do not have alternative benefits for us. Revenue is recognized over time as services are performed and customers simultaneously receive and consume the benefits we provide. Output measures such as units delivered are utilized to assess progress against specific contractual performance obligations for the majority of our services. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the services to be provided. For us, the output method using units delivered best represents the measure of progress against the performance obligations incorporated within the contractual agreements. This method captures the amount of units delivered pursuant to contracts and is used only when our performance does not produce significant amounts of work in process prior to complete satisfaction of the performance obligation. For a portion of contract items, units to be completed consist of multiple tasks. For these items, the transaction price is allocated to each task based on relative standalone measurements, such as selling prices for similar tasks, or in the alternative, the cost to perform the tasks. Revenue is recognized as the tasks are completed as a measurement of progress in the satisfaction of the corresponding performance obligation, and represented approximately 15% of contract revenues during fiscal 2020.

For certain contracts, representing less than 5% of contract revenues during fiscal 2020, fiscal 2019, the 2018 transition period, and fiscal 2017, we use the cost-to-cost measure of progress. These contracts are generally projects that are completed over a period of less than 12 months and for which payment is received in a lump sum at the end of the project. Under the cost-to-cost measure of progress, the extent of progress toward completion is measured based on the ratio of costs incurred to date to the total estimated costs. Contract costs include direct labor, direct materials, and subcontractor costs, as well as an allocation of indirect costs. Contract revenues are recorded as costs are incurred. We accrue the entire amount of a contract loss, if any, at the time the loss is determined to be probable and can be reasonably estimated.

Accounts Receivable, Net. We grant credit to our customers, generally without collateral, under normal payment terms (typically 30 to 90 days after invoicing). Generally, invoicing occurs within 45 days after the related services are performed. Accounts receivable represents an unconditional right to consideration arising from our performance under contracts with customers. Accounts receivable include billed accounts receivable, unbilled accounts receivable, and retainage. The carrying value of such receivables, net of the allowance for doubtful accounts, represents their estimated realizable value. Unbilled accounts receivable represent amounts we have an unconditional right to receive payment for although invoicing is subject to the completion of certain processes or other requirements. Such requirements may include the passage of time, completion of other items within a statement of work, or other contractual billing requirements. Certain of our contracts contain retainage provisions whereby a portion of the revenue earned is withheld from payment as a form of security until contractual provisions are satisfied. The collectability of retainage is included in our overall assessment of the collectability of accounts receivable. We expect to collect the outstanding balance of current accounts receivable, net (including trade accounts receivable, unbilled accounts receivable, and retainage) within the next 12 months. As of January 26, 2019, accounts receivable of $24.8 million from Windstream were classified as non-current in other assets and were net of the related allowance for doubtful accounts. On February 25, 2019, Windstream filed a voluntary petition under Chapter 11 of the United States Bankruptcy Code in the U.S. Bankruptcy Court for the Southern District of New York. As of January 25, 2020, all Windstream’s accounts receivable was classified as current. We estimate our allowance for doubtful accounts by evaluating specific accounts receivable balances based on historical collection trends, the age of outstanding receivables, and the credit worthiness of our customers.

We have participated in a customer-sponsored vendor payment program for one of our customers since fiscal 2016. All eligible accounts receivable from this customer are included in the program and payment is received pursuant to a non-recourse sale to a bank partner of the customer. This program effectively reduces the time to collect these receivables as compared to that customer’s standard payment terms. We incur a discount fee to the bank on the payments received that is reflected as an expense component in other income, net, in the consolidated statements of operations. The operations of this program have not changed since we began participating.

Contract Liabilities. Contract liabilities consist of amounts invoiced to customers in excess of revenue recognized. Our contract assets and liabilities are reported in a net position on a contract by contract basis at the end of each reporting period. As of January 25, 2020 and January 26, 2019, the contract liabilities balance is classified as current based on the timing of when we expect to complete the tasks required for the recognition of revenue.

Inventories. Inventories consist of materials and supplies used in the ordinary course of business and are carried at the lower of cost (using the first-in, first-out method) or net realizable value. Inventories also include certain job specific materials that are valued using the specific identification method. For contracts where we are required to supply part or all of the materials on behalf of a customer, the loss of a customer or declines in contract volumes could result in an impairment of the value of materials purchased.

Property and Equipment. Property and equipment are stated at cost and depreciated on a straight-line basis over their estimated useful lives (see Note 9, Property and Equipment, for the range of useful lives). Leasehold improvements are depreciated on a straight-line basis over the lesser of the estimated useful life of the asset or the remaining lease term. Maintenance and repairs are expensed as incurred and major improvements are capitalized. When assets are sold or retired, the cost and related accumulated depreciation are removed from the accounts and the resulting gain or loss is included in other income. Capitalized software consists primarily of costs to purchase and develop internal-use software and is amortized over its useful life as a component of depreciation expense. Property and equipment includes internally developed capitalized computer software at net book value of $21.2 million and $28.5 million as of January 25, 2020 and January 26, 2019, respectively.

Goodwill and Intangible Assets. Goodwill and other indefinite-lived intangible assets are assessed annually for impairment, or more frequently if events occur that would indicate a potential reduction in the fair value of a reporting unit below its carrying value. We perform our annual impairment review of goodwill at the reporting unit level. Each of our operating segments with goodwill represents a reporting unit for the purpose of assessing impairment. If we determine the fair value of the reporting unit’s goodwill or other indefinite-lived intangible assets is less than their carrying value as a result of an annual or interim test, an impairment loss is recognized and reflected in operating income or loss in the consolidated statements of operations during the period incurred.

We complete our annual goodwill impairment assessment as of the first day of the fourth fiscal quarter of each year. As a result of the change in our fiscal year end in fiscal 2018, the annual goodwill impairment assessment date was changed to the first day of the fiscal quarter ending on the last Saturday in January, as this became the first day of our fourth fiscal quarter. The change in the annual goodwill impairment assessment date was deemed a change in accounting principle, which we believe to be preferable as the change was made to better align the annual goodwill impairment test with the change in our annual planning and budgeting process related to the new fiscal year end. This change in accounting principle did not delay, accelerate or avoid a goodwill impairment charge and had no effect on the consolidated financial statements, including any cumulative effect on retained earnings.

We review finite-lived intangible assets for impairment whenever an event occurs or circumstances change that indicate that the carrying amount of such assets may not be fully recoverable. Recoverability is determined based on an estimate of undiscounted future cash flows resulting from the use of an asset and its eventual disposition. If an asset is not recoverable, an impairment loss is measured by comparing the fair value of the asset to its carrying value. If we determine the fair value of an asset is less than the carrying value, an impairment loss is recognized in operating income or loss in the consolidated statements of operations during the period incurred.

We use judgment in assessing whether goodwill and intangible assets are impaired. Estimates of fair value are based on our projection of revenues, operating costs, and cash flows taking into consideration historical and anticipated future results, general economic and market conditions, as well as the impact of planned business or operational strategies. We determine the fair value of our reporting units using a weighing of fair values derived in equal proportions from the income approach and market approach valuation methodologies. The income approach uses the discounted cash flow method and the market approach uses the guideline company method. Changes in our judgments and projections could result in significantly different estimates of fair value, potentially resulting in impairments of goodwill and other intangible assets. The inputs used for fair value measurements of the reporting units and other related indefinite-lived intangible assets are the lowest level (Level 3) inputs. See Note 10, Goodwill and Intangible Assets, for additional information regarding our annual assessment of goodwill and other indefinite-lived intangible assets.

Business Combinations. We account for business combinations under the acquisition method of accounting. The purchase price of each business acquired is allocated to the tangible and intangible assets acquired and the liabilities assumed based on information regarding their respective fair values on the date of acquisition. Any excess of the purchase price over the fair value of the separately identifiable assets acquired and the liabilities assumed is allocated to goodwill. Management determines the

fair values used in purchase price allocations for intangible assets based on historical data, estimated discounted future cash flows, expected royalty rates for trademarks and trade names, as well as certain other information. The valuation of assets acquired and liabilities assumed requires a number of judgments and is subject to revision as additional information about the fair value of assets and liabilities becomes available. Additional information, which existed as of the acquisition date but unknown to us at that time, may become known during the remainder of the measurement period. This measurement period may not exceed 12 months from the acquisition date. We will recognize any adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustments are determined. Additionally, in the same period in which adjustments are recognized, we will record the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of any change to the provisional amounts, calculated as if the accounting adjustment had been completed at the acquisition date. Acquisition costs are expensed as incurred. The results of operations of businesses acquired are included in the consolidated financial statements from their dates of acquisition.

Long-Lived Tangible Assets. We review long-lived tangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be fully recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of an asset group and its eventual disposition. Measurement of an impairment loss is based on the fair value of the asset compared to its carrying value. Long-lived tangible assets to be disposed of are reported at the lower of their carrying amount or fair value less costs to sell.

Accrued Insurance Claims. For claims within our insurance program, we retain the risk of loss, up to certain limits, for matters related to automobile liability, general liability (including damages associated with underground facility locating services), workers’ compensation, and employee group health. We have established reserves that we believes to be adequate based on current evaluations and our experience with these types of claims. A liability for unpaid claims and the associated claim expenses, including incurred but not reported losses, is determined with the assistance of an actuary and reflected in the consolidated financial statements as accrued insurance claims. The effect on our financial statements is generally limited to the amount needed to satisfy our insurance deductibles or retentions.

We estimate the liability for claims based on facts, circumstances, and historical experience. Even though they will not be paid until sometime in the future, recorded loss reserves are not discounted. Factors affecting the determination of the expected cost for existing and incurred but not reported claims include, but are not limited to, the magnitude and quantity of future claims, the payment pattern of claims which have been incurred, changes in the medical condition of claimants, and other factors such as inflation, tort reform or other legislative changes, unfavorable jury decisions and court interpretations.

Per Share Data. Basic earnings per common share is computed based on the weighted average number of common shares outstanding during the period, excluding unvested restricted share units. Diluted earnings per common share includes the weighted average number of common shares outstanding during the period and dilutive potential common shares arising from our stock-based awards (including unvested restricted share units), convertible senior notes, and warrants if their inclusion is dilutive under the treasury stock method. Common stock equivalents related to stock-based awards, convertible senior notes, and warrants are excluded from diluted earnings per common share calculations if their effect would be anti-dilutive.

We adopted the Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”) on a prospective basis effective July 30, 2017, the first day of the 2018 transition period. Under the amended guidance, excess tax benefits and tax deficiencies arising from the vesting and exercise of share-based awards are no longer included in the hypothetical proceeds used to repurchase shares when computing diluted earnings per common share under the treasury stock method. See Note 4, Computation of Earnings Per Share, for additional information related to ASU 2016-09’s impact on per share data.

Stock-Based Compensation. We have stock-based compensation plans under which we grant stock-based awards, including stock options, time-based restricted share units (“RSUs”), and performance-based restricted share units (“Performance RSUs”) to attract, retain, and reward talented employees, officers, and directors, and to align stockholder and employee interests. The resulting compensation expense is recognized on a straight-line basis over the vesting period, net of actual forfeitures, and is included in general and administrative expenses in the consolidated statements of operations. This expense fluctuates over time as a result of the vesting periods of the stock-based awards and, for our Performance RSUs, the expected achievement of performance measures.

Compensation expense for stock-based awards is based on fair value at the measurement date. The fair value of stock options is estimated on the date of grant using the Black-Scholes option pricing model. This valuation is affected by our stock price as well as other inputs, including the expected common stock price volatility over the expected life of the options, the expected term of the stock option, risk-free interest rates, and expected dividends, if any. Stock options vest ratably over a four-

year period and are exercisable over a period of up to ten years. The fair value of RSUs and Performance RSUs is estimated on the date of grant and is equal to the closing market price per share of our common stock on that date. RSUs generally vest ratably over a four-year period. Performance RSUs vest ratably over a three-year period, if certain performance measures are achieved. Each RSU and Performance RSU is settled in one share of the Company’s common stock upon vesting.

For Performance RSUs, we evaluate compensation expense quarterly and recognize expense only if we determine it is probable that the performance measures for the awards will be met. The performance measures for target awards are based on our operating earnings (adjusted for certain amounts) as a percentage of contract revenues and our operating cash flow level (adjusted for certain amounts) for the applicable four-quarter performance period. Additionally, certain awards include three-year performance measures that are more difficult to achieve than those required to earn target awards and, if met, result in supplemental shares awarded. The performance measures for supplemental awards are based on three-year cumulative operating earnings (adjusted for certain amounts) as a percentage of contract revenues and three-year cumulative operating cash flow level (adjusted for certain amounts). In a period we determine it is no longer probable that we will achieve certain performance measures for the awards, we reverse the stock-based compensation expense that we had previously recognized and associated with the portion of Performance RSUs that are no longer expected to vest. The amount of the expense ultimately recognized depends on the number of awards that actually vest. Accordingly, stock-based compensation expense may vary from period to period. For additional information on our stock-based compensation plans, stock options, RSUs, and Performance RSUs, see Note 19, Stock-Based Awards.

Income Taxes. We account for income taxes under the asset and liability method. This approach requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of assets and liabilities. Our effective income tax rate differs from the statutory rate for the tax jurisdictions where we operate, primarily as the result of the impact of non-deductible and non-taxable items, tax credits recognized in relation to pre-tax results, certain tax impacts from the vesting and exercise of share-based awards, and certain tax impacts from the Tax Cuts and Jobs Act of 2017 (“Tax Reform”). Tax Reform had a substantial impact on our consolidated financial statements for the 2018 transition period. See Note 15, Income Taxes, for further information.

Measurement of our tax position is based on the applicable statutes, federal and state case law, and our interpretations of tax regulations. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income during the period that includes the enactment date. We record net deferred tax assets to the extent we believe these assets will more likely than not be realized. In making such determination, we consider all relevant factors, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent financial operations. In the event we determine that we would be able to realize deferred income tax assets in excess of their net recorded amount, we would adjust the valuation allowance, which would reduce the provision for income taxes.

We recognize tax benefits in the amount that we deem, more likely than not, will be realized upon ultimate settlement of any tax uncertainty. Tax positions that fail to qualify for recognition are recognized during the period in which the more-likely-than-not standard has been reached, when the tax positions are resolved with the respective taxing authority or when the statute of limitations for tax examination has expired. We recognize applicable interest related to tax amounts in interest expense and penalties within general and administrative expenses.

Fair Value of Financial Instruments. Our financial instruments primarily consist of cash and equivalents, restricted cash, accounts receivable, income taxes receivable and payable, accounts payable, certain accrued expenses, and long-term debt. The carrying amounts of these items approximate fair value due to their short maturity, except for the fair value of our long-term debt, which is based on observable market-based inputs (Level 2). See Note 14, Debt, for further information regarding the fair value of such financial instruments. Our cash and equivalents are based on quoted market prices in active markets for identical assets (Level 1) as of January 25, 2020 and January 26, 2019. During fiscal 2020, fiscal 2019, the 2018 transition, and fiscal 2017, we had no material nonrecurring fair value measurements of assets or liabilities subsequent to their initial recognition.

Taxes Collected from Customers. ASC Topic 606, Taxes Collected from Customers and Remitted to Governmental Authorities, addresses the income statement presentation of any taxes collected from customers and remitted to a government authority and provides that the presentation of taxes on either a gross basis or a net basis is an accounting policy decision that should be disclosed. Our policy is to present contract revenues net of sales taxes.