The preparation of financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Estimates are revised as additional information becomes available. Estimates and assumptions are used for, but not limited to, revenue recognition, income taxes, fair value and impairment of goodwill and valuation of assets and certain contingent liabilities. Actual results could differ from these estimates.

As a defense contractor engaging in long-term contracts, substantially all of our revenue is derived from long-term service contracts. The unit of account for revenue in Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers (Topic 606) is a performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. To determine the proper revenue recognition method, consideration is given as to whether a single contract should be accounted for as more than one performance obligation. For most of our contracts, the customer contracts with us to perform an integrated set of tasks and deliverables as a single service solution, whereby each service is not separately identifiable from other promises in the contract and therefore is not distinct. As a result, when this integrated set of tasks exists, the contract is accounted for as one performance obligation. The vast majority of our contracts have a single performance obligation. Unexercised contract options and indefinite delivery and indefinite quantity (IDIQ) contracts are considered to be separate performance obligations when the option or IDIQ task order is exercised or awarded. Our performance obligations are satisfied over time as services are provided throughout the contract term. We recognize revenue over time using the input method (e.g., costs incurred to date relative to total estimated costs at completion) to measure progress. Our over time recognition is reinforced by the fact that our customers simultaneously receive and consume the benefits of our services as they are performed. For most U.S. government contracts, this continuous transfer of control to the customer is supported by clauses in the contract that allow the customer to unilaterally terminate the contract for convenience, pay us for costs incurred plus a reasonable profit and take control of any work in process. This continuous transfer of control requires that we track progress towards completion of performance obligations in order to measure and recognize revenue.

Accounting for contracts and programs involves the use of various techniques to estimate total contract revenue and costs. For contracts, we estimate the profit on a contract as the difference between the total estimated revenue and expected costs to complete a contract and recognize that profit over the life of the contract. Contract estimates are based on various assumptions to project the outcome of future events. These assumptions include labor productivity and availability; the complexity of the services being performed; the cost and availability of materials; the performance of subcontractors; and negotiations with the customer on contract modifications.

The nature of our contracts gives rise to several types of variable consideration, including award and incentive fees, inspection of supplies and services, and fluctuation in allowable indirect reimbursable costs. We include award or incentive fees in the estimated transaction price when there is certainty and a basis to reasonably estimate the amount of the fee. These estimates are based on historical award experience, anticipated performance and our best judgment at the time. The inspection of supplies and services is a factor because the U.S. government can reduce the transaction price if we do not perform the services in compliance with contract requirements. The fluctuation of allowable indirect reimbursable costs is a factor because the U.S. government has the right to review our accounting records and retroactively adjust the reimbursable rate. Any prior adjustments are reflected in the U.S. government reserve amounts recorded in our financial statements. We estimate variable consideration at the most likely amount that we expect to be entitled to receive. Refer to Note 18, "Commitments and Contingencies" for additional information regarding U.S. government reserve amounts.

As a significant change in one or more of these estimates could affect the profitability of our contracts, we review and update our contract estimates regularly. We recognize adjustments in estimated profit on executed contracts cumulatively. The impact of the adjustments on profit recorded to date is recognized in the period the adjustment is identified. Revenue and profit in future periods of contract performance are recognized using the adjusted estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, we recognize the total loss in the quarter it is identified.

Contracts are often modified to account for changes in contract specifications and requirements. If the modification either creates new enforceable rights and obligations or changes the existing enforceable rights and obligations, the modification will be treated as a separate contract. Our contract modifications, except for those to exercise option years, have not been distinct from the existing contract and have been accounted for as if they were part of that existing contract.

The timing of revenue recognition, billings and cash collections results in billed and unbilled accounts receivable (contract assets) and customer advances and deposits (contract liabilities) on the Consolidated Balance Sheets. Amounts are billed as work progresses in accordance with agreed-upon contractual terms at periodic intervals (e.g., biweekly or monthly). Generally, billing occurs subsequent to revenue recognition, resulting in contract assets. However, we may receive advances or deposits from our customers, before revenue is recognized, resulting in contract liabilities. These advance billings and payments are not considered significant financing components because they are frequently intended to fund current operating expenses under the contract. These assets and liabilities are reported on the Consolidated Balance Sheets on a contract-by-contract basis at the end of each reporting period.

We compute earnings per common share on the basis of the weighted average number of common shares, and, where dilutive, common share equivalents, outstanding during the indicated periods.

Property, plant and equipment, net are stated at cost less accumulated depreciation. Major improvements are capitalized at cost while expenditures for maintenance, repairs and minor improvements are expensed. For asset sales or retirements, the assets and related accumulated depreciation and amortization are eliminated from the accounts and any resulting gain or loss is reflected in operating income.

Goodwill represents purchase consideration paid in a business combination that exceeds the fair values assigned to the net assets of acquired businesses. Goodwill is not amortized, but instead is tested for impairment annually (or more frequently if impairment indicators arise, such as changes to the reporting unit structure or significant adverse changes in the business climate). We conduct our annual impairment testing during the fourth fiscal quarter. In reviewing goodwill for impairment, we have the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the estimated fair value of a reporting unit is less than its carrying amount. If we elect to perform a qualitative assessment and determine that an impairment is more likely than not, the entity is then required to perform the existing two-step quantitative impairment test as described below. Otherwise, no further analysis is required. We also may elect not to perform the qualitative assessment and, instead, proceed directly to the two-step quantitative impairment test.

The quantitative impairment test is a two-step test. In the first step, the estimated fair value of the reporting unit is developed and compared to the carrying value of the reporting unit. If the estimated fair value of the reporting unit exceeds its carrying value, goodwill is not impaired and the second step of the impairment test is not performed. If the carrying value of the reporting unit exceeds its estimated fair value, then the second step of the impairment test is performed in order to measure the impairment loss to be recorded. If the carrying value of the reporting unit's goodwill exceeds its implied fair value, then we record an impairment loss equal to the difference. We estimate the fair value of our reporting unit using an income approach and a market approach. Under the income approach, we estimate fair value based on the present value of estimated future cash flows. Under the market approach, we compare our company to select reasonably similar publicly traded companies.

On January 1, 2019, the Company adopted the new lease accounting standard ASC Topic 842, Leases (ASC Topic 842). Operating leases are included on our Consolidated Balance Sheets as right-of-use (ROU) assets, other accrued liabilities and other non-current liabilities.

We record accruals for commitments and loss contingencies when they are probable of occurrence and the amounts can be reasonably estimated. In addition, legal fees are accrued for cases where a loss is probable and the related fees can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount of loss. We review these accruals quarterly and adjust the accruals to reflect the impact of negotiations, settlements, rulings, advice of legal counsel and other updated information.

We periodically initiate management-approved restructuring activities to achieve cost savings through reduced operational redundancies and to strategically position ourselves in the market in response to prevailing economic conditions and associated customer demand. Costs associated with restructuring actions can include severance and related benefit charges. For involuntary separation plans, a liability is recognized when it is probable, reasonably estimable, and communicated to employees. For voluntary separation plans, a liability is recognized when the employee irrevocably accepts the termination.

The financial statements of programs for which the functional currency is not the U.S. dollar are translated into U.S. dollars. Balance sheet accounts are translated at the exchange rate in effect at the end of each period; income statement accounts are translated at the average rates of exchange prevailing during the period. Gains and losses on foreign currency translations are recorded as translation adjustments to other comprehensive (loss) income. Net gains or losses from foreign currency transactions are reported in selling, general and administrative expenses and have historically been immaterial.