Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]
Organization	Organization – We are a global security and aerospace company principally engaged in the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services. We also provide a broad range of management, engineering, technical, scientific, logistics, system integration and cybersecurity services. We serve both U.S. and international customers with products and services that have defense, civil and commercial applications, with our principal customers being agencies of the U.S. Government.
Basis of presentation	Basis of presentation – Our consolidated financial statements include the accounts of subsidiaries we control and variable interest entities if we are the primary beneficiary. We eliminate intercompany balances and transactions in consolidation. Our receivables, inventories, customer advances and amounts in excess of costs incurred and certain amounts in other current liabilities primarily are attributable to long-term contracts or programs in progress for which the related operating cycles are longer than one year. In accordance with industry practice, we include these items in current assets and current liabilities. Unless otherwise noted, we present all per share amounts cited in these consolidated financial statements on a “per diluted share” basis.
Use of estimates	Use of estimates – We prepare our consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP). In doing so, we are required to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base these estimates on historical experience and on various other assumptions that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying amounts of assets and liabilities that are not readily apparent from other sources. Our actual results may differ materially from these estimates. Significant estimates inherent in the preparation of our consolidated financial statements include, but are not limited to, accounting for sales and cost recognition, postretirement benefit plans, assets for the portion of environmental costs that are probable of future recovery and liabilities, evaluation of goodwill and other assets for impairment, income taxes including deferred income taxes, fair value measurements and contingencies.
Revenue Recognition, Contract assets and Contract liabilities	Revenue Recognition – The majority of our net sales are generated from long-term contracts with the U.S. Government and international customers (including foreign military sales (FMS) contracted through the U.S. Government) for the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services. We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. For certain contracts that meet the foregoing requirements, primarily international direct commercial sale contracts, we are required to obtain certain regulatory approvals. In these cases, we recognize revenue when it is probable that we will receive regulatory approvals based upon all known facts and circumstances. We provide our products and services under fixed-price and cost-reimbursable contracts. Under fixed-price contracts, we agree to perform the specified work for a pre-determined price. To the extent our actual costs vary from the estimates upon which the price was negotiated, we will generate more or less profit or could incur a loss. Some fixed-price contracts have a performance-based component under which we may earn incentive payments or incur financial penalties based on our performance. Cost-reimbursable contracts provide for the payment of allowable costs incurred during performance of the contract plus a fee up to a ceiling based on the amount that has been funded. Typically, we enter into three types of cost-reimbursable contracts: cost-plus-award-fee, cost-plus-incentive-fee, and cost-plus-fixed-fee. Cost-plus-award-fee contracts provide for an award fee that varies within specified limits based on the customer’s assessment of our performance against a predetermined set of criteria, such as targets based on cost, quality, technical and schedule criteria. Cost-plus-incentive-fee contracts provide for reimbursement of costs plus a fee, which is adjusted by a formula based on the relationship of total allowable costs to total target costs (i.e., incentive based on cost) or reimbursement of costs plus an incentive to exceed stated performance targets (i.e., incentive based on performance). The fixed-fee in a cost-plus-fixed-fee contract is negotiated at the inception of the contract and that fixed-fee does not vary with actual costs. We assess each contract at its inception to determine whether it should be combined with other contracts. When making this determination, we consider factors such as whether two or more contracts were negotiated and executed at or near the same time or were negotiated with an overall profit objective. If combined, we treat the combined contracts as a single contract for revenue recognition purposes. We evaluate the products or services promised in each contract at inception to determine whether the contract should be accounted for as having one or more performance obligations. The products and services in our contracts are typically not distinct from one another due to their complex relationships and the significant contract management functions required to perform under the contract. Accordingly, our contracts are typically accounted for as one performance obligation. In limited cases, our contracts have more than one distinct performance obligation, which occurs when we perform activities that are not highly complex or interrelated or involve different product lifecycles. Significant judgment is required in determining performance obligations, and these decisions could change the amount of revenue and profit recorded in a given period. We classify net sales as products or services on our consolidated statements of earnings based on the predominant attributes of the performance obligations. We determine the transaction price for each contract based on the consideration we expect to receive for the products or services being provided under the contract. For contracts where a portion of the price may vary, we estimate variable consideration at the most likely amount, which is included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur. We analyze the risk of a significant revenue reversal and if necessary constrain the amount of variable consideration recognized in order to mitigate this risk. At the inception of a contract we estimate the transaction price based on our current rights and do not contemplate future modifications (including unexercised options) or follow-on contracts until they become legally enforceable. Contracts are often subsequently modified to include changes in specifications, requirements or price, which may create new or change existing enforceable rights and obligations. Depending on the nature of the modification, we consider whether to account for the modification as an adjustment to the existing contract or as a separate contract. Generally, modifications to our contracts are not distinct from the existing contract due to the significant integration and interrelated tasks provided in the context of the contract. Therefore, such modifications are accounted for as if they were part of the existing contract and recognized as a cumulative adjustment to revenue. For contracts with multiple performance obligations, we allocate the transaction price to each performance obligation based on the estimated standalone selling price of the product or service underlying each performance obligation. The standalone selling price represents the amount we would sell the product or service to a customer on a standalone basis (i.e., not bundled with any other products or services). Our contracts with the U.S. Government, including FMS contracts, are subject to the Federal Acquisition Regulations (FAR) and the price is typically based on estimated or actual costs plus a reasonable profit margin. As a result of these regulations, the standalone selling price of products or services in our contracts with the U.S. Government and FMS contracts are typically equal to the selling price stated in the contract. For non-U.S. Government contracts with multiple performance obligations, we evaluate whether the stated selling prices for the products or services represent their standalone selling prices. We primarily sell customized solutions unique to a customer’s specifications. When it is necessary to allocate the transaction price to multiple performance obligations, we typically use the expected cost plus a reasonable profit margin to estimate the standalone selling price of each product or service. We occasionally sell standard products or services with observable standalone sales transactions. In these situations, the observable standalone sales transactions are used to determine the standalone selling price. We recognize revenue as performance obligations are satisfied and the customer obtains control of the products and services. In determining when performance obligations are satisfied, we consider factors such as contract terms, payment terms and whether there is an alternative future use of the product or service. Substantially all of our revenue is recognized over time as we perform under the contract because control of the work in process transfers continuously to the customer. For most contracts with the U.S. Government and FMS contracts, this continuous transfer of control of the work in process to the customer is supported by clauses in the contract that give the customer ownership of work in process and allow the customer to unilaterally terminate the contract for convenience and pay us for costs incurred plus a reasonable profit. For most non-U.S. Government contracts, primarily international direct commercial contracts, continuous transfer of control to our customer is supported because we deliver products that do not have an alternative use to us and if our customer were to terminate the contract for reasons other than our non-performance we would have the right to recover damages which would include, among other potential damages, the right to payment for our work performed to date plus a reasonable profit. For performance obligations to deliver products with continuous transfer of control to the customer, revenue is recognized based on the extent of progress towards completion of the performance obligation, generally using the percentage-of-completion cost-to-cost measure of progress for our contracts because it best depicts the transfer of control to the customer as we incur costs on our contracts. Under the percentage-of-completion cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs to complete the performance obligation(s). For performance obligations to provide services to the customer, revenue is recognized over time based on costs incurred or the right to invoice method (in situations where the value transferred matches our billing rights) as our customer receives and consumes the benefits. For performance obligations in which control does not continuously transfer to the customer, we recognize revenue at the point in time in which each performance obligation is fully satisfied. This coincides with the point in time the customer obtains control of the product or service, which typically occurs upon customer acceptance or receipt of the product or service, given that we maintain control of the product or service until that point.Backlog (i.e., unfulfilled or remaining performance obligations) represents the sales we expect to recognize for our products and services for which control has not yet transferred to the customer. It is converted into sales in future periods as work is performed or deliveries are made. For our cost-reimbursable and fixed-priced-incentive contracts, the estimated consideration we expect to receive pursuant to the terms of the contract may exceed the contractual award amount. The estimated consideration is determined at the outset of the contract and is continuously reviewed throughout the contract period. In determining the estimated consideration, we consider the risks related to the technical, schedule and cost impacts to complete the contract and an estimate of any variable consideration. Periodically, we review these risks and may increase or decrease backlog accordingly. As the risks on such contracts are successfully retired, the estimated consideration from customers may be reduced, resulting in a reduction of backlog without a corresponding recognition of sales. For arrangements with the U.S. Government and FMS contracts, we generally do not begin work on contracts until funding is appropriated by the customer. Billing timetables and payment terms on our contracts vary based on a number of factors, including the contract type. Typical payment terms under fixed-price contracts with the U.S. Government provide that the customer pays either performance-based payments (PBPs) based on the achievement of contract milestones or progress payments based on a percentage of costs we incur. For the majority of our international direct commercial contracts to deliver complex systems, we typically receive advance payments prior to commencement of work, as well as milestone payments that are paid in accordance with the terms of our contract as we perform. We recognize a liability for payments in excess of revenue recognized, which is presented as a contract liability on the balance sheet. The portion of payments retained by the customer until final contract settlement is not considered a significant financing component because the intent is to protect the customer from our failure to adequately complete some or all of the obligations under the contract. Payments received from customers in advance of revenue recognition are not considered to be significant financing components because they are used to meet working capital demands that can be higher in the early stages of a contract. For fixed-price and cost-reimbursable contracts, we present revenues recognized in excess of billings as contract assets on the balance sheet. Amounts billed and due from our customers under both contract types are classified as receivables on the balance sheet. Significant estimates and assumptions are made in estimating contract sales and costs, including the profit booking rate. At the outset of a long-term contract, we identify and monitor risks to the achievement of the technical, schedule and cost aspects of the contract, as well as variable consideration, and assess the effects of those risks on our estimates of sales and total costs to complete the contract. The estimates consider the technical requirements (e.g., a newly-developed product versus a mature product), the schedule and associated tasks (e.g., the number and type of milestone events) and costs (e.g., material, labor, subcontractor, overhead, general and administrative and the estimated costs to fulfill our industrial cooperation agreements, sometimes referred to as offset or localization agreements, required under certain contracts with international customers). The initial profit booking rate of each contract considers risks surrounding the ability to achieve the technical requirements, schedule and costs in the initial estimated total costs to complete the contract. Profit booking rates may increase during the performance of the contract if we successfully retire risks surrounding the technical, schedule and cost aspects of the contract, which decreases the estimated total costs to complete the contract or may increase the variable consideration we expect to receive on the contract. Conversely, our profit booking rates may decrease if the estimated total costs to complete the contract increase or our estimates of variable consideration we expect to receive decrease. All of the estimates are subject to change during the performance of the contract and may affect the profit booking rate. When estimates of total costs to be incurred on a contract exceed total estimates of the transaction price, a provision for the entire loss is determined at the contract level and is recorded in the period in which the loss is determined. Comparability of our segment sales, operating profit and operating margin may be impacted favorably or unfavorably by changes in profit booking rates on our contracts for which we recognize revenue over time using the percentage-of-completion cost-to-cost method to measure progress towards completion. Increases in the profit booking rates, typically referred to as risk retirements, usually relate to revisions in the estimated total costs to fulfill the performance obligations that reflect improved conditions on a particular contract. Conversely, conditions on a particular contract may deteriorate, resulting in an increase in the estimated total costs to fulfill the performance obligations and a reduction in the profit booking rate. Increases or decreases in profit booking rates are recognized in the current period and reflect the inception-to-date effect of such changes. Segment operating profit and margin may also be impacted favorably or unfavorably by other items, which may or may not impact sales. Favorable items may include the positive resolution of contractual matters, cost recoveries on severance and restructuring charges, insurance recoveries and gains on sales of assets. Unfavorable items may include the adverse resolution of contractual matters; restructuring charges, except for significant severance actions, which are excluded from segment operating results; reserves for disputes; certain asset impairments; and losses on sales of certain assets.Contract assets – Contract assets include unbilled amounts typically resulting from sales under contracts when the percentage-of-completion cost-to-cost method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the customer. The amounts may not exceed their estimated net realizable value. Contract assets are classified as current based on our contract operating cycle.Contract liabilities – Contract liabilities include advance payments and billings in excess of revenue recognized. Contract liabilities are classified as current based on our contract operating cycle and reported on a contract-by-contract basis, net of revenue recognized, at the end of each reporting period.
Research and development and similar costs	Research and development and similar costs – We conduct research and development (R&D) activities using our own funds (referred to as company-funded R&D or independent research and development (IR&D)) and under contractual arrangements with our customers (referred to as customer-funded R&D) to enhance existing products and services and to develop future technologies. R&D costs include basic research, applied research, concept formulation studies, design, development, and related test activities. Company-funded R&D costs are allocated to customer contracts as part of the general and administrative overhead costs and generally recoverable on our customer contracts with the U.S. Government. Customer-funded R&D costs are charged directly to the related customer contract. Substantially all R&D costs are charged to cost of sales as incurred.
Stock-based compensation	Stock-based compensation – Compensation cost related to all share-based payments is measured at the grant date based on the estimated fair value of the award. We generally recognize the compensation cost ratably over a three-year vesting period, net of estimated forfeitures. At each reporting date, the number of shares is adjusted to the number ultimately expected to vest.
Income taxes	Income taxes – We calculate our provision for income taxes using the asset and liability method, under which deferred tax assets and liabilities are recognized based on the future tax consequences attributable to temporary differences that exist between the financial statement carrying amount of assets and liabilities and their respective tax bases, as well as from operating loss and tax credit carry-forwards. We measure deferred tax assets and liabilities using enacted tax rates that will apply in the years in which we expect the temporary differences to be recovered or paid. We periodically assess our tax exposures related to periods that are open to examination. Based on the latest available information, we evaluate our tax positions to determine whether the position will more likely than not be sustained upon examination by the Internal Revenue Service (IRS) or other taxing authorities. If we cannot reach a more-likely-than-not determination, no benefit is recorded. If we determine that the tax position is more likely than not to be sustained, we record the largest amount of benefit that is more likely than not to be realized when the tax position is settled. We record interest and penalties related to income taxes as a component of income tax expense on our consolidated statements of earnings. Interest and penalties were not material.
Cash and cash equivalents	Cash and cash equivalents – Cash equivalents include highly liquid instruments with original maturities of 90 days or less.
Receivables	Receivables – Receivables, net represent our unconditional right to consideration under the contract and include amounts billed and currently due from customers. The amounts are stated at their net estimated realizable value.
Inventories	Inventories – We record inventories at the lower of cost or estimated net realizable value. If events or changes in circumstances indicate that the utility of our inventories have diminished through damage, deterioration, obsolescence, changes in price or other causes, a loss is recognized in the period in which it occurs. We capitalize labor, material, subcontractor and overhead costs as work-in-process for contracts where control has not yet passed to the customer. In addition, we capitalize costs incurred to fulfill a contract in advance of contract award in inventories as work-in-process if we determine that contract award is probable. We determine the costs of other product and supply inventories by using the first-in first-out or average cost methods.
Property, plant and equipment	Property, plant and equipment – We record property, plant and equipment at cost. We provide for depreciation and amortization on plant and equipment generally using accelerated methods during the first half of the estimated useful lives of the assets and the straight-line method thereafter. The estimated useful lives of our plant and equipment generally range from 10 to 40 years for buildings and five to 15 years for machinery and equipment. No depreciation expense is recorded on construction in progress until such assets are placed into operation.We review the carrying amounts of long-lived assets for impairment if events or changes in the facts and circumstances indicate that their carrying amounts may not be recoverable. We assess impairment by comparing the estimated undiscounted future cash flows of the related asset grouping to its carrying amount. If an asset is determined to be impaired, we recognize an impairment charge in the current period for the difference between the fair value of the asset and its carrying amount.
Capitalized software	Capitalized software – We capitalize certain costs associated with the development or purchase of internal-use software. The amounts capitalized are included in other noncurrent assets on our consolidated balance sheets and are amortized on a straight-line basis over the estimated useful life of the resulting software, which ranges from two to six years.
Goodwill	Goodwill and Intangible Assets – The assets and liabilities of acquired businesses are recorded under the acquisition method of accounting at their estimated fair values at the date of acquisition. Goodwill represents costs in excess of fair values assigned to the underlying identifiable net assets of acquired businesses. Intangible assets from acquired businesses are recognized at fair value on the acquisition date and consist of customer programs, trademarks, customer relationships, technology and other intangible assets. Customer programs include values assigned to major programs of acquired businesses and represent the aggregate value associated with the customer relationships, contracts, technology and trademarks underlying the associated program and are amortized on a straight-line basis over a period of expected cash flows used to measure fair value, which ranges from nine to 20 years. We perform an impairment test of our goodwill at least annually in the fourth quarter or more frequently whenever events or changes in circumstances indicate the carrying value of goodwill may be impaired. Such events or changes in circumstances may include a significant deterioration in overall economic conditions, changes in the business climate of our industry, a decline in our market capitalization, operating performance indicators, competition, reorganizations of our business, U.S. Government budget restrictions or the disposal of all or a portion of a reporting unit. Our goodwill has been allocated to and is tested for impairment at a level referred to as the reporting unit, which is our business segment level or a level below the business segment. The level at which we test goodwill for impairment requires us to determine whether the operations below the business segment constitute a self-sustaining business for which discrete financial information is available and segment management regularly reviews the operating results. We may use either a qualitative or quantitative approach when testing a reporting unit’s goodwill for impairment. For selected reporting units where we use the qualitative approach, we perform a qualitative evaluation of events and circumstances impacting the reporting unit to determine the likelihood of goodwill impairment. Based on that qualitative evaluation, if we determine it is more likely than not that the fair value of a reporting unit exceeds its carrying amount, no further evaluation is necessary. Otherwise we perform a quantitative impairment test. We perform quantitative tests for most reporting units at least once every three years. However, for certain reporting units we may perform a quantitative impairment test every year. For the quantitative impairment test we compare the fair value of a reporting unit to its carrying value, including goodwill. If the fair value of a reporting unit exceeds its carrying value, goodwill of the reporting unit is not impaired. If the carrying value of the reporting unit, including goodwill, exceeds its fair value, a goodwill impairment loss is recognized in an amount equal to that excess. We generally estimate the fair value of each reporting unit using a combination of a discounted cash flow (DCF) analysis and market-based valuation methodologies such as comparable public company trading values and values observed in recent business acquisitions. Determining fair value requires the exercise of significant judgments, including the amount and timing of expected future cash flows, long-term growth rates, discount rates and relevant comparable public company earnings multiples and relevant transaction multiples. The cash flows employed in the DCF analysis are based on our best estimate of future sales, earnings and cash flows after considering factors such as general market conditions, U.S. Government budgets, existing firm orders, expected future orders, contracts with suppliers, labor agreements, changes in working capital, long term business plans and recent operating performance. The discount rates utilized in the DCF analysis are based on the respective reporting unit’s weighted average cost of capital, which takes into account the relative weights of each component of capital structure (equity and debt) and represents the expected cost of new capital, adjusted as appropriate to consider the risk inherent in future cash flows of the respective reporting unit. The carrying value of each reporting unit includes the assets and liabilities employed in its operations, goodwill and allocations of certain assets and liabilities held at the business segment and corporate levels. During the fourth quarters of 2020, 2019 and 2018, we performed our annual goodwill impairment test for each of our reporting units. The results of our annual impairment tests of goodwill indicated that no impairment existed.
Intangible assets	Acquired intangible assets deemed to have indefinite lives are not amortized, but are subject to annual impairment testing. This testing compares carrying value to fair value and, when appropriate, the carrying value of these assets is reduced to fair value. Finite-lived intangibles are amortized to expense over the applicable useful lives, ranging from three to 20 years, based on the nature of the asset and the underlying pattern of economic benefit as reflected by future net cash inflows. We perform an impairment test of finite-lived intangibles whenever events or changes in circumstances indicate their carrying value may be impaired.
Postretirement benefit plans	Postretirement benefit plans – Many of our employees are covered by defined benefit pension plans and we provide certain health care and life insurance benefits to eligible retirees (collectively, postretirement benefit plans). GAAP requires that the amounts we record related to our postretirement benefit plans be computed, based on service to date, using actuarial valuations that are based in part on certain key economic assumptions we make, including the discount rate, the expected long-term rate of return on plan assets and other actuarial assumptions including participant longevity (also known as mortality), health care cost trend rates and employee turnover, each as appropriate based on the nature of the plans. A market-related value of our plan assets, determined using actual asset gains or losses over the prior three year period, is used to calculate the amount of deferred asset gains or losses to be amortized. These asset gains or losses, along with those resulting from adjustments to our benefit obligation, will be amortized to expense using the corridor method, where gains and losses are recognized over a period of years to the extent they exceed 10% of the greater of plan assets or benefit obligations. This amortization period extended in 2020 due to the freeze of our salaried pension plans to use the average remaining life expectancy of the participants instead of average future service. We recognize on a plan-by-plan basis the funded status of our postretirement benefit plans under GAAP as either an asset recorded within other noncurrent assets or a liability recorded within noncurrent liabilities on our consolidated balance sheets. The GAAP funded status is measured as the difference between the fair value of the plan’s assets and the benefit obligation of the plan. The funded status under the Employee Retirement Income Security Act of 1974 (ERISA), as amended by the Pension Protection Act of 2006 (PPA), is calculated on a different basis than under GAAP.
Environmental matters	Environmental matters – We record a liability for environmental matters when it is probable that a liability has been incurred and the amount can be reasonably estimated. The amount of liability recorded is based on our estimate of the costs to be incurred for remediation at a particular site. We do not discount the recorded liabilities, as the amount and timing of future cash payments are not fixed or cannot be reliably determined. Our environmental liabilities are recorded on our consolidated balance sheets within other liabilities, both current and noncurrent. We expect to include a substantial portion of environmental costs in our net sales and cost of sales in future periods pursuant to U.S. Government agreement or regulation. At the time a liability is recorded for future environmental costs, we record a receivable for estimated future recovery considered probable through the pricing of products and services to agencies of the U.S. Government, regardless of the contract form (e.g., cost-reimbursable, fixed-price). We continuously evaluate the recoverability of our assets for the portion of environmental costs that are probable of future recovery by assessing, among other factors, U.S. Government regulations, our U.S. Government business base and contract mix, our history of receiving reimbursement of such costs, and recent efforts by some U.S. Government representatives to limit such reimbursement. We include the portion of those environmental costs expected to be allocated to our non-U.S. Government contracts, or that is determined to not be recoverable under U.S. Government contracts, in our cost of sales at the time the liability is established. Our assets for the portion of environmental costs that are probable of future recovery are recorded on our consolidated balance sheets within other assets, both current and noncurrent. We project costs and recovery of costs over approximately 20 years.
Investments in marketable securities	Investments in marketable securities – Investments in marketable securities consist of debt and equity securities which are recorded at fair value.Our investments are held in a separate trust, which includes investments to fund our deferred compensation plan liabilities.Gains and losses on these investments are included in other unallocated, net within cost of sales on our consolidated statements of earnings in order to align the classification of changes in the market value of investments held for the plan with changes in the value of the corresponding plan liabilities.
Equity method investments	Equity method investments – Investments where we have the ability to exercise significant influence, but do not control, are accounted for under the equity method of accounting and are included in other noncurrent assets on our consolidated balance sheets. Significant influence typically exists if we have a 20% to 50% ownership interest in the investee. Under this method of accounting, our share of the net earnings or losses of the investee is included in operating profit in other income, net on our consolidated statements of earnings since the activities of the investee are closely aligned with the operations of the business segment holding the investment. We evaluate our equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amounts of such investments may be impaired. If a decline in the value of an equity method investment is determined to be other than temporary, a loss is recorded in earnings in the current period.
Derivative financial instruments	Derivative financial instruments – We use derivative instruments principally to reduce our exposure to market risks from changes in foreign currency exchange rates and interest rates. We do not enter into or hold derivative instruments for speculative trading purposes. We transact business globally and are subject to risks associated with changing foreign currency exchange rates. We enter into foreign currency hedges such as forward and option contracts that change in value as foreign currency exchange rates change. Our most significant foreign currency exposures relate to the British pound sterling, the euro, the Canadian dollar and the Australian dollar. These contracts hedge forecasted foreign currency transactions in order to mitigate fluctuations in our earnings and cash flows associated with changes in foreign currency exchange rates. We designate foreign currency hedges as cash flow hedges. We also are exposed to the impact of interest rate changes primarily through our borrowing activities. For fixed rate borrowings, we may use variable interest rate swaps, effectively converting fixed rate borrowings to variable rate borrowings in order to hedge changes in the fair value of the debt. These swaps are designated as fair value hedges. For variable rate borrowings, we may use fixed interest rate swaps, effectively converting variable rate borrowings to fixed rate borrowings in order to mitigate the impact of interest rate changes on earnings. These swaps are designated as cash flow hedges. We also may enter into derivative instruments that are not designated as hedges and do not qualify for hedge accounting, which are intended to mitigate certain economic exposures.We record derivatives at their fair value. The classification of gains and losses resulting from changes in the fair values of derivatives is dependent on our intended use of the derivative and its resulting designation. Adjustments to reflect changes in fair values of derivatives attributable to highly effective hedges are either reflected in earnings and largely offset by corresponding adjustments to the hedged items or reflected net of income taxes in accumulated other comprehensive loss until the hedged transaction is recognized in earnings. Changes in the fair value of the derivatives that are not highly effective, if any, are immediately recognized in earnings.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Compensation—Retirement Benefits—Defined Benefit Plans—General Effective January 1, 2020, we adopted Accounting Standards Update (ASU) 2018-14, Compensation—Retirement Benefits—Defined Benefit Plans—General (Topic 715-20): Disclosure Framework—Changes to the Disclosure Requirements For Defined Benefit Plans. The new standard modifies the annual disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The guidance requires disclosure changes to be presented on a retrospective basis. As this standard relates only to financial disclosures, its adoption did not have an impact to our results of operations, financial position or cash flows. Financial Instruments—Credit Losses Effective January 1, 2020, we adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments using the modified retrospective approach. The new standard changes how we account for credit losses for financial assets and certain other instruments, including trade receivables and contract assets, that are not measured at fair value through net income. Under legacy standards, we recognized an impairment of receivables when it was probable that a loss had been incurred. Under the new standard, we are required to recognize estimated credit losses expected to occur over the estimated life or remaining contractual life of an asset (which includes losses that may be incurred in future periods) using a broader range of information including reasonable and supportable forecasts about future economic conditions. The adoption of the standard did not have a significant impact on our results of operations, financial position or cash flows. Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting In 2017, the United Kingdom’s Financial Conduct Authority announced that after 2021 it would no longer compel banks to submit the rates required to calculate the London Interbank Offered Rate (LIBOR) and other interbank offered rates, which have been widely used as reference rates for various securities and financial contracts, including loans, debt and derivatives. This announcement indicates that the continuation of LIBOR on the current basis is not guaranteed after 2021. Regulators in the U.S. and other jurisdictions have been working to replace these rates with alternative reference interest rates that are supported by transactions in liquid and observable markets, such as the Secured Overnight Financing Rate (SOFR). Currently, our credit facility and certain of our debt and derivative instruments reference LIBOR-based rates. The discontinuation of LIBOR will require these arrangements to be modified in order to replace LIBOR with an alternative reference interest rate, which could impact our future cost of funds. Our credit facility includes a provision for the determination of a successor LIBOR rate. In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which temporarily simplifies the accounting for contract modifications, including hedging relationships, due to the transition from LIBOR and other interbank offered rates to alternative reference interest rates. For example, entities can elect not to remeasure the contracts at the modification date or reassess a previous accounting determination if certain conditions are met. Additionally, entities can elect to continue applying hedge accounting for hedging relationships affected by reference rate reform if certain conditions are met. The new standard was effective upon issuance and generally can be applied to applicable contract modifications through December 31, 2022. We are currently evaluating the impact of the transition from LIBOR to alternative reference interest rates, but do not expect a significant impact to our operating results, financial position or cash flows.
Earnings per share computation	We compute basic and diluted earnings per common share by dividing net earnings by the respective weighted average number of common shares outstanding for the periods presented. Our calculation of diluted earnings per common share also includes the dilutive effects for the assumed vesting of outstanding restricted stock units (RSUs), performance stock units (PSUs) and exercise of outstanding stock options based on the treasury stock method.
Acquired finite lived intangible assets	Acquired finite-lived intangible assets are amortized to expense primarily on a straight-line basis over the following estimated useful lives: customer programs, from nine to 20 years; customer relationships, from four to 10 years; and other intangibles, from three to 10 years.
Inventories, costs to fulfill a contract	Costs incurred to fulfill a contract in advance of the contract being awarded are included in inventories as work-in-process if we determine that those costs relate directly to a contract or to an anticipated contract that we can specifically identify and contract award is probable, the costs generate or enhance resources that will be used in satisfying performance obligations, and the costs are recoverable (referred to as pre-contract costs). Pre-contract costs that are initially capitalized in inventory are generally recognized as cost of sales consistent with the transfer of products and services to the customer upon the receipt of the anticipated contract. All other pre-contract costs, including start-up costs, are expensed as incurred.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2020

Organization – We are a global security and aerospace company principally engaged in the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services. We also provide a broad range of management, engineering, technical, scientific, logistics, system integration and cybersecurity services. We serve both U.S. and international customers with products and services that have defense, civil and commercial applications, with our principal customers being agencies of the U.S. Government.

Basis of presentation

Basis of presentation – Our consolidated financial statements include the accounts of subsidiaries we control and variable interest entities if we are the primary beneficiary. We eliminate intercompany balances and transactions in consolidation. Our receivables, inventories, customer advances and amounts in excess of costs incurred and certain amounts in other current liabilities primarily are attributable to long-term contracts or programs in progress for which the related operating cycles are longer than one year. In accordance with industry practice, we include these items in current assets and current liabilities. Unless otherwise noted, we present all per share amounts cited in these consolidated financial statements on a “per diluted share” basis.

Use of estimates

Use of estimates – We prepare our consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP). In doing so, we are required to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base these estimates on historical experience and on various other assumptions that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying amounts of assets and liabilities that are not readily apparent from other sources. Our actual results may differ materially from these estimates. Significant estimates inherent in the preparation of our consolidated financial statements include, but are not limited to, accounting for sales and cost recognition, postretirement benefit plans, assets for the portion of environmental costs that are probable of future recovery and liabilities, evaluation of goodwill and other assets for impairment, income taxes including deferred income taxes, fair value measurements and contingencies.

Revenue Recognition, Contract assets and Contract liabilities

Revenue Recognition – The majority of our net sales are generated from long-term contracts with the U.S. Government and international customers (including foreign military sales (FMS) contracted through the U.S. Government) for the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services. We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. For certain contracts that meet the foregoing requirements, primarily international direct commercial sale contracts, we are required to obtain certain regulatory approvals. In these cases, we recognize revenue when it is probable that we will receive regulatory approvals based upon all known facts and circumstances. We provide our products and services under fixed-price and cost-reimbursable contracts.

Under fixed-price contracts, we agree to perform the specified work for a pre-determined price. To the extent our actual costs vary from the estimates upon which the price was negotiated, we will generate more or less profit or could incur a loss. Some fixed-price contracts have a performance-based component under which we may earn incentive payments or incur financial penalties based on our performance.

Cost-reimbursable contracts provide for the payment of allowable costs incurred during performance of the contract plus a fee up to a ceiling based on the amount that has been funded. Typically, we enter into three types of cost-reimbursable contracts: cost-plus-award-fee, cost-plus-incentive-fee, and cost-plus-fixed-fee. Cost-plus-award-fee contracts provide for an award fee that varies within specified limits based on the customer’s assessment of our performance against a predetermined set of criteria, such as targets based on cost, quality, technical and schedule criteria. Cost-plus-incentive-fee contracts provide for reimbursement of costs plus a fee, which is adjusted by a formula based on the relationship of total allowable costs to total target costs (i.e., incentive based on cost) or reimbursement of costs plus an incentive to exceed stated performance targets (i.e., incentive based on performance). The fixed-fee in a cost-plus-fixed-fee contract is negotiated at the inception of the contract and that fixed-fee does not vary with actual costs.

We assess each contract at its inception to determine whether it should be combined with other contracts. When making this determination, we consider factors such as whether two or more contracts were negotiated and executed at or near the same time or were negotiated with an overall profit objective. If combined, we treat the combined contracts as a single contract for revenue recognition purposes.

We evaluate the products or services promised in each contract at inception to determine whether the contract should be accounted for as having one or more performance obligations. The products and services in our contracts are typically not distinct from one another due to their complex relationships and the significant contract management functions required to perform under the contract. Accordingly, our contracts are typically accounted for as one performance obligation. In limited cases, our contracts have more than one distinct performance obligation, which occurs when we perform activities that are not highly complex or interrelated or involve different product lifecycles. Significant judgment is required in determining performance obligations, and these decisions could change the amount of revenue and profit recorded in a given period. We classify net sales as products or services on our consolidated statements of earnings based on the predominant attributes of the performance obligations.

We determine the transaction price for each contract based on the consideration we expect to receive for the products or services being provided under the contract. For contracts where a portion of the price may vary, we estimate variable consideration at the most likely amount, which is included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur. We analyze the risk of a significant revenue reversal and if necessary constrain the amount of variable consideration recognized in order to mitigate this risk.

At the inception of a contract we estimate the transaction price based on our current rights and do not contemplate future modifications (including unexercised options) or follow-on contracts until they become legally enforceable. Contracts are often subsequently modified to include changes in specifications, requirements or price, which may create new or change existing enforceable rights and obligations. Depending on the nature of the modification, we consider whether to account for the modification as an adjustment to the existing contract or as a separate contract. Generally, modifications to our contracts are not distinct from the existing contract due to the significant integration and interrelated tasks provided in the context of the contract. Therefore, such modifications are accounted for as if they were part of the existing contract and recognized as a cumulative adjustment to revenue.

For contracts with multiple performance obligations, we allocate the transaction price to each performance obligation based on the estimated standalone selling price of the product or service underlying each performance obligation. The standalone selling price represents the amount we would sell the product or service to a customer on a standalone basis (i.e., not bundled with any other products or services). Our contracts with the U.S. Government, including FMS contracts, are subject to the Federal Acquisition Regulations (FAR) and the price is typically based on estimated or actual costs plus a reasonable profit margin. As a result of these regulations, the standalone selling price of products or services in our contracts with the U.S. Government and FMS contracts are typically equal to the selling price stated in the contract.

For non-U.S. Government contracts with multiple performance obligations, we evaluate whether the stated selling prices for the products or services represent their standalone selling prices. We primarily sell customized solutions unique to a customer’s specifications. When it is necessary to allocate the transaction price to multiple performance obligations, we typically use the expected cost plus a reasonable profit margin to estimate the standalone selling price of each product or service. We occasionally sell standard products or services with observable standalone sales transactions. In these situations, the observable standalone sales transactions are used to determine the standalone selling price.

We recognize revenue as performance obligations are satisfied and the customer obtains control of the products and services. In determining when performance obligations are satisfied, we consider factors such as contract terms, payment terms and whether there is an alternative future use of the product or service. Substantially all of our revenue is recognized over time as we perform under the contract because control of the work in process transfers continuously to the customer. For most contracts with the U.S. Government and FMS contracts, this continuous transfer of control of the work in process to the customer is supported by clauses in the contract that give the customer ownership of work in process and allow the customer to unilaterally terminate the contract for convenience and pay us for costs incurred plus a reasonable profit. For most non-U.S. Government contracts, primarily international direct commercial contracts, continuous transfer of control to our customer is supported because we deliver products that do not have an alternative use to us and if our customer were to terminate the contract for reasons other than our non-performance we would have the right to recover damages which would include, among other potential damages, the right to payment for our work performed to date plus a reasonable profit.

For performance obligations to deliver products with continuous transfer of control to the customer, revenue is recognized based on the extent of progress towards completion of the performance obligation, generally using the percentage-of-completion cost-to-cost measure of progress for our contracts because it best depicts the transfer of control to the customer as we incur costs on our contracts. Under the percentage-of-completion cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs to complete the performance obligation(s). For performance obligations to provide services to the customer, revenue is recognized over time based on costs incurred or the right to invoice method (in situations where the value transferred matches our billing rights) as our customer receives and consumes the benefits.

For performance obligations in which control does not continuously transfer to the customer, we recognize revenue at the point in time in which each performance obligation is fully satisfied. This coincides with the point in time the customer obtains control of the product or service, which typically occurs upon customer acceptance or receipt of the product or service, given that we maintain control of the product or service until that point.Backlog (i.e., unfulfilled or remaining performance obligations) represents the sales we expect to recognize for our products and services for which control has not yet transferred to the customer. It is converted into sales in future periods as work is performed or deliveries are made. For our cost-reimbursable and fixed-priced-incentive contracts, the estimated consideration we expect to receive pursuant to the terms of the contract may exceed the contractual award amount. The estimated consideration is determined at the outset of the contract and is continuously reviewed throughout the contract period. In determining the estimated consideration, we consider the risks related to the technical, schedule and cost impacts to complete the contract and an estimate of any variable consideration. Periodically, we review these risks and may increase or decrease backlog accordingly. As the risks on such contracts are successfully retired, the estimated consideration from customers may be reduced, resulting in a reduction of backlog without a corresponding recognition of sales.

For arrangements with the U.S. Government and FMS contracts, we generally do not begin work on contracts until funding is appropriated by the customer. Billing timetables and payment terms on our contracts vary based on a number of factors, including the contract type. Typical payment terms under fixed-price contracts with the U.S. Government provide that the customer pays either performance-based payments (PBPs) based on the achievement of contract milestones or progress payments based on a percentage of costs we incur. For the majority of our international direct commercial contracts to deliver complex systems, we typically receive advance payments prior to commencement of work, as well as milestone payments that are paid in accordance with the terms of our contract as we perform. We recognize a liability for payments in excess of revenue recognized, which is presented as a contract liability on the balance sheet. The portion of payments retained by the customer until final contract settlement is not considered a significant financing component because the intent is to protect the customer from our failure to adequately complete some or all of the obligations under the contract. Payments received from customers in advance of revenue recognition are not considered to be significant financing components because they are used to meet working capital demands that can be higher in the early stages of a contract.

For fixed-price and cost-reimbursable contracts, we present revenues recognized in excess of billings as contract assets on the balance sheet. Amounts billed and due from our customers under both contract types are classified as receivables on the balance sheet.

Significant estimates and assumptions are made in estimating contract sales and costs, including the profit booking rate. At the outset of a long-term contract, we identify and monitor risks to the achievement of the technical, schedule and cost aspects of the contract, as well as variable consideration, and assess the effects of those risks on our estimates of sales and total costs to complete the contract. The estimates consider the technical requirements (e.g., a newly-developed product versus a mature product), the schedule and associated tasks (e.g., the number and type of milestone events) and costs (e.g., material, labor, subcontractor, overhead, general and administrative and the estimated costs to fulfill our industrial cooperation agreements, sometimes referred to as offset or localization agreements, required under certain contracts with international customers). The initial profit booking rate of each contract considers risks surrounding the ability to achieve the technical requirements, schedule and costs in the initial estimated total costs to complete the contract. Profit booking rates may increase during the performance of the contract if we successfully retire risks surrounding the technical, schedule and cost aspects of the contract, which decreases the estimated total costs to complete the contract or may increase the variable consideration we expect to receive on the contract. Conversely, our profit booking rates may decrease if the estimated total costs to complete the contract increase or our estimates of variable consideration we expect to receive decrease. All of the estimates are subject to change during the performance of the contract and may affect the profit booking rate. When estimates of total costs to be incurred on a contract exceed total estimates of the transaction price, a provision for the entire loss is determined at the contract level and is recorded in the period in which the loss is determined.

Comparability of our segment sales, operating profit and operating margin may be impacted favorably or unfavorably by changes in profit booking rates on our contracts for which we recognize revenue over time using the percentage-of-completion cost-to-cost method to measure progress towards completion. Increases in the profit booking rates, typically referred to as risk retirements, usually relate to revisions in the estimated total costs to fulfill the performance obligations that reflect improved conditions on a particular contract. Conversely, conditions on a particular contract may deteriorate, resulting in an increase in the estimated total costs to fulfill the performance obligations and a reduction in the profit booking rate. Increases or decreases in profit booking rates are recognized in the current period and reflect the inception-to-date effect of such changes. Segment operating profit and margin may also be impacted favorably or unfavorably by other items, which may or may not impact sales.

Favorable items may include the positive resolution of contractual matters, cost recoveries on severance and restructuring charges, insurance recoveries and gains on sales of assets. Unfavorable items may include the adverse resolution of contractual matters; restructuring charges, except for significant severance actions, which are excluded from segment operating results; reserves for disputes; certain asset impairments; and losses on sales of certain assets.Contract assets – Contract assets include unbilled amounts typically resulting from sales under contracts when the percentage-of-completion cost-to-cost method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the customer. The amounts may not exceed their estimated net realizable value. Contract assets are classified as current based on our contract operating cycle.Contract liabilities – Contract liabilities include advance payments and billings in excess of revenue recognized. Contract liabilities are classified as current based on our contract operating cycle and reported on a contract-by-contract basis, net of revenue recognized, at the end of each reporting period.

Research and development and similar costs

Research and development and similar costs – We conduct research and development (R&D) activities using our own funds (referred to as company-funded R&D or independent research and development (IR&D)) and under contractual arrangements with our customers (referred to as customer-funded R&D) to enhance existing products and services and to develop future technologies. R&D costs include basic research, applied research, concept formulation studies, design, development, and related test activities. Company-funded R&D costs are allocated to customer contracts as part of the general and administrative overhead costs and generally recoverable on our customer contracts with the U.S. Government. Customer-funded R&D costs are charged directly to the related customer contract. Substantially all R&D costs are charged to cost of sales as incurred.

Stock-based compensation

Stock-based compensation – Compensation cost related to all share-based payments is measured at the grant date based on the estimated fair value of the award. We generally recognize the compensation cost ratably over a three-year vesting period, net of estimated forfeitures. At each reporting date, the number of shares is adjusted to the number ultimately expected to vest.

Income taxes

Income taxes – We calculate our provision for income taxes using the asset and liability method, under which deferred tax assets and liabilities are recognized based on the future tax consequences attributable to temporary differences that exist between the financial statement carrying amount of assets and liabilities and their respective tax bases, as well as from operating loss and tax credit carry-forwards. We measure deferred tax assets and liabilities using enacted tax rates that will apply in the years in which we expect the temporary differences to be recovered or paid.

We periodically assess our tax exposures related to periods that are open to examination. Based on the latest available information, we evaluate our tax positions to determine whether the position will more likely than not be sustained upon examination by the Internal Revenue Service (IRS) or other taxing authorities. If we cannot reach a more-likely-than-not determination, no benefit is recorded. If we determine that the tax position is more likely than not to be sustained, we record the largest amount of benefit that is more likely than not to be realized when the tax position is settled. We record interest and penalties related to income taxes as a component of income tax expense on our consolidated statements of earnings. Interest and penalties were not material.

Cash and cash equivalents

Cash and cash equivalents – Cash equivalents include highly liquid instruments with original maturities of 90 days or less.

Receivables

Receivables – Receivables, net represent our unconditional right to consideration under the contract and include amounts billed and currently due from customers. The amounts are stated at their net estimated realizable value.

Inventories

Inventories – We record inventories at the lower of cost or estimated net realizable value. If events or changes in circumstances indicate that the utility of our inventories have diminished through damage, deterioration, obsolescence, changes in price or other causes, a loss is recognized in the period in which it occurs. We capitalize labor, material, subcontractor and overhead costs as work-in-process for contracts where control has not yet passed to the customer. In addition, we capitalize costs incurred to fulfill a contract in advance of contract award in inventories as work-in-process if we determine that contract award is probable. We determine the costs of other product and supply inventories by using the first-in first-out or average cost methods.

Property, plant and equipment

Property, plant and equipment – We record property, plant and equipment at cost. We provide for depreciation and amortization on plant and equipment generally using accelerated methods during the first half of the estimated useful lives of the assets and the straight-line method thereafter. The estimated useful lives of our plant and equipment generally range from 10 to 40 years for buildings and five to 15 years for machinery and equipment. No depreciation expense is recorded on construction in progress until such assets are placed into operation.We review the carrying amounts of long-lived assets for impairment if events or changes in the facts and circumstances indicate that their carrying amounts may not be recoverable. We assess impairment by comparing the estimated undiscounted future cash flows of the related asset grouping to its carrying amount. If an asset is determined to be impaired, we recognize an impairment charge in the current period for the difference between the fair value of the asset and its carrying amount.

Capitalized software

Capitalized software – We capitalize certain costs associated with the development or purchase of internal-use software. The amounts capitalized are included in other noncurrent assets on our consolidated balance sheets and are amortized on a straight-line basis over the estimated useful life of the resulting software, which ranges from two to six years.

Goodwill

Goodwill and Intangible Assets – The assets and liabilities of acquired businesses are recorded under the acquisition method of accounting at their estimated fair values at the date of acquisition. Goodwill represents costs in excess of fair values assigned to the underlying identifiable net assets of acquired businesses. Intangible assets from acquired businesses are recognized at fair value on the acquisition date and consist of customer programs, trademarks, customer relationships, technology and other intangible assets. Customer programs include values assigned to major programs of acquired businesses and represent the aggregate value associated with the customer relationships, contracts, technology and trademarks underlying the associated program and are amortized on a straight-line basis over a period of expected cash flows used to measure fair value, which ranges from nine to 20 years. We perform an impairment test of our goodwill at least annually in the fourth quarter or more frequently whenever events or changes in circumstances indicate the carrying value of goodwill may be impaired. Such events or changes in circumstances may include a significant deterioration in overall economic conditions, changes in the business climate of our industry, a decline in our market capitalization, operating performance indicators, competition, reorganizations of our business, U.S. Government budget restrictions or the disposal of all or a portion of a reporting unit. Our goodwill has been allocated to and is tested for impairment at a level referred to as the reporting unit, which is our business segment level or a level below the business segment. The level

at which we test goodwill for impairment requires us to determine whether the operations below the business segment constitute a self-sustaining business for which discrete financial information is available and segment management regularly reviews the operating results.

We may use either a qualitative or quantitative approach when testing a reporting unit’s goodwill for impairment. For selected reporting units where we use the qualitative approach, we perform a qualitative evaluation of events and circumstances impacting the reporting unit to determine the likelihood of goodwill impairment. Based on that qualitative evaluation, if we determine it is more likely than not that the fair value of a reporting unit exceeds its carrying amount, no further evaluation is necessary. Otherwise we perform a quantitative impairment test. We perform quantitative tests for most reporting units at least once every three years. However, for certain reporting units we may perform a quantitative impairment test every year.

For the quantitative impairment test we compare the fair value of a reporting unit to its carrying value, including goodwill. If the fair value of a reporting unit exceeds its carrying value, goodwill of the reporting unit is not impaired. If the carrying value of the reporting unit, including goodwill, exceeds its fair value, a goodwill impairment loss is recognized in an amount equal to that excess. We generally estimate the fair value of each reporting unit using a combination of a discounted cash flow (DCF) analysis and market-based valuation methodologies such as comparable public company trading values and values observed in recent business acquisitions. Determining fair value requires the exercise of significant judgments, including the amount and timing of expected future cash flows, long-term growth rates, discount rates and relevant comparable public company earnings multiples and relevant transaction multiples. The cash flows employed in the DCF analysis are based on our best estimate of future sales, earnings and cash flows after considering factors such as general market conditions, U.S. Government budgets, existing firm orders, expected future orders, contracts with suppliers, labor agreements, changes in working capital, long term business plans and recent operating performance. The discount rates utilized in the DCF analysis are based on the respective reporting unit’s weighted average cost of capital, which takes into account the relative weights of each component of capital structure (equity and debt) and represents the expected cost of new capital, adjusted as appropriate to consider the risk inherent in future cash flows of the respective reporting unit. The carrying value of each reporting unit includes the assets and liabilities employed in its operations, goodwill and allocations of certain assets and liabilities held at the business segment and corporate levels.

During the fourth quarters of 2020, 2019 and 2018, we performed our annual goodwill impairment test for each of our reporting units. The results of our annual impairment tests of goodwill indicated that no impairment existed.

Intangible assets

Acquired intangible assets deemed to have indefinite lives are not amortized, but are subject to annual impairment testing. This testing compares carrying value to fair value and, when appropriate, the carrying value of these assets is reduced to fair value. Finite-lived intangibles are amortized to expense over the applicable useful lives, ranging from three to 20 years, based on the nature of the asset and the underlying pattern of economic benefit as reflected by future net cash inflows. We perform an impairment test of finite-lived intangibles whenever events or changes in circumstances indicate their carrying value may be impaired.

Postretirement benefit plans

Postretirement benefit plans – Many of our employees are covered by defined benefit pension plans and we provide certain health care and life insurance benefits to eligible retirees (collectively, postretirement benefit plans). GAAP requires that the amounts we record related to our postretirement benefit plans be computed, based on service to date, using actuarial valuations that are based in part on certain key economic assumptions we make, including the discount rate, the expected long-term rate of return on plan assets and other actuarial assumptions including participant longevity (also known as mortality), health care cost trend rates and employee turnover, each as appropriate based on the nature of the plans.

A market-related value of our plan assets, determined using actual asset gains or losses over the prior three year period, is used to calculate the amount of deferred asset gains or losses to be amortized. These asset gains or losses, along with those resulting from adjustments to our benefit obligation, will be amortized to expense using the corridor method, where gains and losses are recognized over a period of years to the extent they exceed 10% of the greater of plan assets or benefit obligations. This amortization period extended in 2020 due to the freeze of our salaried pension plans to use the average remaining life expectancy of the participants instead of average future service.

We recognize on a plan-by-plan basis the funded status of our postretirement benefit plans under GAAP as either an asset recorded within other noncurrent assets or a liability recorded within noncurrent liabilities on our consolidated balance sheets. The GAAP funded status is measured as the difference between the fair value of the plan’s assets and the benefit obligation of the plan. The funded status under the Employee Retirement Income Security Act of 1974 (ERISA), as amended by the Pension Protection Act of 2006 (PPA), is calculated on a different basis than under GAAP.

Environmental matters

Environmental matters – We record a liability for environmental matters when it is probable that a liability has been incurred and the amount can be reasonably estimated. The amount of liability recorded is based on our estimate of the costs to be incurred for remediation at a particular site. We do not discount the recorded liabilities, as the amount and timing of future cash payments are not fixed or cannot be reliably determined. Our environmental liabilities are recorded on our consolidated balance sheets within other liabilities, both current and noncurrent. We expect to include a substantial portion of environmental costs in our net sales and cost of sales in future periods pursuant to U.S. Government agreement or regulation. At the time a liability is recorded for future environmental costs, we record a receivable for estimated future recovery considered probable through the pricing of products and services to agencies of the U.S. Government, regardless of the contract form (e.g., cost-reimbursable, fixed-price). We continuously evaluate the recoverability of our assets for the portion of environmental costs that are probable of future recovery by assessing, among other factors, U.S. Government regulations, our U.S. Government business base and contract mix, our history of receiving reimbursement of such costs, and recent efforts by some U.S. Government representatives to limit such reimbursement. We include the portion of those environmental costs expected to be allocated to our non-U.S. Government contracts, or that is determined to not be recoverable under U.S. Government contracts, in our cost of sales at the time the liability is established. Our assets for the portion of environmental costs that are probable of future recovery are recorded on our consolidated balance sheets within other assets, both current and noncurrent. We project costs and recovery of costs over approximately 20 years.

Investments in marketable securities

Investments in marketable securities – Investments in marketable securities consist of debt and equity securities which are recorded at fair value.Our investments are held in a separate trust, which includes investments to fund our deferred compensation plan liabilities.Gains and losses on these investments are included in other unallocated, net within cost of sales on our consolidated statements of earnings in order to align the classification of changes in the market value of investments held for the plan with changes in the value of the corresponding plan liabilities.

Equity method investments

Equity method investments – Investments where we have the ability to exercise significant influence, but do not control, are accounted for under the equity method of accounting and are included in other noncurrent assets on our consolidated balance sheets. Significant influence typically exists if we have a 20% to 50% ownership interest in the investee. Under this method of accounting, our share of the net earnings or losses of the investee is included in operating profit in other income, net on our consolidated statements of earnings since the activities of the investee are closely aligned with the operations of the business segment holding the investment. We evaluate our equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amounts of such investments may be impaired. If a decline in the value of an equity method investment is determined to be other than temporary, a loss is recorded in earnings in the current period.

Derivative financial instruments

Derivative financial instruments – We use derivative instruments principally to reduce our exposure to market risks from changes in foreign currency exchange rates and interest rates. We do not enter into or hold derivative instruments for speculative trading purposes. We transact business globally and are subject to risks associated with changing foreign currency exchange rates. We enter into foreign currency hedges such as forward and option contracts that change in value as foreign currency exchange rates change. Our most significant foreign currency exposures relate to the British pound sterling, the euro, the Canadian dollar and the Australian dollar. These contracts hedge forecasted foreign currency transactions in order to mitigate fluctuations in our earnings and cash flows associated with changes in foreign currency exchange rates. We designate foreign currency hedges as cash flow hedges. We also are exposed to the impact of interest rate changes primarily through our borrowing activities. For fixed rate borrowings, we may use variable interest rate swaps, effectively converting fixed rate borrowings to variable rate borrowings in order to hedge changes in the fair value of the debt. These swaps are designated as fair value hedges. For variable rate borrowings, we may use fixed interest rate swaps, effectively converting variable rate borrowings to fixed rate borrowings in order to mitigate the impact of interest rate changes on earnings. These swaps are designated as cash flow hedges. We also may enter into derivative instruments that are not designated as hedges and do not qualify for hedge accounting, which are intended to mitigate certain economic exposures.We record derivatives at their fair value. The classification of gains and losses resulting from changes in the fair values of derivatives is dependent on our intended use of the derivative and its resulting designation. Adjustments to reflect changes in fair values of derivatives attributable to highly effective hedges are either reflected in earnings and largely offset by corresponding adjustments to the hedged items or reflected net of income taxes in accumulated other comprehensive loss until the hedged transaction is recognized in earnings. Changes in the fair value of the derivatives that are not highly effective, if any, are immediately recognized in earnings.

Recent Accounting Pronouncements

Compensation—Retirement Benefits—Defined Benefit Plans—General

Effective January 1, 2020, we adopted Accounting Standards Update (ASU) 2018-14, Compensation—Retirement Benefits—Defined Benefit Plans—General (Topic 715-20): Disclosure Framework—Changes to the Disclosure Requirements For Defined Benefit Plans. The new standard modifies the annual disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The guidance requires disclosure changes to be presented on a retrospective basis. As this standard relates only to financial disclosures, its adoption did not have an impact to our results of operations, financial position or cash flows.

Financial Instruments—Credit Losses

Effective January 1, 2020, we adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments using the modified retrospective approach. The new standard changes how we account for credit losses for financial assets and certain other instruments, including trade receivables and contract assets, that are not measured at fair value through net income. Under legacy standards, we recognized an impairment of receivables when it was probable that a loss had been incurred. Under the new standard, we are required to recognize estimated credit losses expected to occur over the estimated life or remaining contractual life of an asset (which includes losses that may be incurred in future periods) using a broader range of information including reasonable and supportable forecasts about future economic conditions. The adoption of the standard did not have a significant impact on our results of operations, financial position or cash flows.

Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting

In 2017, the United Kingdom’s Financial Conduct Authority announced that after 2021 it would no longer compel banks to submit the rates required to calculate the London Interbank Offered Rate (LIBOR) and other interbank offered rates, which have been widely used as reference rates for various securities and financial contracts, including loans, debt and derivatives. This announcement indicates that the continuation of LIBOR on the current basis is not guaranteed after 2021. Regulators in the U.S. and other jurisdictions have been working to replace these rates with alternative reference interest rates that are supported by transactions in liquid and observable markets, such as the Secured Overnight Financing Rate (SOFR). Currently, our credit facility and certain of our debt and derivative instruments reference LIBOR-based rates. The discontinuation of LIBOR will require these arrangements to be modified in order to replace LIBOR with an alternative reference interest rate, which could impact our future cost of funds. Our credit facility includes a provision for the determination of a successor LIBOR rate.

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which temporarily simplifies the accounting for contract modifications, including hedging relationships, due to the transition from LIBOR and other interbank offered rates to alternative reference interest rates. For example, entities can elect not to remeasure the contracts at the modification date or reassess a previous accounting determination if certain conditions are met. Additionally, entities can elect to continue applying hedge accounting for hedging relationships affected by reference rate reform if certain conditions are met. The new standard was effective upon issuance and generally can be applied to applicable contract modifications through December 31, 2022. We are currently evaluating the impact of the transition from LIBOR to alternative reference interest rates, but do not expect a significant impact to our operating results, financial position or cash flows.

Earnings per share computation

We compute basic and diluted earnings per common share by dividing net earnings by the respective weighted average number of common shares outstanding for the periods presented. Our calculation of diluted earnings per common share also includes the dilutive effects for the assumed vesting of outstanding restricted stock units (RSUs), performance stock units (PSUs) and exercise of outstanding stock options based on the treasury stock method.

Acquired finite lived intangible assets

Acquired finite-lived intangible assets are amortized to expense primarily on a straight-line basis over the following estimated useful lives: customer programs, from nine to 20 years; customer relationships, from four to 10 years; and other intangibles, from three to 10 years.

Inventories, costs to fulfill a contract

Costs incurred to fulfill a contract in advance of the contract being awarded are included in inventories as work-in-process if we determine that those costs relate directly to a contract or to an anticipated contract that we can specifically identify and contract award is probable, the costs generate or enhance resources that will be used in satisfying performance obligations, and the costs are recoverable (referred to as pre-contract costs). Pre-contract costs that are initially capitalized in inventory are generally recognized as cost of sales consistent with the transfer of products and services to the customer upon the receipt of the anticipated contract. All other pre-contract costs, including start-up costs, are expensed as incurred.