Summary Of Significant Accounting Policies (Policy)

12 Months Ended

Dec. 31, 2011

Summary Of Significant Accounting Policies [Abstract]

Principles Of Consolidation And Basis Of Presentation

Principles of Consolidation and Basis of Presentation

The Consolidated Financial Statements included in this report have been prepared by management of The Boeing Company (herein referred to as "Boeing," the "Company," "we," "us," or "our"). These statements include the accounts of all majority-owned subsidiaries and variable interest entities that are required to be consolidated. All significant intercompany accounts and transactions have been eliminated. Certain amounts have been reclassified to conform to the current year presentation.

Use Of Estimates

Use of Estimates

Management makes assumptions and estimates to prepare financial statements in conformity with accounting principles generally accepted in the United States of America. Those assumptions and estimates directly affect the amounts reported in the Consolidated Financial Statements. Significant estimates for which changes in the near term are considered reasonably possible and that may have a material impact on the financial statements are disclosed in these notes to the Consolidated Financial Statements.

Operating Cycle

Operating Cycle

For classification of certain current assets and liabilities, we use the duration of the related contract or program as our operating cycle, which is generally longer than one year and could exceed three years.

Revenue And Related Cost Recognition

Revenue and Related Cost Recognition

Contract Accounting Contract accounting is used for development and production activities predominantly by Boeing Defense, Space & Security (BDS). The majority of business conducted by BDS is performed under contracts with the U.S. government and other customers that extend over several years. Contract accounting involves a judgmental process of estimating the total sales and costs for each contract resulting in the development of estimated cost of sales percentages. For each contract, the amount reported as cost of sales is determined by applying the estimated cost of sales percentage to the amount of revenue recognized.

Changes in estimated revenues, cost of sales and the related effect to operating income are recognized using a cumulative catch-up adjustment which recognizes in the current period the cumulative effect of the changes on current and prior periods based on a contract's percent complete. In 2011, 2010 and 2009 net favorable cumulative catch-up adjustments increased operating earnings by $229, $125 and $29 respectively and EPS by $0.23, $0.12 and $0.03 respectively. Significant adjustments recorded during the three years ended December 31, 2011 relate to reach-forward losses on the AEW&C and the KC-767 International Tanker programs.

We combine contracts for accounting purposes when they are negotiated as a package with an overall profit margin objective. These essentially represent an agreement to do a single project for a single customer, involve interrelated construction activities with substantial common costs, and are performed concurrently or sequentially. When a group of contracts is combined, revenue and profit are earned uniformly over the performance of the combined contracts. Similarly, we may segment a single contract or group of contracts when a clear economic decision has been made during contract negotiations that would produce different rates of profitability for each element or phase of the contract.

Sales related to fixed-price contracts are recognized as deliveries are made, except for certain fixed-price contracts that require substantial performance over an extended period before deliveries begin, for which sales are recorded based on the attainment of performance milestones. Sales related to contracts in which we are reimbursed for costs incurred plus an agreed upon profit are recorded as costs are incurred. The Federal Acquisition Regulations provide guidance on the types of cost that will be reimbursed in establishing contract price. Contracts may contain provisions to earn incentive and award fees if specified targets are achieved. Incentive and award fees that can be reasonably estimated and are probable are recorded over the performance period of the contract. Incentive and award fees that cannot be reasonably estimated are recorded when awarded.

Program Accounting Our Commercial Airplanes segment predominantly uses program accounting to account for cost of sales related to its programs. Program accounting is applicable to products manufactured for delivery under production-type contracts where profitability is realized over multiple contracts and years. Under program accounting, inventoriable production costs, program tooling and other non-recurring costs, and routine warranty costs are accumulated and charged to cost of sales by program instead of by individual units or contracts. A program consists of the estimated number of units (accounting quantity) of a product to be produced in a continuing, long-term production effort for delivery under existing and anticipated contracts. The determination of the accounting quantity is limited by the ability to make reasonably dependable estimates of the revenue and cost of existing and anticipated contracts. To establish the relationship of sales to cost of sales, program accounting requires estimates of (a) the number of units to be produced and sold in a program, (b) the period over which the units can reasonably be expected to be produced, and (c) the units' expected sales prices, production costs, program tooling and other non-recurring costs, and routine warranty costs for the total program.

We recognize sales for commercial airplane deliveries as each unit is completed and accepted by the customer. Sales recognized represent the price negotiated with the customer, adjusted by an escalation formula as specified in the customer agreement. The amount reported as cost of sales is determined by applying the estimated cost of sales percentage for the total remaining program to the amount of sales recognized for airplanes delivered and accepted by the customer. Changes in estimated revenues, cost of sales and the related effects on program margins are recognized prospectively except in cases where the program is determined to have a reach-forward loss in which case the loss is recognized in the current period.

Concession Sharing Arrangements We account for sales concessions to our customers in consideration of their purchase of products and services as a reduction to revenue when the related products and services are delivered. The sales concessions incurred may be partially reimbursed by certain suppliers in accordance with concession sharing arrangements. We record these reimbursements, which are presumed to represent reductions in the price of the vendor's products or services, as a reduction in Cost of products.

Spare Parts Revenue We recognize sales of spare parts upon delivery and the amount reported as cost of sales is recorded at average cost.

Service Revenue Service revenue is recognized when the service is performed with the exception of U.S. government service agreements, which are accounted for using contract accounting. Service activities primarily include: support agreements associated with military aircraft and helicopter contracts, ongoing maintenance of International Space Station and Space Shuttle, commercial Delta launches and technical and flight operation services for commercial aircraft. Service revenue and associated cost of sales from pay-in-advance subscription fees are deferred and recognized as services are rendered.

Financial Services Revenue We record financial services revenue associated with sales-type/finance leases, operating leases, and notes receivable.

Lease and financing revenue arrangements are included in Sales of services on the Consolidated Statements of Operations. For sales-type/finance leases, we record an asset at lease inception. This asset is recorded at the aggregate future minimum lease payments, estimated residual value of the leased equipment, and deferred incremental direct costs less unearned income. Income is recognized over the life of the lease to approximate a level rate of return on the net investment. Residual values, which are reviewed periodically, represent the estimated amount we expect to receive at lease termination from the disposition of the leased equipment. Actual residual values realized could differ from these estimates. Declines in estimated residual value that are deemed other-than-temporary are recognized as Cost of services in the period in which the declines occur.

For operating leases, revenue on leased aircraft and equipment is recorded on a straight-line basis over the term of the lease. Operating lease assets, included in Customer financing, are recorded at cost and depreciated over the period that we project we will hold the asset to an estimated residual value, using the straight-line method. We periodically review our estimates of residual value and recognize forecasted changes by prospectively adjusting depreciation expense.

For notes receivable, notes are recorded net of any unamortized discounts and deferred incremental direct costs. Interest income and amortization of any discounts are recorded ratably over the related term of the note.

Reinsurance Revenue Our wholly-owned insurance subsidiary, Astro Ltd., participates in a reinsurance pool for workers' compensation. The member agreements and practices of the reinsurance pool minimize any participating members' individual risk. Reinsurance revenues were $144, $139 and $122 during 2011, 2010 and 2009, respectively. Reinsurance costs related to premiums and claims paid to the reinsurance pool were $142, $123 and $118 during 2011, 2010 and 2009, respectively. Revenues and costs are presented net in Cost of services in the Consolidated Statements of Operations.

Fleet Support

Fleet Support

We provide assistance and services to facilitate efficient and safe aircraft operation to the operators of all our commercial airplane models. Collectively known as fleet support services, these activities and services include flight and maintenance training, field service support, engineering services, and technical data and documents. Fleet support activity begins prior to aircraft delivery as the customer receives training, manuals, and technical consulting support. This activity continues throughout the aircraft's operational life. Services provided after delivery include field service support, consulting on maintenance, repair, and operational issues brought forth by the customer or regulators, updating manuals and engineering data, and the issuance of service bulletins that impact the entire model's fleet. Field service support involves our personnel located at customer facilities providing and coordinating fleet support activities and requests. The costs for fleet support are expensed as incurred as Cost of services.

Research And Development

Research and Development

Research and development includes costs incurred for experimentation, design, testing, and bid and proposal efforts related to government products and services which are expensed as incurred unless the costs are related to certain contractual arrangements with customers. Costs that are incurred pursuant to such contractual arrangements are recorded over the period that revenue is recognized, consistent with our contract accounting policy. We have certain research and development arrangements that meet the requirement for best efforts research and development accounting. Accordingly, the amounts funded by the customer are recognized as an offset to our research and development expense rather than as contract revenues.

We have established cost sharing arrangements with some suppliers for the 787 program. Our cost sharing arrangements state that the supplier contributions are for reimbursements of costs we incur for experimentation, basic design, and testing activities during the 787 development. In each arrangement, we retain substantial rights to the 787 part or component covered by the arrangement. The amounts received from these cost sharing arrangements are recorded as a reduction to research and development expenses since we have no obligation to refund any amounts received per the arrangements regardless of the outcome of the development efforts. Specifically, under the terms of each agreement, payments received from suppliers for their share of the costs are typically based on milestones and are recognized as earned when we achieve the milestone events and no ongoing obligation on our part exists. In the event we receive a milestone payment prior to the completion of the milestone, the amount is classified in Accrued liabilities until earned.

Share-Based Compensation

Share-Based Compensation

We provide various forms of share-based compensation to our employees. For awards settled in shares, we measure compensation expense based on the grant-date fair value net of estimated forfeitures. For awards settled in cash, or that may be settled in cash, we measure compensation expense based on the fair value at each reporting date net of estimated forfeitures. The expense is recognized over the requisite service period, which is generally the vesting period of the award.

Income Taxes

Income Taxes

Provisions for federal, state, and non-U.S. income taxes are calculated on reported Earnings before income taxes based on current tax law and also include, in the current period, the cumulative effect of any changes in tax rates from those used previously in determining deferred tax assets and liabilities. Such provisions differ from the amounts currently receivable or payable because certain items of income and expense are recognized in different time periods for financial reporting purposes than for income tax purposes. Significant judgment is required in determining income tax provisions and evaluating tax positions.

The accounting for uncertainty in income taxes requires a more-likely-than-not threshold for financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. We record a liability for the difference between the benefit recognized and measured for financial statement purposes and the tax position taken or expected to be taken on our tax return. To the extent that our assessment of such tax positions changes, the change in estimate is recorded in the period in which the determination is made. Tax-related interest and penalties are classified as a component of Income tax expense.

Postretirement Plans

Postretirement Plans

The majority of our employees are covered by defined benefit pension plans. All nonunion and some union employees hired after December 31, 2008 are not covered by defined benefit plans. We also provide postretirement benefit plans other than pensions, consisting principally of health care coverage to eligible retirees and qualifying dependents. Benefits under the pension and other postretirement benefit plans are generally based on age at retirement and years of service and, for some pension plans, benefits are also based on the employee's annual earnings. The net periodic cost of our pension and other postretirement plans is determined using the projected unit credit method and several actuarial assumptions, the most significant of which are the discount rate, the long-term rate of asset return, and medical trend (rate of growth for medical costs). A portion of net periodic pension and other postretirement income or expense is not recognized in net earnings in the year incurred because it is allocated to production as product costs, and reflected in inventory at the end of a reporting period. Actuarial gains and losses, which occur when actual experience differs from actuarial assumptions, are reflected in Shareholders' equity (net of taxes). If actuarial gains and losses exceed ten percent of the greater of plan assets or plan liabilities we amortize them over the average future service period of employees. The funded status of our pension and postretirement plans is reflected on the Consolidated Statements of Financial Position.

Postemployment Plans

Postemployment Plans

We record a liability for postemployment benefits, such as severance or job training, when payment is probable, the amount is reasonably estimable, and the obligation relates to rights that have vested or accumulated.

Environmental Remediation

Environmental Remediation

We are subject to federal and state requirements for protection of the environment, including those for discharge of hazardous materials and remediation of contaminated sites. We routinely assess, based on in-depth studies, expert analyses and legal reviews, our contingencies, obligations, and commitments for remediation of contaminated sites, including assessments of ranges and probabilities of recoveries from other responsible parties and/or insurance carriers. Our policy is to accrue and charge to current expense identified exposures related to environmental remediation sites when it is probable that a liability has been incurred and the amount can be reasonably estimated. The amount of the liability is based on our best estimate or the low end of a range of reasonably possible exposure for investigation, cleanup, and monitoring costs to be incurred. Estimated remediation costs are not discounted to present value as the timing of payments cannot be reasonably estimated. We may be able to recover a portion of the remediation costs from insurers or other third parties. Such recoveries are recorded when realization of the claim for recovery is deemed probable.

Cash And Cash Equivalents

Cash and Cash Equivalents

Cash and cash equivalents consist of highly liquid instruments, such as commercial paper, time deposits, and other money market instruments, which have original maturities of three months or less. We aggregate our cash balances by bank where conditions for right of set-off are met, and reclassify any negative balances, consisting mainly of uncleared checks, to Accounts payable. Negative balances reclassified to Accounts payable were $132 and $209 at December 31, 2011 and 2010.

Inventories

Inventories

Inventoried costs on commercial aircraft programs and long-term contracts include direct engineering, production and tooling and other non-recurring costs, and applicable overhead, which includes fringe benefits, production related indirect and plant management salaries and plant services, not in excess of estimated net realizable value. To the extent a material amount of such costs are related to an abnormal event or are fixed costs not appropriately attributable to our programs or contracts, they are expensed in the current period rather than inventoried. Inventoried costs include amounts relating to programs and contracts with long-term production cycles, a portion of which is not expected to be realized within one year. Included in inventory for federal government contracts is an allocation of allowable costs related to manufacturing process reengineering.

Commercial aircraft programs inventory includes deferred production costs. Deferred production costs represent actual costs incurred for production of early units that exceed the estimated average cost of all units in the program accounting quantity. Higher production costs are experienced at the beginning of a new or derivative airplane program. Units produced early in a program require substantially more effort (labor and other resources) than units produced later in a program because of volume efficiencies and the effects of learning. We expect that these deferred costs will be fully recovered when all units included in the accounting quantity are delivered as the expected unit cost for later deliveries is below the estimated average cost of all units in the program.

The determination of net realizable value of long-term contract costs is based upon quarterly reviews that estimate costs to be incurred to complete all contract requirements. When actual contract costs and the estimate to complete exceed total estimated contract revenues, a loss provision is recorded. The determination of net realizable value of commercial aircraft program costs is based upon quarterly program reviews that estimate revenue and cost to be incurred to complete the program accounting quantity. When estimated costs to complete exceed estimated program revenues to go, a program loss provision is recorded in the current period for the estimated loss on all undelivered units in the accounting quantity.

Used aircraft purchased by the Commercial Airplanes segment and general stock materials are stated at cost not in excess of net realizable value. See 'Aircraft Valuation' within this Note for a discussion of our valuation of used aircraft. Spare parts inventory is stated at lower of average unit cost or market. We review our commercial spare parts and general stock materials quarterly to identify impaired inventory, including excess or obsolete inventory, based on historical sales trends, expected production usage, and the size and age of the aircraft fleet using the part. Impaired inventories are charged to Cost of products in the period the impairment occurs.

Included in inventory for commercial aircraft programs are amounts paid or credited in cash, or other consideration to certain airline customers, that are referred to as early issue sales consideration. Early issue sales consideration is recognized as a reduction to revenue when the delivery of the aircraft under contract occurs. If an airline customer does not perform and take delivery of the contracted aircraft, we believe that we would have the ability to recover amounts paid. However, to the extent early issue sales consideration exceeds advances and is not considered to be otherwise recoverable, it would be written off in the current period.

We net advances and progress billings on long-term contracts against inventory in the Consolidated Statements of Financial Position. Advances and progress billings in excess of related inventory are reported in Advances and billings in excess of related costs.

Precontract Costs

Precontract Costs

We may, from time to time, incur costs to begin fulfilling the statement of work under a specific anticipated contract that we are still negotiating with a customer. If we determine it is probable that we will be awarded the specific anticipated contract, then we capitalize the precontract costs we incur, excluding start-up costs which are expensed as incurred. Capitalized precontract costs are included in Inventories, net of advances and progress billings, in the accompanying Consolidated Statements of Financial Position. Should the contract not be awarded or otherwise determined to no longer be probable of award, the capitalized costs would be written off.

Property, Plant And Equipment

Property, Plant and Equipment

Property, plant and equipment are recorded at cost, including applicable construction-period interest, less accumulated depreciation and are depreciated principally over the following estimated useful lives: new buildings and land improvements, from 10 to 40 years; and new machinery and equipment, from 3 to 20 years. The principal methods of depreciation are as follows: buildings and land improvements, 150% declining balance; and machinery and equipment, sum-of-the-years' digits. Capitalized internal use software is included in Other assets and amortized using the straight line method over five years. We periodically evaluate the appropriateness of remaining depreciable lives assigned to long-lived assets, including assets that may be subject to a management plan for disposition.

Long-lived assets held for sale are stated at the lower of cost or fair value less cost to sell. Long-lived assets held for use are subject to an impairment assessment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If the carrying value is no longer recoverable based upon the undiscounted future cash flows of the asset, the amount of the impairment is the difference between the carrying amount and the fair value of the asset.

Asset Retirement Obligations

Asset Retirement Obligations

We record all known asset retirement obligations for which the liability's fair value can be reasonably estimated, including certain asbestos removal, asset decommissioning and contractual lease restoration obligations. Recorded amounts are not material.

We also have known conditional asset retirement obligations, such as certain asbestos remediation and asset decommissioning activities to be performed in the future, that are not reasonably estimable due to insufficient information about the timing and method of settlement of the obligation. Accordingly, these obligations have not been recorded in the Consolidated Financial Statements. A liability for these obligations will be recorded in the period when sufficient information regarding timing and method of settlement becomes available to make a reasonable estimate of the liability's fair value. In addition, there may be conditional asset retirement obligations that we have not yet discovered (e.g. asbestos may exist in certain buildings but we have not become aware of it through the normal course of business), and therefore, these obligations also have not been included in the Consolidated Financial Statements.

Goodwill And Other Acquired Intangibles

Goodwill and Other Acquired Intangibles

Goodwill and other acquired intangible assets with indefinite lives are not amortized, but are tested for impairment annually and when an event occurs or circumstances change such that it is more likely than not that an impairment may exist. Our annual testing date is April 1.

We test goodwill for impairment by first comparing the carrying value of net assets to the fair value of the related operations. If the fair value is determined to be less than carrying value, a second step is performed to compute the amount of the impairment. In this process, a fair value for goodwill is estimated, based in part on the fair value of the operations, and is compared to its carrying value. The shortfall of the fair value below carrying value represents the amount of goodwill impairment.

Indefinite-lived intangibles consist of brand and tradenames acquired in business combinations. We test these intangibles for impairment by comparing their carrying value to current projections of discounted cash flows attributable to the brand and tradenames. Any excess carrying value over the amount of discounted cash flows represents the amount of the impairment.

Our finite-lived acquired intangible assets are amortized on a straight-line basis over their estimated useful lives as follows: developed technology, from 4 to 14 years; product know-how, from 3 to 30 years; customer base, from 3 to 19 years; distribution rights, from 3 to 30 years; and other, from 1 to 32 years. We evaluate the potential impairment of finite-lived acquired intangible assets whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If the carrying value is no longer recoverable based upon the undiscounted future cash flows of the asset, the amount of the impairment is the difference between the carrying amount and the fair value of the asset.

Investments

Investments

Time deposits are held-to-maturity investments that are carried at cost.

The equity method of accounting is used to account for investments for which we have the ability to exercise significant influence, but not control, over an investee. Significant influence is generally deemed to exist if we have an ownership interest in the voting stock of an investee of between 20% and 50%.

We classify investment income and loss on our Consolidated Statements of Operations based on whether the investment is operating or non-operating in nature. Operating investments align strategically and are integrated with our operations. Earnings from operating investments, including our share of income or loss from equity method investments, dividend income from certain cost method investments, and any impairments or gain/loss on the disposition of these investments, are recorded in Income from operating investments, net. Non-operating investments are those we hold for non-strategic purposes. Earnings from non-operating investments, including interest and dividends on marketable securities, and any impairments or gain/loss on the disposition of these investments are recorded in Other income/(expense), net.

Derivatives

Derivatives

All derivative instruments are recognized in the financial statements and measured at fair value regardless of the purpose or intent of holding them. We use derivative instruments to principally manage a variety of market risks. For derivatives designated as hedges of the exposure to changes in fair value of the recognized asset or liability or a firm commitment (referred to as fair value hedges), the gain or loss is recognized in earnings in the period of change together with the offsetting loss or gain on the hedged item attributable to the risk being hedged. The effect of that accounting is to include in earnings the extent to which the hedge is not effective in achieving offsetting changes in fair value. For our cash flow hedges, the effective portion of the derivative's gain or loss is initially reported in Shareholders' equity (as a component of Accumulated other comprehensive loss) and is subsequently reclassified into earnings in the same period or periods during which the hedged forecasted transaction affects earnings. The ineffective portion of the gain or loss of a cash flow hedge is reported in earnings immediately. We also hold certain instruments for economic purposes that are not designated for hedge accounting treatment. For these derivative instruments, the changes in their fair value are also recorded in earnings immediately.

Aircraft Valuation

Aircraft Valuation

Used aircraft under trade-in commitments and aircraft under repurchase commitments In conjunction with signing a definitive agreement for the sale of new aircraft (Sale Aircraft), we have entered into trade-in commitments with certain customers that give them the right to trade in used aircraft at a specified price upon the purchase of Sale Aircraft. Additionally, we have entered into contingent repurchase commitments with certain customers wherein we agree to repurchase the Sale Aircraft at a specified price, generally 10 to 15 years after delivery of the Sale Aircraft. Our repurchase of the Sale Aircraft is contingent upon a future, mutually acceptable agreement for the sale of additional new aircraft. If we execute an agreement for the sale of additional new aircraft, and if the customer exercises its right to sell the Sale Aircraft to us, a contingent repurchase commitment would become a trade-in commitment. Our historical experience is that contingent repurchase commitments infrequently become trade-in commitments.

All trade-in commitments at December 31, 2011 and 2010 were solely attributable to Sale Aircraft and did not originate from contingent repurchase commitments. Exposure related to trade-in commitments may take the form of:

(1) adjustments to revenue for the difference between the contractual trade-in price in the definitive agreement and our best estimate of the fair value of the trade-in aircraft as of the date of such agreement, which would be recorded in Inventory and recognized upon delivery of the Sale Aircraft, and/or

(2) charges to cost of products for adverse changes in the fair value of trade-in aircraft that occur subsequent to signing of a definitive agreement for Sale Aircraft but prior to the purchase of the used trade-in aircraft. Estimates based on current aircraft values would be included in Accrued liabilities.

The fair value of trade-in aircraft is determined using aircraft-specific data such as model, age and condition, market conditions for specific aircraft and similar models, and multiple valuation sources. This process uses our assessment of the market for each trade-in aircraft, which in most instances begins years before the return of the aircraft. There are several possible markets in which we continually pursue opportunities to place used aircraft. These markets include, but are not limited to, the resale market, which could potentially include the cost of long-term storage; the leasing market, with the potential for refurbishment costs to meet the leasing customer's requirements; or the scrap market. Trade-in aircraft valuation varies significantly depending on which market we determine is most likely for each aircraft. On a quarterly basis, we update our valuation analysis based on the actual activities associated with placing each aircraft into a market. This quarterly valuation process yields results that are typically lower than residual value estimates by independent sources and tends to more accurately reflect results upon the actual placement of the aircraft.

Used aircraft acquired by the Commercial Airplanes segment are included in Inventories at the lower of cost or market as it is our intent to sell these assets. To mitigate costs and enhance marketability, aircraft may be placed on operating lease. While on operating lease, the assets are included in Customer financing.

Assets under operating lease, assets held for sale or re-lease and collateral underlying receivables Customer financing includes operating lease equipment, notes receivables, and sales-type/finance leases. Sales-type/finance leases are treated as receivables, and allowances for losses are established as necessary.

We assess the fair value of the assets we own, including equipment under operating leases, assets held for sale or re-lease, and collateral underlying receivables, to determine if their fair values are less than the related assets' carrying values. Differences between carrying values and fair values of sales-type/finance leases and notes and other receivables, as determined by collateral value, are considered in determining the allowance for losses on receivables.

We use a median calculated from published collateral values from multiple third-party aircraft value publications based on the type and age of the aircraft to determine the fair value of aircraft. Under certain circumstances, we apply judgment based on the attributes of the specific aircraft or equipment, usually when the features or use of the aircraft vary significantly from the more generic aircraft attributes covered by outside publications.

Impairment review for assets under operating leases and held for sale or re-lease We evaluate for impairment assets under operating lease or assets held for sale or re-lease when events or changes in circumstances indicate that the expected undiscounted cash flow from the asset may be less than the carrying value. We use various assumptions when determining the expected undiscounted cash flow, including our intentions for how long we will hold an asset subject to operating lease before it is sold, the expected future lease rates, lease terms, residual value of the asset, periods in which the asset may be held in preparation for a follow-on lease, maintenance costs, remarketing costs and the remaining economic life of the asset. We record assets held for sale at the lower of carrying value or fair value less costs to sell.

When we determine that impairment is indicated for an asset, the amount of impairment expense recorded is the excess of the carrying value over the fair value of the asset.

Allowance for losses on customer financing receivables We record the potential impairment of customer financing receivables in our portfolio in a valuation account, the balance of which is an accounting estimate of probable but unconfirmed losses in the receivables portfolio. The allowance for losses on receivables relates to two components of receivables: (a) receivables that are evaluated individually for impairment and (b) all other receivables.

We determine a receivable is impaired when, based on current information and events, it is probable that we will be unable to collect amounts due according to the original contractual terms of the receivable agreement, without regard to any subsequent restructurings. Factors considered in assessing collectibility include, but are not limited to, a customer's extended delinquency, requests for restructuring and filings for bankruptcy. We determine a specific impairment allowance based on the difference between the carrying value of the receivable and the estimated fair value of the related collateral we would expect to realize.

We review the adequacy of the allowance attributable to the remaining receivables (after excluding receivables subject to a specific impairment allowance) by assessing both the collateral exposure and the applicable cumulative default rate. Collateral exposure for a particular receivable is the excess of the carrying value of the receivable over the fair value of the related collateral. A receivable with an estimated fair value in excess of the carrying value is considered to have no collateral exposure. The applicable cumulative default rate is determined using two components: customer credit ratings and weighted average remaining contract term. Internally assigned credit ratings, our credit quality indicator, are determined for each customer in the portfolio. Those ratings are updated based upon public information and information obtained directly from our customers.

We have entered into agreements with certain customers that would entitle us to look beyond the specific collateral underlying the receivable for purposes of determining the collateral exposure as described above. Should the proceeds from the sale of the underlying collateral asset resulting from a default condition be insufficient to cover the carrying value of our receivable (creating a shortfall condition), these agreements would, for example, permit us to take the actions necessary to sell or retain certain other assets in which the customer has an equity interest and use the proceeds to cover the shortfall.

Each quarter we review customer credit ratings, published historical credit default rates for different rating categories, and multiple third-party aircraft value publications as a basis to validate the reasonableness of the allowance for losses on receivables. There can be no assurance that actual results will not differ from estimates or that the consideration of these factors in the future will not result in an increase or decrease to the allowance for losses on receivables.

Warranties

Warranties

In conjunction with certain product sales, we provide warranties that cover factors such as non-conformance to specifications and defects in material and design. The majority of our warranties are issued by our Commercial Airplanes segment. Generally, aircraft sales are accompanied by a three to four-year standard warranty for systems, accessories, equipment, parts, and software manufactured by us or manufactured to certain standards under our authorization. These warranties are included in the programs' estimate at completion. On occasion we have made commitments beyond the standard warranty obligation to correct fleet-wide major issues of a particular model, resulting in additional accrued warranty expense. Warranties issued by our BDS segments principally relate to sales of military aircraft and weapons hardware and are included in the contract cost estimates. These sales are generally accompanied by a six to twelve-month warranty period and cover systems, accessories, equipment, parts, and software manufactured by us to certain contractual specifications. Estimated costs related to standard warranties are recorded in the period in which the related product sales occur. The warranty liability recorded at each balance sheet date reflects the estimated number of months of warranty coverage outstanding for products delivered times the average of historical monthly warranty payments, as well as additional amounts for certain major warranty issues that exceed a normal claims level. Estimated costs of these additional warranty issues are considered changes to the initial liability estimate.

We provide guarantees to certain commercial airplane customers which include compensation provisions for failure to meet specified aircraft performance targets. We account for these performance guarantees as warranties. The estimated liability for these warranties is based on known and anticipated operational characteristics and forecasted customer operation of the aircraft relative to contractually specified performance targets, and anticipated settlements when contractual remedies are not specified. Estimated payments are recorded as a reduction of revenue at delivery of the related aircraft. We have agreements that require certain suppliers to compensate us for amounts paid to customers for failure of supplied equipment to meet specified performance targets. Claims against suppliers under these agreements are included in Inventories and recorded as a reduction in Cost of products at delivery of the related aircraft. These performance warranties and claims against suppliers are included in the programs' estimate at completion.

Supplier Penalties

Supplier Penalties

We record an accrual for supplier penalties when an event occurs that makes it probable that a supplier penalty will be incurred and the amount is reasonably estimable. Until an event occurs, we fully anticipate accepting all products procured under production-related contracts.

Guarantees

Guarantees

We record a liability in Accrued liabilities for the fair value of guarantees that are issued or modified after December 31, 2002. For a residual value guarantee where we received a cash premium, the liability is equal to the cash premium received at the guarantee's inception. For credit and performance guarantees, the liability is equal to the present value of the expected loss. We determine the expected loss by multiplying the creditor's default rate by the guarantee amount reduced by the expected recovery, if applicable, for each future period the credit or performance guarantee will be outstanding. If at inception of a guarantee, we determine there is a probable related contingent loss, we will recognize a liability for the greater of (a) the fair value of the guarantee as described above or (b) the probable contingent loss amount.