Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Organization and Nature of Operations

Organization and Nature of Operations. Kaiser Aluminum Corporation specializes in the production of semi-fabricated specialty aluminum products, such as aluminum plate and sheet and extruded and drawn products, primarily used in aerospace/high strength, automotive, general engineering and other industrial end market applications. Our business is organized into one operating segment, Fabricated Products. See Note 13 for additional information regarding our reportable segment and business unit.

Principles of Consolidation and Basis of Presentation

Principles of Consolidation and Basis of Presentation. The consolidated financial statements include the accounts of our wholly owned subsidiaries and are prepared in accordance with United States generally accepted accounting principles ("GAAP") and the rules and regulations of the Securities and Exchange Commission (the "SEC"). Intercompany balances and transactions are eliminated.

Use of Estimates in the Preparation of Financial Statements

Use of Estimates in the Preparation of Financial Statements. The preparation of financial statements in accordance with GAAP requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities known to exist as of the date the financial statements are published and the reported amounts of revenues and expenses during the reporting period. Uncertainties with respect to such estimates and assumptions are inherent in the preparation of our consolidated financial statements; accordingly, it is possible that the actual results could differ from these estimates and assumptions, which could have a material effect on the reported amounts of our consolidated financial position and results of operations.

Recognition of Sales

Recognition of Sales. Sales are generally recognized on a gross basis when all of the following criteria are met: (i) persuasive evidence of an arrangement exists; (ii) title, ownership and risk of loss has passed to the customer; (iii) the price to the customer is fixed or determinable; and (iv) collection of the resulting receivable is reasonably assured. A provision for estimated sales returns from and allowances to customers is made in the same period as the related revenues are recognized, based on historical experience or the specific identification of an event necessitating a reserve.

Stock-Based Compensation

Stock-Based Compensation. Stock-based compensation in the form of service-based awards is provided to executive officers, certain employees and non-employee directors and is accounted for at fair value. We measure the cost of services received in exchange for an award of equity instruments based on the grant-date fair value of the award and the number of awards expected to ultimately vest. The grant-date fair value is determined based on the stock price on the date of grant, adjusted for expected dividends to be paid during the vesting period.

We also grant performance-based awards to executive officers and other key employees. Performance awards granted prior to 2014 are subject to performance conditions pertaining to specified financial metrics and are valued based on the stock price at the date of grant, adjusted for expected dividend equivalents to be paid during the vesting period. Performance awards granted after 2014 are subject to performance conditions pertaining to total shareholder return and are valued on the date of grant using a Monte Carlo valuation model. The key assumptions in applying this model are an expected volatility and a risk-free interest rate. For more information on our stock-based compensation, see Note 8.

The cost of service-based awards, including time-vested restricted stock and performance shares, is recognized as an expense over the requisite service period of the award on a straight-line basis. For performance shares granted prior to 2014, the related expense is updated quarterly by adjusting the estimated number of shares expected to vest based on the most probable outcome of the performance condition (see Note 8).

Shipping and Handling Costs

Shipping and Handling Costs. Shipping and handling costs are recorded as a component of Cost of products sold, excluding depreciation, amortization and other items.

Advertising Costs

Advertising Costs. Advertising costs, which are included in Selling, general, administrative, research and development ("SG&A and R&D"), are expensed as incurred. Advertising costs for 2015, 2014 and 2013 were $1.2 million, $0.6 million and $1.3 million, respectively.

Research and Development Costs

Research and Development Costs. Research and development costs, which are included in SG&A and R&D, are expensed as incurred. Research and development costs for 2015, 2014 and 2013 were $9.5 million, $8.9 million and $7.8 million, respectively.

Major Maintenance Activities

Major Maintenance Activities. All major maintenance costs are accounted for using the direct expensing method.

Cash and Cash Equivalents

Cash and Cash Equivalents. We consider only those short-term, highly liquid investments with original maturities of 90 days or less when purchased to be cash equivalents. Our cash equivalents consist primarily of funds in commercial paper, money market funds and other highly liquid investments, which are classified within Level 1 of the fair value hierarchy with the exception of commercial paper, which is classified within Level 2 of the fair value hierarchy.

Restricted Cash

Restricted Cash. We are required to keep on deposit certain amounts that are pledged or held as collateral relating to workers’ compensation and other agreements. We account for such deposits as restricted cash (see Note 2). From time to time, such restricted funds could be returned to us or we could be required to pledge additional cash.

Trade Receivables and Allowance for Doubtful Accounts

Trade Receivables and Allowance for Doubtful Accounts. Trade receivables primarily consist of amounts billed to customers for products sold. Accounts receivable are generally due within 30 to 60 days. For the majority of our receivables, we establish an allowance for doubtful accounts based upon collection experience and other factors. On certain other receivables where we are aware of a specific customer’s inability or reluctance to pay, an allowance for doubtful accounts is established against amounts due, to reduce the net receivable balance to the amount we reasonably expect to collect. However, if circumstances change, our estimate of the recoverability of accounts receivable could be different. Circumstances that could affect our estimates include, but are not limited to, customer credit issues and general economic conditions. Accounts are written off once deemed to be uncollectible. Any subsequent cash collections relating to accounts that have been previously written off are typically recorded as a reduction to total bad debt expense in the period of payment. Write-offs for 2015, 2014 and 2013 were immaterial to the consolidated financial statements.

Inventories

Inventories. Inventories are stated at the lower of cost or market value. On December 31, 2015, we recorded an inventory write-down of $2.6 million to reflect the net realizable value as of that date. The net realizable value reflected: (i) a reduction in the Midwest Transaction Price and (ii) commitments as of that date from customers to purchase our inventory at prices that exceeded the Midwest Transaction Price reduced by an approximate normal profit margin. If we continue to encounter reductions in the price of aluminum and/or if we experience a decrease in our net realizable value of inventory, we may be subject to additional inventory lower of cost or market value adjustments.

Finished products, work-in-process and raw material inventories are stated on the last-in, first-out ("LIFO") basis. At December 31, 2015, after adjusting for the inventory write down discussed above, the stated LIFO value of inventory represented its net realizable value (less a normal profit margin) and exceeded the current cost of our inventory by $24.1 million. At December 31, 2014, the current cost of our inventory exceeded its stated LIFO value by $37.6 million. Other inventories, principally operating supplies and repair and maintenance parts, are stated at average cost. Inventory costs consist of material, labor and manufacturing overhead, including depreciation. Abnormal costs, such as idle facility expenses, freight, handling costs and spoilage, are accounted for as current period charges. All of our inventories at December 31, 2015 and December 31, 2014 were included in the Fabricated Products segment (see Note 2 for the components of inventories).

Property, Plant and Equipment - Net

Property, Plant and Equipment – Net. Property, plant and equipment is recorded at cost (see Note 2). Construction in progress is included within Property, plant and equipment – net on the Consolidated Balance Sheets. Interest related to the construction of qualifying assets is capitalized as part of the construction costs. The aggregate amount of interest capitalized is limited to the interest expense incurred in the period. The amount of interest expense capitalized as construction in progress was $1.8 million, $2.5 million and $3.4 million during 2015, 2014 and 2013, respectively.

Depreciation is computed using the straight-line method at rates based on the estimated useful lives of the various classes of assets. Capital lease assets and leasehold improvements are depreciated on a straight-line basis over the shorter of the estimated useful lives of the assets or the lease term. The principal estimated useful lives are as follows:

	Range (in years)
Land improvements	3	-	25
Buildings and leasehold improvements	15	-	45
Machinery and equipment	1	-	24
Capital lease assets	3	-	5

Depreciation expense is not included in Cost of products sold, excluding depreciation and amortization and other items, but is included in Depreciation and amortization on the Statements of Consolidated (Loss) Income. For 2015, 2014 and 2013, we recorded depreciation expense of $30.3 million, $29.0 million and $25.8 million, respectively, relating to our operating facilities in our Fabricated Products segment. An immaterial amount of depreciation expense was also recorded within All Other for all periods presented in this Report.

Property, plant and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset or group of assets may not be recoverable. We regularly assess whether events and circumstances with the potential to trigger impairment have occurred and rely on a number of factors, including operating results, business plans, economic projections and anticipated future cash flow, to make such assessments. We use an estimate of the future undiscounted cash flows of the related asset or asset group over the estimated remaining life of such asset(s) in measuring whether the asset(s) are recoverable. Measurement of the amount of impairment, if any, is based on the difference between the carrying value of the asset(s) and the estimated fair value of such asset(s). Fair value is determined through a series of standard valuation techniques.

We recorded impairment charges of $0.1 million and $1.5 million in 2015 and 2014, respectively, to reflect the scrap value of idled assets we determined not to deploy for future use. There were no impairment charges in 2013. Asset impairment charges are included in Other operating charges, net in the Statements of Consolidated (Loss) Income and are included in the Fabricated Products segment.

We classify assets as held for sale only when an asset is being actively marketed and expected to sell within 12 months. Assets held for sale are initially measured at the lesser of the assets' carrying amount and the fair value less costs to sell.

Available for Sale Securities

Available for Sale Securities. We account for investments in certain marketable debt securities as available for sale securities. Such securities are recorded at fair value (see Note 11), with net unrealized gains and losses, net of income taxes, reflected in Accumulated other comprehensive income (loss) as a component of Stockholders' equity. Realized gains and losses from the sale of marketable debt securities, if any, are determined on a specific identification basis. Debt investment securities with an original maturity of 90 days or less are classified as Cash and cash equivalents (see Note 2). Debt investment securities with an original maturity of greater than 90 days are presented as Short-term investments on the Consolidated Balance Sheets. In addition to debt investment securities, we also hold assets in various investment funds managed by a third-party trust in connection with our deferred compensation program (see Note 6).

Deferred Financing Costs

Deferred Financing Costs. Costs incurred in connection with debt financing are deferred and amortized over the estimated term of the related borrowing. Such amortization is included in Interest expense and may be capitalized as part of construction in progress (see Note 2 and Note 3).

Goodwill and Intangible Assets

Goodwill and Intangible Assets. Goodwill is tested for impairment during the fourth quarter on an annual basis, as well as on an interim basis, as warranted, at the time of relevant events and changes in circumstances. Intangible assets with definite lives are initially recognized at fair value and subsequently amortized over the estimated useful lives to reflect the pattern in which the economic benefits of the intangible assets are consumed. In the event the pattern cannot be reliably determined, we use a straight-line amortization method. Whenever events or changes in circumstances indicate that the carrying amount of the intangible assets may not be recoverable, the intangible assets are reviewed for impairment. We concluded there was no impairment of the carrying value of goodwill at December 31, 2015 or December 31, 2014 (see Note 4).

Conditional Asset Retirement Obligations ("CAROs")

Conditional Asset Retirement Obligations ("CAROs"). We have CAROs at several of our Fabricated Products facilities. The vast majority of such CAROs consist primarily of incremental costs that would be associated with the removal and disposal of asbestos (all of which is believed to be fully contained and encapsulated within walls, floors, roofs, ceilings or piping) at certain of our older facilities if such facilities were to undergo major renovation or be demolished. We estimate incremental costs for special handling, removal and disposal costs of materials that may or will give rise to CAROs and then discount the expected costs back to the current year using a credit-adjusted, risk-free rate. When it is unclear when or if CAROs will be triggered, we use probability weighting for possible timing scenarios to determine the probability-weighted liability amounts that should be recognized in our consolidated financial statements (see Note 11).

Self Insurance of Employee Health and Workers' Compensation Liabilities

Self Insurance of Employee Health and Workers' Compensation Liabilities. We self-insure the majority of the costs of employee health care benefits and workers' compensation benefits and rely on insurance coverage to protect us from large losses on individual claims. Workers' compensation liabilities are based on a combination of estimates for: (i) incurred-but-not-reported claims and (ii) the ultimate expense of incurred claims. Such estimates are based on judgment, using our historical claims data and information and analysis provided by actuarial and claims advisors, our insurance carriers and other professionals. Our undiscounted workers' compensation liabilities were estimated at $23.5 million and $25.9 million at December 31, 2015 and December 31, 2014, respectively. However, we account for our workers' compensation accrued liability on a discounted basis, using a discount rate of 1.75% at both December 31, 2015 and December 31, 2014. Accrued liabilities for employee healthcare benefits, which are estimates of unpaid incurred medical and prescription drug costs as provided by our healthcare administrators, were $3.2 million and $2.9 million at December 31, 2015 and December 31, 2014, respectively.

Environmental Contingencies

Environmental Contingencies. With respect to environmental loss contingencies, we record a loss contingency whenever a contingency is probable and reasonably estimable (see Note 9). Accruals for estimated losses from environmental remediation obligations are generally recognized no later than the completion of the remedial feasibility study. Such accruals are adjusted as information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted to their present value. Accruals for expected environmental costs are included in Other accrued liabilities or Long-term liabilities, as appropriate (see Note 2). Environmental expense relating to continuing operations is included in Cost of products sold, excluding depreciation and amortization and other items in the Statements of Consolidated (Loss) Income. Environmental expense relating to non-operating locations is included in SG&A and R&D in the Statements of Consolidated (Loss) Income.

Derivative Financial Instruments

Derivative Financial Instruments. Hedging transactions using derivative financial instruments are primarily designed to mitigate our exposure to changes in the market price of aluminum and energy and, to a lesser extent, to mitigate our exposure to changes in foreign currency exchange rates. From time to time, we also enter into hedging arrangements in connection with financing transactions to mitigate financial risks.

We do not utilize derivative financial instruments for trading or other speculative purposes. Our derivative activities are initiated within guidelines established by management and approved by our Board of Directors. Hedging transactions are executed centrally on behalf of all of our operations to minimize transaction costs, monitor consolidated net exposures and allow for increased responsiveness to changes in market factors.

We recognize derivative instruments as assets or liabilities in our Consolidated Balance Sheets and measure these instruments at fair value by "marking-to-market" all of our hedging positions at each period's end (see Note 11). Because we do not meet the documentation requirements for hedge (deferral) accounting related to aluminum and energy derivatives, unrealized and realized gains and losses associated with these hedges are reflected as a reduction or increase, respectively, in Cost of products sold - Unrealized loss (gain) on derivative instruments and unrealized and realized gains and losses relating to hedges of financing transactions are reflected as a component of Other income (expense) (see Note 15). Our accounting policy for foreign currency related derivatives is discussed in "Foreign Currency Risk Management" below. See Note 10 for additional information about realized and unrealized gains and losses relating to our derivative financial instruments.

Our derivative contacts for metal, natural gas, electricity and foreign currency potentially subject us to concentrations of credit risk if a counterparty fails to perform its obligations on derivative contracts with us or fails to return cash collateral that we previously posted with the counterparty. To mitigate this risk, we only enter into hedges with major financial institutions and/or trading firms that are investment grade or better, and we diversify our hedging positions among multiple counterparties to minimize exposure to any single counterparty. Additionally, we enter into reciprocal margin arrangements whereby: (i) we deposit margin collateral with a counterparty to the extent that the net market value of our derivative positions with such counterparty is a liability to us and exceeds a specified dollar threshold or (ii) the counterparty deposits margin collateral with us to the extent that the net market value of our derivative positions with such counterparty is an asset to us and exceeds a specified dollar threshold. At both December 31, 2015 and December 31, 2014, we had no margin deposits with or from our counterparties. As a result of our efforts to manage our counterparty exposures, we believe the risk of loss is remote and, in any event, would not be material.

Additionally, our firm price customer sales commitments create incremental customer credit risk related to metal price movements. Under certain circumstances, we mitigate this risk by periodically requiring cash collateral from them, which we classify as deferred revenue and include as a component of Other accrued liabilities on our Consolidated Balance Sheets. At December 31, 2015, cash collateral totaled $0.9 million. For more information about concentration risks concerning customers and suppliers, see Note 13.

Fair Value Measurement

Fair Value Measurements. We apply the provisions of Accounting Standards Codification ("ASC") Topic 820, Fair Value Measurements and Disclosures, in measuring the fair value of our derivative contracts and plan assets invested by certain of our employee benefit plans (see Note 11).

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy consists of three broad levels and is described below:

• Level 1 – Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

• Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, including: quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates); and inputs that are derived principally from or corroborated by observable market data by correlation or other means.

• Level 3 – Inputs that are both significant to the fair value measurement and unobservable.

Income Taxes

Income Taxes. Deferred income taxes reflect the future tax effect of temporary differences between the carrying amount of assets and liabilities for financial and income tax reporting and are measured by applying statutory tax rates in effect for the year during which the differences are expected to reverse. In accordance with ASC Topic 740, Income Taxes, we use a "more likely than not" threshold for recognition of tax attributes that are subject to uncertainties and measure any reserves in respect of such expected benefits based on their probability. Deferred tax assets are reduced by a valuation allowance to the extent it is more likely than not that the deferred tax assets will not be realized (see Note 5).

Earnings per Share

Net (Loss) Income per Share. Basic net (loss) income per share is computed by dividing distributed and undistributed net (loss) income allocable to common shares by the weighted-average number of common shares outstanding during the applicable period. The basic weighted-average number of common shares outstanding during the period excludes unvested share-based payment awards. Diluted net (loss) income per share was calculated under the treasury stock method for 2015, 2014 and 2013, which in all years was more dilutive than the two-class method (see Note 12).

Leases

Leases. For leases that contain predetermined fixed escalations of the minimum rent, we recognize the related rent expense on a straight-line basis from the date we take possession of the property to the end of the initial lease term. We record any difference between the straight-line rent amounts and the amount payable under the lease as part of deferred rent in Other accrued liabilities or Long-term liabilities, as appropriate. Deferred rent for all periods presented was not material.

Foreign Currency

Foreign Currency. Certain of our foreign subsidiaries use the local currency as their functional currency; our assets and liabilities are translated at exchange rates in effect at the balance sheet date; and our statement of (loss) income is translated at weighted-average monthly rates of exchange prevailing during the year. Resulting translation adjustments are recorded directly to a separate component of stockholders’ equity in accordance with ASC Topic 830, Foreign Currency Matters. At both December 31, 2015 and December 31, 2014, the amount of translation adjustment relating to foreign subsidiaries using local currency as their functional currency was immaterial. Where the U.S. dollar is the functional currency of a foreign facility or subsidiary, re-measurement adjustments are recorded in Other income (expense).

Foreign Currency Risk Management. From time to time, we enter into foreign currency forward contracts to protect the value of anticipated foreign currency expenses associated with cash commitments for equipment purchases. These derivative instruments are designated and qualify for cash flow hedge accounting and are adjusted to current market values each reporting period. Both realized and unrealized periodic gains and losses of derivative instruments designated as cash flow hedges are deferred in Accumulated other comprehensive loss until depreciation on the underlying equipment commences. Upon commencement, realized gains and losses are recorded in Net income (loss) as an adjustment to depreciation expense in the period in which depreciation is recognized on the underlying equipment. Depending on the time to maturity and asset or liability position, the carrying values of cash flow hedges are included in Prepaid expenses and other current assets, Other assets, Other accrued liabilities or Long-term liabilities. We report the effective portion of our cash flow hedges in the same financial statement line item as changes in the fair value of the hedged item.

In order to qualify for hedge accounting treatment, derivative instruments must be effective at reducing the risk associated with the exposure being hedged and must be designated as a hedge at the inception of the instrument contract. Hedge effectiveness is assessed periodically. Any derivative instrument not designated as a hedge, or so designated but ineffective, is adjusted to market value and recognized in net income immediately. If a cash flow hedge ceases to qualify for hedge accounting treatment, the derivative instrument would continue to be carried on the balance sheet at fair value until settled and future adjustments to the derivative instrument’s fair value would be recognized in Net (loss) income immediately. If a forecasted equipment purchase was no longer probable to occur, amounts previously deferred in Accumulated other comprehensive income would be recognized immediately in Net (loss) income. See Note 10 for additional information.

New Accounting Pronouncements

New Accounting Pronouncements. Accounting Standards Update("ASU") No. 2014-12, Compensation - Stock Compensation (Topic 718): Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period - Consensus of the FASB Emerging Issues Task Force("ASU 2014-12"), was issued in June 2014. ASU 2014-12 requires an entity to treat a performance target that affects vesting and that could be achieved after the requisite service period as a performance condition. Our adoption of this ASU in the first quarter of 2015 did not have a material impact on our consolidated financial statements.

ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs("ASU 2015-03"), was issued in April 2015. ASU 2015-03 requires debt issuance costs related to a recognized debt liability to be presented in an entity’s balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts, instead of being presented as a deferred charge in the balance sheet. In August 2015, ASU No. 2015-15, Interest - Imputation of Interest (Subtopic 835-30) - Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements ("ASU 2015-15") was issued to address the presentation and subsequent measurement of debt issuance costs related to line-of-credit arrangements. The recognition and measurement guidance for debt issuance costs is not affected by ASU 2015-03 and ASU 2015-15. An entity is required to adopt ASU 2015-03 and ASU 2015-15 for reporting periods beginning on or after December 15, 2015. We do not expect the adoption of these ASUs to have a material impact on our consolidated financial statements.

ASU No. 2015-07, Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) ("ASU 2015-07"), was issued in May 2015. This ASU removes the requirement to categorize within the fair value hierarchy table investments without readily determinable fair values in entities that elect to measure fair value using net asset value per share ("NAV") or its equivalent. ASU 2015-07 requires that these investments continue to be shown in the fair value disclosure in order to allow the disclosure to reconcile to the investment amount presented in the balance sheet. An entity is required to adopt ASU 2015-07 for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. We do not expect the adoption of this ASU to have a material impact on our consolidated financial statements.

ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date ("ASU 2015-14"), was issued in August 2015. ASU 2015-14 defers the effective date of ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which was issued in May 2014 and requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services, by one year for all entities and permits early adoption on a limited basis. We expect to adopt ASU 2014-09 for the fiscal year ending December 31, 2018 and will continue to assess the impact of the adoption on our consolidated financial statements; however, based on our assessments to date, we do not expect the adoption of this ASU to have a material impact on our consolidated financial statements.

ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes ("ASU 2015-17"), was issued in November 2015. ASU 2015-17 requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. This ASU does not, however, change the existing requirement that deferred tax liabilities and assets of a tax-paying component of an entity be offset and presented as a single amount. We do not expect the adoption of ASU 2015-17 in the first quarter of 2016 to have a material impact on our consolidated financial statements.