Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation: The consolidated financial statements include the accounts of West after the elimination of intercompany transactions. We have no participation or other rights in variable interest entities. In April 2019, we acquired the business of our distributor in South Korea for $18.9 million. As a result of the acquisition, we recorded inventories, property, plant and equipment, goodwill and a customer relationships intangible asset of $4.5 million, $0.6 million, $2.6 million and $11.2 million, respectively. The goodwill was recorded within our Proprietary Products reportable segment. The results of this acquisition have been included in our consolidated financial statements since the acquisition date.
Use of Estimates	Use of Estimates: The financial statements are prepared in conformity with U.S. GAAP. These principles require management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingencies in the financial statements. Actual amounts realized may differ from these estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents: Cash equivalents include time deposits, certificates of deposit and all highly liquid short-term instruments with maturities of three months or less at the time of purchase.
Accounts Receivable	Accounts Receivable: Our accounts receivable balance was net of an allowance for doubtful accounts of $1.1 million and $0.5 million at December 31, 2020 and 2019, respectively. Under the current expected credit loss model, we have adopted a provision matrix approach, utilizing historical loss rates based on the number of days past due, adjusted to reflect current economic conditions and forecasts of future economic conditions.
Inventories	Inventories: Inventories are valued at the lower of cost (on a first-in, first-out basis) and net realizable value.
Property, Plant and Equipment	Property, Plant and Equipment: Property, plant and equipment assets are carried at cost. Maintenance and minor repairs and renewals are charged to expense as incurred. Costs incurred for computer software developed or obtained for internal use are capitalized for application development activities and immediately expensed for preliminary project activities or post-implementation activities. Upon sale or retirement of depreciable assets, costs and related accumulated depreciation are eliminated, and gains or losses are recognized in other expense (income). Depreciation and amortization are computed principally using the straight-line method over the estimated useful lives of the assets, or the remaining term of the lease, if shorter.
Leases	Leases: Operating lease right-of-use assets are initially measured at cost, which comprises the initial amount of the lease liability adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred less any lease incentives received. Operating lease right-of-use assets are subsequently measured throughout the lease term at the carrying amount of the lease liability, plus initial direct costs, plus (minus) any prepaid (accrued) lease payments, less the unamortized balance of lease incentives received. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Operating lease liabilities are initially measured at the present value of the unpaid lease payments at the lease commencement date. We had no finance leases as of December 31, 2020. Please refer to Note 6, Leases, for additional information.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets: Long-lived assets, including property, plant and equipment and operating lease right-of-use assets, are tested for impairment whenever circumstances indicate that the carrying value of these assets may not be recoverable. An asset is considered impaired if the carrying value of the asset exceeds the sum of the future expected undiscounted cash flows to be derived from the asset. Once an asset is considered impaired, an impairment loss is recorded within other expense (income) for the difference between the asset’s carrying value and its fair value. For assets held and used in the business, management determines fair value using estimated future cash flows to be derived from the asset, discounted to a net present value using an appropriate discount rate. For assets held for sale or for investment purposes, management determines fair value by estimating the proceeds to be received upon sale of the asset, less disposition costs.
Impairment of Goodwill and Other Intangible Assets	Impairment of Goodwill and Other Intangible Assets: Goodwill is tested for impairment at least annually, following the completion of our annual budget and long-range planning process, or whenever circumstances indicate that the carrying value of these assets may not be recoverable. Goodwill is tested for impairment at the reporting unit level, which is the same as, or one level below, our operating segments. A goodwill impairment charge represents the amount by which a reporting unit’s carrying amount exceeds its fair value, not to exceed the total amount of goodwill allocated to that reporting unit. Accounting guidance also allows entities to first assess qualitative factors, including macroeconomic conditions, industry and market considerations, cost factors, and overall financial performance, to determine whether it is necessary to perform the quantitative goodwill impairment test. We elected to follow this guidance for our annual impairment test. Based upon our assessment, we determined that it was not more likely than not that the fair value of each of our reporting units was less than its carrying amount and determined that it was not necessary to perform the quantitative goodwill impairment test. Intangible assets with finite lives are amortized using the straight-line method over their estimated useful lives of 3 to 25 years, and reviewed for impairment whenever circumstances indicate that the carrying value of these assets may not be recoverable.
Employee Benefits	Employee Benefits: The measurement of the obligations under our defined benefit pension and postretirement medical plans are subject to a number of assumptions. These include the rate of return on plan assets (for funded plans) and the rate at which the future obligations are discounted to present value. For our funded plans, we consider the current and expected asset allocations of our plan assets, as well as historical and expected rates of return, in estimating the long-term rate of return on plan assets. U.S. GAAP requires the recognition of an asset or liability for the funded status of a defined benefit postretirement plan, as measured by the difference between the fair value of plan assets, if any, and the benefit obligation. For a pension plan, the benefit obligation is the projected benefit obligation; for any other postretirement plan, such as a retiree health plan, the benefit obligation is the accumulated postretirement benefit obligation. Please refer to Note 15, Benefit Plans, for a more detailed discussion of our pension and other retirement plans.
Financial Instruments	Financial Instruments: All derivatives are recognized as either assets or liabilities in the balance sheet and recorded at their fair value. For a derivative designated as hedging the exposure to variable cash flows of a forecasted transaction (referred to as a cash flow hedge), the effective portion of the derivative’s gain or loss is initially reported as a component of other comprehensive income (“OCI”), net of tax, and subsequently reclassified into earnings when the forecasted transaction affects earnings. For a derivative designated as hedging the exposure to changes in the fair value of a recognized asset or liability or a firm commitment (referred to as a fair value hedge), the derivative’s gain or loss is recognized in earnings in the period of change together with the offsetting loss or gain on the hedged item. For a derivative designated as hedging the foreign currency exposure of a net investment in a foreign operation, the gain or loss is reported in OCI, net of tax, as part of the cumulative translation adjustment. The ineffective portion of any derivative used in a hedging transaction is recognized immediately into earnings. Derivative financial instruments that are not designated as hedges are also recorded at fair value, with the change in fair value recognized immediately into earnings. We do not purchase or hold any derivative financial instrument for investment or trading purposes.
Foreign Currency Translation	Foreign Currency Translation: Foreign currency transaction gains and losses are recognized in the determination of net income. Foreign currency translation adjustments of subsidiaries and affiliates operating outside of the U.S. are accumulated in other comprehensive loss, a separate component of equity.
Revenue Recognition	Revenue Recognition: Our revenue results from the sale of goods or services and reflects the consideration to which we expect to be entitled in exchange for those goods or services. We record revenue based on a five-step model, in accordance with Accounting Standards Codification ("ASC") 606. Following the identification of a contract with a customer, we identify the performance obligations (goods or services) in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize the revenue when (or as) we satisfy the performance obligations by transferring the promised goods or services to our customers. A good or service is transferred when (or as) the customer obtains control of that good or service. Some customers receive pricing rebates upon attaining established sales volumes. We record rebate costs when sales occur based on our assessment of the likelihood that the required volumes will be attained. We also maintain an allowance for product returns, as we believe that we are able to reasonably estimate the amount of returns based on our substantial historical experience and specific identification of customer claims. Please refer to Note 3, Revenue, for additional information.
Shipping and Handling Costs	Shipping and Handling Costs: Shipping and handling costs are included in cost of goods and services sold. Shipping and handling costs billed to customers in connection with the sale are included in net sales.
Research and Development	Research and Development: Research and development expenditures are for the creation, engineering and application of new or improved products and processes. Expenditures include primarily salaries and outside services for those directly involved in research and development activities and are primarily expensed as incurred.
Environmental Remediation and Compliance Costs	Environmental Remediation and Compliance Costs: Environmental remediation costs are accrued when such costs are probable and reasonable estimates are determinable. Cost estimates include investigation, cleanup and monitoring activities; such estimates are adjusted, if necessary, based on additional findings. Environmental compliance costs are expensed as incurred as part of normal operations.
Litigation	Litigation: From time to time, we are involved in legal proceedings, investigations and claims generally incidental to our normal business activities. In accordance with U.S. GAAP, we accrue for loss contingencies when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. These estimates are based on an analysis made by internal and external legal counsel considering information known at the time. Legal costs in connection with loss contingencies are expensed as incurred.
Income Taxes	Income Taxes: Deferred income taxes are recognized by applying enacted statutory tax rates to tax loss carryforwards and temporary differences between the tax basis and financial statement carrying values of our assets and liabilities. The enacted statutory tax rate applied is based on the rate expected to be applicable at the time of the forecasted utilization of the loss carryforward or reversal of the temporary difference. Valuation allowances on deferred tax assets are established when it is more likely than not that all or a portion of a deferred tax asset will not be realized. The realizability of deferred tax assets is subject to our estimates of future taxable income, generally at the respective subsidiary company and the country level. In response to the 2017 Tax Act, we reevaluated our position regarding permanent reinvestment of foreign subsidiary earnings and profits through 2017 (with the exception of China and Mexico) and decided that those profits were no longer permanently reinvested. As of January 1, 2018, we reasserted indefinite reinvestment related to all post-2017 unremitted earnings in all of our foreign subsidiaries. Please refer to Note 17, Income Taxes, for additional information. We recognize interest costs related to income taxes in interest expense and penalties within other expense (income). The tax law ordering approach is used for purposes of determining whether an excess tax benefit has been realized during the year.
Stock-based Compensation	Stock-Based Compensation: Under the fair value provisions of U.S. GAAP, stock-based compensation cost is measured at the grant date based on the value of the award and is recognized as expense over the vesting period. In order to determine the fair value of stock options on the grant date, we use the Black-Scholes valuation model. Please refer to Note 14, Stock-Based Compensation, for a more detailed discussion of our stock-based compensation plans.
Net Income Per Share	Net Income Per Share: Basic net income per share is computed by dividing net income attributable to common shareholders by the weighted average number of shares of common stock outstanding during each period. Net income per share assuming dilution considers the dilutive effect of outstanding stock options and other stock awards based on the treasury stock method. The treasury stock method assumes the use of exercise proceeds to repurchase common stock at the average fair market value in the period.
New Accounting Standards	Recently Adopted Standards In December 2019, the Financial Accounting Standards Board (“FASB”) issued guidance which simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC Topic 740 and by clarifying and amending existing ASC Topic 740 guidance. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2020. We early adopted this guidance, which did not have a material impact to our financial statements. In April 2019, the FASB issued guidance which clarifies and improves areas related to the new credit losses, hedging, and recognition and measurement standards. This guidance is effective for the same fiscal years in which the original standards are effective or, if already implemented, annual periods beginning after the issuance of this guidance. We adopted this guidance as of January 1, 2020, on a prospective basis. The adoption did not have a material impact on our financial statements. In August 2018, the FASB issued guidance which modifies the disclosure requirements for defined benefit pension plans and other postretirement plans. The guidance removes disclosures that no longer are considered cost beneficial, clarifies the specific requirements of disclosures, and adds disclosure requirements identified as relevant. This guidance is effective for fiscal years ending after December 15, 2020. We adopted this guidance and the respective disclosure updates are reflected in our financial statements, which did not have a material impact. In August 2018, the FASB issued guidance to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by this update. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. We adopted this guidance as of January 1, 2020, on a prospective basis. The adoption did not have a material impact on our financial statements. In August 2018, the FASB issued guidance which modifies the disclosure requirements on fair value measurements by removing, modifying, or adding certain disclosures. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. We adopted this guidance as of January 1, 2020. The adoption did not have a material impact on our financial statements. Please refer to Note 12, Fair Value Measurements, for additional details. In June 2016, the FASB issued guidance which provides financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments held by a reporting entity, including accounts receivable, at each reporting date. Under the previous guidance, an entity reflected credit losses on financial assets measured on an amortized cost basis only when it was probable that losses had incurred, generally considering only past events and current conditions when determining incurred loss. The new guidance requires the recognition of an allowance that reflects the current estimate of credit losses expected to be incurred over the life of the financial asset, based not only on historical experience and current conditions, but also on reasonable and supportable forecasts. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. We adopted this guidance as of January 1, 2020, on a modified retrospective basis, to the accounts receivable and contract asset balances as of January 1, 2020. Under the current expected credit loss model, we have adopted a provision matrix approach, utilizing historical loss rates based on the number of days past due, adjusted to reflect current economic conditions and forecasts of future economic conditions. The effect of the adoption on the financial statement line items of accounts receivable and contract assets was not material as of January 1, 2020. As a result of our adoption, we recorded a cumulative-effect adjustment of $0.1 million within retained earnings in our consolidated balance sheet as of January 1, 2020, to reflect the incremental estimated lifetime expected credit losses on the accounts receivable balance as of January 1, 2020. We have not presented the amortized cost basis within each credit quality indicator by year of origination as all of our accounts receivable are due within one year or less. Standards Issued Not Yet Adopted In March 2020, the FASB issued guidance which provides optional expedients and exceptions to address the impact of reference rate reform where contracts, hedging relationships and other transactions that reference the London Interbank Offered Rate ("LIBOR") or another reference rate need to be discontinued. This guidance was effective upon issuance and generally can be applied through December 31, 2022. We are currently evaluating the impact to our financial statements, the transition, and disclosure requirements of this guidance.

Basis of Presentation and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2020

Principles of Consolidation: The consolidated financial statements include the accounts of West after the elimination of intercompany transactions. We have no participation or other rights in variable interest entities.

In April 2019, we acquired the business of our distributor in South Korea for $18.9 million. As a result of the acquisition, we recorded inventories, property, plant and equipment, goodwill and a customer relationships intangible asset of $4.5 million, $0.6 million, $2.6 million and $11.2 million, respectively. The goodwill was recorded within our Proprietary Products reportable segment. The results of this acquisition have been included in our consolidated financial statements since the acquisition date.

Use of Estimates

Use of Estimates: The financial statements are prepared in conformity with U.S. GAAP. These principles require management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingencies in the financial statements. Actual amounts realized may differ from these estimates.

Cash and Cash Equivalents

Cash and Cash Equivalents: Cash equivalents include time deposits, certificates of deposit and all highly liquid short-term instruments with maturities of three months or less at the time of purchase.

Accounts Receivable

Accounts Receivable: Our accounts receivable balance was net of an allowance for doubtful accounts of $1.1 million and $0.5 million at December 31, 2020 and 2019, respectively. Under the current expected credit loss model, we have adopted a provision matrix approach, utilizing historical loss rates based on the number of days past due, adjusted to reflect current economic conditions and forecasts of future economic conditions.

Inventories

Inventories: Inventories are valued at the lower of cost (on a first-in, first-out basis) and net realizable value.

Property, Plant and Equipment

Property, Plant and Equipment: Property, plant and equipment assets are carried at cost. Maintenance and minor repairs and renewals are charged to expense as incurred. Costs incurred for computer software developed or obtained for internal use are capitalized for application development activities and immediately expensed for preliminary project activities or post-implementation activities. Upon sale or retirement of depreciable assets, costs and related accumulated depreciation are eliminated, and gains or losses are recognized in other expense (income). Depreciation and amortization are computed principally using the straight-line method over the estimated useful lives of the assets, or the remaining term of the lease, if shorter.

Leases

Leases: Operating lease right-of-use assets are initially measured at cost, which comprises the initial amount of the lease liability adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred less any lease incentives received. Operating lease right-of-use assets are subsequently measured throughout the lease term at the carrying amount of the lease liability, plus initial direct costs, plus (minus) any prepaid (accrued) lease payments, less the unamortized balance of lease incentives received. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Operating lease liabilities are initially measured at the present value of the unpaid lease payments at the lease commencement date. We had no finance leases as of December 31, 2020. Please refer to Note 6, Leases, for additional information.

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets: Long-lived assets, including property, plant and equipment and operating lease right-of-use assets, are tested for impairment whenever circumstances indicate that the carrying value of these assets may not be recoverable. An asset is considered impaired if the carrying value of the asset exceeds the sum of the future expected undiscounted cash flows to be derived from the asset. Once an asset is considered impaired, an impairment loss is recorded within other expense (income) for the difference between the asset’s carrying value and its fair value. For assets held and used in the business, management determines fair value using estimated future cash flows to be derived from the asset, discounted to a net present value using an appropriate discount rate. For assets held for sale or for investment purposes, management determines fair value by estimating the proceeds to be received upon sale of the asset, less disposition costs.

Impairment of Goodwill and Other Intangible Assets

Impairment of Goodwill and Other Intangible Assets: Goodwill is tested for impairment at least annually, following the completion of our annual budget and long-range planning process, or whenever circumstances indicate that the carrying value of these assets may not be recoverable. Goodwill is tested for impairment at the reporting unit level, which is the same as, or one level below, our operating segments. A goodwill impairment charge represents the amount by which a reporting unit’s carrying amount exceeds its fair value, not to exceed the total amount of goodwill allocated to that reporting unit. Accounting guidance also allows entities to first assess qualitative factors, including macroeconomic conditions, industry and market considerations, cost factors, and overall financial performance, to determine whether it is necessary to perform the quantitative goodwill impairment test. We elected to follow this guidance for our annual impairment test. Based upon our assessment, we determined that it was not more likely than not that the fair value of each of our reporting units was less than its carrying amount and determined that it was not necessary to perform the quantitative goodwill impairment test.

Intangible assets with finite lives are amortized using the straight-line method over their estimated useful lives of 3 to 25 years, and reviewed for impairment whenever circumstances indicate that the carrying value of these assets may not be recoverable.

Employee Benefits

Employee Benefits: The measurement of the obligations under our defined benefit pension and postretirement medical plans are subject to a number of assumptions. These include the rate of return on plan assets (for funded plans) and the rate at which the future obligations are discounted to present value. For our funded plans, we consider the current and expected asset allocations of our plan assets, as well as historical and expected rates of return, in estimating the long-term rate of return on plan assets. U.S. GAAP requires the recognition of an asset or liability for the funded status of a defined benefit postretirement plan, as measured by the difference between the fair value of plan assets, if any, and the benefit obligation. For a pension plan, the benefit obligation is the projected benefit obligation; for any other postretirement plan, such as a retiree health plan, the benefit obligation is the accumulated postretirement benefit obligation. Please refer to Note 15, Benefit Plans, for a more detailed discussion of our pension and other retirement plans.

Financial Instruments

Financial Instruments: All derivatives are recognized as either assets or liabilities in the balance sheet and recorded at their fair value. For a derivative designated as hedging the exposure to variable cash flows of a forecasted transaction (referred to as a cash flow hedge), the effective portion of the derivative’s gain or loss is initially reported as a component of other comprehensive income (“OCI”), net of tax, and subsequently reclassified into earnings when the forecasted transaction affects earnings. For a derivative designated as hedging the exposure to changes in the fair value of a recognized asset or liability or a firm commitment (referred to as a fair value hedge), the derivative’s gain or loss is recognized in earnings in the period of change together with the offsetting loss or gain on the hedged item. For a derivative designated as hedging the foreign currency exposure of a net investment in a foreign operation, the gain or loss is reported in OCI, net of tax, as part of the cumulative translation adjustment. The ineffective portion of any derivative used in a hedging transaction is recognized immediately into earnings. Derivative financial instruments that are not designated as hedges are also recorded at fair value, with the change in fair value recognized immediately into earnings. We do not purchase or hold any derivative financial instrument for investment or trading purposes.

Foreign Currency Translation

Foreign Currency Translation: Foreign currency transaction gains and losses are recognized in the determination of net income. Foreign currency translation adjustments of subsidiaries and affiliates operating outside of the U.S. are accumulated in other comprehensive loss, a separate component of equity.

Revenue Recognition

Revenue Recognition: Our revenue results from the sale of goods or services and reflects the consideration to which we expect to be entitled in exchange for those goods or services. We record revenue based on a five-step model, in accordance with Accounting Standards Codification ("ASC") 606. Following the identification of a contract with a customer, we identify the performance obligations (goods or services) in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize the revenue when (or as) we satisfy the performance obligations by transferring the promised goods or services to our customers. A good or service is transferred when (or as) the customer obtains control of that good or service. Some customers receive pricing rebates upon attaining established sales volumes. We record rebate costs when sales occur based on our assessment of the likelihood that the required volumes will be attained. We also maintain an allowance for product returns, as we believe that we are able to reasonably estimate the amount of returns based on our substantial historical experience and specific identification of customer claims. Please refer to Note 3, Revenue, for additional information.

Shipping and Handling Costs

Shipping and Handling Costs: Shipping and handling costs are included in cost of goods and services sold. Shipping and handling costs billed to customers in connection with the sale are included in net sales.

Research and Development

Research and Development: Research and development expenditures are for the creation, engineering and application of new or improved products and processes. Expenditures include primarily salaries and outside services for those directly involved in research and development activities and are primarily expensed as incurred.

Environmental Remediation and Compliance Costs

Environmental Remediation and Compliance Costs: Environmental remediation costs are accrued when such costs are probable and reasonable estimates are determinable. Cost estimates include investigation, cleanup and monitoring activities; such estimates are adjusted, if necessary, based on additional findings. Environmental compliance costs are expensed as incurred as part of normal operations.

Litigation

Litigation: From time to time, we are involved in legal proceedings, investigations and claims generally incidental to our normal business activities. In accordance with U.S. GAAP, we accrue for loss contingencies when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. These estimates are based on an analysis made by internal and external legal counsel considering information known at the time. Legal costs in connection with loss contingencies are expensed as incurred.

Income Taxes

Income Taxes: Deferred income taxes are recognized by applying enacted statutory tax rates to tax loss carryforwards and temporary differences between the tax basis and financial statement carrying values of our assets and liabilities. The enacted statutory tax rate applied is based on the rate expected to be applicable at the time of the forecasted utilization of the loss carryforward or reversal of the temporary difference. Valuation allowances on deferred tax assets are established when it is more likely than not that all or a portion of a deferred tax asset will not be realized. The realizability of deferred tax assets is subject to our estimates of future taxable income, generally at the respective subsidiary company and the country level. In response to the 2017 Tax Act, we reevaluated our position regarding permanent reinvestment of foreign subsidiary earnings and profits through 2017 (with the exception of China and Mexico) and decided that those profits were no longer permanently reinvested. As of January 1, 2018, we reasserted indefinite reinvestment related to all post-2017 unremitted earnings in all of our foreign subsidiaries. Please refer to Note 17, Income Taxes, for additional information. We recognize interest costs related to income taxes in interest expense and penalties within other expense (income). The tax law ordering approach is used for purposes of determining whether an excess tax benefit has been realized during the year.

Stock-based Compensation

Stock-Based Compensation: Under the fair value provisions of U.S. GAAP, stock-based compensation cost is measured at the grant date based on the value of the award and is recognized as expense over the vesting period. In order to determine the fair value of stock options on the grant date, we use the Black-Scholes valuation model. Please refer to Note 14, Stock-Based Compensation, for a more detailed discussion of our stock-based compensation plans.

Net Income Per Share

Net Income Per Share: Basic net income per share is computed by dividing net income attributable to common shareholders by the weighted average number of shares of common stock outstanding during each period. Net income per share assuming dilution considers the dilutive effect of outstanding stock options and other stock awards based on the treasury stock method. The treasury stock method assumes the use of exercise proceeds to repurchase common stock at the average fair market value in the period.

New Accounting Standards

Recently Adopted Standards

In December 2019, the Financial Accounting Standards Board (“FASB”) issued guidance which simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC Topic 740 and by clarifying and amending existing ASC Topic 740 guidance. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2020. We early adopted this guidance, which did not have a material impact to our financial statements.

In April 2019, the FASB issued guidance which clarifies and improves areas related to the new credit losses, hedging, and recognition and measurement standards. This guidance is effective for the same fiscal years in which the original standards are effective or, if already implemented, annual periods beginning after the issuance of this guidance. We adopted this guidance as of January 1, 2020, on a prospective basis. The adoption did not have a material impact on our financial statements.

In August 2018, the FASB issued guidance which modifies the disclosure requirements for defined benefit pension plans and other postretirement plans. The guidance removes disclosures that no longer are considered cost beneficial, clarifies the specific requirements of disclosures, and adds disclosure requirements identified as relevant. This guidance is effective for fiscal years ending after December 15, 2020. We adopted this guidance and the respective disclosure updates are reflected in our financial statements, which did not have a material impact.

In August 2018, the FASB issued guidance to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by this update. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. We adopted this guidance as of January 1, 2020, on a prospective basis. The adoption did not have a material impact on our financial statements.

In August 2018, the FASB issued guidance which modifies the disclosure requirements on fair value measurements by removing, modifying, or adding certain disclosures. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. We adopted this guidance as of January 1, 2020. The adoption did not have a material impact on our financial statements. Please refer to Note 12, Fair Value Measurements, for additional details.

In June 2016, the FASB issued guidance which provides financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments held by a reporting entity, including accounts receivable, at each reporting date. Under the previous guidance, an entity reflected credit losses on financial assets measured on an amortized cost basis only when it was probable that losses had incurred, generally considering only past events and current conditions when determining incurred loss. The new guidance requires the recognition of an allowance that reflects the current estimate of credit losses expected to be incurred over the life of the financial asset, based not only on historical experience and current conditions, but also on reasonable and supportable forecasts. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. We adopted this guidance as of January 1, 2020, on a modified retrospective basis, to the accounts receivable and contract asset balances as of January 1, 2020. Under the current expected credit loss model, we have adopted a provision matrix approach, utilizing historical loss rates based on the number of days past due, adjusted to reflect current economic conditions and forecasts of future economic conditions. The effect of the adoption on the financial statement line items of accounts receivable and contract assets was not material as of January 1, 2020. As a result of our adoption, we recorded a cumulative-effect adjustment of $0.1 million within retained earnings in our consolidated balance sheet as of January 1, 2020, to reflect the incremental estimated lifetime expected credit losses on the accounts receivable balance as of January 1, 2020. We have not presented the amortized cost basis within each credit quality indicator by year of origination as all of our accounts receivable are due within one year or less.

Standards Issued Not Yet Adopted

In March 2020, the FASB issued guidance which provides optional expedients and exceptions to address the impact of reference rate reform where contracts, hedging relationships and other transactions that reference the London Interbank Offered Rate ("LIBOR") or another reference rate need to be discontinued. This guidance was effective upon issuance and generally can be applied through December 31, 2022. We are currently evaluating the impact to our financial statements, the transition, and disclosure requirements of this guidance.