Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Accounting, Policy	The accompanying consolidated financial data has been prepared by the Company pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) and is presented in conformity with U.S. generally accepted accounting principles (“US GAAP”).
Consolidation, Policy	The accompanying consolidated financial statements include the accounts of Micrel, Incorporated and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
Use of Estimates, Policy	In accordance with US GAAP, management utilizes certain estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments. Management bases its estimates and judgments on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. The primary estimates underlying the Company’s financial statements include allowances for doubtful accounts receivable, allowances for product returns and price adjustments, provisions for obsolete and slow moving inventory, share-based compensation, income taxes, litigation losses, valuation of auction-rate securities and accruals for other liabilities. Actual results could differ from those estimates.
Cash and Cash Equivalents, Policy	The Company considers all highly liquid investments with remaining maturities of three months or less at the time of purchase to be cash equivalents.
Investment, Policy	Investments purchased with remaining maturity of greater than three months and less than 12 months are classified as short-term. Investments purchased with remaining maturity dates of 12 months or greater are classified either as short-term or as long-term based on maturities and the Company’s intent with regard to those securities (expectations of sales and redemptions). Short-term investments at December 31, 2014, consisted primarily of liquid municipal securities, corporate debt securities, commercial paper and U.S. government agencies securities and were classified as available-for-sale securities. Long-term investments at December 31, 2014, consisted of auction-rate notes secured by student loans and were classified as available-for-sale securities. Available-for sale securities are stated at market value with unrealized gains and losses included in accumulated other comprehensive loss, a component of shareholders’ equity. At December 31, 2014, accumulated other comprehensive loss of $0.1 million consisted of unrealized gains and losses on investments. Unrealized losses are charged against income when a decline in the fair market value of an individual security is determined to be other than temporary. Realized gains and losses on investments are included in other income or expense.
Concentration of Risk, Policy	Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash and cash equivalents, investments and accounts receivable. Risks associated with cash are mitigated by banking with creditworthy institutions. Cash equivalents and investments consist primarily of commercial paper, money market funds, corporate debt securities, municipal securities and auction-rate notes and are regularly monitored by management. Credit risk with respect to the trade receivables is spread over geographically diverse customers. The Company performs ongoing credit evaluations of its customers and maintains an allowance for potential credit losses. At December 31, 2014, distributors A, C and B accounted for 24%, 15%, and 13%, respectively, of total accounts receivable. At December 31, 2013, distributors A and B accounted for 36%, and 11%, respectively, of total accounts receivable. Micrel currently purchases certain components from a limited group of vendors. The packaging of the Company’s products is performed by, and certain of the raw materials included in such products are obtained from, a limited group of suppliers. The wafer supply for the Company’s LAN products is currently dependent upon two large third-party wafer foundry suppliers. Although the Company seeks to reduce its dependence on limited source suppliers, disruption or termination of any of these sources could occur and such disruptions could have an adverse effect on the Company’s financial condition, results of operations, or cash flows. The Company participates in a dynamic high technology industry and believes that changes in any of the following areas could have a material adverse effect on the Company’s future financial position, results of operations, or cash flows: changes in the overall demand for products offered by the Company; competitive pressures in the form of new products or price reductions on current products; advances and trends in new technologies and industry standards; changes in product mix; changes in third-party manufacturers; changes in key suppliers; changes in certain strategic relationships or customer relationships; litigation or claims against the Company based on intellectual property, patents, product, regulatory or other factors; risks associated with the ability to obtain necessary components; risks associated with the Company’s ability to attract and retain employees necessary to support its growth.
Inventory, Policy	Inventories are stated at the lower of cost (first-in, first-out method) or market. The Company records adjustments to write down the cost of obsolete and excess inventory to the estimated market value based on historical and forecasted demand for its products. Once an inventory write-down provision is established, it is maintained until the product to which it relates is sold or otherwise disposed of.
Property, Plant and Equipment, Policy	Property, plant and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets.
Goodwill, Policy	Goodwill represents the excess of the purchase price over the fair value of net tangible and identifiable intangible assets acquired. Goodwill is measured and tested for impairment annually at the reporting unit level during the last quarter of the Company's fiscal year, or more frequently if the Company believes indicators of impairment exist. Events that could trigger a more frequent impairment review may include adverse industry or economic trends, restructuring actions, lower projections of profitability, or a sustained decline in our market capitalization. The Company has allocated its goodwill to its timing and communications reporting unit. Qualitative factors are assessed to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount. If the qualitative assessment indicates that the carrying amount is more likely than not higher than the fair value, goodwill is tested for impairment based on a two-step test. The first step requires comparing the fair value of our reporting unit to its net book value, including goodwill. Determining the fair value of a reporting unit is judgmental in nature and involves the use of significant estimates and assumptions. These estimates and assumptions include projected revenues and forecasted operating margins used to calculate projected future cash flows, risk-adjusted discount rates, future economic and market conditions and determination of appropriate market comparables. The Company bases its fair value estimates on assumptions it believes to be reasonable. Actual future results may differ from those estimates. Future competitive, market and economic conditions could negatively impact key assumptions including our market capitalization or the carrying value of the Company’s net assets which could require it to realize an impairment of its goodwill. A potential impairment exists if the fair value of the reporting unit is less than its net book value. The second step of the process is only performed if a potential impairment exists, and it involves determining the difference between the fair value of the reporting unit’s net assets other than goodwill to the fair value of the reporting unit and if the difference is less than the net book value of goodwill, an impairment exists and is recorded. No goodwill impairment was recognized in 2014, 2013 and 2012.
Impairment of Long-Lived Assets, Policy	The Company reviews its purchased intangible assets with finite lives for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Recoverability of these intangible assets is assessed based on the estimated undiscounted future cash flows expected to result from the use of the asset. If the undiscounted future cash flows are less than the carrying amount, the purchased intangible assets with finite lives are considered to be impaired. The amount of the impairment is measured as the difference between the carrying amount of these assets and the fair value. The Company’s business combinations have included the purchase of in-process research and development assets that are not amortizable until the underlying project is complete. The Company assesses that its in-process research and development project is complete when all material research and development costs have been incurred and no significant risks remain. The Company reviews the carrying value of indefinite-lived intangible assets for impairment at least annually during the last quarter of its fiscal year, or more frequently if it believes indicators of impairment exist. In 2012, the Company recorded an impairment of $1.0 million as a component of research and development expense for a developed technology which was replaced by more advanced technologies. In 2014 and 2013, no indicators of impairment were identified.
Revenue Recognition, Policy	The Company generates revenue by selling products to original equipment manufacturers (“OEM”), sell-through distributors and sell-in distributors. The Company’s policy is to recognize revenue from sales to customers when the rights and risks of ownership have passed to the customer, when persuasive evidence of an arrangement exists, the product has been delivered, the price is fixed or determinable and collection of the resulting receivable is reasonably assured. The Company provides certain sell-through distributors price protection rights and pricing adjustments subsequent to the initial product shipment to allow them to price the Company's products competitively for specific resale opportunities. As these price adjustments have historically been significant, and price adjustments are difficult to reliably estimate, the Company defers recognition of revenue and related cost of revenues (in the balance sheet line item “deferred income on shipments to distributors”) derived from sales to these distributors until they have resold the Company’s products to their customers. Although revenue and related cost of revenues are not recognized, the Company records an accounts receivable and relieves inventory at the time of initial product shipment. The Company's standard terms are EXW or FCA shipping point, payment terms are enforced from shipment date and legal title and risk of inventory loss passes to the sell-through distributor upon shipment. In addition, the Company estimates and records an adjustment for sell-through distributor price adjustments for which the specific resale transaction has been completed but the price adjustment claim has not yet been received by the Company. During the third quarter of 2014, the Company amended the terms of its agreements with certain sell-through distributors. These amendments included the removal of significant return rights, price protection and pricing adjustments subsequent to the initial product shipment. Therefore, upon amendment of the agreements, these distributors were changed from sell-through distributors to sell-in distributors and the Company recognized the revenue for sales to these distributors upon the initial product shipments to these distributors, net of estimated allowance for returns established based upon historical return rates. In addition, revenue was recognized for unsold inventory held by these distributors on the date of change. The effect of changing these sell-through distributors to sell-in distributors resulted in a one-time increase in revenue of approximately $5.1 million and related cost of revenues of $1.6 million related to unsold inventory held by these distributors at June 30, 2014. Sales to OEM customers and sell-in distributors are recognized based upon the shipment terms of the sale transaction when all other revenue recognition criteria have been met. The Company does not grant return rights, price protection or pricing adjustments to OEM customers. The Company offers limited contractual stock rotation rights to sell-in distributors. At the time of shipment to sell-in distributors, an allowance for returns is established based upon historical return rates, and an allowance for price adjustments is established based on an estimate of price adjustments to be granted. Actual future returns and price adjustments could be different than the allowance established.
Trade and Other Accounts Receivable, Policy	The Company’s accounts receivable balances represent trade accounts receivables which have been recorded at invoiced amount and do not bear interest. The Company maintains an allowance for doubtful accounts for estimated uncollectible accounts receivable. This estimate is based on an analysis of specific customer creditworthiness and historical bad debt experience.
Shipping and Handling Cost, Policy	Shipping and handling costs are included in sales and marketing expense and are recognized as period expenses as incurred.
Commitments and Contingencies, Policy	An estimated liability is accrued when it is determined to be probable that a liability has been incurred and the amount of loss can be reasonably estimated. The liability accrual is charged to income in the period such determination is made. Legal fees are expensed as incurred. The Company regularly evaluates current information available to determine whether such accruals should be made.
Research and Development Expense, Policy	Research and development costs are expensed as incurred and consist primarily of payroll and other headcount related costs and cost of materials associated with the development of new wafer fabrication processes and the definition, design and development of semiconductor products. The Company also expenses prototype wafers and new production mask sets related to new products as research and development costs until products based on new designs are released to production.
Self-Insurance, Policy	The Company utilizes third-party insurance carriers subject to varying retention levels of self insurance. The Company is self-insured for a portion of the losses and liabilities primarily associated with earthquake damage, workers’ compensation claims and health benefit claims. Losses are accrued based upon the Company’s estimates of the aggregate liability for claims incurred using historical experience.
Advertising Costs, Policy	The Company expenses advertising costs to selling, general and administrative expense as incurred. Advertising expenses for 2014, 2013 and 2012 were $0.3 million, $0.1 million and $1.0 million, respectively.
Income Tax, Policy	Deferred tax assets and liabilities are recognized for the expected future tax consequences of events that have been reflected in the financial statements. Deferred tax assets and liabilities are determined based on the differences between the book and tax bases of assets and liabilities and operating loss carryforwards, using tax rates expected to be in effect for the years in which the differences are expected to reverse. A valuation allowance is provided to reduce net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained based on the technical merits of the position. The tax benefit of any tax position that meets the more-likely-than-not recognition threshold is calculated at the largest amount that is more than 50% likely of being realized upon resolution of the uncertainty. To the extent a full benefit is not expected to be realized on the uncertain tax position, a reduction to a deferred asset is recorded or an income tax liability is established. Interest and penalties on income tax obligations, including uncertain tax positions, are included in the income tax provision.
Share-based Compensation, Policy	Share-based compensation is measured at the grant date based on the fair value of the award and is recognized over the employee's requisite service period as expense in the consolidated statements of operations. Share-based compensation costs for stock option grants are based on the fair value calculated from a stock option pricing model on the date of grant. The Company has utilized the Black-Scholes option pricing model to determine the fair value for stock option grants. The fair value of stock option grants is recognized as compensation expense on a straight-line basis over the vesting period of the grants. Compensation expense recognized is shown in the operating activities section of the consolidated statements of cash flows. Cash flows resulting from the tax benefits from tax deductions in excess of the compensation cost recognized (excess tax benefits) is shown in the financing activities section of the consolidated statements of cash flows.
Net Income Per Common and Equivalent Share, Policy	Basic net income per share is computed by dividing net income attributable to Micrel, Incorporated shareholders by the number of weighted-average common shares outstanding. Diluted net income per share reflects potential dilution from outstanding stock options and restricted stock units (“RSUs”) using the treasury stock method.
Fair Value of Financial Instruments, Policy	Financial instruments included in the Company’s consolidated balance sheets at December 31, 2014 and 2013, consist of cash, cash equivalents, accounts receivable, accounts payable and investments. For cash, the carrying amount is the fair value. The carrying amount for cash equivalents, accounts receivable and accounts payable approximates fair value because of the short maturity of those instruments. The fair values of investments are based on quoted market prices, quoted prices for similar assets or valuation models for investments for which quoted market prices are unavailable.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2014

The accompanying consolidated financial data has been prepared by the Company pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) and is presented in conformity with U.S. generally accepted accounting principles (“US GAAP”).

Consolidation, Policy

The accompanying consolidated financial statements include the accounts of Micrel, Incorporated and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.

Use of Estimates, Policy

In accordance with US GAAP, management utilizes certain estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments. Management bases its estimates and judgments on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. The primary estimates underlying the Company’s financial statements include allowances for doubtful accounts receivable, allowances for product returns and price adjustments, provisions for obsolete and slow moving inventory, share-based compensation, income taxes, litigation losses, valuation of auction-rate securities and accruals for other liabilities. Actual results could differ from those estimates.

Cash and Cash Equivalents, Policy

The Company considers all highly liquid investments with remaining maturities of three months or less at the time of purchase to be cash equivalents.

Investment, Policy

Investments purchased with remaining maturity of greater than three months and less than 12 months are classified as short-term. Investments purchased with remaining maturity dates of 12 months or greater are classified either as short-term or as long-term based on maturities and the Company’s intent with regard to those securities (expectations of sales and redemptions). Short-term investments at December 31, 2014, consisted primarily of liquid municipal securities, corporate debt securities, commercial paper and U.S. government agencies securities and were classified as available-for-sale securities. Long-term investments at December 31, 2014, consisted of auction-rate notes secured by student loans and were classified as available-for-sale securities. Available-for sale securities are stated at market value with unrealized gains and losses included in accumulated other comprehensive loss, a component of shareholders’ equity. At December 31, 2014, accumulated other comprehensive loss of $0.1 million consisted of unrealized gains and losses on investments. Unrealized losses are charged against income when a decline in the fair market value of an individual security is determined to be other than temporary. Realized gains and losses on investments are included in other income or expense.

Concentration of Risk, Policy

Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash and cash equivalents, investments and accounts receivable. Risks associated with cash are mitigated by banking with creditworthy institutions. Cash equivalents and investments consist primarily of commercial paper, money market funds, corporate debt securities, municipal securities and auction-rate notes and are regularly monitored by management. Credit risk with respect to the trade receivables is spread over geographically diverse customers. The Company performs ongoing credit evaluations of its customers and maintains an allowance for potential credit losses. At December 31, 2014, distributors A, C and B accounted for 24%, 15%, and 13%, respectively, of total accounts receivable. At December 31, 2013, distributors A and B accounted for 36%, and 11%, respectively, of total accounts receivable.

Micrel currently purchases certain components from a limited group of vendors. The packaging of the Company’s products is performed by, and certain of the raw materials included in such products are obtained from, a limited group of suppliers. The wafer supply for the Company’s LAN products is currently dependent upon two large third-party wafer foundry suppliers. Although the Company seeks to reduce its dependence on limited source suppliers, disruption or termination of any of these sources could occur and such disruptions could have an adverse effect on the Company’s financial condition, results of operations, or cash flows.

The Company participates in a dynamic high technology industry and believes that changes in any of the following areas could have a material adverse effect on the Company’s future financial position, results of operations, or cash flows: changes in the overall demand for products offered by the Company; competitive pressures in the form of new products or price reductions on current products; advances and trends in new technologies and industry standards; changes in product mix; changes in third-party manufacturers; changes in key suppliers; changes in certain strategic relationships or customer relationships; litigation or claims against the Company based on intellectual property, patents, product, regulatory or other factors; risks associated with the ability to obtain necessary components; risks associated with the Company’s ability to attract and retain employees necessary to support its growth.

Inventory, Policy

Inventories are stated at the lower of cost (first-in, first-out method) or market. The Company records adjustments to write down the cost of obsolete and excess inventory to the estimated market value based on historical and forecasted demand for its products. Once an inventory write-down provision is established, it is maintained until the product to which it relates is sold or otherwise disposed of.

Property, Plant and Equipment, Policy

Property, plant and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets.

Goodwill, Policy

Goodwill represents the excess of the purchase price over the fair value of net tangible and identifiable intangible assets acquired. Goodwill is measured and tested for impairment annually at the reporting unit level during the last quarter of the Company's fiscal year, or more frequently if the Company believes indicators of impairment exist. Events that could trigger a more frequent impairment review may include adverse industry or economic trends, restructuring actions, lower projections of profitability, or a sustained decline in our market capitalization. The Company has allocated its goodwill to its timing and communications reporting unit.

Qualitative factors are assessed to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount. If the qualitative assessment indicates that the carrying amount is more likely than not higher than the fair value, goodwill is tested for impairment based on a two-step test. The first step requires comparing the fair value of our reporting unit to its net book value, including goodwill. Determining the fair value of a reporting unit is judgmental in nature and involves the use of significant estimates and assumptions. These estimates and assumptions include projected revenues and forecasted operating margins used to calculate projected future cash flows, risk-adjusted discount rates, future economic and market conditions and determination of appropriate market comparables. The Company bases its fair value estimates on assumptions it believes to be reasonable. Actual future results may differ from those estimates. Future competitive, market and economic conditions could negatively impact key assumptions including our market capitalization or the carrying value of the Company’s net assets which could require it to realize an impairment of its goodwill.

A potential impairment exists if the fair value of the reporting unit is less than its net book value. The second step of the process is only performed if a potential impairment exists, and it involves determining the difference between the fair value of the reporting unit’s net assets other than goodwill to the fair value of the reporting unit and if the difference is less than the net book value of goodwill, an impairment exists and is recorded. No goodwill impairment was recognized in 2014, 2013 and 2012.

Impairment of Long-Lived Assets, Policy

The Company reviews its purchased intangible assets with finite lives for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Recoverability of these intangible assets is assessed based on the estimated undiscounted future cash flows expected to result from the use of the asset. If the undiscounted future cash flows are less than the carrying amount, the purchased intangible assets with finite lives are considered to be impaired. The amount of the impairment is measured as the difference between the carrying amount of these assets and the fair value.

The Company’s business combinations have included the purchase of in-process research and development assets that are not amortizable until the underlying project is complete. The Company assesses that its in-process research and development project is complete when all material research and development costs have been incurred and no significant risks remain. The Company reviews the carrying value of indefinite-lived intangible assets for impairment at least annually during the last quarter of its fiscal year, or more frequently if it believes indicators of impairment exist.

In 2012, the Company recorded an impairment of $1.0 million as a component of research and development expense for a developed technology which was replaced by more advanced technologies. In 2014 and 2013, no indicators of impairment were identified.

Revenue Recognition, Policy

The Company generates revenue by selling products to original equipment manufacturers (“OEM”), sell-through distributors and sell-in distributors. The Company’s policy is to recognize revenue from sales to customers when the rights and risks of ownership have passed to the customer, when persuasive evidence of an arrangement exists, the product has been delivered, the price is fixed or determinable and collection of the resulting receivable is reasonably assured.

The Company provides certain sell-through distributors price protection rights and pricing adjustments subsequent to the initial product shipment to allow them to price the Company's products competitively for specific resale opportunities. As these price adjustments have historically been significant, and price adjustments are difficult to reliably estimate, the Company defers recognition of revenue and related cost of revenues (in the balance sheet line item “deferred income on shipments to distributors”) derived from sales to these distributors until they have resold the Company’s products to their customers. Although revenue and related cost of revenues are not recognized, the Company records an accounts receivable and relieves inventory at the time of initial product shipment. The Company's standard terms are EXW or FCA shipping point, payment terms are enforced from shipment date and legal title and risk of inventory loss passes to the sell-through distributor upon shipment. In addition, the Company estimates and records an adjustment for sell-through distributor price adjustments for which the specific resale transaction has been completed but the price adjustment claim has not yet been received by the Company.

During the third quarter of 2014, the Company amended the terms of its agreements with certain sell-through distributors. These amendments included the removal of significant return rights, price protection and pricing adjustments subsequent to the initial product shipment. Therefore, upon amendment of the agreements, these distributors were changed from sell-through distributors to sell-in distributors and the Company recognized the revenue for sales to these distributors upon the initial product shipments to these distributors, net of estimated allowance for returns established based upon historical return rates. In addition, revenue was recognized for unsold inventory held by these distributors on the date of change. The effect of changing these sell-through distributors to sell-in distributors resulted in a one-time increase in revenue of approximately $5.1 million and related cost of revenues of $1.6 million related to unsold inventory held by these distributors at June 30, 2014.

Sales to OEM customers and sell-in distributors are recognized based upon the shipment terms of the sale transaction when all other revenue recognition criteria have been met. The Company does not grant return rights, price protection or pricing adjustments to OEM customers. The Company offers limited contractual stock rotation rights to sell-in distributors. At the time of shipment to sell-in distributors, an allowance for returns is established based upon historical return rates, and an allowance for price adjustments is established based on an estimate of price adjustments to be granted. Actual future returns and price adjustments could be different than the allowance established.

Trade and Other Accounts Receivable, Policy

The Company’s accounts receivable balances represent trade accounts receivables which have been recorded at invoiced amount and do not bear interest. The Company maintains an allowance for doubtful accounts for estimated uncollectible accounts receivable. This estimate is based on an analysis of specific customer creditworthiness and historical bad debt experience.

Shipping and Handling Cost, Policy

Shipping and handling costs are included in sales and marketing expense and are recognized as period expenses as incurred.

Commitments and Contingencies, Policy

An estimated liability is accrued when it is determined to be probable that a liability has been incurred and the amount of loss can be reasonably estimated. The liability accrual is charged to income in the period such determination is made. Legal fees are expensed as incurred. The Company regularly evaluates current information available to determine whether such accruals should be made.

Research and Development Expense, Policy

Research and development costs are expensed as incurred and consist primarily of payroll and other headcount related costs and cost of materials associated with the development of new wafer fabrication processes and the definition, design and development of semiconductor products. The Company also expenses prototype wafers and new production mask sets related to new products as research and development costs until products based on new designs are released to production.

Self-Insurance, Policy

The Company utilizes third-party insurance carriers subject to varying retention levels of self insurance. The Company is self-insured for a portion of the losses and liabilities primarily associated with earthquake damage, workers’ compensation claims and health benefit claims. Losses are accrued based upon the Company’s estimates of the aggregate liability for claims incurred using historical experience.

Advertising Costs, Policy

The Company expenses advertising costs to selling, general and administrative expense as incurred. Advertising expenses for 2014, 2013 and 2012 were $0.3 million, $0.1 million and $1.0 million, respectively.

Income Tax, Policy

Deferred tax assets and liabilities are recognized for the expected future tax consequences of events that have been reflected in the financial statements. Deferred tax assets and liabilities are determined based on the differences between the book and tax bases of assets and liabilities and operating loss carryforwards, using tax rates expected to be in effect for the years in which the differences are expected to reverse. A valuation allowance is provided to reduce net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained based on the technical merits of the position. The tax benefit of any tax position that meets the more-likely-than-not recognition threshold is calculated at the largest amount that is more than 50% likely of being realized upon resolution of the uncertainty. To the extent a full benefit is not expected to be realized on the uncertain tax position, a reduction to a deferred asset is recorded or an income tax liability is established. Interest and penalties on income tax obligations, including uncertain tax positions, are included in the income tax provision.

Share-based Compensation, Policy

Share-based compensation is measured at the grant date based on the fair value of the award and is recognized over the employee's requisite service period as expense in the consolidated statements of operations. Share-based compensation costs for stock option grants are based on the fair value calculated from a stock option pricing model on the date of grant. The Company has utilized the Black-Scholes option pricing model to determine the fair value for stock option grants. The fair value of stock option grants is recognized as compensation expense on a straight-line basis over the vesting period of the grants. Compensation expense recognized is shown in the operating activities section of the consolidated statements of cash flows. Cash flows resulting from the tax benefits from tax deductions in excess of the compensation cost recognized (excess tax benefits) is shown in the financing activities section of the consolidated statements of cash flows.

Net Income Per Common and Equivalent Share, Policy

Basic net income per share is computed by dividing net income attributable to Micrel, Incorporated shareholders by the number of weighted-average common shares outstanding. Diluted net income per share reflects potential dilution from outstanding stock options and restricted stock units (“RSUs”) using the treasury stock method.

Fair Value of Financial Instruments, Policy

Financial instruments included in the Company’s consolidated balance sheets at December 31, 2014 and 2013, consist of cash, cash equivalents, accounts receivable, accounts payable and investments. For cash, the carrying amount is the fair value. The carrying amount for cash equivalents, accounts receivable and accounts payable approximates fair value because of the short maturity of those instruments. The fair values of investments are based on quoted market prices, quoted prices for similar assets or valuation models for investments for which quoted market prices are unavailable.