Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 27, 2014
Summary of Significant Accounting Policies [Abstract]
Nature of Operations	Nature of Operations The principal business of Mueller Industries, Inc. is the manufacture and sale of copper tube and fittings; line sets; brass and copper alloy rod, bar, and shapes; aluminum and brass forgings; aluminum and copper impact extrusions; plastic fittings and valves; refrigeration valves and fittings; fabricated tubular products; and steel nipples. The Company also resells imported brass and plastic plumbing valves, malleable iron fittings, faucets, and plumbing specialty products. The Company markets its products to the HVAC, plumbing, refrigeration, hardware, and other industries. Mueller’s operations are located throughout the United States and in Canada, Mexico, Great Britain, and China.
Fiscal Years	Fiscal Years The Company’s fiscal year consists of 52 weeks ending on the last Saturday of December. These dates were December 27, 2014, December 28, 2013, and December 29, 2012.
Principles of Consolidation	Principles of Consolidation The Consolidated Financial Statements include the accounts of Mueller Industries, Inc. and its majority owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. The noncontrolling interest represents a separate private ownership of 49.5 percent of Mueller-Xingrong.
Common Stock Split	Common Stock Split On February 21, 2014, the Company announced a two-for-one stock split of its common stock effected in the form of a stock dividend of one share for each outstanding share. The record date for the stock split was March 14, 2014, and the additional shares were distributed on March 28, 2014. Accordingly, all references to share and per share amounts presented in the Consolidated Financial Statements and this Annual Report on Form 10-K have been adjusted retroactively to reflect the stock split.
Revenue Recognition	Revenue Recognition Revenue is recognized when title and risk of loss pass to the customer, provided collection is determined to be probable and no significant obligations remain for the Company. Estimates for future rebates on certain product lines and product returns are recognized in the period in which the revenue is recorded. The cost of shipping product to customers is expensed as incurred as a component of cost of goods sold.
Cash Equivalents	Cash Equivalents Temporary investments with original maturities of three months or less are considered to be cash equivalents. These investments are stated at cost. At December 27, 2014 and December 28, 2013, temporary investments consisted of money market mutual funds, commercial paper, bank repurchase agreements, and U.S. and foreign government securities totaling $144.9 million and $179.2 million, respectively. Included in other current assets is restricted cash of $8.1 million and $5.2 million at December 27, 2014 and December 28, 2013, respectively. These amounts represent required deposits into brokerage accounts that facilitate the Company’s hedging activities and deposits that secure certain short-term notes issued under Mueller-Xingrong’s credit facility.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The Company provides an allowance for receivables that may not be fully collected. In circumstances where the Company is aware of a customer’s inability to meet their financial obligations (e.g., bankruptcy filings or substantial downgrading of credit ratings), it records an allowance for doubtful accounts against amounts due to reduce the net recognized receivable to the amount it believes most likely will be collected. For all other customers, the Company recognizes an allowance for doubtful accounts based on its historical collection experience. If circumstances change (e.g., greater than expected defaults or an unexpected material change in a major customer’s ability to meet their financial obligations), the Company could change its estimate of the recoverability of amounts due by a material amount.
Inventories	Inventories The Company’s inventories are valued at the lower-of-cost-or-market. The material component of its U.S. copper tube and copper fittings inventories is valued on a LIFO basis. Other manufactured inventories, including the non-material components of U.S. copper tube and copper fittings, are valued on a FIFO basis. Certain inventories purchased for resale are valued on an average cost basis. Elements of cost in finished goods inventory in addition to the cost of material include depreciation, amortization, utilities, maintenance, production wages, and transportation costs. The market price of copper cathode and scrap is subject to volatility. During periods when open market prices decline below net book value, the Company may need to provide an allowance to reduce the carrying value of its inventory. In addition, certain items in inventory may be considered obsolete and, as such, the Company may establish an allowance to reduce the carrying value of those items to their net realizable value. Changes in these estimates related to the value of inventory, if any, may result in a materially adverse impact on the Company’s reported financial position or results of operations. The Company recognizes the impact of any changes in estimates, assumptions, and judgments in income in the period in which it is determined. See “Note 3 – Inventories” for additional information.
Property, Plant, and Equipment	Property, Plant, and Equipment Property, plant, and equipment are stated at cost. Depreciation of buildings, machinery, and equipment is provided on the straight-line method over the estimated useful lives ranging from 20 to 40 years for buildings and five to 20 years for machinery and equipment. Leasehold improvements are amortized over the lesser of their useful life or the remaining lease term. Repairs and maintenance are expensed as incurred. See “Note 5 – Property, Plant, and Equipment, Net” for additional information.
Goodwill	Goodwill Goodwill represents cost in excess of fair values assigned to the underlying net assets of acquired businesses. Goodwill is subject to impairment testing, which is performed by the Company as of the first day of the fourth quarter of each fiscal year, unless circumstances dictate more frequent testing. For testing purposes, the Company defines reporting units as components of its operating segments; components of a segment having similar economic characteristics are combined. The annual impairment test is a two-step process. The first step is the estimation of fair value of reporting units that have goodwill. If this estimate indicates that impairment potentially exists, the second step is performed. Step two, used to measure the amount of goodwill impairment loss, compares the implied fair value of goodwill to the carrying value. In step two the Company is required to allocate the fair value of each reporting unit, as determined in step one, to the fair value of the reporting unit’s assets and liabilities, including unrecognized intangible assets and corporate allocation where applicable, in a hypothetical purchase price allocation as if the reporting unit had been purchased on that date. If the implied fair value of goodwill is less than the carrying value, an impairment charge is recorded. The reporting units with significant recorded goodwill include Standard Products (SPD), Mueller Europe, Limited (MEL), and Westermeyer. SPD and MEL are included in the Plumbing & Refrigeration segment, and Westermeyer is included in the OEM segment. There can be no assurance that additional goodwill impairment will not occur in the future. Because there are no observable inputs available, the Company estimates fair value of reporting units based on a combination of the market approach and income approach (Level 3 hierarchy as defined by Accounting Standards Codification (ASC) 820, Fair Value Measurements and Disclosures (ASC 820)). The market approach measures the fair value of a business through the analysis of publicly traded companies or recent sales of similar businesses. The income approach uses a discounted cash flow model to estimate the fair value of reporting units based on expected cash flows (adjusted for capital investment required to support operations) and a terminal value. This cash flow stream is discounted to its present value to arrive at a fair value for each reporting unit. Future earnings are estimated using the Company’s most recent annual projections, applying a growth rate to future periods. Those projections are directly impacted by the condition of the markets in which the Company’s businesses participate. The discount rate selected for the reporting units is generally based on rates of return available for comparable companies at the date of valuation. See “Note 6 – Goodwill, Net” for additional information.
Self-Insurance Accruals	Self-Insurance Accruals The Company is primarily self-insured for workers’ compensation claims and benefits paid under certain employee health care programs. Accruals are primarily based on estimated undiscounted cost of claims, which includes incurred but not reported claims, and are classified as accrued wages and other employee costs.
Benefit Plans	Benefit Plans The Company sponsors several qualified and nonqualified pension and other postretirement benefit plans in the U.S. and certain foreign locations. The Company recognizes the overfunded or underfunded status of the plans as an asset or liability in the Consolidated Balance Sheet with changes in the funded status recorded through comprehensive income in the year in which those changes occur. The obligations for these plans are actuarially determined and affected by assumptions, including discount rates, expected long-term return on plan assets for defined benefit pension plans, and certain employee-related factors, such as retirement age and mortality. The Company evaluates its assumptions periodically and makes adjustments as necessary. The expected return on plan assets is determined using the market value of plan assets. Differences between assumed and actual returns are amortized to the market value of assets on a straight-line basis over the average remaining service period of the plan participants using the corridor approach. The corridor approach defers all actuarial gains and losses resulting from variances between actual results and actuarial assumptions. These unrecognized gains and losses are amortized when the net gains and losses exceed 10 percent of the greater of the market value of the plan assets or the projected benefit obligation. The amount in excess of the corridor is amortized over the average remaining service period of the plan participants. For 2014, the average remaining service period for the pension plans was nine years. See “Note 13 –Benefit Plans” for additional information.
Environmental Reserves and Environmental Expenses	Environmental Reserves and Environmental Expenses The Company recognizes an environmental liability when it is probable the liability exists and the amount is reasonably estimable. The Company estimates the duration and extent of its remediation obligations based upon reports of outside consultants; internal analyses of cleanup costs and ongoing monitoring costs; communications with regulatory agencies; and changes in environmental law. If the Company were to determine that its estimates of the duration or extent of its environmental obligations were no longer accurate, it would adjust environmental liabilities accordingly in the period that such determination is made. Estimated future expenditures for environmental remediation are not discounted to their present value. Accrued environmental liabilities are not reduced by potential insurance reimbursements. Environmental expenses that relate to ongoing operations are included as a component of cost of goods sold. Environmental expenses related to non-operating properties are included in other income, net on the Consolidated Statements of Income. See “Note 8 – Commitments and Contingencies” for additional information.
Earnings Per Share	Earnings Per Share Basic earnings per share is computed based on the weighted average number of common shares outstanding. Diluted earnings per share reflects the increase in weighted average common shares outstanding that would result from the assumed exercise of outstanding stock options and vesting of restricted stock awards calculated using the treasury stock method. Approximately 180 thousand stock-based awards were excluded from the computation of diluted earnings per share for the year ended December 27, 2014 because they were antidilutive.
Income Taxes	Income Taxes Deferred income tax assets and liabilities are recognized when differences arise between the treatment of certain items for financial statement and tax purposes. Realization of certain components of deferred tax assets is dependent upon the occurrence of future events. The Company records valuation allowances to reduce its deferred tax assets to the amount it believes is more likely than not to be realized. These valuation allowances can be impacted by changes in tax laws, changes to statutory tax rates, and future taxable income levels and are based on the Company’s judgment, estimates, and assumptions regarding those future events. In the event the Company was to determine that it would not be able to realize all or a portion of the net deferred tax assets in the future, it would increase the valuation allowance through a charge to income tax expense in the period that such determination is made. Conversely, if it were to determine that it would be able to realize its deferred tax assets in the future, in excess of the net carrying amounts, the Company would decrease the recorded valuation allowance through a decrease to income tax expense in the period that such determination is made. The Company provides for uncertain tax positions and the related interest and penalties, if any, based upon management’s assessment of whether a tax benefit is more likely than not to be sustained upon examination by tax authorities. Tax benefits for uncertain tax positions that are recognized in the financial statements are measured as the largest amount of benefit, determined on a cumulative probability basis, that is more likely than not to be realized upon ultimate settlement. To the extent the Company prevails in matters for which a liability for an uncertain tax position is established or is required to pay amounts in excess of the liability, the Company’s effective tax rate in a given financial statement period may be affected. These estimates are highly subjective and could be affected by changes in business conditions and other factors. Changes in any of these factors could have a material impact on future income tax expense. See “Note 9 – Income Taxes” for additional information.
Taxes Collected from Customers and Remitted to Governmental Authorities	Taxes Collected from Customers and Remitted to Governmental Authorities Taxes assessed by a governmental authority that are directly imposed on a revenue producing transaction between the Company and its customers, primarily value added taxes in foreign jurisdictions, are accounted for on a net (excluded from revenues and costs) basis.
Stock-Based Compensation	Stock-Based Compensation The Company has in effect stock incentive plans under which stock-based awards have been granted to certain employees and members of its Board of Directors. Stock-based compensation expense is recognized in the Consolidated Statements of Income as a component of selling, general, and administrative expense based on the grant date fair value of the awards. See “Note 11 – Stock-Based Compensation” for additional information.
Concentrations of Credit and Market Risk	Concentrations of Credit and Market Risk Concentrations of credit risk with respect to accounts receivable are limited due to the large number of customers comprising the Company’s customer base, and their dispersion across different geographic areas and different industries, including HVAC, plumbing, refrigeration, hardware, automotive, OEMs, and others. The Company minimizes its exposure to base metal price fluctuations through various strategies. Generally, it prices an equivalent amount of copper raw material, under flexible pricing arrangements it maintains with its suppliers, at the time it determines the selling price of finished products to its customers.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities The Company may utilize futures contracts to manage the volatility related to purchases of copper through cash flow hedges. It may also utilize futures contracts to protect the value of the copper inventory on hand and firm commitments to purchase copper through fair value hedges. The Company may elect to utilize futures contracts as economic hedges that do not qualify for hedge accounting in accordance with ASC 815, Derivatives and Hedging (ASC 815). In addition, the Company may use foreign currency forward contracts to reduce the risk from exchange rate fluctuations on future purchases and intercompany transactions denominated in foreign currencies. All derivatives are recognized in the Consolidated Balance Sheets at their fair value. On the date the derivative contract is entered into, it is designated as (i) a hedge of a forecasted transaction or the variability of cash flow to be paid (cash flow hedge), or (ii) a hedge of the fair value of a recognized asset or liability (fair value hedge). Changes in the fair value of a derivative that is qualified, designated and highly effective as a cash flow hedge are recorded in accumulated other comprehensive income (AOCI), to the extent effective, until they are reclassified to earnings in the same period or periods during which the hedged transaction affects earnings. Changes in the fair value of a derivative that is qualified, designated and highly effective as a fair value hedge, along with the gain or loss on the hedged recognized asset or liability that is attributable to the hedged risk, are recorded in current earnings. Changes in the fair value of undesignated derivative instruments and the ineffective portion of designated derivative instruments are reported in current earnings. The Company documents all relationships between hedging instruments and hedged items, as well as the risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivatives that are designated as fair value hedges to specific assets and liabilities in the Consolidated Balance Sheets and linking cash flow hedges to specific forecasted transactions or variability of cash flow. The Company also assesses, both at the hedge’s inception and on an ongoing basis, whether the designated derivatives that are used in hedging transactions are highly effective in offsetting changes in cash flow or fair values of hedged items. When a derivative is determined not to be highly effective as a hedge or the underlying hedged transaction is no longer probable, hedge accounting is discontinued prospectively, in accordance with the derecognition criteria for hedge accounting. The Company primarily executes derivative contracts with major financial institutions. These counterparties expose the Company to credit risk in the event of non-performance. The amount of such exposure is limited to the fair value of the contract plus the unpaid portion of amounts due to the Company pursuant to terms of the derivative instruments, if any. If a downgrade in the credit rating of these counterparties occurs, management believes that this exposure is mitigated by provisions in the derivative arrangements which allow for the legal right of offset of any amounts due to the Company from the counterparties with any amounts payable to the counterparties by the Company. As a result, management considers the risk of loss from counterparty default to be minimal. See “Note 14 – Derivative Instruments and Hedging Activities” for additional information.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts for cash and cash equivalents, accounts receivable, and accounts payable approximate fair value due to the short-term maturity of these instruments. The fair value of long-term debt at December 27, 2014 approximates the carrying value on that date. The estimated fair values were determined based on quoted market prices and the current rates offered for debt with similar terms and maturities. The fair value of long-term debt is classified as Level 2 within the fair value hierarchy. This classification is defined as a fair value determined using market-based inputs other than quoted prices that are observable for the liability, either directly or indirectly.Outstanding borrowings have variable interest rates that re-price frequently at current market rates.
Foreign Currency Translation	Foreign Currency Translation For foreign subsidiaries in which the functional currency is other than the U.S. dollar, balance sheet accounts are translated at exchange rates in effect at the end of the year and income statement accounts are translated at average exchange rates for the year. Translation gains and losses are included in equity as a component of OCI. Included in the Consolidated Statements of Income were transaction gains of $0.1 million in 2014, losses of $0.1 million in 2013, and losses of $0.3 million in 2012.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S. GAAP) requires management to make estimates, assumptions, and judgments that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In April 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No, 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (ASU 2014-08). The ASU significantly changed the criteria for reporting a discontinued operation and added disclosure requirements for discontinued operations and other disposal transactions. It is effective for annual reporting periods beginning after December 15, 2014 and is applied prospectively. The Company has elected early adoption of ASU 2014-08 effective September 28, 2014. The new guidance did not have a significant impact on the Company’s Consolidated Financial Statements or related disclosures. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09). The ASU will supersede virtually all existing revenue recognition guidance under U.S. GAAP and will be effective for annual reporting periods beginning after December 15, 2016. The fundamental principles of the new guidance are that companies should recognize revenue in a manner that reflects the timing of the transfer of services to customers and the amount of revenue recognized reflects the consideration that a company expects to receive for the goods and services provided. The new guidance establishes a five-step approach for the recognition of revenue. The Company is in the process of evaluating the impact of ASU 2014-09 on its Consolidated Financial Statements.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 27, 2014

Summary of Significant Accounting Policies [Abstract]

The principal business of Mueller Industries, Inc. is the manufacture and sale of copper tube and fittings; line sets; brass and copper alloy rod, bar, and shapes; aluminum and brass forgings; aluminum and copper impact extrusions; plastic fittings and valves; refrigeration valves and fittings; fabricated tubular products; and steel nipples. The Company also resells imported brass and plastic plumbing valves, malleable iron fittings, faucets, and plumbing specialty products. The Company markets its products to the HVAC, plumbing, refrigeration, hardware, and other industries. Mueller’s operations are located throughout the United States and in Canada, Mexico, Great Britain, and China.

Fiscal Years

The Company’s fiscal year consists of 52 weeks ending on the last Saturday of December. These dates were December 27, 2014, December 28, 2013, and December 29, 2012.

Principles of Consolidation

The Consolidated Financial Statements include the accounts of Mueller Industries, Inc. and its majority owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. The noncontrolling interest represents a separate private ownership of 49.5 percent of Mueller-Xingrong.

Common Stock Split

On February 21, 2014, the Company announced a two-for-one stock split of its common stock effected in the form of a stock dividend of one share for each outstanding share. The record date for the stock split was March 14, 2014, and the additional shares were distributed on March 28, 2014. Accordingly, all references to share and per share amounts presented in the Consolidated Financial Statements and this Annual Report on Form 10-K have been adjusted retroactively to reflect the stock split.

Revenue Recognition

Revenue is recognized when title and risk of loss pass to the customer, provided collection is determined to be probable and no significant obligations remain for the Company. Estimates for future rebates on certain product lines and product returns are recognized in the period in which the revenue is recorded. The cost of shipping product to customers is expensed as incurred as a component of cost of goods sold.

Cash Equivalents

Temporary investments with original maturities of three months or less are considered to be cash equivalents. These investments are stated at cost. At December 27, 2014 and December 28, 2013, temporary investments consisted of money market mutual funds, commercial paper, bank repurchase agreements, and U.S. and foreign government securities totaling $144.9 million and $179.2 million, respectively. Included in other current assets is restricted cash of $8.1 million and $5.2 million at December 27, 2014 and December 28, 2013, respectively. These amounts represent required deposits into brokerage accounts that facilitate the Company’s hedging activities and deposits that secure certain short-term notes issued under Mueller-Xingrong’s credit facility.

Allowance for Doubtful Accounts

The Company provides an allowance for receivables that may not be fully collected. In circumstances where the Company is aware of a customer’s inability to meet their financial obligations (e.g., bankruptcy filings or substantial downgrading of credit ratings), it records an allowance for doubtful accounts against amounts due to reduce the net recognized receivable to the amount it believes most likely will be collected. For all other customers, the Company recognizes an allowance for doubtful accounts based on its historical collection experience. If circumstances change (e.g., greater than expected defaults or an unexpected material change in a major customer’s ability to meet their financial obligations), the Company could change its estimate of the recoverability of amounts due by a material amount.

Inventories

The Company’s inventories are valued at the lower-of-cost-or-market. The material component of its U.S. copper tube and copper fittings inventories is valued on a LIFO basis. Other manufactured inventories, including the non-material components of U.S. copper tube and copper fittings, are valued on a FIFO basis. Certain inventories purchased for resale are valued on an average cost basis. Elements of cost in finished goods inventory in addition to the cost of material include depreciation, amortization, utilities, maintenance, production wages, and transportation costs.

The market price of copper cathode and scrap is subject to volatility. During periods when open market prices decline below net book value, the Company may need to provide an allowance to reduce the carrying value of its inventory. In addition, certain items in inventory may be considered obsolete and, as such, the Company may establish an allowance to reduce the carrying value of those items to their net realizable value. Changes in these estimates related to the value of inventory, if any, may result in a materially adverse impact on the Company’s reported financial position or results of operations. The Company recognizes the impact of any changes in estimates, assumptions, and judgments in income in the period in which it is determined. See “Note 3 – Inventories” for additional information.

Property, Plant, and Equipment

Property, plant, and equipment are stated at cost. Depreciation of buildings, machinery, and equipment is provided on the straight-line method over the estimated useful lives ranging from 20 to 40 years for buildings and five to 20 years for machinery and equipment. Leasehold improvements are amortized over the lesser of their useful life or the remaining lease term. Repairs and maintenance are expensed as incurred. See “Note 5 – Property, Plant, and Equipment, Net” for additional information.

Goodwill

Goodwill represents cost in excess of fair values assigned to the underlying net assets of acquired businesses. Goodwill is subject to impairment testing, which is performed by the Company as of the first day of the fourth quarter of each fiscal year, unless circumstances dictate more frequent testing. For testing purposes, the Company defines reporting units as components of its operating segments; components of a segment having similar economic characteristics are combined. The annual impairment test is a two-step process. The first step is the estimation of fair value of reporting units that have goodwill. If this estimate indicates that impairment potentially exists, the second step is performed. Step two, used to measure the amount of goodwill impairment loss, compares the implied fair value of goodwill to the carrying value. In step two the Company is required to allocate the fair value of each reporting unit, as determined in step one, to the fair value of the reporting unit’s assets and liabilities, including unrecognized intangible assets and corporate allocation where applicable, in a hypothetical purchase price allocation as if the reporting unit had been purchased on that date. If the implied fair value of goodwill is less than the carrying value, an impairment charge is recorded. The reporting units with significant recorded goodwill include Standard Products (SPD), Mueller Europe, Limited (MEL), and Westermeyer. SPD and MEL are included in the Plumbing & Refrigeration segment, and Westermeyer is included in the OEM segment. There can be no assurance that additional goodwill impairment will not occur in the future.

Because there are no observable inputs available, the Company estimates fair value of reporting units based on a combination of the market approach and income approach (Level 3 hierarchy as defined by Accounting Standards Codification (ASC) 820, Fair Value Measurements and Disclosures (ASC 820)). The market approach measures the fair value of a business through the analysis of publicly traded companies or recent sales of similar businesses. The income approach uses a discounted cash flow model to estimate the fair value of reporting units based on expected cash flows (adjusted for capital investment required to support operations) and a terminal value. This cash flow stream is discounted to its present value to arrive at a fair value for each reporting unit. Future earnings are estimated using the Company’s most recent annual projections, applying a growth rate to future periods. Those projections are directly impacted by the condition of the markets in which the Company’s businesses participate. The discount rate selected for the reporting units is generally based on rates of return available for comparable companies at the date of valuation. See “Note 6 – Goodwill, Net” for additional information.

Self-Insurance Accruals

The Company is primarily self-insured for workers’ compensation claims and benefits paid under certain employee health care programs. Accruals are primarily based on estimated undiscounted cost of claims, which includes incurred but not reported claims, and are classified as accrued wages and other employee costs.

Benefit Plans

The Company sponsors several qualified and nonqualified pension and other postretirement benefit plans in the U.S. and certain foreign locations. The Company recognizes the overfunded or underfunded status of the plans as an asset or liability in the Consolidated Balance Sheet with changes in the funded status recorded through comprehensive income in the year in which those changes occur. The obligations for these plans are actuarially determined and affected by assumptions, including discount rates, expected long-term return on plan assets for defined benefit pension plans, and certain employee-related factors, such as retirement age and mortality. The Company evaluates its assumptions periodically and makes adjustments as necessary.

The expected return on plan assets is determined using the market value of plan assets. Differences between assumed and actual returns are amortized to the market value of assets on a straight-line basis over the average remaining service period of the plan participants using the corridor approach. The corridor approach defers all actuarial gains and losses resulting from variances between actual results and actuarial assumptions. These unrecognized gains and losses are amortized when the net gains and losses exceed 10 percent of the greater of the market value of the plan assets or the projected benefit obligation. The amount in excess of the corridor is amortized over the average remaining service period of the plan participants. For 2014, the average remaining service period for the pension plans was nine years. See “Note 13 –Benefit Plans” for additional information.

Environmental Reserves and Environmental Expenses

The Company recognizes an environmental liability when it is probable the liability exists and the amount is reasonably estimable. The Company estimates the duration and extent of its remediation obligations based upon reports of outside consultants; internal analyses of cleanup costs and ongoing monitoring costs; communications with regulatory agencies; and changes in environmental law. If the Company were to determine that its estimates of the duration or extent of its environmental obligations were no longer accurate, it would adjust environmental liabilities accordingly in the period that such determination is made. Estimated future expenditures for environmental remediation are not discounted to their present value. Accrued environmental liabilities are not reduced by potential insurance reimbursements.

Environmental expenses that relate to ongoing operations are included as a component of cost of goods sold. Environmental expenses related to non-operating properties are included in other income, net on the Consolidated Statements of Income. See “Note 8 – Commitments and Contingencies” for additional information.

Earnings Per Share

Basic earnings per share is computed based on the weighted average number of common shares outstanding. Diluted earnings per share reflects the increase in weighted average common shares outstanding that would result from the assumed exercise of outstanding stock options and vesting of restricted stock awards calculated using the treasury stock method. Approximately 180 thousand stock-based awards were excluded from the computation of diluted earnings per share for the year ended December 27, 2014 because they were antidilutive.

Income Taxes

Deferred income tax assets and liabilities are recognized when differences arise between the treatment of certain items for financial statement and tax purposes. Realization of certain components of deferred tax assets is dependent upon the occurrence of future events. The Company records valuation allowances to reduce its deferred tax assets to the amount it believes is more likely than not to be realized. These valuation allowances can be impacted by changes in tax laws, changes to statutory tax rates, and future taxable income levels and are based on the Company’s judgment, estimates, and assumptions regarding those future events. In the event the Company was to determine that it would not be able to realize all or a portion of the net deferred tax assets in the future, it would increase the valuation allowance through a charge to income tax expense in the period that such determination is made. Conversely, if it were to determine that it would be able to realize its deferred tax assets in the future, in excess of the net carrying amounts, the Company would decrease the recorded valuation allowance through a decrease to income tax expense in the period that such determination is made.

The Company provides for uncertain tax positions and the related interest and penalties, if any, based upon management’s assessment of whether a tax benefit is more likely than not to be sustained upon examination by tax authorities. Tax benefits for uncertain tax positions that are recognized in the financial statements are measured as the largest amount of benefit, determined on a cumulative probability basis, that is more likely than not to be realized upon ultimate settlement. To the extent the Company prevails in matters for which a liability for an uncertain tax position is established or is required to pay amounts in excess of the liability, the Company’s effective tax rate in a given financial statement period may be affected.

These estimates are highly subjective and could be affected by changes in business conditions and other factors. Changes in any of these factors could have a material impact on future income tax expense. See “Note 9 – Income Taxes” for additional information.

Taxes Collected from Customers and Remitted to Governmental Authorities

Taxes assessed by a governmental authority that are directly imposed on a revenue producing transaction between the Company and its customers, primarily value added taxes in foreign jurisdictions, are accounted for on a net (excluded from revenues and costs) basis.

Stock-Based Compensation

The Company has in effect stock incentive plans under which stock-based awards have been granted to certain employees and members of its Board of Directors. Stock-based compensation expense is recognized in the Consolidated Statements of Income as a component of selling, general, and administrative expense based on the grant date fair value of the awards. See “Note 11 – Stock-Based Compensation” for additional information.

Concentrations of Credit and Market Risk

Concentrations of credit risk with respect to accounts receivable are limited due to the large number of customers comprising the Company’s customer base, and their dispersion across different geographic areas and different industries, including HVAC, plumbing, refrigeration, hardware, automotive, OEMs, and others.

The Company minimizes its exposure to base metal price fluctuations through various strategies. Generally, it prices an equivalent amount of copper raw material, under flexible pricing arrangements it maintains with its suppliers, at the time it determines the selling price of finished products to its customers.

Derivative Instruments and Hedging Activities

The Company may utilize futures contracts to manage the volatility related to purchases of copper through cash flow hedges. It may also utilize futures contracts to protect the value of the copper inventory on hand and firm commitments to purchase copper through fair value hedges. The Company may elect to utilize futures contracts as economic hedges that do not qualify for hedge accounting in accordance with ASC 815, Derivatives and Hedging (ASC 815). In addition, the Company may use foreign currency forward contracts to reduce the risk from exchange rate fluctuations on future purchases and intercompany transactions denominated in foreign currencies.

All derivatives are recognized in the Consolidated Balance Sheets at their fair value. On the date the derivative contract is entered into, it is designated as (i) a hedge of a forecasted transaction or the variability of cash flow to be paid (cash flow hedge), or (ii) a hedge of the fair value of a recognized asset or liability (fair value hedge). Changes in the fair value of a derivative that is qualified, designated and highly effective as a cash flow hedge are recorded in accumulated other comprehensive income (AOCI), to the extent effective, until they are reclassified to earnings in the same period or periods during which the hedged transaction affects earnings. Changes in the fair value of a derivative that is qualified, designated and highly effective as a fair value hedge, along with the gain or loss on the hedged recognized asset or liability that is attributable to the hedged risk, are recorded in current earnings. Changes in the fair value of undesignated derivative instruments and the ineffective portion of designated derivative instruments are reported in current earnings.

The Company documents all relationships between hedging instruments and hedged items, as well as the risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivatives that are designated as fair value hedges to specific assets and liabilities in the Consolidated Balance Sheets and linking cash flow hedges to specific forecasted transactions or variability of cash flow.

The Company also assesses, both at the hedge’s inception and on an ongoing basis, whether the designated derivatives that are used in hedging transactions are highly effective in offsetting changes in cash flow or fair values of hedged items. When a derivative is determined not to be highly effective as a hedge or the underlying hedged transaction is no longer probable, hedge accounting is discontinued prospectively, in accordance with the derecognition criteria for hedge accounting.

The Company primarily executes derivative contracts with major financial institutions. These counterparties expose the Company to credit risk in the event of non-performance. The amount of such exposure is limited to the fair value of the contract plus the unpaid portion of amounts due to the Company pursuant to terms of the derivative instruments, if any. If a downgrade in the credit rating of these counterparties occurs, management believes that this exposure is mitigated by provisions in the derivative arrangements which allow for the legal right of offset of any amounts due to the Company from the counterparties with any amounts payable to the counterparties by the Company. As a result, management considers the risk of loss from counterparty default to be minimal. See “Note 14 – Derivative Instruments and Hedging Activities” for additional information.

Fair Value of Financial Instruments

The carrying amounts for cash and cash equivalents, accounts receivable, and accounts payable approximate fair value due to the short-term maturity of these instruments.

The fair value of long-term debt at December 27, 2014 approximates the carrying value on that date. The estimated fair values were determined based on quoted market prices and the current rates offered for debt with similar terms and maturities. The fair value of long-term debt is classified as Level 2 within the fair value hierarchy. This classification is defined as a fair value determined using market-based inputs other than quoted prices that are observable for the liability, either directly or indirectly.Outstanding borrowings have variable interest rates that re-price frequently at current market rates.

Foreign Currency Translation

For foreign subsidiaries in which the functional currency is other than the U.S. dollar, balance sheet accounts are translated at exchange rates in effect at the end of the year and income statement accounts are translated at average exchange rates for the year. Translation gains and losses are included in equity as a component of OCI. Included in the Consolidated Statements of Income were transaction gains of $0.1 million in 2014, losses of $0.1 million in 2013, and losses of $0.3 million in 2012.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S. GAAP) requires management to make estimates, assumptions, and judgments that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.

Recently Issued Accounting Standards

In April 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No, 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (ASU 2014-08). The ASU significantly changed the criteria for reporting a discontinued operation and added disclosure requirements for discontinued operations and other disposal transactions. It is effective for annual reporting periods beginning after December 15, 2014 and is applied prospectively. The Company has elected early adoption of ASU 2014-08 effective September 28, 2014. The new guidance did not have a significant impact on the Company’s Consolidated Financial Statements or related disclosures.

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09). The ASU will supersede virtually all existing revenue recognition guidance under U.S. GAAP and will be effective for annual reporting periods beginning after December 15, 2016. The fundamental principles of the new guidance are that companies should recognize revenue in a manner that reflects the timing of the transfer of services to customers and the amount of revenue recognized reflects the consideration that a company expects to receive for the goods and services provided. The new guidance establishes a five-step approach for the recognition of revenue. The Company is in the process of evaluating the impact of ASU 2014-09 on its Consolidated Financial Statements.