Mueller Industries (MLI) 10-K 24 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 27, 2014	Feb. 20, 2015	Jun. 28, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	MUELLER INDUSTRIES INC
Entity Central Index Key	89439
Current Fiscal Year End Date	-15
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$1,619,095,888
Entity Common Stock, Shares Outstanding		56,924,463
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	27-Dec-14

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Proforma net sales	$2,364,227	$2,158,541	$2,189,938
Cost of goods sold	2,043,719	1,862,089	1,904,463
Depreciation and amortization	33,735	32,394	31,495
Selling, general, and administrative expense	131,740	134,914	129,456
Insurance settlements	0	-106,332	-1,500
Gain on sale of assets	-6,259	-39,765	0
Impairment charges	0	4,304	0
Litigation settlements	0	0	-4,050
Severance	7,296	0	3,369
Operating income	153,996	270,937	126,705
Interest expense	-5,740	-3,990	-6,890
Other (expense) income, net	-243	4,451	539
Income before income taxes	148,013	271,398	120,354
Income tax expense	-45,479	-98,109	-36,681
Consolidated net income	102,534	173,289	83,673
Less net income attributable to noncontrolling interest	-974	-689	-1,278
Net income attributable to Mueller Industries, Inc.	$101,560	$172,600	$82,395
Weighted average shares for basic earnings per share (in shares)	56,042	55,742	70,664
Effect of dilutive stock-based awards (in shares)	726	742	828
Adjusted weighted average shares for diluted earnings per share (in shares)	56,768	56,484	71,492
Basic earnings per share (in dollars per share)	$1.81	$3.10	$1.17
Diluted earnings per share (in dollars per share)	$1.79	$3.06	$1.15
Dividends per share (in dollars per share)	$0.30	$0.25	$0.21

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013		Dec. 29, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Consolidated net income	$102,534		$173,289		$83,673
Other comprehensive (loss) income, net of tax:
Foreign currency translation	-6,766		3,285		8,070
Net change with respect to derivative instruments and hedging activities	-2,499	[1]	1,713	[1]	255	[1]
Net actuarial (loss) gain on pension and postretirement obligations	-23,006	[2]	27,369	[2]	-847	[2]
Other, net	15		151		14
Total other comprehensive (loss) income	-32,256		32,518		7,492
Comprehensive income	70,278		205,807		91,165
Less comprehensive income attributable to noncontrolling interest	-822		-1,404		-1,984
Comprehensive income attributable to Mueller Industries, Inc.	$69,456		$204,403		$89,181
[1]	Net of taxes of $1,362 in 2014, $(962) in 2013, and $(162) in 2012
[2]	Net of taxes of $10,180 in 2014, $(15,015) in 2013, and $94 in 2012

CONSOLIDATED_STATEMENTS_OF_COM1

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Net change with respect to derivative instruments and hedging activities, tax	$1,362	($962)	($162)
Net actuarial gain/loss on pension and postretirement obligations, tax	$10,180	($15,015)	$94

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 27, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$352,134	$311,800
Accounts receivable, less allowance for doubtful accounts of $666 in 2014 and $2,391 in 2013	275,065	271,847
Inventories	256,585	251,716
Other current assets	57,429	39,354
Total current assets	941,213	874,717
Property, plant, and equipment, net	245,910	244,457
Goodwill, net	102,909	94,357
Other assets	38,064	34,236
Total Assets	1,328,096	1,247,767
Current liabilities:
Current portion of debt	36,194	29,083
Accounts payable	100,735	80,897
Accrued wages and other employee costs	41,595	37,109
Other current liabilities	59,545	72,167
Total current liabilities	238,069	219,256
Long-term debt, less current portion	205,250	206,250
Pension liabilities	20,070	10,645
Postretirement benefits other than pensions	21,486	16,781
Environmental reserves	21,842	22,144
Deferred income taxes	24,556	35,975
Other noncurrent liabilities	1,389	849
Total liabilities	532,662	511,900
Mueller Industries, Inc. stockholders' equity:
Preferred stock - $1.00 par value; shares authorized 5,000,000; none outstanding	0	0
Common stock - $.01 par value; shares authorized 100,000,000; issued 80,183,004; outstanding 56,901,445 in 2014 and 56,604,674 in 2013	802	401
Additional paid-in capital	268,575	267,142
Retained earnings	992,798	908,274
Accumulated other comprehensive loss	-42,923	-10,819
Treasury common stock, at cost	-457,102	-461,593
Total Mueller Industries, Inc. stockholders' equity	762,150	703,405
Noncontrolling interest	33,284	32,462
Total equity	795,434	735,867
Commitments and contingencies
Total Liabilities and Equity	$1,328,096	$1,247,767

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 27, 2014	Dec. 28, 2013
In Thousands, except Share data, unless otherwise specified
Current assets:
Allowance for doubtful accounts	$666	$2,391
Mueller Industries, Inc. stockholders' equity:
Preferred stock- par value (in dollars per share)	$1	$1
Preferred stock- shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares outstanding (in shares)	0	0
Common stock- par value (in dollars per share)	$0.01	$0.01
Common stock- shares authorized (in shares)	100,000,000	100,000,000
Common stock- shares issued (in shares)	80,183,004	80,183,004
Common stock- shares outstanding (in shares)	56,901,445	56,604,674

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Operating activities:
Consolidated net income	$102,534	$173,289	$83,673
Reconciliation of net income to net cash provided by operating activities:
Depreciation	30,205	30,946	30,326
Amortization of intangibles	3,530	1,448	1,169
Amortization of debt issuance costs	341	299	438
Stock-based compensation expense	6,265	5,704	6,136
Insurance settlements	0	-106,332	-1,500
(Gain) loss on disposal of assets	-5,405	-42,300	1,411
Insurance proceeds - noncapital related	0	32,395	14,250
Impairment charges	0	4,304	0
Income tax benefit from exercise of stock options	-837	-719	-2,528
Deferred income taxes	-6,495	19,213	-1,284
(Recovery of) provision for doubtful accounts receivable	-500	-273	837
Changes in assets and liabilities, net of businesses acquired and sold:
Receivables	-21,432	19,383	-23,690
Inventories	1,381	5,963	-4,834
Other assets	-23,652	562	-14,985
Current liabilities	5,849	-14,139	8,368
Other liabilities	-2,223	-1,935	9,345
Other, net	1,044	705	1,165
Net cash provided by operating activities	90,605	128,513	108,297
Investing activities:
Proceeds from sale of assets, net of cash transferred	33,788	65,147	517
Acquisition of businesses, net of cash acquired	-30,137	-55,276	-11,561
Capital expenditures	-39,173	-41,349	-56,825
Insurance proceeds	0	29,910	42,250
Net (deposits into) withdrawals from restricted cash balances	-2,902	-1,417	9,243
Net cash used in investing activities	-38,424	-2,985	-16,376
Financing activities:
Dividends paid to stockholders of Mueller Industries, Inc.	-16,819	-13,941	-14,891
Repurchase of common stock	0	0	-427,446
Repayments of long-term debt	-1,050	-1,000	-149,176
Issuance (repayment) of debt by joint venture, net	7,258	857	-14,429
Issuance of long-term debt	0	0	200,000
Net cash used to settle stock-based awards	-777	-228	-4,181
Income tax benefit from exercise of stock options	837	719	2,528
Debt issuance costs	0	-50	-1,053
Net cash used in financing activities	-10,551	-13,643	-408,648
Effect of exchange rate changes on cash	-1,296	981	1,499
Increase (decrease) in cash and cash equivalents	40,334	112,866	-315,228
Cash and cash equivalents at the beginning of the year	311,800	198,934	514,162
Cash and cash equivalents at the end of the year	$352,134	$311,800	$198,934

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (USD $)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]	Total
In Thousands, unless otherwise specified
Balance at Dec. 31, 2011	$401	$266,936	$682,380	($49,409)	($44,620)	$29,074
Balance (in shares) at Dec. 31, 2011	80,183				3,710
Common stock:
Issuance of shares under two-for-one stock split	0	0
Additional paid-in capital:
Issuance of shares under incentive stock option plans		-4,303			20,881
Stock-based compensation expense		6,136
Income tax benefit from exercise of stock options		2,528
Issuance of restricted stock		-3,471			3,471
Retained earnings:
Net income attributable to Mueller Industries, Inc.			82,395				82,395
Dividends paid or payable to stockholders of Mueller Industries, Inc.			-14,998
Accumulated other comprehensive (loss) income:
Total other comprehensive (loss) income attributable to Mueller Industries, Inc.				6,786
Treasury stock:
Issuance of shares under incentive stock option plans (in shares)					-1,152
Repurchase of common stock (in shares)					21,710
Repurchase of common stock					-448,205
Issuance of restricted stock (in shares)					-284
Noncontrolling interest:
Net income attributable to noncontrolling interest						1,278	1,278
Foreign currency translation						706	8,070
Balance at Dec. 29, 2012	401	267,826	749,777	-42,623	-468,473	31,058
Balance (in shares) at Dec. 29, 2012	80,183				23,984
Common stock:
Issuance of shares under two-for-one stock split	0	0
Additional paid-in capital:
Issuance of shares under incentive stock option plans		-1,205			4,716
Stock-based compensation expense		5,704
Income tax benefit from exercise of stock options		719
Issuance of restricted stock		-5,902			5,902
Retained earnings:
Net income attributable to Mueller Industries, Inc.			172,600				172,600
Dividends paid or payable to stockholders of Mueller Industries, Inc.			-14,103
Accumulated other comprehensive (loss) income:
Total other comprehensive (loss) income attributable to Mueller Industries, Inc.				31,804
Treasury stock:
Issuance of shares under incentive stock option plans (in shares)					-244
Repurchase of common stock (in shares)					140
Repurchase of common stock					-3,738
Issuance of restricted stock (in shares)					-302
Noncontrolling interest:
Net income attributable to noncontrolling interest						689	689
Foreign currency translation						715	3,285
Balance at Dec. 28, 2013	401	267,142	908,274	-10,819	-461,593	32,462	735,867
Balance (in shares) at Dec. 28, 2013	80,183				23,578
Common stock:
Issuance of shares under two-for-one stock split	401	-401
Additional paid-in capital:
Issuance of shares under incentive stock option plans		-1,646			4,504
Stock-based compensation expense		6,265
Income tax benefit from exercise of stock options		837
Issuance of restricted stock		-3,622			3,819
Retained earnings:
Net income attributable to Mueller Industries, Inc.			101,560				101,560
Dividends paid or payable to stockholders of Mueller Industries, Inc.			-17,036
Accumulated other comprehensive (loss) income:
Total other comprehensive (loss) income attributable to Mueller Industries, Inc.				-32,104
Treasury stock:
Issuance of shares under incentive stock option plans (in shares)					-208
Repurchase of common stock (in shares)					107
Repurchase of common stock					-3,832
Issuance of restricted stock (in shares)					-195
Noncontrolling interest:
Net income attributable to noncontrolling interest						974	974
Foreign currency translation						-152	-6,766
Balance at Dec. 27, 2014	$802	$268,575	$992,798	($42,923)	($457,102)	$33,284	$795,434
Balance (in shares) at Dec. 27, 2014	80,183				23,282

CONSOLIDATED_STATEMENTS_OF_CHA1

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical)	12 Months Ended
	Dec. 27, 2014
Common stock:
Conversion ratio for stock split	2
Common Stock [Member]
Common stock:
Conversion ratio for stock split	2
Additional Paid-in Capital [Member]
Common stock:
Conversion ratio for stock split	2

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 27, 2014
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1 – Summary of Significant Accounting Policies
	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
	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.

Acquisitions_and_Dispositions

Acquisitions and Dispositions	12 Months Ended
	Dec. 27, 2014
Acquisitions and Dispositions [Abstract]
Acquisitions and Dispositions	Note 2 – Acquisitions and Dispositions
	Acquisitions
	On October 18, 2013, the Company entered into a definitive agreement with KME Yorkshire Limited to acquire certain assets and assume certain liabilities of its copper tube business. Yorkshire Copper Tube (Yorkshire) produces European standard copper distribution tubes. This transaction received regulatory approval in the United Kingdom on February 11, 2014 and closed on February 28, 2014. The purchase price was approximately $30.1 million, paid in cash. The acquisition of Yorkshire complements the Company’s existing copper tube businesses in the Plumbing & Refrigeration segment. In 2012, Yorkshire had annual revenue of approximately $196.1 million. During the third quarter of 2014, the purchase price allocation, including all fair value measurements, was finalized. The fair value of the assets acquired totaled $20.7 million, consisting primarily of inventories of $17.6 million, property, plant, and equipment of $2.1 million, and other current assets of $1.0 million. The fair value of the liabilities assumed totaled $15.6 million, consisting primarily of accounts payable and accrued expenses of $15.2 million and other current liabilities of $0.4 million. Of the remaining purchase price, $8.1 million was allocated to tax-deductible goodwill and $16.9 million was allocated to other intangible assets.
	The Company recognized approximately $7.3 million of severance costs related to the reorganization of Yorkshire during 2014 and expects to recognize an additional $2.7 million of expense in 2015.
	On October 17, 2013, the Company entered into a Stock Purchase Agreement with Commercial Metals Company and Howell Metal Company (Howell) providing for the purchase of all of the outstanding capital stock of Howell for approximately $55.3 million in cash, net of working capital adjustments. Howell manufactures copper tube and line sets for U.S. distribution. The acquisition of Howell complements the Company’s copper tube and line sets businesses, both components of the Plumbing & Refrigeration segment. For the twelve months ended August 31, 2013, Howell’s net sales for copper tube and line sets totaled $156.3 million. During the first quarter of 2014, the purchase price allocation, including all fair value measurements, was finalized. The fair value of the assets acquired totaled $63.0 million, consisting primarily of receivables of $14.6 million, inventories of $27.6 million, property, plant, and equipment of $20.3 million, and other current assets of $0.5 million. The fair value of the liabilities assumed totaled $11.4 million, consisting primarily of accounts payable and accrued expenses of $9.9 million and other current liabilities of $1.5 million. Of the remaining purchase price, $2.3 million was allocated to other intangible assets and $1.3 million to tax-deductible goodwill.
	On August 16, 2012, the Company acquired 100 percent of the outstanding stock of Westermeyer Industries, Inc. (Westermeyer) for approximately $11.6 million in cash. Westermeyer, located in Bluffs, Illinois, designs, manufactures, and distributes high-pressure components and accessories for the air-conditioning and refrigeration markets. The acquisition of Westermeyer complements the Company’s existing refrigeration business, a component of the OEM segment. The fair value of the assets acquired totaled $7.5 million, consisting of receivables of $2.0 million, inventories of $1.9 million, and property, plant, and equipment of $3.6 million. These assets were partially offset by current liabilities of approximately $1.0 million. Of the remaining purchase price, $2.3 million was allocated to tax-deductible goodwill and $2.7 million to other intangible assets.
	These acquisitions were accounted for using the acquisition method of accounting. Therefore, the results of operations of the acquired businesses were included in the Company’s Consolidated Financial Statements from their respective acquisition dates. The purchase price for these acquisitions, which was financed by available cash balances, has been allocated to the assets and liabilities of the acquired businesses based on their respective fair market values.
	Dispositions
	On November 21, 2014, the Company entered into a Share Purchase Agreement with Travis Perkins PLC to sell all of the outstanding capital stock of Mueller Primaflow Limited (Primaflow), the Company’s United Kingdom based plumbing and heating systems import distribution business, for approximately $24.9 million. Primaflow, which serves markets in the United Kingdom and Ireland, was included in the Plumbing & Refrigeration segment and reported net sales of $57.5 million and after-tax net income of $4.4 million for the 2014 fiscal year. The carrying value of the assets disposed totaled $25.3 million, consisting primarily of accounts receivable and inventories. The carrying value of the liabilities disposed totaled $7.1 million, consisting primarily of accounts payable and other current liabilities. In addition, the Company recognized a cumulative translation loss of $6.0 million. The net gain on the sale of this business was immaterial to the Consolidated Financial Statements.
	During November 2014, the Company sold its ABS plastic pipe manufacturing assets. These assets had a carrying value of approximately $1.9 million and were part of the SPD reporting unit, which is a component of the Plumbing & Refrigeration segment. The sales price was $6.0 million, which resulted in a pre-tax gain of $4.1 million.
	On August 9, 2013, the Company sold certain of its plastic fittings manufacturing assets located in Portage, Michigan and Ft. Pierce, Florida. Simultaneously, the Company entered into a lease agreement with the purchaser of the assets to continue to manufacture and distribute Schedule 40 plastic fittings utilizing the Ft. Pierce assets for a period of approximately eight to 14 months (Transition Period). The total sales price was $66.2 million, of which $61.2 million was received on August 9, 2013; the remaining $5.0 million was received during the second quarter of 2014. This transaction resulted in a pre-tax gain of $39.8 million in the third quarter of 2013, or 41 cents per diluted share after tax.
	The net book value of the plastic fittings manufacturing assets disposed was $15.9 million. For goodwill testing purposes, these assets were part of the SPD reporting unit which is a component of the Company’s Plumbing & Refrigeration segment. Because these assets met the definition of a business in accordance with ASC 805, Business Combinations, $10.5 million of the SPD reporting unit’s goodwill balance was allocated to the disposal group. The amount of goodwill allocated was based on the relative fair values of the asset group which was disposed and the portion of the SPD reporting unit which was retained.
	The Company has continued to manufacture and supply plastic drain, waste, and vent (DWV) fittings, and extended its third party supply agreement to complement its product offering with purchased products it does not manufacture with the remaining assets. This supply agreement was originally entered into after the majority of the Company’s plastic manufacturing assets were destroyed in the 2011 fire at its Wynne, Arkansas facility.
	With the decision to cease the Company’s manufacturing operations in Portage, there was an evaluation of the remaining long-lived assets for impairment, and it was determined that the carrying values of the land and building were no longer recoverable. An impairment charge of $3.2 million was recognized during the third quarter of 2013 to adjust the carrying values of the land and building to their estimated fair value. The fair value estimate was determined by obtaining and evaluating recent sales data for similar assets (Level 2 hierarchy as defined by ASC 820). During March 2014, the land and building in Portage were sold for $4.7 million, resulting in a pre-tax gain of $1.4 million.

Inventories

Inventories	12 Months Ended
	Dec. 27, 2014
Inventories [Abstract]
Inventories	Note 3 – Inventories
	(In thousands)	2014			2013
	Raw materials and supplies	$	53,586		$	54,613
	Work-in-process		39,707			43,796
	Finished goods		168,481			159,422
	Valuation reserves		(5,189	)		(6,115	)
	Inventories	$	256,585		$	251,716
	Inventories valued using the LIFO method totaled $25.9 million at December 27, 2014 and $34.9 million at December 28, 2013. At December 27, 2014 and December 28, 2013, the approximate FIFO cost of such inventories was $104.8 million and $117.9 million, respectively. Additionally, the Company valued certain inventories purchased for resale on an average cost basis. The value of those inventories was $47.7 million at December 27, 2014 and $54.7 million at December 28, 2013.
	During 2011, inventory quantities valued using the LIFO method declined which resulted in liquidation of LIFO inventory layers. This liquidation resulted from intercompany sales; therefore, the gain from the LIFO liquidation of approximately $8.0 million was deferred.During the first quarter of 2012, the Company sold this inventory to third parties and recognized the gain. This recognition resulted in a reduction of approximately $8.0 million to cost of sales, or seven cents per diluted share after tax for 2012.
	At the end of 2014 and 2013, the FIFO value of inventory consigned to others was $4.3 million.

Consolidated_Financial_Stateme

Consolidated Financial Statement Details	12 Months Ended
	Dec. 27, 2014
Consolidated Financial Statement Details [Abstract]
Consolidated Financial Statement Details	Note 4 – Consolidated Financial Statement Details
	Other Current Liabilities
	Included in other current liabilities were accrued discounts and allowances of $45.3 million at December 27, 2014 and $43.2 million at December 28, 2013.
	Other (Expense) Income, Net
	(In thousands)	2014			2013			2012
	Gain on the sale of non-operating property	$	—		$	3,000		$	—
	Interest income		573			906			847
	Environmental expense, non-operating properties		(822	)		(823	)		(1,128	)
	Other		6			1,368			820
	Other (expense) income, net	$	(243	)	$	4,451		$	539

Property_Plant_and_Equipment_N

Property, Plant, and Equipment, Net	12 Months Ended
	Dec. 27, 2014
Property, Plant, and Equipment, Net [Abstract]
Property, Plant, and Equipment, Net	Note 5 – Property, Plant, and Equipment, Net
	(In thousands)	2014			2013
	Land and land improvements	$	12,198		$	13,153
	Buildings		120,035			132,331
	Machinery and equipment		561,093			561,005
	Construction in progress		44,787			25,691
			738,113			732,180
	Less accumulated depreciation		(492,203	)		(487,723	)
	Property, plant, and equipment, net	$	245,910		$	244,457

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 27, 2014
Goodwill and Other Intangible Assets [Abstract]
Goodwill and Other Intangible Assets	Note 6 – Goodwill and Other Intangible Assets
	Goodwill
	The changes in the carrying amount of goodwill were as follows:
	(In thousands)		Plumbing & Refrigeration Segment			OEM Segment				Total
	Balance at December 29, 2012:
	Goodwill		$	141,684		$	12,300			$	153,984
	Accumulated impairment and amortization			(39,434	)		(9,971	)			(49,405	)
				102,250			2,329				104,579
	Additions			310			—				310
	Disposition			(10,532	)		—				(10,532	)
	Balance at December 28, 2013:
	Goodwill			131,462			12,300				143,762
	Accumulated impairment and amortization			(39,434	)		(9,971	)			(49,405	)
				92,028			2,329				94,357
	Additions(1)			9,123			—				9,123
	Currency translation			(571	)		—				(571	)
	Balance at December 27, 2014:
	Goodwill			140,014			12,300				152,314
	Accumulated impairment and amortization			(39,434	)		(9,971	)			(49,405	)
	Goodwill, net		$	100,580		$	2,329			$	102,909
	(1)Includes finalization of the purchase price allocation adjustment for Howell of $1.0 million
	In 2013, the Company acquired Howell. Of the $55.3 million purchase price, $1.3 million was allocated to goodwill. In 2014, the Company acquired Yorkshire. Of the $30.1 million purchase price, $8.1 million was allocated to goodwill.
	As discussed in Note 2, $10.5 million of goodwill relating to the SPD reporting unit was disposed of in 2013 in conjunction with the sale of a business.
	There were no impairment charges resulting from the 2014, 2013, or 2012 impairment tests, as the estimated fair value of the reporting units exceeded the carrying value.
	Other Intangible Assets
	The gross and net book value of other intangible assets included in other assets was $7.8 million and $5.5 million, respectively, at December 28, 2013. The carrying amount of intangible assets at December 27, 2014 was as follows:
	(In thousands)	Estimated Useful Life		Gross Carrying Amount			Accumulated Amortization				Net Carrying Amount
	Customer relationships	20 years		$	11,852		$	(526	)		$	11,326
	Non-compete agreements	3-5 years			4,495			(1,307	)			3,188
	Patents and technology	10 years			6,852			(4,744	)			2,108
	Trade names and licenses	3 years			1,670			(252	)			1,418
	Other	2-5 years			877			(453	)			424
	Other intangible assets			$	25,746		$	(7,282	)		$	18,464
	With the acquisition of Howell in 2013, $2.3 million of the purchase price was allocated to other intangible assets relating to trade names and customer relationships. During 2014, the purchase price allocation, including fair value adjustments, was finalized. With the acquisition of Yorkshire in 2014, $16.9 million of the purchase price was allocated to other intangible assets. This included customer relationships, non-compete agreements, and trade names and licenses. The remaining change was related to currency translation.
	Amortization expense for intangible assets was $3.2 million in 2014, $0.9 million in 2013, and $0.7 million in 2012. Future amortization expense is estimated as follows:
	(In thousands)		Amount
	2015		$	3,412
	2016			2,519
	2017			1,334
	2018			1,079
	2019			1,011
	Thereafter			9,109
	Expected amortization expense		$	18,464

Debt

Debt	12 Months Ended
	Dec. 27, 2014
Debt [Abstract]
Debt	Note 7 – Debt
	(In thousands)	2014			2013
	Term Loan Facility with interest at 1.53%, due 2017	$	200,000		$	200,000
	Mueller-Xingrong credit facility with interest at 5.60%, due 2015		29,968			28,033
	2001 Series IRB’s with interest at 1.13%, due through 2021		6,250			7,250
	Other		5,226			50
			241,444			235,333
	Less current portion of debt		(36,194	)		(29,083	)
	Long-term debt	$	205,250		$	206,250
	Effective May 29, 2014, the Company elected to modify its credit agreement (the Credit Agreement) entered into on March 7, 2011 to reduce the unsecured $350.0 million revolving credit facility to $200.0 million. The Credit Agreement also provides for a $200.0 million Term Loan Facility, which, together with the Revolving Loan Facility, mature on December 11, 2017. Borrowings under the Credit Agreement bear interest, at the Company’s option, at LIBOR or Base Rate as defined by the Credit Agreement, plus a variable premium. LIBOR advances may be based upon the one, three, or six-month LIBOR. The variable premium is based upon the Company’s debt to total capitalization ratio, and can range from 112.5 to 162.5 basis points for LIBOR based loans and 12.5 to 62.5 basis points for Base Rate loans. At December 27, 2014, the premium was 137.5 basis points for LIBOR loans and 37.5 basis points for Base Rate loans. Additionally, a facility fee is payable quarterly on the total commitment and varies from 25.0 to 37.5 basis points based upon the Company’s debt to total capitalization ratio. Availability of funds under the Revolving Credit Facility is reduced by the amount of certain outstanding letters of credit, which are used to secure the Company’s payment of insurance deductibles and certain retiree health benefits, totaling approximately $10.5 million at December 27, 2014. Terms of the letters of credit are generally one year but are renewable annually. There were no borrowings outstanding on the Revolving Credit Facility at the end of 2014.
	On March 21, 2014, Mueller Europe, Limited (MEL) entered into a credit agreement (the Invoice Facility) establishing a total borrowing capacity of £40.0 million, or approximately $62.2 million. The Invoice Facility has an initial term of two years. Borrowings outstanding under the Invoice Facility are secured by MEL’s trade account receivables denominated in British pounds which totaled $57.9 million at December 27, 2014. There were no borrowings outstanding at the end of 2014.
	On September 23, 2013, Mueller-Xingrong entered into a secured revolving credit facility (the JV Credit Agreement), which matured on September 24, 2014. At the maturity date, individual draws on the JV Credit Agreement had maturity dates ranging up to nine months. Borrowings under the JV Credit Agreement bear an interest rate at the latest base-lending rate published by the People’s Bank of China, which was 5.6 percent at December 27, 2014. On February 2, 2015, Mueller-Xingrong entered into a new secured revolving credit agreement with a total borrowing capacity of RMB 230 million (or approximately $37.1 million). In addition, Mueller-Xingrong occasionally finances working capital through various accounts receivable and bank draft discount arrangements. Total borrowings at Mueller-Xingrong were $35.2 million at December 27, 2014.
	Covenants contained in the Company’s financing obligations require, among other things, the maintenance of minimum levels of tangible net worth and the satisfaction of certain minimum financial ratios. At December 27, 2014, the Company was in compliance with all debt covenants.
	Aggregate annual maturities of the Company’s debt are as follows:
	(In thousands)	Amount
	2015	$	36,194
	2016		1,000
	2017		201,000
	2018		1,000
	2019		1,000
	Thereafter		1,250
	Long-term debt	$	241,444
	Net interest expense consisted of the following:
	(In thousands)	2014			2013			2012
	Interest expense	$	6,393		$	5,147		$	6,890
	Capitalized interest		(653	)		(1,157	)		—
		$	5,740		$	3,990		$	6,890
	Interest paid in 2014, 2013, and 2012 was $5.7 million, $4.9 million, and $8.4 million, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 27, 2014
Commitments and Contingencies [Abstract]
Commitments and Contingencies	Note 8 – Commitments and Contingencies
	Environmental
	The Company is subject to environmental standards imposed by federal, state, local, and foreign environmental laws and regulations. For all properties, the Company has provided and charged to expense $1.2 million in 2014, $1.0 million in 2013, and $3.1 million in 2012 for pending environmental matters. Environmental costs related to non-operating properties are classified as a component of other income, net and costs related to operating properties are classified as cost of goods sold. Environmental reserves totaled $22.7 million at December 27, 2014 and $23.6 million at December 28, 2013. As of December 27, 2014, the Company expects to spend $0.7 million in 2015, $0.8 million in 2016, $0.7 million in 2017, $0.7 million in 2018, $0.8 million in 2019, and $9.4 million thereafter for ongoing projects. The timing of a potential payment for a $9.5 million settlement offer related to the Southeast Kansas Sites has not yet been determined.
	Non-operating Properties
	Southeast Kansas Sites
	The Kansas Department of Health and Environment (KDHE) has contacted the Company regarding environmental contamination at three former smelter sites in Kansas (Altoona, Iola and East La Harpe). While the Company believes that legally it is not a successor to the companies that operated these smelter sites, it is discussing possible settlement with KDHE and other potentially responsible parties (PRP) in order to avoid litigation. In 2008, the Company established a reserve of $9.5 million for this matter. Another PRP has conducted a site investigation of the Altoona site under a consent decree with KDHE. The Company and two other PRPs have conducted a site study evaluation of the East La Harpe site under KDHE supervision, and are now discussing sharing the costs of a possible cleanup. The EPA is in the early stages of study and remediation in the vicinity of the Iola site, which it added to the National Priority List (NPL) in May, 2013 as the “Former United Zinc & Associated Smelters” site. The NPL is a list of priority sites where the EPA has determined that there has been a release or threatened release of hazardous substances that warrant investigation and, if appropriate, remedial action. The NPL does not assign liability to any party including the owner or operator of a property placed on the NPL.
	Shasta Area Mine Sites
	Mining Remedial Recovery Company (MRRC), a wholly owned subsidiary, owns certain inactive mines in Shasta County, California. MRRC has continued a program, begun in the late 1980s, of sealing mine portals with concrete plugs in mine adits, which were discharging water. The sealing program achieved significant reductions in the metal load in discharges from these adits; however, additional reductions are required pursuant to an order issued by the California Regional Water Quality Control Board (QCB). In response to a 1996 Order issued by the QCB, MRRC completed a feasibility study in 1997 describing measures designed to mitigate the effects of acid rock drainage. In December 1998, the QCB modified the 1996 order extending MRRC’s time to comply with water quality standards. In September 2002, the QCB adopted a new order requiring MRRC to adopt Best Management Practices (BMP) to control discharges of acid mine drainage. That order extended the time to comply with water quality standards until September 2007. During that time, implementation of BMP further reduced impacts of acid rock drainage; however, full compliance has not been achieved. The QCB is presently renewing MRRC’s discharge permit and will concurrently issue a new order. It is expected that the new ten-year permit will include an order requiring continued implementation of BMP through 2025 to address residual discharges of acid rock drainage. At this site, MRRC spent approximately $1.7 million from 2012 through 2014 and estimates that it will spend between approximately $10.5 million and $13.0 million over the next 20 years.
	Lead Refinery Site
	U.S.S. Lead Refinery, Inc. (Lead Refinery), a non-operating wholly owned subsidiary of Mining Remedial Recovery Company, has conducted corrective action and interim remedial activities and studies (collectively, Site Activities) at Lead Refinery’s East Chicago, Indiana site pursuant to the Resource Conservation and Recovery Act. Site Activities, which began in December 1996, have been substantially concluded. Lead Refinery is required to perform monitoring and maintenance activities with respect to Site Activities pursuant to a post-closure permit issued by the Indiana Department of Environmental Management effective as of March 2, 2013. Lead Refinery spent approximately $0.1 million annually in 2014, 2013 and 2012 with respect to this site. Approximate costs to comply with the post-closure permit, including associated general and administrative costs, are between $1.9 million and $3.6 million over the next 20 years.
	On April 9, 2009, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the EPA added the Lead Refinery site, and properties surrounding the Lead Refinery site, to the NPL. On July 17, 2009, Lead Refinery received a written notice from the EPA that the agency is of the view that Lead Refinery may be a PRP under CERCLA in connection with the release or threat of release of hazardous substances including lead into properties surrounding the Lead Refinery site. The EPA has identified two other PRPs in connection with the release or threat of release of hazardous substances into properties surrounding the Lead Refinery site. In November 2012, the EPA adopted a remedy in connection with properties surrounding the Lead Refinery site. In September 2014, the EPA announced that it had entered into a settlement with the two other PRPs whereby they will pay approximately $26.0 million to fund the cleanup of approximately 300 properties surrounding the Lead Refinery site. The EPA has not contacted Lead Refinery regarding settlement of the agency’s potential claims related to the properties surrounding the Lead Refinery site.
	As of December 27, 2014, the EPA has not conducted an investigation of the Lead Refinery site, proposed remedies for the Lead Refinery site, or informed Lead Refinery that it is a PRP at the Lead Refinery site. The Company is unable to determine the likelihood of a material adverse outcome or the amount or range of a potential loss with respect to placement of the Lead Refinery site and adjacent properties on the NPL. Lead Refinery lacks the financial resources needed to undertake any investigations or remedial action that may be required by the EPA pursuant to CERCLA.
	Operating Properties
	Mueller Copper Tube Products, Inc.
	In 1999, Mueller Copper Tube Products, Inc. (MCTP), a wholly owned subsidiary, commenced a cleanup and remediation of soil and groundwater at its Wynne, Arkansas plant. MCTP is currently removing trichloroethylene, a cleaning solvent formerly used by MCTP, from the soil and groundwater. On August 30, 2000, MCTP received approval of its Final Comprehensive Investigation Report and Storm Water Drainage Investigation Report addressing the treatment of soils and groundwater from the Arkansas Department of Environmental Quality (ADEQ). The Company established a reserve for this project in connection with the acquisition of MCTP in 1998. Effective November 17, 2008, MCTP entered into a Settlement Agreement and Administrative Order by Consent to submit a Supplemental Investigation Work Plan (SIWP) and subsequent Final Remediation Work Plan for the site. By letter dated January 20, 2010, ADEQ approved the SIWP as submitted, with changes acceptable to the Company. On December 16, 2011, MCTP entered into an amended Administrative Order by Consent to prepare and implement a revised Remediation Work Plan regarding final remediation for the Site. Construction and installation of the remediation system is under way. The remediation system was activated in February 2014. Costs to implement the work plans, including associated general and administrative costs, are approximately $0.8 million to $1.3 million over the next ten years.
	United States Department of Commerce Antidumping Review
	On December 23, 2009, the DOC initiated an antidumping administrative review of the antidumping duty order covering circular welded non-alloy steel pipe and tube from Mexico for the November 1, 2008 through October 31, 2009 period of review. The DOC selected Mueller Comercial as a respondent in the review. On June 21, 2011, the DOC published the final results of the review and assigned Mueller Comercial an antidumping duty rate of 19.8 percent. On August 22, 2011, the Company appealed the final results to the CIT. On December 21, 2012, the CIT issued a decision upholding the Department’s final results in part. The CIT issued its final judgment on May 2, 2013. On May 6, 2013, the Company appealed the CIT decision to the U.S. Court of Appeals for the Federal Circuit (Federal Circuit). On May 29, 2014, the Federal Circuit issued its decision vacating the CIT’s decision and remanding the case back to DOC to reconsider the Company’s rate. The Company and the United States have reached an agreement to settle the appeal. The Company anticipates that certain of its subsidiaries will incur antidumping duties on subject imports made during the period of review and, as such, established a reserve of approximately $1.1 million for this matter.
	Subsequent to October 31, 2009, Mueller Comercial did not ship subject merchandise to the United States. Therefore, there is zero antidumping duty liability for periods of review after October 31, 2009.
	Leases
	The Company leases certain facilities, vehicles, and equipment under operating leases expiring on various dates through 2019. The lease payments under these agreements aggregate to approximately $6.2 million in 2015, $3.9 million in 2016, $2.6 million in 2017, $2.1 million in 2018, and $0.4 million in 2019. Total lease expense amounted to $9.8 million in 2014, $9.1 million in 2013, and $8.5 million in 2012.
	Consulting Agreement
	During 2004, the Company entered into a consulting and non-compete agreement (the Consulting Agreement) with Mr. Harvey L. Karp, at that time Chairman of the Board. The Consulting Agreement provides for post-employment services to be provided by Mr. Karp for a six-year period. During the first four years of the Consulting Agreement, an annual fee equal to two-thirds of the executive’s Final Base Compensation (as defined in the Consulting Agreement) is payable. During the final two years, the annual fee is set at one-third of the executive’s Final Base Compensation. During the term of the Consulting Agreement, Mr. Karp agrees not to engage in Competitive Activity (as defined in the Consulting Agreement) and is entitled to receive certain other benefits from the Company.
	On November 3, 2011, Mr. Karp notified the Company that he would resign as Chairman of the Company and as a member of the Board of Directors of the Company effective as of December 31, 2011. Following his resignation, on January 1, 2012, the Consulting Agreement commenced. Based upon the value of the non-compete provisions of the Consulting Agreement, the Company expenses the value of the Consulting Agreement over its term. The maximum amount payable under the remaining term of the Consulting Agreement is $2.7 million.
	Other
	In July 2009, there was an explosion at the Company’s copper tube facility in Fulton, Mississippi, resulting in damage to certain production equipment. In 2010, the Company recorded a gain of $1.5 million related to the property damage claim. In 2012, the Company settled the business interruption portion of this claim and recognized a $1.5 million gain.
	In September 2011, a portion of the Company’s Wynne, Arkansas manufacturing operation was damaged by fire. Certain inventories, production equipment, and building structures were extensively damaged. During 2013, the Company settled the claim with its insurer for total proceeds of $127.3 million, net of the deductible of $0.5 million. As a result of the settlement with its insurer, all proceeds received and all costs previously deferred (which were recorded as other current liabilities in prior periods) were recognized, resulting in a pre-tax gain of $106.3 million in 2013, or $1.17 per diluted share after tax. The Company received proceeds of $62.3 million and $55.0 million in 2013 and 2012, respectively.
	In October 2012, the Company settled a lawsuit against a former supplier. In connection with the settlement, the Company received a $5.8 million cash payment which is recorded in the Consolidated Statement of Income net of legal costs.
	Additionally, the Company is involved in certain litigation as a result of claims that arose in the ordinary course of business, which management believes will not have a material adverse effect on the Company’s financial position, results of operations, or cash flows. It may also realize the benefit of certain legal claims and litigation in the future; these gain contingencies are not recognized in the Consolidated Financial Statements.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 27, 2014
Income Taxes [Abstract]
Income Taxes	Note 9 – Income Taxes
	The components of income before income taxes were taxed under the following jurisdictions:
	(In thousands)	2014			2013			2012
	Domestic	$	135,445		$	262,220		$	105,945
	Foreign		12,568			9,178			14,409
	Income before income taxes	$	148,013		$	271,398		$	120,354
	Income tax expense consists of the following:
	(In thousands)	2014			2013			2012
	Current tax expense:
	Federal	$	45,723		$	69,565		$	33,152
	Foreign		2,346			2,608			1,764
	State and local		3,905			6,723			3,049
	Current tax expense		51,974			78,896			37,965
	Deferred tax (benefit) expense:
	Federal		(2,469	)		17,694			570
	Foreign		890			(376	)		(2,015	)
	State and local		(4,916	)		1,895			161
	Deferred tax (benefit) expense		(6,495	)		19,213			(1,284	)
	Income tax expense	$	45,479		$	98,109		$	36,681
	No provision is made for U.S. income taxes applicable to undistributed earnings of foreign subsidiaries that are indefinitely reinvested in foreign operations. It is not practicable to compute the potential deferred tax liability associated with these undistributed foreign earnings. The Company has approximately $75.0 million of undistributed foreign earnings for which it has not recorded deferred tax liabilities.
	The difference between the reported income tax expense and a tax determined by applying the applicable U.S. federal statutory income tax rate to income before income taxes is reconciled as follows:
	(In thousands)	2014			2013			2012
	Expected income tax expense	$	51,805		$	94,989		$	42,124
	State and local income tax, net of federal benefit		3,355			6,405			3,178
	Effect of foreign statutory rate different from U.S. and other foreign adjustments		(1,094	)		(1,026	)		(2,637	)
	Valuation allowance changes		(5,732	)		—			(1,224	)
	U.S. production activities deduction		(4,025	)		(4,445	)		(2,975	)
	Goodwill disposition		—			1,790			—
	Tax contingency changes		—			(140	)		(3,224	)
	Other, net		1,170			536			1,439
	Income tax expense	$	45,479		$	98,109		$	36,681
	During 2014, the Company released a valuation allowance of $5.7 million, or ten cents per diluted share, related to certain state income tax credits. As a result of legislative changes enacted in 2014, the Company now expects to be able to use such credits within the foreseeable future. During 2012, the Company released a valuation allowance of $1.2 million, or two cents per diluted share, due to the expectation that certain state tax attributes would be utilized.
	The following summarizes the activity related to the Company’s unrecognized tax benefits:
	(In thousands)	2014			2013
	Beginning balance	$	2,828		$	3,259
	Increases related to prior year tax positions		—			—
	Increases related to current year tax positions		—			—
	Decreases related to prior year tax positions		(2,828	)		—
	Decreases related to settlements with taxing authorities		—			(431	)
	Decreases due to lapses in the statute of limitations		—			—
	Ending balance	$	—		$	2,828
	The $2.8 million reduction of unrecognized tax benefits in 2014 had no impact on the effective tax rate. The Company includes interest and penalties related to income tax matters as a component of income tax expense. The net reduction to income tax expense related to penalties and interest was immaterial in 2014, 2013, and 2012.
	The Internal Revenue Service completed its audit of the Company’s 2012 tax return during 2014, the result of which was immaterial to the Consolidated Financial Statements. The Company is currently under audit in various other jurisdictions.
	The statute of limitations is still open for the Company’s federal tax return and most state income tax returns for 2011 and all subsequent years. The statutes of limitations for certain state and foreign returns are also open for some earlier tax years due to differing statute periods. While the Company believes that it is adequately reserved for possible audit adjustments, the final resolution of these examinations cannot be determined with certainty and could result in final settlements that differ from current estimates.
	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are presented below:
	(In thousands)	2014			2013
	Deferred tax assets:
	Inventories	$	12,815		$	11,136
	Other postretirement benefits and accrued items		14,550			13,548
	Pension		4,792			—
	Other reserves		10,262			12,931
	Federal and foreign tax attributes		6,451			5,913
	State tax attributes, net of federal benefit		22,928			24,663
	Share-based compensation		3,016			2,486
	Total deferred tax assets		74,814			70,677
	Less valuation allowance		(17,119	)		(22,544	)
	Deferred tax assets, net of valuation allowance		57,695			48,133
	Deferred tax liabilities:
	Property, plant, and equipment		57,089			60,425
	Pension		—			4,507
	Other		1,721			2,209
	Total deferred tax liabilities		58,810			67,141
	Net deferred tax liability	$	(1,115	)	$	(19,008	)
	As of December 27, 2014, after consideration of the federal impact, the Company had state income tax credit carryforwards of $4.1 million, all of which expire by 2017, and other state income tax credit carryforwards of $11.1 million with unlimited lives. The Company had state net operating loss (NOL) carryforwards with potential tax benefits of $7.8 million expiring between 2017 and 2029. The state tax credit and NOL carryforwards are offset by valuation allowances totaling $11.8 million.
As of December 27, 2014, the Company had federal and foreign tax attributes with potential tax benefits of $6.4 million, of which $4.5 million has an unlimited life and $1.9 million expire from 2015 to 2019. These attributes were offset by valuation allowances of $3.4 million.
The change in the valuation allowance was primarily related to the release of the $5.7 million valuation allowance related to the state income tax credits as a result of 2014 legislative changes. The remainder of the change had no material impact on the effective tax rate.
Income taxes paid were approximately $47.3 million in 2014, $80.1 million in 2013, and $38.4 million in 2012.

Equity

Equity	12 Months Ended
	Dec. 27, 2014
Equity [Abstract]
Equity	Note 10 – Equity
	The Company’s Board of Directors has extended, until October 2015, its authorization to repurchase up to 20 million shares of the Company’s common stock through open market transactions or through privately negotiated transactions. The Company has no obligation to purchase any shares and may cancel, suspend, or extend the time period for the purchase of shares at any time. Any purchases will be funded primarily through existing cash and cash from operations. The Company may hold any shares purchased in treasury or use a portion of the repurchased shares for its stock-based compensation plans, as well as for other corporate purposes. From its initial authorization in 1999 through December 27, 2014, the Company had repurchased approximately 4.7 million shares under this authorization.
	The Company entered into an agreement with Leucadia National Corporation (Leucadia) pursuant to which the Company repurchased from Leucadia 20.8 million shares of the Company’s common stock on September 24, 2012 at a total cost of $427.3 million. The Company’s repurchase transaction with Leucadia was completed outside of the repurchase authorization previously approved by the Board of Directors.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 27, 2014
Stock-Based Compensation [Abstract]
Stock-Based Compensation	Note 11 – 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. Under these existing plans, the Company may grant options to purchase shares of common stock at prices not less than the fair market value of the stock on the date of grant, as well as restricted stock awards. Generally, the awards vest annually over a five-year period beginning one year from the date of grant. Any unexercised options expire after not more than ten years.
	In May 2014, the Company’s stockholders approved the 2014 Incentive Plan (2014 Plan). The 2014 Plan authorizes the award of stock-based incentives to employees and non-employee directors. Awards include options to purchase stock at specified prices during specified time periods, restricted stock, restricted stock units, stock appreciation rights, and performance awards, including cash awards. The 2014 Plan reserved 1.5 million shares of common stock which may be issued or transferred upon the exercise of options.
	During the years ended December 27, 2014, December 28, 2013, and December 29, 2012, the Company recognized stock-based compensation, as a component of selling, general, and administrative expense, in its Consolidated Statements of Income of $6.3 million, $5.7 million, and $4.0 million, respectively. The tax benefit from exercise of share-based awards was $0.8 million in 2014, $0.7 million in 2013, and $2.6 million in 2012.
	On October 26, 2012, the Company’s Chief Financial Officer (CFO) resigned. In connection with the resignation, on November 7, 2012, the Company entered into a separation agreement with its former CFO. Included in the separation agreement were provisions to allow (i) continued vesting of options to purchase shares of the Company’s common stock and unvested shares of restricted stock previously granted and (ii) continued exercisability of vested options through the later of the original expiration date or October 30, 2015 without regard to service. This modification to remove the service condition resulted in the recognition of $2.1 million of compensation cost on the modification date which is included in severance expense in the 2012 Consolidated Statement of Income.
	Stock Options
	The fair value of each option is estimated as a single award and amortized into compensation expense on a straight-line or accrual basis over its vesting period based on its vesting schedule. The weighted average grant-date fair value of options granted during 2014, 2013, and 2012 was $9.00, $8.77, and $7.45, respectively.
	The Company estimates the fair value of all stock option awards as of the grant date by applying the Black-Scholes-Merton option pricing model. The use of this valuation model in the determination of compensation expense involves certain assumptions that are judgmental and/or highly sensitive including the expected life of the option, stock price volatility, risk-free interest rate, and dividend yield. Additionally, forfeitures are estimated at the time of valuation and reduce expense ratably over the vesting period. The forfeiture rate, which is adjusted periodically based on actual forfeitures, was 16.4 percent in 2014 and 16.5 percent in 2012. Due to the nature of the awards granted in 2013, a forfeiture rate was not considered necessary. The weighted average of key assumptions used in determining the fair value of options granted and a discussion of the methodology used to develop each assumption are as follows:
		2014			2013		2012
	Expected term	5.6 years			5.9 years		6.5 years
	Expected price volatility		34.30%			39.70%		37.50%
	Risk-free interest rate		1.70%			0.70%		0.70%
	Dividend yield		1.00%			0.90%		0.90%
	Expected term – This is the period of time estimated based on historical experience over which the options granted are expected to remain outstanding. An increase in the expected term will increase compensation expense.
	Expected price volatility – This is a measure of the amount by which a price has fluctuated or is expected to fluctuate. The Company uses actual historical changes in the market value of its stock to calculate the volatility assumption. Daily market value changes from the date of grant over a past period representative of the expected term of the options are used. An increase in the expected price volatility rate will increase compensation expense.
	Risk-free interest rate – This is the U.S. Treasury rate for the week of the grant, having a term representative of the expected term of the options. An increase in the risk-free rate will increase compensation expense.
	Dividend yield – This rate is the annual dividends per share as a percentage of the Company’s stock price. An increase in the dividend yield will decrease compensation expense.
	The total intrinsic value of options exercised was $3.5 million, $2.9 million, and $12.1 million in 2014, 2013, and 2012, respectively. The total fair value of options that vested was $1.0 million, $1.1 million, and $1.7 million in 2014, 2013, and 2012, respectively.
	At December 27, 2014, the aggregate intrinsic value of all outstanding options was $18.2 million with a weighted average remaining contractual term of 5.1 years. Of the outstanding options, 795 thousand are currently exercisable with an aggregate intrinsic value of $15.1 million, a weighted average exercise price of $15.07, and a weighted average remaining contractual term of 4.0 years.
	The total compensation expense not yet recognized related to unvested options at December 27, 2014 was $1.4 million with an average expense recognition period of 3.0 years.
	Restricted Stock Awards
	The fair value of each restricted stock award equals the fair value of the Company’s stock on the grant date and is amortized into compensation expense on a straight-line or accrual basis over its vesting period based on its vesting schedule. The weighted average grant-date fair value of awards granted during 2014, 2013, and 2012 was $28.80, $28.32, and $21.42, respectively.
	The aggregate intrinsic value of outstanding and unvested awards was $24.7 million at December 27, 2014. Total compensation expense for restricted stock awards not yet recognized was $13.3 million with an average expense recognition period of 3.6 years. The total fair value of awards that vested was $4.2 million, $1.8 million, and $1.7 million in 2014, 2013, and 2012, respectively.
	The Company generally issues treasury shares when options are exercised or restricted stock awards are granted. A summary of the activity and related information follows:
		Stock Options					Restricted Stock Awards
	(Shares in thousands)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Grant Date Fair Value
	Outstanding at December 28, 2013		1,177		$	14.67		732		$	21.75
	Granted		202			28.79		197			28.8
	Exercised		(231	)		13.2		(200	)		21
	Forfeited		(21	)		21.22		(2	)		28.28
	Outstanding at December 27, 2014		1,127			17.38		727			25.21
	Approximately 1.6 million shares were available for future stock incentive awards at December 27, 2014.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 27, 2014
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 12 – Accumulated Other Comprehensive Income (Loss)
	AOCI includes certain foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency, net deferred gains and losses on certain derivative instruments accounted for as cash flow hedges, adjustments to pension and OPEB liabilities, and unrealized gains and losses on marketable securities classified as available-for-sale.
	The following table provides changes in AOCI by component, net of taxes and noncontrolling interest (amounts in parentheses indicate debits to AOCI):
	(In thousands)	Cumulative Translation Adjustment			Unrealized (Losses)/ Gains on Derivatives			Minimum Pension/OPEB Liability Adjustment				Unrealized Gains on Equity Investments		Total
	Balance at December 29, 2012	$	(3,032	)	$	(167	)	$	(39,527	)		$	103	$	(42,623	)
	Other comprehensive income (loss) before reclassifications		2,570			(2,102	)		24,851				152		25,471
	Amounts reclassified from AOCI		—			3,815			2,518				—		6,333
	Balance at December 28, 2013		(462	)		1,546			(12,158	)			255		(10,819	)
	Other comprehensive income (loss) before reclassifications		(12,613	)		(2,766	)		(23,475	)			15		(38,839	)
	Amounts reclassified from AOCI		5,999			267			469				—		6,735
	Balance at December 27, 2014	$	(7,076	)	$	(953	)	$	(35,164	)		$	270	$	(42,923	)
	Reclassification adjustments out of AOCI were as follows:
			Amount reclassified from AOCI
	(In thousands)		2014			2013			2012		Affected Line Item
	Unrealized losses on derivatives:
	Commodity contracts	$	328		$	5,618		$	763		Cost of goods sold
	Foreign currency contracts		—			54			—		Depreciation expense
			(61	)		(1,857	)		(294	)	Income tax expense
			267			3,815			469		Net of tax
			—			—			—		Noncontrolling interest
		$	267		$	3,815		$	469		Net of tax and noncontrolling interest
	Amortization of net loss and prior service cost on employee benefit plans	$	541		$	3,844		$	3,809		Selling, general, and administrative expense
			(72	)		(1,326	)		(1,308	)	Income tax expense
			469			2,518			2,501		Net of tax
			—			—			—		Noncontrolling interest
		$	469		$	2,518		$	2,501		Net of tax and noncontrolling interest
	Loss recognized upon sale of business	$	5,999		$	—		$	—		Gain on sale of assets
			—			—			—		Income tax benefit
			5,999			—			—		Net of tax
			—			—			—		Noncontrolling interest
		$	5,999		$	—		$	—		Net of tax and noncontrolling interest

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 27, 2014
Benefit Plans [Abstract]
Benefit Plans	Note 13 – Benefit Plans
	Pension and Other Postretirement Plans
	The Company sponsors several qualified and nonqualified pension plans and other postretirement benefit plans for certain employees. The following tables provide a reconciliation of the changes in the plans’ benefit obligations and the fair value of the plans’ assets for 2014 and 2013, and a statement of the plans’ aggregate funded status:
			Pension Benefits						Other Benefits
	(In thousands)		2014			2013			2014			2013
	Change in benefit obligation:
	Obligation at beginning of year		$	184,058		$	196,167		$	15,381		$	18,096
	Service cost			973			948			348			413
	Interest cost			8,590			7,774			685			647
	Actuarial loss (gain)			30,138			(11,635	)		4,272			(2,554	)
	Benefit payments			(11,064	)		(10,668	)		(1,142	)		(1,211	)
	Foreign currency translation adjustment			(4,957	)		1,472			(237	)		(10	)
	Obligation at end of year			207,738			184,058			19,307			15,381
	Change in fair value of plan assets:
	Fair value of plan assets at beginning of year			188,870			160,980			—			—
	Actual return on plan assets			12,716			35,578			—			—
	Employer contributions			3,275			1,551			1,142			1,211
	Benefit payments			(11,064	)		(10,668	)		(1,142	)		(1,211	)
	Foreign currency translation adjustment			(3,781	)		1,429			—			—
	Fair value of plan assets at end of year			190,016			188,870			—			—
	(Underfunded) funded status at end of year		$	(17,722	)	$	4,812		$	(19,307	)	$	(15,381	)
	The following represents amounts recognized in AOCI (before the effect of income taxes):
			Pension Benefits						Other Benefits
	(In thousands)		2014			2013			2014			2013
	Unrecognized net actuarial loss (gain)		$	49,830		$	21,128		$	473		$	(4,016	)
	Unrecognized prior service cost			—			1			14			20
	The Company sponsors one pension plan in the U.K. which comprised 40 percent of the above benefit obligation at December 27, 2014 and December 28, 2013, and 34 percent of the above plan assets at December 27, 2014 and December 28, 2013, respectively.
	As of December 27, 2014, $2.9 million of the actuarial net loss will, through amortization, be recognized as components of net periodic benefit cost in 2015.
	The aggregate status of all overfunded plans is recognized as an asset and the aggregate status of all underfunded plans is recognized as a liability in the Consolidated Balance Sheets. The amounts recognized as a liability are classified as current or long-term on a plan-by-plan basis. Liabilities are classified as current to the extent the actuarial present value of benefits payable within the next 12 months exceeds the fair value of plan assets, with all remaining amounts being classified as long-term. As of December 27, 2014 and December 28, 2013, the total funded status of the plans recognized in the Consolidated Balance Sheets was as follows:
			Pension Benefits						Other Benefits
	(In thousands)		2014			2013			2014			2013
	Long-term asset		$	2,348		$	15,457		$	—		$	—
	Current liability			—			—			(1,251	)		(1,033	)
	Long-term liability			(20,070	)		(10,645	)		(18,056	)		(14,348	)
	Total (underfunded) funded status		$	(17,722	)	$	4,812		$	(19,307	)	$	(15,381	)
	The components of net periodic benefit cost are as follows:
	(In thousands)		2014			2013			2012
	Pension benefits:
	Service cost		$	973		$	948		$	884
	Interest cost			8,590			7,774			8,472
	Expected return on plan assets			(13,669	)		(11,059	)		(10,263	)
	Amortization of prior service cost			1			1			1
	Amortization of net loss			752			4,005			3,883
	Net periodic benefit (income) cost		$	(3,353	)	$	1,669		$	2,977
	Other benefits:
	Service cost		$	348		$	413		$	380
	Interest cost			685			647			635
	Amortization of prior service cost (credit)			6			(2	)		(2	)
	Amortization of net gain			(218	)		(160	)		(73	)
	Net periodic benefit cost		$	821		$	898		$	940
	The weighted average assumptions used in the measurement of the Company’s benefit obligations are as follows:
			Pension Benefits						Other Benefits
			2014			2013			2014			2013
	Discount rate			4.03	%		4.82	%		4.33	%		4.89	%
	Expected long-term return on plan assets			5.58	%		7.4	%		N/A			N/A
	Rate of compensation increases			N/A			N/A			5	%		5.5	%
	Rate of inflation			3.1	%		3.4	%		N/A			N/A
	The weighted average assumptions used in the measurement of the Company’s net periodic benefit cost are as follows:
			Pension Benefits									Other Benefits
			2014			2013			2012			2014			2013			2012
	Discount rate			4.82	%		4.13	%		4.8	%		4.89	%		4.06	%		4.97	%
	Expected long-term return on plan assets			7.4	%		7.15	%		7.11	%		N/A			N/A			N/A
	Rate of compensation increases			N/A			N/A			N/A			5.5	%		5.04	%		5.04	%
	Rate of inflation			3.4	%		2.7	%		3	%		N/A			N/A			N/A
The Company’s Mexican postretirement plans use the rate of compensation increase in the benefit formulas. Past service on the U.K. pension plan will be adjusted for the effects of inflation. All other pension and postretirement plans use benefit formulas based on length of service.
The annual assumed rate of increase in the per capita cost of covered benefits (i.e., health care cost trend rate) is assumed to range from 7.0 to 9.0 percent for 2015, gradually decrease to 4.5 percent through 2022, and remain at that level thereafter. The health care cost trend rate assumption could have a significant effect on the amounts reported. For example, increasing the assumed health care cost trend rates by one percentage point would increase the accumulated postretirement benefit obligation by $2.0 million and the service and interest cost components of net periodic postretirement benefit costs by $0.1 million for 2015. Decreasing the assumed health care cost trend rates by one percentage point in each year would decrease the accumulated postretirement benefit obligation and the service and interest cost components of net periodic postretirement benefit costs for 2015 by $1.7 million and $0.1 million, respectively.
Pension Assets
The weighted average asset allocation of the Company’s pension fund assets are as follows:
		Pension Plan Assets
Asset category		2014			2013
Equity securities (includes equity mutual funds)			49	%		86	%
Fixed income securities (includes fixed income mutual funds)			4			4
Cash and equivalents (includes money market funds)			44			7
Alternative investments			3			3
Total			100	%		100	%
At December 27, 2014, the long-term target allocation, by asset category, of assets of its defined benefit pension plans was: (i) fixed income securities - at least 60 percent; (ii) equity securities, including equity index funds - not more than 30 percent; and (iii) alternative investments - not more than 5 percent.
The pension plan obligations are long-term and, accordingly, the plan assets are invested for the long-term. Plan assets are monitored periodically. Based upon results, investment managers and/or asset classes are redeployed when considered necessary. None of the plans’ assets are expected to be returned to the Company during the next fiscal year. The assets of the plans do not include investments in securities issued by the Company.
The estimated rates of return on plan assets are the expected future long-term rates of earnings on plan assets and are forward-looking assumptions that materially affect pension cost. Establishing the expected future rates of return on pension assets is a judgmental matter. The Company reviews the expected long-term rates of return on an annual basis and revises as appropriate. The expected long-term rate of return on plan assets was 5.58 percent for 2014 and 7.40 percent in 2013. For 2014, the Company lowered its expected return assumption, as it refined its asset and liability management strategy. In lowering this assumption, management considered the historical returns, investment strategy, and target composition of each plan’s portfolio.
The Company’s investments for its pension plans are reported at fair value. The following methods and assumptions were used to estimate the fair value of the Company’s plan asset investments:
Cash and money market funds – Valued at cost, which approximates fair value.
Common stock – Valued at the closing price reported on the active market on which the individual securities are traded.
Mutual funds – Valued at the net asset value of shares held by the plans at December 27, 2014 and December 28, 2013, respectively, based upon quoted market prices.
Limited partnerships – Limited partnerships include investments in various Cayman Island multi-strategy hedge funds. The plans’ investments in limited partnerships are valued at the estimated fair value of the class shares owned by the plans based upon the equity in the estimated fair value of those shares. The estimated fair values of the limited partnerships are determined by the investment managers. In determining fair value, the investment managers of the limited partnerships utilize the estimated net asset valuations of the underlying investment entities. The underlying investment entities value securities and other financial instruments on a mark-to-market or estimated fair value basis. The estimated fair value is determined by the investment managers based upon, among other things, the type of investments, purchase price, marketability, current financial condition, operating results, and other information. The estimated fair values of substantially all of the investments of the underlying investment entities, which may include securities for which prices are not readily available, are determined by the investment managers or management of the respective underlying investment entities and may not reflect amounts that could be realized upon immediate sale. Accordingly, the estimated fair values may differ significantly from the values that would have been used had a ready market existed for these investments.
The following table sets forth by level, within the fair value hierarchy, the assets of the plans at fair value:
		Fair Value Measurements at December 27, 2014
(In thousands)		Level 1			Level 2			Level 3			Total
Cash and money market funds		$	84,377		$	—		$	—		$	84,377
Common stock (1)			26,105			—			—			26,105
Mutual funds (2)			11,397			63,067			—			74,464
Limited partnerships			—			—			5,070			5,070
Total		$	121,879		$	63,067		$	5,070		$	190,016
		Fair Value Measurements at December 28, 2013
(In thousands)		Level 1			Level 2			Level 3			Total
Cash and money market funds		$	13,992		$	—		$	—		$	13,992
Common stock (3)			79,497			—			—			79,497
Mutual funds (4)			27,166			63,435			—			90,601
Limited partnerships			—			—			4,780			4,780
Total		$	120,655		$	63,435		$	4,780		$	188,870
-1	Approximately 51 percent of common stock represents investments in U.S. companies primarily in the health care, utilities, financials, consumer staples, industrials, and information technology sectors. All investments in common stock are listed on U.S. stock exchanges.
-2	Approximately 40 percent of mutual funds are actively managed funds and approximately 60 percent of mutual funds are index funds. Additionally, 23 percent of the mutual funds’ assets are invested in U.S. equities, 67 percent in non-U.S. equities, and 10 percent in non-U.S. fixed income securities.
-3	Approximately 84 percent of common stock represents investments in U.S. companies primarily in the health care, utilities, financials, consumer staples, industrials, and information technology sectors. All investments in common stock are listed on U.S. stock exchanges.
-4	Approximately 32 percent of mutual funds are actively managed funds and approximately 68 percent of mutual funds are index funds. Additionally, 33 percent of the mutual funds’ assets are invested in U.S. equities, 58 percent in non-U.S. equities, and 9 percent in non-U.S. fixed income securities.
The table below reflects the changes in the assets of the plan measured at fair value on a recurring basis using significant unobservable inputs (Level 3 hierarchy as defined by ASC 820, Fair Value Measurements and Disclosures (ASC 820)) during the year ended December 27, 2014:
(In thousands)		Limited Partnerships
Balance, December 28, 2013		$	4,780
Redemptions			(401	)
Subscriptions			401
Net appreciation in fair value			290
Balance, December 27, 2014		$	5,070
Contributions and Benefit Payments
The Company expects to contribute approximately $1.5 million to its pension plans and $1.3 million to its other postretirement benefit plans in 2015. The Company expects future benefits to be paid from the plans as follows:
(In thousands)		Pension Benefits			Other Benefits
2015		$	11,303		$	1,251
2016			11,492			1,137
2017			11,671			1,133
2018			11,878			1,203
2019			12,116			1,171
2020-2024			64,358			6,488
Total		$	122,818		$	12,383
Multiemployer Plan
The Company contributes to the IAM National Pension Fund, National Pension Plan (IAM Plan), a multiemployer defined benefit plan. Participation in the IAM Plan was negotiated under the terms of two collective bargaining agreements in Port Huron, Michigan, the Local 218 IAM and Local 44 UAW that expire on May 1, 2016 and July 20, 2016, respectively. The Employer Identification Number for this plan is 51-6031295.
The risks of participating in multiemployer plans are different from single-employer plans in the following aspects: (i) Assets contributed to the multiemployer plan by one employer may be used to provide benefits to employees of other participating employers; (ii) if a participating employer stops contributing to the plan, the underfunded obligations of the plan may be borne by the remaining participating employers; (iii) if the Company chooses to stop participating in the plan, the Company may be required to pay the plan an amount based on the underfunded status of the plan, referred to as a withdrawal liability.
The Company makes contributions to the IAM Plan trusts that cover certain union employees; contributions by employees are not permitted. Contributions to the IAM Plan were $1.0 million in 2014, $0.9 million in 2013, and $1.0 million in 2012. The Company’s contributions are less than five percent of total employer contributions made to the IAM Plan indicated in the most recently filed Form 5500.
Under the Pension Protection Act of 2006, the IAM Plan’s actuary must certify the plan’s zone status annually. Plans in the red zone are generally less than 65 percent funded, plans in the yellow zone are less than 80 percent funded, and plans in the green zone are at least 80 percent funded. If a plan is determined to be in endangered status, red zone or yellow zone, the plan’s trustees must develop a formal plan of corrective action, a Financial Improvement Plan and/or a Rehabilitation Plan. For 2014 and 2013 the IAM Plan was determined to have green zone status; therefore, no formal plan of corrective action is either pending or has been implemented.
401(k) Plans
The Company sponsors voluntary employee savings plans that qualify under Section 401(k) of the Internal Revenue Code of 1986. Compensation expense for the Company’s matching contribution to the 401(k) plans was $4.1 million in 2014, $3.2 million in 2013, and $2.9 million in 2012. The Company match is a cash contribution. Participants direct the investment of their account balances by allocating among a range of asset classes including mutual funds (equity, fixed income, and balanced funds), and money market funds. The plans do not allow direct investment in securities issued by the Company.
UMWA Benefit Plans
In October 1992, the Coal Industry Retiree Health Benefit Act of 1992 (the Act) was enacted. The Act mandates a method of providing for postretirement benefits to the United Mine Workers of America (UMWA) current and retired employees, including some retirees who were never employed by the Company. In October 1993, beneficiaries were assigned to the Company and the Company began its mandated contributions to the UMWA Combined Benefit Fund, a multiemployer trust. Beginning in 1994, the Company was required to make contributions for assigned beneficiaries under an additional multiemployer trust created by the Act, the UMWA 1992 Benefit Plan. The ultimate amount of the Company’s liability under the Act will vary due to factors which include, among other things, the validity, interpretation, and regulation of the Act, its joint and several obligation, the number of valid beneficiaries assigned, and the extent to which funding for this obligation will be satisfied by transfers of excess assets from the 1950 UMWA pension plan and transfers from the Abandoned Mine Reclamation Fund. Contributions to the plan were $249 thousand, $290 thousand, and $315 thousand for the years ended December 27, 2014, December 28, 2013, and December 29, 2012, respectively.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 27, 2014
Derivative Instruments and Hedging Activities [Abstract]
Derivative Instruments and Hedging Activities	Note 14 – Derivative Instruments and Hedging Activities
	The Company’s earnings and cash flows are subject to fluctuations due to changes in commodity prices, foreign currency exchange rates, and interest rates. The Company uses derivative instruments such as commodity futures contracts, foreign currency forward contracts, and interest rate swaps to manage these exposures.
	Commodity Futures Contracts
	Copper and brass represent the largest component of the Company’s variable costs of production. The cost of these materials is subject to global market fluctuations caused by factors beyond the Company’s control. The Company occasionally enters into forward fixed-price arrangements with certain customers; the risk of these arrangements is generally managed with commodity futures contracts. These futures contracts have been designated as cash flow hedges.
	At December 27, 2014, the Company held open futures contracts to purchase approximately $23.7 million of copper over the next 12 months related to fixed price sales orders. The fair value of those futures contracts was an $809 thousand loss position, which was determined by obtaining quoted market prices (Level 1 hierarchy as defined by ASC 820). In the next twelve months, the Company will reclassify into earnings realized gains or losses relating to cash flow hedges. At December 27, 2014, this amount was approximately $538 thousand of deferred net losses, net of tax.
	The Company may also enter into futures contracts to protect the value of inventory against market fluctuations. These futures contracts have been designated as fair value hedges.
	At December 27, 2014, the Company held open futures contracts to sell approximately $1.6 million of copper over the next three months related to copper inventory. The fair value of those futures contracts was an $87 thousand gain position, which was determined by obtaining quoted market prices (Level 1 hierarchy as defined by ASC 820). During the fourth quarter of 2013, the Company dedesignated previous hedges on its inventory because the hedging relationship was no longer deemed to be highly effective. These contracts no longer qualified as hedging instruments as of December 28, 2013.
	Foreign Currency Forward Contracts
	During 2012 and 2013, the Company entered into certain contracts to purchase heavy machinery and equipment denominated in euros. In anticipation of entering into these contracts, the Company entered into forward contracts to purchase euros to protect against adverse foreign exchange rate fluctuations.
	At December 27, 2014, the Company held open forward contracts to purchase approximately 1.5 million euros over the next three months. The fair value of these contracts, which was determined by obtaining quoted market prices (Level 1 hierarchy as defined by ASC 820), was an $81 thousand loss position recorded in other current liabilities at December 27, 2014, and an $836 thousand gain position recorded in other current assets at December 28, 2013. At December 27, 2014, there was $157 thousand of deferred gains, net of tax, included in AOCI that is expected to be reclassified into depreciation expense over the useful life of the heavy machinery and equipment.
	Interest Rate Swap
	On February 20, 2013, the Company entered into a two-year forward-starting interest rate swap agreement with an effective date of January 12, 2015, and an underlying notional amount of $200.0 million, pursuant to which the Company receives variable interest payments based on one-month LIBOR and pays fixed interest at a rate of 1.4 percent. Based on the Company’s current variable premium pricing on its Term Loan Facility, the all-in fixed rate on the effective date is 2.7 percent. The interest rate swap will mature on December 11, 2017, and is structured to offset the interest rate risk associated with the Company’s floating-rate, LIBOR-based Term Loan Facility Agreement. The swap was designated and accounted for as a cash flow hedge from inception.
	The fair value of the interest rate swap is estimated based on the present value of the difference between expected cash flows calculated at the contracted interest rate and the expected cash flows at the current market interest rate using observable benchmarks for LIBOR forward rates at the end of the period (Level 2 hierarchy as defined by ASC 820). Interest payable and receivable under the swap agreement will be accrued and recorded as an adjustment to interest expense. The fair value of the interest rate swap was a $927 thousand loss position recorded in other liabilities at December 27, 2014, and a $1.3 million gain position recorded in other assets at December 28, 2013. At December 27, 2014, there was $601 thousand of deferred losses, net of tax, included in AOCI that is expected to be reclassified into interest expense over the term of the hedged item.
	The Company presents its derivative assets and liabilities in the Consolidated Balance Sheets on a net basis by counterparty. The following table summarizes the location and fair value of the derivative instruments and disaggregates the net derivative assets and liabilities into gross components on a contract-by-contract basis:
		Asset Derivatives									Liability Derivatives
				Fair Value								Fair Value
	(In thousands)	Balance Sheet Location		2014				2013			Balance Sheet Location	2014			2013
	Hedging instrument:
	Commodity contracts - gains	Other current assets		$	99			$	448		Other current liabilities	$	15		$	340
	Commodity contracts - losses	Other current assets			(4	)			(10	)	Other current liabilities		(832	)		(2,107	)
	Foreign currency contracts	Other current assets			—				836		Other current liabilities		(81	)		—
	Interest rate swap	Other assets			—				1,324		Other liabilities		(927	)		—
	Total derivatives (1)			$	95			$	2,598			$	(1,825	)	$	(1,767	)
	(1) Does not include the impact of cash collateral provided to counterparties.
	The following tables summarize the effects of derivative instruments on the Consolidated Statements of Income:
	(In thousands)	Location		2014				2013
	Fair value hedges:
	Gain on commodity contracts (qualifying)	Cost of goods sold		$	6,783			$	5,115
	Loss on hedged item - Inventory	Cost of goods sold			(5,958	)			(4,827	)
	Undesignated derivatives:
	Gain (loss) on commodity contracts (nonqualifying)	Cost of goods sold		$	1,466			$	(611	)
	The following tables summarize amounts recognized in and reclassified from AOCI during the period:
			Year Ended December 27, 2014
	(In thousands)		(Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax				Classification Gains (Losses)			Loss (Gain) Reclassified from AOCI (Effective Portion), Net of Tax
	Cash flow hedges:
	Commodity contracts		$	(1,088	)		Cost of goods sold		$	267
	Foreign currency contracts			(275	)		Depreciation expense			—
	Interest rate swap			(1,435	)		Interest expense			—
			Year Ended December 28, 2013
	(In thousands)		(Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax				Classification Gains (Losses)			Loss (Gain) Reclassified from AOCI (Effective Portion), Net of Tax
	Cash flow hedges:
	Commodity contracts		$	(3,337	)		Cost of goods sold		$	3,781
	Foreign currency contracts			401			Depreciation expense			34
	Interest rate swap			834			Interest expense			—
	The Company enters into futures and forward contracts that closely match the terms of the underlying transactions. As a result, the ineffective portion of the open hedge contracts through December 27, 2014 was not material to the Consolidated Statements of Income.
	The Company primarily enters into International Swaps and Derivatives Association (ISDA) master netting agreements with major financial institutions that permit the net settlement of amounts owed under their respective derivative contracts. Under these master netting agreements, net settlement generally permits the Company or the counterparty to determine the net amount payable for contracts due on the same date and in the same currency for similar types of derivative transactions. The master netting agreements generally also provide for net settlement of all outstanding contracts with a counterparty in the case of an event of default or a termination event. The Company does not offset fair value amounts for derivative instruments and fair value amounts recognized for the right to reclaim cash collateral. At December 27, 2014 and December 28, 2013, the Company had recorded restricted cash in other current assets of $0.5 million and $2.1 million, respectively, as collateral related to open derivative contracts under the master netting arrangements.

Industry_Segments

Industry Segments	12 Months Ended
	Dec. 27, 2014
Industry Segments [Abstract]
Industry Segments	Note 15 – Industry Segments
	The Company’s reportable segments are Plumbing & Refrigeration and OEM. For disclosure purposes, as permitted under ASC 280, Segment Reporting, certain operating segments are aggregated into reportable segments. The Plumbing & Refrigeration segment is composed of Standard Products (SPD), European Operations, and Mexican Operations. The OEM segment is composed of Industrial Products (IPD), Engineered Products (EPD), and Mueller-Xingrong. These segments are classified primarily by the markets for their products. Performance of segments is generally evaluated by their operating income. Intersegment transactions are generally conducted on an arms-length basis.
	SPD manufactures copper tube and fittings, plastic fittings, and line sets. SPD also imports and resells brass and plastic plumbing valves, malleable iron fittings, faucets, and plumbing specialty products. These products are manufactured in the U.S. Outside the U.S., the Company’s European Operations manufacture copper tube, which is sold in Europe. Mexican Operations consist of pipe nipple manufacturing and import distribution businesses including product lines of malleable iron fittings and other plumbing specialties. The Plumbing & Refrigeration segment’s products are sold primarily to plumbing, refrigeration, and air-conditioning wholesalers, hardware wholesalers and co-ops, and building product retailers.
	IPD manufactures brass rod, impact extrusions, and forgings as well as a variety of end products including plumbing brass, automotive components, valves, and fittings. EPD manufactures and fabricates valves and assemblies for the refrigeration, air-conditioning, gas appliance, and barbecue grill markets and specialty copper, copper-alloy, and aluminum tube. Mueller-Xingrong manufactures engineered copper tube primarily for air-conditioning applications. These products are sold primarily to OEM customers.
	Summarized product line, geographic, and segment information is shown in the following tables. Geographic sales data indicates the location from which products are shipped. Unallocated expenses include general corporate expenses, plus certain charges or credits not included in segment activity.
	During 2014, 2013, and 2012, no single customer exceeded 10 percent of worldwide sales.
	Net Sales by Major Product Line:
	(In thousands)	2014				2013				2012
	Tube and fittings	$	1,143,164			$	972,107			$	986,825
	Brass rod and forgings		556,985				553,896				583,940
	OEM components, tube & assemblies		345,991				337,772				335,461
	Valves and plumbing specialties		262,504				239,822				231,278
	Other		55,583				54,944				52,434
		$	2,364,227			$	2,158,541			$	2,189,938
	Geographic Information:
	(In thousands)	2014				2013				2012
	Net sales:
	United States	$	1,752,548			$	1,676,385			$	1,696,589
	United Kingdom		326,832				229,659				234,684
	Other		284,847				252,497				258,665
		$	2,364,227			$	2,158,541			$	2,189,938
	(In thousands)	2014				2013				2012
	Long-lived assets:
	United States	$	322,178			$	325,667			$	306,023
	United Kingdom		43,064				22,159				23,496
	Other		21,641				25,224				27,442
		$	386,883			$	373,050			$	356,961
	Net assets of foreign operations at December 27, 2014 included $112.6 million in the United Kingdom, $50.4 million in Mexico, $45.7 million in Luxembourg, and $23.9 million in China.
	Segment Information:
		For the Year Ended December 27, 2014
	(In thousands)	Plumbing & Refrigeration Segment				OEM				Corporate and Eliminations			Total
						Segment
	Net sales	$	1,416,701			$	959,914			$	(12,388	)	$	2,364,227
	Cost of goods sold		1,215,282				840,823				(12,386	)		2,043,719
	Depreciation and amortization		19,613				11,919				2,203			33,735
	Selling, general, and administrative expense		87,539				21,458				22,743			131,740
	Gain on sale of assets		(6,259	)			—				—			(6,259	)
	Severance		7,296				—				—			7,296
	Operating income		93,230				85,714				(24,948	)		153,996
	Interest expense													(5,740	)
	Other expense, net													(243	)
	Income before income taxes												$	148,013
		For the Year Ended December 28, 2013
	(In thousands)	Plumbing & Refrigeration Segment				OEM				Corporate and Eliminations			Total
						Segment
	Net sales	$	1,225,306			$	947,784			$	(14,549	)	$	2,158,541
	Cost of goods sold		1,043,059				833,518				(14,488	)		1,862,089
	Depreciation and amortization		17,117				13,025				2,252			32,394
	Selling, general, and administrative expense		85,471				24,479				24,964			134,914
	Insurance settlement		(103,895	)			—				(2,437	)		(106,332	)
	Gain on sale of plastic fittings manufacturing assets		(39,765	)			—				—			(39,765	)
	Impairment charges		4,173				131				—			4,304
	Operating income		219,146				76,631				(24,840	)		270,937
	Interest expense													(3,990	)
	Other income, net													4,451
	Income before income taxes												$	271,398
		For the Year Ended December 29, 2012
	(In thousands)	Plumbing & Refrigeration Segment				OEM				Corporate and Eliminations			Total
						Segment
	Net sales	$	1,238,230			$	974,606			$	(22,898	)	$	2,189,938
	Cost of goods sold		1,060,755				866,404				(22,696	)		1,904,463
	Depreciation and amortization		16,513				13,435				1,547			31,495
	Selling, general, and administrative expense		75,448				27,680				26,328			129,456
	Litigation settlement		—				—				(4,050	)		(4,050	)
Insurance settlement		(1,500	)			—				—			(1,500	)
Severance		—				—				3,369			3,369
Operating income		87,014				67,087				(27,396	)		126,705
Interest expense													(6,890	)
Other expense, net													539
Income before income taxes												$	120,354
(In thousands)	2014			2013			2012
Expenditures for long-lived assets (including business acquisitions):
Plumbing & Refrigeration	$	55,098		$	47,222		$	24,030
OEM		10,788			14,845			24,137
General corporate		400			3,253			17,290
	$	66,286		$	65,320		$	65,457
Segment assets:
Plumbing & Refrigeration	$	664,784		$	625,371		$	531,429
OEM		313,245			305,052			290,058
General corporate		350,067			317,344			282,668
	$	1,328,096		$	1,247,767		$	1,104,155

Quarterly_Financial_Informatio

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 27, 2014
Quarterly Financial Information (Unaudited) [Abstract]
Quarterly Financial Information (Unaudited)	Note 16 – Quarterly Financial Information (Unaudited) (6)
		First		Second			Third			Fourth
	(In thousands, except per share data)	Quarter		Quarter			Quarter			Quarter
	2014
	Net sales	$	574,374	$	649,691		$	602,820		$	537,342
	Gross profit (1)		78,597		91,916			81,542			68,453
	Consolidated net income (5)		24,954		35,209			24,322			18,049	-2
	Net income attributable to Mueller Industries, Inc.		24,706		35,045			23,823			17,987
	Basic earnings per share		0.44		0.63			0.42			0.32
	Diluted earnings per share		0.44		0.62			0.42			0.32
	Dividends per share		0.075		0.075			0.075			0.075
	2013
	Net sales	$	559,690	$	582,282		$	528,854		$	487,715
	Gross profit (1)		76,840		81,157			72,552			65,903
	Consolidated net income		26,434		91,842	-3		39,993	-4		15,020
	Net income attributable to Mueller Industries, Inc.		26,202		91,150			39,864			15,384
	Basic earnings per share		0.47		1.64			0.71			0.28
	Diluted earnings per share		0.46		1.62			0.71			0.27
	Dividends per share		0.0625		0.0625			0.0625			0.0625
	(1) Gross profit is net sales less cost of goods sold, which excludes depreciation and amortization.
	(2) Includes $4.8 million pre-tax gain on sale of assets and $4.2 million of pre-tax charges related to severance.
	(3) Includes $106.3 million pre-tax gain from settlement of insurance claims.
	(4) Includes $39.8 million pre-tax gain on sale of manufacturing assets and pre-tax impairment charges of $4.3 million primarily
	related to real property associated with the aforementioned plastics sale transaction.
	(5) Includes income earned by Howell, acquired during Q4 2013, and losses incurred by Yorkshire, acquired during Q1 2014.
	(6) The sum of quarterly amounts may not equal the annual amounts reported due to rounding. In addition, the earnings per share amounts are computed independently for each quarter while the full year is based on the weighted average shares outstanding.

SCHEDULE_IIVALUATION_AND_QUALI

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 27, 2014
SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS [Abstract]
SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS	MUELLER INDUSTRIES, INC.
	SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS
	Years Ended December 27, 2014, December 28, 2013, and December 29, 2012
				Additions
		Balance at		Charged to								Balance
		beginning		costs and			Other					at end
	(In thousands)	of year		expenses			additions			Deductions		of year
	2014
	Allowance for doubtful accounts	$	2,391	$	(500	)	$	18	-1	$	1,243	$	666
	Environmental reserves	$	23,637	$	1,187		$	—		$	2,163	$	22,661
	Valuation allowance for deferred tax assets	$	22,544	$	(5,630	)	$	2,282		$	2,077	$	17,119
	2013
	Allowance for doubtful accounts	$	1,644	$	273		$	812	-1	$	338	$	2,391
	Environmental reserves	$	24,635	$	986		$	—		$	1,984	$	23,637
	Valuation allowance for deferred tax assets	$	30,394	$	332		$	—		$	8,182	$	22,544
	2012
	Allowance for doubtful accounts	$	1,564	$	867		$	109	-1	$	896	$	1,644
	Environmental reserves	$	22,892	$	3,056		$	—		$	1,313	$	24,635
	Valuation allowance for deferred tax assets	$	29,705	$	(1,224	)	$	1,913		$	—	$	30,394
	(1) Other consists primarily of bad debt recoveries as well as the effect of fluctuating foreign currency exchange rates in all years presented.

Summary_of_Significant_Account1

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.

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 27, 2014
Inventories [Abstract]
Inventories	(In thousands)	2014			2013
	Raw materials and supplies	$	53,586		$	54,613
	Work-in-process		39,707			43,796
	Finished goods		168,481			159,422
	Valuation reserves		(5,189	)		(6,115	)
	Inventories	$	256,585		$	251,716

Consolidated_Financial_Stateme1

Consolidated Financial Statement Details (Tables)	12 Months Ended
	Dec. 27, 2014
Consolidated Financial Statement Details [Abstract]
Other (Expense) Income, Net	Other (Expense) Income, Net
	(In thousands)	2014			2013			2012
	Gain on the sale of non-operating property	$	—		$	3,000		$	—
	Interest income		573			906			847
	Environmental expense, non-operating properties		(822	)		(823	)		(1,128	)
	Other		6			1,368			820
	Other (expense) income, net	$	(243	)	$	4,451		$	539

Property_Plant_and_Equipment_N1

Property, Plant, and Equipment, Net (Tables)	12 Months Ended
	Dec. 27, 2014
Property, Plant, and Equipment, Net [Abstract]
Property, Plant, and Equipment, Net	(In thousands)	2014			2013
	Land and land improvements	$	12,198		$	13,153
	Buildings		120,035			132,331
	Machinery and equipment		561,093			561,005
	Construction in progress		44,787			25,691
			738,113			732,180
	Less accumulated depreciation		(492,203	)		(487,723	)
	Property, plant, and equipment, net	$	245,910		$	244,457

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 27, 2014
Goodwill and Other Intangible Assets [Abstract]
Changes in the carrying amount of goodwill	The changes in the carrying amount of goodwill were as follows:
	(In thousands)		Plumbing & Refrigeration Segment			OEM Segment				Total
	Balance at December 29, 2012:
	Goodwill		$	141,684		$	12,300			$	153,984
	Accumulated impairment and amortization			(39,434	)		(9,971	)			(49,405	)
				102,250			2,329				104,579
	Additions			310			—				310
	Disposition			(10,532	)		—				(10,532	)
	Balance at December 28, 2013:
	Goodwill			131,462			12,300				143,762
	Accumulated impairment and amortization			(39,434	)		(9,971	)			(49,405	)
				92,028			2,329				94,357
	Additions(1)			9,123			—				9,123
	Currency translation			(571	)		—				(571	)
	Balance at December 27, 2014:
	Goodwill			140,014			12,300				152,314
	Accumulated impairment and amortization			(39,434	)		(9,971	)			(49,405	)
	Goodwill, net		$	100,580		$	2,329			$	102,909
	(1)Includes finalization of the purchase price allocation adjustment for Howell of $1.0 million
Carrying amount of intangible assets	The carrying amount of intangible assets at December 27, 2014 was as follows:
	(In thousands)	Estimated Useful Life		Gross Carrying Amount			Accumulated Amortization				Net Carrying Amount
	Customer relationships	20 years		$	11,852		$	(526	)		$	11,326
	Non-compete agreements	3-5 years			4,495			(1,307	)			3,188
	Patents and technology	10 years			6,852			(4,744	)			2,108
	Trade names and licenses	3 years			1,670			(252	)			1,418
	Other	2-5 years			877			(453	)			424
	Other intangible assets			$	25,746		$	(7,282	)		$	18,464
Amortization expense for intangible assets	Future amortization expense is estimated as follows:
	(In thousands)		Amount
	2015		$	3,412
	2016			2,519
	2017			1,334
	2018			1,079
	2019			1,011
	Thereafter			9,109
	Expected amortization expense		$	18,464

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 27, 2014
Debt [Abstract]
Debt	(In thousands)	2014			2013
	Term Loan Facility with interest at 1.53%, due 2017	$	200,000		$	200,000
	Mueller-Xingrong credit facility with interest at 5.60%, due 2015		29,968			28,033
	2001 Series IRB’s with interest at 1.13%, due through 2021		6,250			7,250
	Other		5,226			50
			241,444			235,333
	Less current portion of debt		(36,194	)		(29,083	)
	Long-term debt	$	205,250		$	206,250
Aggregate annual maturities of debt	Aggregate annual maturities of the Company’s debt are as follows:
	(In thousands)	Amount
	2015	$	36,194
	2016		1,000
	2017		201,000
	2018		1,000
	2019		1,000
	Thereafter		1,250
	Long-term debt	$	241,444
Net interest expense	Net interest expense consisted of the following:
	(In thousands)	2014			2013			2012
	Interest expense	$	6,393		$	5,147		$	6,890
	Capitalized interest		(653	)		(1,157	)		—
		$	5,740		$	3,990		$	6,890

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 27, 2014
Income Taxes [Abstract]
Components of income before income taxes	The components of income before income taxes were taxed under the following jurisdictions:
	(In thousands)	2014			2013			2012
	Domestic	$	135,445		$	262,220		$	105,945
	Foreign		12,568			9,178			14,409
	Income before income taxes	$	148,013		$	271,398		$	120,354
Components of income tax expense	Income tax expense consists of the following:
	(In thousands)	2014			2013			2012
	Current tax expense:
	Federal	$	45,723		$	69,565		$	33,152
	Foreign		2,346			2,608			1,764
	State and local		3,905			6,723			3,049
	Current tax expense		51,974			78,896			37,965
	Deferred tax (benefit) expense:
	Federal		(2,469	)		17,694			570
	Foreign		890			(376	)		(2,015	)
	State and local		(4,916	)		1,895			161
	Deferred tax (benefit) expense		(6,495	)		19,213			(1,284	)
	Income tax expense	$	45,479		$	98,109		$	36,681
Income tax reconciliation	(In thousands)	2014			2013			2012
	Expected income tax expense	$	51,805		$	94,989		$	42,124
	State and local income tax, net of federal benefit		3,355			6,405			3,178
	Effect of foreign statutory rate different from U.S. and other foreign adjustments		(1,094	)		(1,026	)		(2,637	)
	Valuation allowance changes		(5,732	)		—			(1,224	)
	U.S. production activities deduction		(4,025	)		(4,445	)		(2,975	)
	Goodwill disposition		—			1,790			—
	Tax contingency changes		—			(140	)		(3,224	)
	Other, net		1,170			536			1,439
	Income tax expense	$	45,479		$	98,109		$	36,681
Unrecognized tax benefits reconciliation	The following summarizes the activity related to the Company’s unrecognized tax benefits:
	(In thousands)	2014			2013
	Beginning balance	$	2,828		$	3,259
	Increases related to prior year tax positions		—			—
	Increases related to current year tax positions		—			—
	Decreases related to prior year tax positions		(2,828	)		—
	Decreases related to settlements with taxing authorities		—			(431	)
	Decreases due to lapses in the statute of limitations		—			—
	Ending balance	$	—		$	2,828
Components of deferred tax assets and liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are presented below:
	(In thousands)	2014			2013
	Deferred tax assets:
	Inventories	$	12,815		$	11,136
	Other postretirement benefits and accrued items		14,550			13,548
	Pension		4,792			—
	Other reserves		10,262			12,931
	Federal and foreign tax attributes		6,451			5,913
	State tax attributes, net of federal benefit		22,928			24,663
	Share-based compensation		3,016			2,486
	Total deferred tax assets		74,814			70,677
	Less valuation allowance		(17,119	)		(22,544	)
	Deferred tax assets, net of valuation allowance		57,695			48,133
	Deferred tax liabilities:
	Property, plant, and equipment		57,089			60,425
	Pension		—			4,507
	Other		1,721			2,209
	Total deferred tax liabilities		58,810			67,141
	Net deferred tax liability	$	(1,115	)	$	(19,008	)

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 27, 2014
Stock-Based Compensation [Abstract]
Weighted average assumptions used in calculating fair value of stock options	The weighted average of key assumptions used in determining the fair value of options granted and a discussion of the methodology used to develop each assumption are as follows:
		2014			2013		2012
	Expected term	5.6 years			5.9 years		6.5 years
	Expected price volatility		34.30%			39.70%		37.50%
	Risk-free interest rate		1.70%			0.70%		0.70%
	Dividend yield		1.00%			0.90%		0.90%
Summary of the stock option activity	A summary of the activity and related information follows:
		Stock Options					Restricted Stock Awards
	(Shares in thousands)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Grant Date Fair Value
	Outstanding at December 28, 2013		1,177		$	14.67		732		$	21.75
	Granted		202			28.79		197			28.8
	Exercised		(231	)		13.2		(200	)		21
	Forfeited		(21	)		21.22		(2	)		28.28
	Outstanding at December 27, 2014		1,127			17.38		727			25.21

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 27, 2014
Accumulated Other Comprehensive Income (Loss) [Abstract]
Changes in accumulated OCI by component, net of taxes and noncontrolling interest	The following table provides changes in AOCI by component, net of taxes and noncontrolling interest (amounts in parentheses indicate debits to AOCI):
	(In thousands)	Cumulative Translation Adjustment			Unrealized (Losses)/ Gains on Derivatives			Minimum Pension/OPEB Liability Adjustment				Unrealized Gains on Equity Investments		Total
	Balance at December 29, 2012	$	(3,032	)	$	(167	)	$	(39,527	)		$	103	$	(42,623	)
	Other comprehensive income (loss) before reclassifications		2,570			(2,102	)		24,851				152		25,471
	Amounts reclassified from AOCI		—			3,815			2,518				—		6,333
	Balance at December 28, 2013		(462	)		1,546			(12,158	)			255		(10,819	)
	Other comprehensive income (loss) before reclassifications		(12,613	)		(2,766	)		(23,475	)			15		(38,839	)
	Amounts reclassified from AOCI		5,999			267			469				—		6,735
	Balance at December 27, 2014	$	(7,076	)	$	(953	)	$	(35,164	)		$	270	$	(42,923	)
Reclassification adjustments out of accumulated OCI	Reclassification adjustments out of AOCI were as follows:
			Amount reclassified from AOCI
	(In thousands)		2014			2013			2012		Affected Line Item
	Unrealized losses on derivatives:
	Commodity contracts	$	328		$	5,618		$	763		Cost of goods sold
	Foreign currency contracts		—			54			—		Depreciation expense
			(61	)		(1,857	)		(294	)	Income tax expense
			267			3,815			469		Net of tax
			—			—			—		Noncontrolling interest
		$	267		$	3,815		$	469		Net of tax and noncontrolling interest
	Amortization of net loss and prior service cost on employee benefit plans	$	541		$	3,844		$	3,809		Selling, general, and administrative expense
			(72	)		(1,326	)		(1,308	)	Income tax expense
			469			2,518			2,501		Net of tax
			—			—			—		Noncontrolling interest
		$	469		$	2,518		$	2,501		Net of tax and noncontrolling interest
	Loss recognized upon sale of business	$	5,999		$	—		$	—		Gain on sale of assets
			—			—			—		Income tax benefit
			5,999			—			—		Net of tax
			—			—			—		Noncontrolling interest
		$	5,999		$	—		$	—		Net of tax and noncontrolling interest

Benefit_Plans_Tables

Benefit Plans (Tables)	12 Months Ended
	Dec. 27, 2014
Benefit Plans [Abstract]
Reconciliation of the changes in the plans' benefit obligations and the fair value of the plans assets	The following tables provide a reconciliation of the changes in the plans’ benefit obligations and the fair value of the plans’ assets for 2014 and 2013, and a statement of the plans’ aggregate funded status:
			Pension Benefits						Other Benefits
	(In thousands)		2014			2013			2014			2013
	Change in benefit obligation:
	Obligation at beginning of year		$	184,058		$	196,167		$	15,381		$	18,096
	Service cost			973			948			348			413
	Interest cost			8,590			7,774			685			647
	Actuarial loss (gain)			30,138			(11,635	)		4,272			(2,554	)
	Benefit payments			(11,064	)		(10,668	)		(1,142	)		(1,211	)
	Foreign currency translation adjustment			(4,957	)		1,472			(237	)		(10	)
	Obligation at end of year			207,738			184,058			19,307			15,381
	Change in fair value of plan assets:
	Fair value of plan assets at beginning of year			188,870			160,980			—			—
	Actual return on plan assets			12,716			35,578			—			—
	Employer contributions			3,275			1,551			1,142			1,211
	Benefit payments			(11,064	)		(10,668	)		(1,142	)		(1,211	)
	Foreign currency translation adjustment			(3,781	)		1,429			—			—
	Fair value of plan assets at end of year			190,016			188,870			—			—
	(Underfunded) funded status at end of year		$	(17,722	)	$	4,812		$	(19,307	)	$	(15,381	)
Amounts recognized in accumulated OCI (before the effect of income taxes)	The following represents amounts recognized in AOCI (before the effect of income taxes):
			Pension Benefits						Other Benefits
	(In thousands)		2014			2013			2014			2013
	Unrecognized net actuarial loss (gain)		$	49,830		$	21,128		$	473		$	(4,016	)
	Unrecognized prior service cost			—			1			14			20
Funded status of the plans recognized	As of December 27, 2014 and December 28, 2013, the total funded status of the plans recognized in the Consolidated Balance Sheets was as follows:
			Pension Benefits						Other Benefits
	(In thousands)		2014			2013			2014			2013
	Long-term asset		$	2,348		$	15,457		$	—		$	—
	Current liability			—			—			(1,251	)		(1,033	)
	Long-term liability			(20,070	)		(10,645	)		(18,056	)		(14,348	)
	Total (underfunded) funded status		$	(17,722	)	$	4,812		$	(19,307	)	$	(15,381	)
Components of net periodic benefit costs	The components of net periodic benefit cost are as follows:
	(In thousands)		2014			2013			2012
	Pension benefits:
	Service cost		$	973		$	948		$	884
	Interest cost			8,590			7,774			8,472
	Expected return on plan assets			(13,669	)		(11,059	)		(10,263	)
	Amortization of prior service cost			1			1			1
	Amortization of net loss			752			4,005			3,883
	Net periodic benefit (income) cost		$	(3,353	)	$	1,669		$	2,977
	Other benefits:
	Service cost		$	348		$	413		$	380
	Interest cost			685			647			635
	Amortization of prior service cost (credit)			6			(2	)		(2	)
	Amortization of net gain			(218	)		(160	)		(73	)
	Net periodic benefit cost		$	821		$	898		$	940
Weighted average assumptions used in the measurement of the Company's benefit obligation and net periodic benefit cost are as follows	The weighted average assumptions used in the measurement of the Company’s benefit obligations are as follows:
			Pension Benefits						Other Benefits
			2014			2013			2014			2013
	Discount rate			4.03	%		4.82	%		4.33	%		4.89	%
	Expected long-term return on plan assets			5.58	%		7.4	%		N/A			N/A
	Rate of compensation increases			N/A			N/A			5	%		5.5	%
	Rate of inflation			3.1	%		3.4	%		N/A			N/A
	The weighted average assumptions used in the measurement of the Company’s net periodic benefit cost are as follows:
			Pension Benefits									Other Benefits
			2014			2013			2012			2014			2013			2012
	Discount rate			4.82	%		4.13	%		4.8	%		4.89	%		4.06	%		4.97	%
	Expected long-term return on plan assets			7.4	%		7.15	%		7.11	%		N/A			N/A			N/A
	Rate of compensation increases			N/A			N/A			N/A			5.5	%		5.04	%		5.04	%
	Rate of inflation			3.4	%		2.7	%		3	%		N/A			N/A			N/A
Weighted average asset allocation of pension fund assets	The weighted average asset allocation of the Company’s pension fund assets are as follows:
			Pension Plan Assets
	Asset category		2014			2013
	Equity securities (includes equity mutual funds)			49	%		86	%
	Fixed income securities (includes fixed income mutual funds)			4			4
	Cash and equivalents (includes money market funds)			44			7
	Alternative investments			3			3
	Total			100	%		100	%
Plan assets at fair value within the fair value hierarchy, by level	The following table sets forth by level, within the fair value hierarchy, the assets of the plans at fair value:
			Fair Value Measurements at December 27, 2014
	(In thousands)		Level 1			Level 2			Level 3			Total
	Cash and money market funds		$	84,377		$	—		$	—		$	84,377
	Common stock (1)			26,105			—			—			26,105
	Mutual funds (2)			11,397			63,067			—			74,464
	Limited partnerships			—			—			5,070			5,070
	Total		$	121,879		$	63,067		$	5,070		$	190,016
			Fair Value Measurements at December 28, 2013
	(In thousands)		Level 1			Level 2			Level 3			Total
	Cash and money market funds		$	13,992		$	—		$	—		$	13,992
	Common stock (3)			79,497			—			—			79,497
	Mutual funds (4)			27,166			63,435			—			90,601
	Limited partnerships			—			—			4,780			4,780
	Total		$	120,655		$	63,435		$	4,780		$	188,870
	-1	Approximately 51 percent of common stock represents investments in U.S. companies primarily in the health care, utilities, financials, consumer staples, industrials, and information technology sectors. All investments in common stock are listed on U.S. stock exchanges.
	-2	Approximately 40 percent of mutual funds are actively managed funds and approximately 60 percent of mutual funds are index funds. Additionally, 23 percent of the mutual funds’ assets are invested in U.S. equities, 67 percent in non-U.S. equities, and 10 percent in non-U.S. fixed income securities.
	-3	Approximately 84 percent of common stock represents investments in U.S. companies primarily in the health care, utilities, financials, consumer staples, industrials, and information technology sectors. All investments in common stock are listed on U.S. stock exchanges.
	-4	Approximately 32 percent of mutual funds are actively managed funds and approximately 68 percent of mutual funds are index funds. Additionally, 33 percent of the mutual funds’ assets are invested in U.S. equities, 58 percent in non-U.S. equities, and 9 percent in non-U.S. fixed income securities.
Plan assets measured at fair value using significant unobservable inputs	The table below reflects the changes in the assets of the plan measured at fair value on a recurring basis using significant unobservable inputs (Level 3 hierarchy as defined by ASC 820, Fair Value Measurements and Disclosures (ASC 820)) during the year ended December 27, 2014:
	(In thousands)		Limited Partnerships
	Balance, December 28, 2013		$	4,780
	Redemptions			(401	)
	Subscriptions			401
	Net appreciation in fair value			290
	Balance, December 27, 2014		$	5,070
Future benefit plans payments	The Company expects to contribute approximately $1.5 million to its pension plans and $1.3 million to its other postretirement benefit plans in 2015. The Company expects future benefits to be paid from the plans as follows:
	(In thousands)		Pension Benefits			Other Benefits
	2015		$	11,303		$	1,251
	2016			11,492			1,137
	2017			11,671			1,133
	2018			11,878			1,203
	2019			12,116			1,171
	2020-2024			64,358			6,488
	Total		$	122,818		$	12,383
	Multiemployer Plan

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 27, 2014
Derivative Instruments and Hedging Activities [Abstract]
Derivative instruments designated as cash flow hedges reflected in the financial statements	The following table summarizes the location and fair value of the derivative instruments and disaggregates the net derivative assets and liabilities into gross components on a contract-by-contract basis:
		Asset Derivatives									Liability Derivatives
				Fair Value								Fair Value
	(In thousands)	Balance Sheet Location		2014				2013			Balance Sheet Location	2014			2013
	Hedging instrument:
	Commodity contracts - gains	Other current assets		$	99			$	448		Other current liabilities	$	15		$	340
	Commodity contracts - losses	Other current assets			(4	)			(10	)	Other current liabilities		(832	)		(2,107	)
	Foreign currency contracts	Other current assets			—				836		Other current liabilities		(81	)		—
	Interest rate swap	Other assets			—				1,324		Other liabilities		(927	)		—
	Total derivatives (1)			$	95			$	2,598			$	(1,825	)	$	(1,767	)
	(1) Does not include the impact of cash collateral provided to counterparties.
Schedule of fair value hedges	The following tables summarize the effects of derivative instruments on the Consolidated Statements of Income:
	(In thousands)	Location		2014				2013
	Fair value hedges:
	Gain on commodity contracts (qualifying)	Cost of goods sold		$	6,783			$	5,115
	Loss on hedged item - Inventory	Cost of goods sold			(5,958	)			(4,827	)
	Undesignated derivatives:
	Gain (loss) on commodity contracts (nonqualifying)	Cost of goods sold		$	1,466			$	(611	)
Summary of activities related to derivative instruments classified as cash flow hedges	The following tables summarize amounts recognized in and reclassified from AOCI during the period:
			Year Ended December 27, 2014
	(In thousands)		(Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax				Classification Gains (Losses)			Loss (Gain) Reclassified from AOCI (Effective Portion), Net of Tax
	Cash flow hedges:
	Commodity contracts		$	(1,088	)		Cost of goods sold		$	267
	Foreign currency contracts			(275	)		Depreciation expense			—
	Interest rate swap			(1,435	)		Interest expense			—
			Year Ended December 28, 2013
	(In thousands)		(Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax				Classification Gains (Losses)			Loss (Gain) Reclassified from AOCI (Effective Portion), Net of Tax
	Cash flow hedges:
	Commodity contracts		$	(3,337	)		Cost of goods sold		$	3,781
	Foreign currency contracts			401			Depreciation expense			34
	Interest rate swap			834			Interest expense			—

Industry_Segments_Tables

Industry Segments (Tables)	12 Months Ended
	Dec. 27, 2014
Industry Segments [Abstract]
Net sales by major product line	Net Sales by Major Product Line:
	(In thousands)	2014				2013				2012
	Tube and fittings	$	1,143,164			$	972,107			$	986,825
	Brass rod and forgings		556,985				553,896				583,940
	OEM components, tube & assemblies		345,991				337,772				335,461
	Valves and plumbing specialties		262,504				239,822				231,278
	Other		55,583				54,944				52,434
		$	2,364,227			$	2,158,541			$	2,189,938
Geographic information	Geographic Information:
	(In thousands)	2014				2013				2012
	Net sales:
	United States	$	1,752,548			$	1,676,385			$	1,696,589
	United Kingdom		326,832				229,659				234,684
	Other		284,847				252,497				258,665
		$	2,364,227			$	2,158,541			$	2,189,938
	(In thousands)	2014				2013				2012
	Long-lived assets:
	United States	$	322,178			$	325,667			$	306,023
	United Kingdom		43,064				22,159				23,496
	Other		21,641				25,224				27,442
		$	386,883			$	373,050			$	356,961
Summary of segment information	Segment Information:
		For the Year Ended December 27, 2014
	(In thousands)	Plumbing & Refrigeration Segment				OEM				Corporate and Eliminations			Total
						Segment
	Net sales	$	1,416,701			$	959,914			$	(12,388	)	$	2,364,227
	Cost of goods sold		1,215,282				840,823				(12,386	)		2,043,719
	Depreciation and amortization		19,613				11,919				2,203			33,735
	Selling, general, and administrative expense		87,539				21,458				22,743			131,740
	Gain on sale of assets		(6,259	)			—				—			(6,259	)
	Severance		7,296				—				—			7,296
	Operating income		93,230				85,714				(24,948	)		153,996
	Interest expense													(5,740	)
	Other expense, net													(243	)
	Income before income taxes												$	148,013
		For the Year Ended December 28, 2013
	(In thousands)	Plumbing & Refrigeration Segment				OEM				Corporate and Eliminations			Total
						Segment
	Net sales	$	1,225,306			$	947,784			$	(14,549	)	$	2,158,541
	Cost of goods sold		1,043,059				833,518				(14,488	)		1,862,089
	Depreciation and amortization		17,117				13,025				2,252			32,394
	Selling, general, and administrative expense		85,471				24,479				24,964			134,914
	Insurance settlement		(103,895	)			—				(2,437	)		(106,332	)
	Gain on sale of plastic fittings manufacturing assets		(39,765	)			—				—			(39,765	)
	Impairment charges		4,173				131				—			4,304
	Operating income		219,146				76,631				(24,840	)		270,937
	Interest expense													(3,990	)
	Other income, net													4,451
	Income before income taxes												$	271,398
		For the Year Ended December 29, 2012
	(In thousands)	Plumbing & Refrigeration Segment				OEM				Corporate and Eliminations			Total
						Segment
	Net sales	$	1,238,230			$	974,606			$	(22,898	)	$	2,189,938
	Cost of goods sold		1,060,755				866,404				(22,696	)		1,904,463
	Depreciation and amortization		16,513				13,435				1,547			31,495
	Selling, general, and administrative expense		75,448				27,680				26,328			129,456
	Litigation settlement		—				—				(4,050	)		(4,050	)
	Insurance settlement		(1,500	)			—				—			(1,500	)
	Severance		—				—				3,369			3,369
	Operating income		87,014				67,087				(27,396	)		126,705
	Interest expense													(6,890	)
	Other expense, net													539
	Income before income taxes												$	120,354
Segment information by assets	(In thousands)	2014			2013			2012
	Expenditures for long-lived assets (including business acquisitions):
	Plumbing & Refrigeration	$	55,098		$	47,222		$	24,030
	OEM		10,788			14,845			24,137
	General corporate		400			3,253			17,290
		$	66,286		$	65,320		$	65,457
	Segment assets:
	Plumbing & Refrigeration	$	664,784		$	625,371		$	531,429
	OEM		313,245			305,052			290,058
	General corporate		350,067			317,344			282,668
		$	1,328,096		$	1,247,767		$	1,104,155

Quarterly_Financial_Informatio1

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 27, 2014
Quarterly Financial Information (Unaudited) [Abstract]
Quarterly Financial Information (Unaudited)		First		Second			Third			Fourth
	(In thousands, except per share data)	Quarter		Quarter			Quarter			Quarter
	2014
	Net sales	$	574,374	$	649,691		$	602,820		$	537,342
	Gross profit (1)		78,597		91,916			81,542			68,453
	Consolidated net income (5)		24,954		35,209			24,322			18,049	-2
	Net income attributable to Mueller Industries, Inc.		24,706		35,045			23,823			17,987
	Basic earnings per share		0.44		0.63			0.42			0.32
	Diluted earnings per share		0.44		0.62			0.42			0.32
	Dividends per share		0.075		0.075			0.075			0.075
	2013
	Net sales	$	559,690	$	582,282		$	528,854		$	487,715
	Gross profit (1)		76,840		81,157			72,552			65,903
	Consolidated net income		26,434		91,842	-3		39,993	-4		15,020
	Net income attributable to Mueller Industries, Inc.		26,202		91,150			39,864			15,384
	Basic earnings per share		0.47		1.64			0.71			0.28
	Diluted earnings per share		0.46		1.62			0.71			0.27
	Dividends per share		0.0625		0.0625			0.0625			0.0625
	(1) Gross profit is net sales less cost of goods sold, which excludes depreciation and amortization.
	(2) Includes $4.8 million pre-tax gain on sale of assets and $4.2 million of pre-tax charges related to severance.
	(3) Includes $106.3 million pre-tax gain from settlement of insurance claims.
	(4) Includes $39.8 million pre-tax gain on sale of manufacturing assets and pre-tax impairment charges of $4.3 million primarily
	related to real property associated with the aforementioned plastics sale transaction.
	(5) Includes income earned by Howell, acquired during Q4 2013, and losses incurred by Yorkshire, acquired during Q1 2014.
	(6) The sum of quarterly amounts may not equal the annual amounts reported due to rounding. In addition, the earnings per share amounts are computed independently for each quarter while the full year is based on the weighted average shares outstanding.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Principles of consolidation [Abstract]
Non-controlling ownership interest of Mueller-Xingrong (in hundredths)	49.50%
Common Stock Split [Abstract]
Conversion ratio for stock split	2
Number of shares given as stock dividend for each outstanding share (in shares)	1
Cash equivalents [Abstract]
Temporary investments	$144.90	$179.20
Restricted cash	8.1	5.2
Benefit Plans [Abstract]
Specified percentage over which unrecognized gains and losses are amortized (in hundredths)	10.00%
Average remaining service period for the pension plans	9 years
Earnings Per Share [Abstract]
Stock-based awards excluded from the computation of diluted earnings per share (in shares)	180,000
Foreign currency translation [Abstract]
Foreign currency transaction (losses) gains	$0.10	($0.10)	($0.30)
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Property, plant and equipment, useful life	20 years
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Property, plant and equipment, useful life	40 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Property, plant and equipment, useful life	5 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Property, plant and equipment, useful life	20 years

Acquisitions_and_Dispositions_

Acquisitions and Dispositions (Details) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

12 Months Ended

Dec. 27, 2014

Jun. 28, 2014

Sep. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 29, 2012

Aug. 09, 2013

Mar. 29, 2014

Nov. 21, 2014

Nov. 30, 2014

Feb. 28, 2014

Aug. 16, 2012

Oct. 17, 2013

Aug. 31, 2013

Business Acquisition [Line Items]

Severance

$4,200,000

$7,296,000

$0

$3,369,000

Proforma net sales

2,364,227,000

2,158,541,000

2,189,938,000

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Cash proceeds from sale of property

5,000,000

Pre-tax gain on sale of property

4,800,000

39,800,000

6,259,000

39,765,000

0

Goodwill allocated to disposal group

10,500,000

Minimum [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Lease-back term

8 months

Maximum [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Lease-back term

14 months

Land and Building Assets [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Cash proceeds from sale of property

4,700,000

Pre-tax gain on sale of property

1,400,000

Impairment charge recognized on fair value of disposed assets

3,200,000

Manufacturing assets [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Carrying value of assets disposed

15,900,000

Cash proceeds from sale of property

61,200,000

Pre-tax gain on sale of property

39,800,000

Total sales price of property

66,200,000

Amount of pre-diluted share after tax

$0.41

Mueller Primaflow Limited [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Proceeds from sale of outstanding capital stock of Primaflow

24,900,000

Net sales

57,500,000

After-tax net income

4,400,000

Carrying value of the assets disposed

25,300,000

Fair value of the liabilities disposed

7,100,000

Cumulative translation loss

-6,000,000

ABS [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Carrying value of assets disposed

1,900,000

Cash proceeds from sale of property

6,000,000

Pre-tax gain on sale of property

4,100,000

KME Yorkshire Limited [Member]

Business Acquisition [Line Items]

Cost of acquisition

30,100,000

Pro forma net sales

196,100,000

Fair value of assets acquired

20,700,000

Fair value of assets acquired - inventories

17,600,000

Fair value of assets acquired - property, plant and equipment

2,100,000

Fair value of assets acquired -other current assets

1,000,000

Fair value of liabilities assumed

15,600,000

Fair value of liabilities assumed - accounts payable and accrued expenses

15,200,000

Fair value of liabilities assumed - other current liabilities

400,000

Remaining purchase price allocated to goodwill

8,100,000

Remaining purchase price allocated to other intangible assets

16,900,000

Severance

7,300,000

KME Yorkshire Limited [Member] | Subsequent Event [Member]

Business Acquisition [Line Items]

Expected additional expenses to be incurred

2,700,000

2,700,000

Westemeyer Industries, Inc. [Member]

Business Acquisition [Line Items]

Cost of acquisition

11,600,000

Fair value of assets acquired

7,500,000

Fair value of assets acquired - inventories

1,900,000

Fair value of assets acquired - receivables

2,000,000

Fair value of assets acquired - property, plant and equipment

3,600,000

Remaining purchase price allocated to goodwill

2,300,000

Remaining purchase price allocated to other intangible assets

2,700,000

Portion of outstanding stock acquired (in hundredths)

100.00%

Fair value of assets acquired - current liabilities

1,000,000

Howell Metal Company [Member]

Business Acquisition [Line Items]

Cost of acquisition

55,300,000

55,300,000

Fair value of assets acquired

63,000,000

Fair value of assets acquired - inventories

27,600,000

Fair value of assets acquired - receivables

14,600,000

Fair value of assets acquired - property, plant and equipment

20,300,000

Fair value of assets acquired -other current assets

500,000

Fair value of liabilities assumed

11,400,000

Fair value of liabilities assumed - accounts payable and accrued expenses

9,900,000

Fair value of liabilities assumed - other current liabilities

1,500,000

Remaining purchase price allocated to goodwill

1,300,000

Remaining purchase price allocated to other intangible assets

2,300,000

2,300,000

Proforma net sales

$156,300,000

Inventories_Details

Inventories (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Dec. 27, 2014	Dec. 28, 2013
Inventories [Abstract]
Raw materials and supplies			$53,586,000	$54,613,000
Work-in-process			39,707,000	43,796,000
Finished goods			168,481,000	159,422,000
Valuation reserves			-5,189,000	-6,115,000
Inventories			256,585,000	251,716,000
Inventories valued using the LIFO method			25,900,000	34,900,000
FIFO cost of inventories			104,800,000	117,900,000
Average cost basis inventories			47,700,000	54,700,000
Deferred LIFO Gain		8,000,000
Effect of liquidation of LIFO layers on cost of sales	8,000,000
Effect of liquidation of LIFO layers per diluted share after tax (in dollars per share)	$0.70
FIFO value of inventory consigned to others			$4,300,000	$4,300,000

Consolidated_Financial_Stateme2

Consolidated Financial Statement Details (Details) (USD $)	12 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Other Current Liabilities [Abstract]
Accrued discounts and allowances	$45,300,000	$43,200,000
Other Income (Expense), Net [Abstract]
Gain on the sale of non-operating property	0	3,000,000	0
Interest income	573,000	906,000	847,000
Environmental expense, non-operating properties	-822,000	-823,000	-1,128,000
Other	6,000	1,368,000	820,000
Other income, net	($243,000)	$4,451,000	$539,000

Property_Plant_and_Equipment_N2

Property, Plant, and Equipment, Net (Details) (USD $)	Dec. 27, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$738,113	$732,180
Less accumulated depreciation	-492,203	-487,723
Property, plant and equipment, net	245,910	244,457
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	12,198	13,153
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	120,035	132,331
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	561,093	561,005
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$44,787	$25,691

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Details) (USD $)	12 Months Ended				0 Months Ended
	Dec. 27, 2014		Dec. 28, 2013	Dec. 29, 2012	Aug. 16, 2012	Oct. 17, 2013	Aug. 09, 2013	Mar. 29, 2014
Goodwill [Roll Forward]
Goodwill	$143,762,000		$153,984,000
Accumulated impairment, beginning balance	-49,405,000		-49,405,000
Goodwill, net	102,909,000		94,357,000	104,579,000
Additions	9,123,000	[1]	310,000
Currency translation	-571,000
Disposition			-10,532,000
Goodwill	152,314,000		143,762,000	153,984,000
Accumulated impairment, ending balance	-49,405,000		-49,405,000	-49,405,000
Purchase price allocation adjustments	1,000,000
Goodwill allocated to disposal group							10,500,000
Amortization expenses	3,200,000		900,000	700,000
Amortization expense for intangible assets
2015	3,412,000
2016	2,519,000
2017	1,334,000
2018	1,079,000
2019	1,011,000
Thereafter	9,109,000
Net Carrying Amount	18,464,000		5,500,000
Carrying amount of intangible assets [Abstract]
Gross Carrying Amount			7,800,000
Net Carrying Amount	18,464,000		5,500,000
Customer Relationships [Member]
Amortization expense for intangible assets
Net Carrying Amount	11,326,000
Carrying amount of intangible assets [Abstract]
Estimated Useful Life	20 years
Gross Carrying Amount	11,852,000
Accumulated Amortization	-526,000
Net Carrying Amount	11,326,000
Non-compete Agreements [Member]
Amortization expense for intangible assets
Net Carrying Amount	3,188,000
Carrying amount of intangible assets [Abstract]
Gross Carrying Amount	4,495,000
Accumulated Amortization	-1,307,000
Net Carrying Amount	3,188,000
Non-compete Agreements [Member] | Minimum [Member]
Carrying amount of intangible assets [Abstract]
Estimated Useful Life	3 years
Non-compete Agreements [Member] | Maximum [Member]
Carrying amount of intangible assets [Abstract]
Estimated Useful Life	5 years
Patents and Technology [Member]
Amortization expense for intangible assets
Net Carrying Amount	2,108,000
Carrying amount of intangible assets [Abstract]
Estimated Useful Life	10 years
Gross Carrying Amount	6,852,000
Accumulated Amortization	-4,744,000
Net Carrying Amount	2,108,000
Trade Names and Licenses [Member]
Amortization expense for intangible assets
Net Carrying Amount	1,418,000
Carrying amount of intangible assets [Abstract]
Estimated Useful Life	3 years
Gross Carrying Amount	1,670,000
Accumulated Amortization	-252,000
Net Carrying Amount	1,418,000
Other [Member]
Amortization expense for intangible assets
Net Carrying Amount	424,000
Carrying amount of intangible assets [Abstract]
Gross Carrying Amount	877,000
Accumulated Amortization	-453,000
Net Carrying Amount	424,000
Other [Member] | Minimum [Member]
Carrying amount of intangible assets [Abstract]
Estimated Useful Life	2 years
Other [Member] | Maximum [Member]
Carrying amount of intangible assets [Abstract]
Estimated Useful Life	5 years
Other Intangible Assets [Member]
Amortization expense for intangible assets
Net Carrying Amount	18,464,000
Carrying amount of intangible assets [Abstract]
Gross Carrying Amount	25,746,000
Accumulated Amortization	-7,282,000
Net Carrying Amount	18,464,000
Westemeyer Industries, Inc. [Member]
Goodwill [Roll Forward]
Cost of acquisition					11,600,000
Allocation to other intangible assets					2,700,000
Howell [Member]
Goodwill [Roll Forward]
Cost of acquisition			55,300,000			55,300,000
Allocation to goodwill			1,300,000
Allocation to other intangible assets			2,300,000					2,300,000
Yorkshire [Member]
Goodwill [Roll Forward]
Cost of acquisition	30,100,000
Allocation to goodwill	8,100,000
Allocation to other intangible assets	16,900,000
Plumbing and Refrigeration Segment [Member]
Goodwill [Roll Forward]
Goodwill	131,462,000		141,684,000
Accumulated impairment, beginning balance	-39,434,000		-39,434,000
Goodwill, net	100,580,000		92,028,000	102,250,000
Additions	9,123,000	[1]	310,000
Currency translation	-571,000
Disposition			-10,532,000
Goodwill	140,014,000		131,462,000
Accumulated impairment, ending balance	-39,434,000		-39,434,000
OEM Segment [Member]
Goodwill [Roll Forward]
Goodwill	12,300,000		12,300,000
Accumulated impairment, beginning balance	-9,971,000		-9,971,000
Goodwill, net	2,329,000		2,329,000	2,329,000
Additions	0	[1]	0
Currency translation	0
Disposition			0
Goodwill	12,300,000		12,300,000
Accumulated impairment, ending balance	($9,971,000)		($9,971,000)
[1]	Includes finalization of the purchase price allocation adjustment for Howell of $1.0 million

Debt_Details

Debt (Details)

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

Dec. 27, 2014

Dec. 28, 2013

Dec. 29, 2012

Sep. 23, 2013

Dec. 27, 2014

Feb. 02, 2015

Feb. 02, 2015

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

29-May-14

Mar. 21, 2014

Mar. 21, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

USD ($)

USD ($)

USD ($)

Mueller Xingrong Credit Facility [Member]

Mueller Xingrong Credit Facility [Member]

Mueller Xingrong Credit Facility [Member]

Mueller Xingrong Credit Facility [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Mueller Europe Limited [Member]

Mueller Europe Limited [Member]

Mueller Europe Limited [Member]

Mueller Xingrong [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

Mueller Xingrong Credit Facility [Member]

Mueller Xingrong Credit Facility [Member]

2001 Series IRB [Member]

2001 Series IRB [Member]

Other [Member]

Other [Member]

Subsequent Event [Member]

Subsequent Event [Member]

USD ($)

LIBOR [Member]

Base Rate [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

USD ($)

USD ($)

USD ($)

GBP (£)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

CNY

LIBOR [Member]

Base Rate [Member]

LIBOR [Member]

Base Rate [Member]

Debt Instrument [Line Items]

Debt

$241,444,000

$235,333,000

$200,000,000

$200,000,000

$29,968,000

$28,033,000

$6,250,000

$7,250,000

$5,226,000

$50,000

Less current portion of debt

-36,194,000

-29,083,000

Long-term debt

205,250,000

206,250,000

Debt, stated interest rate (in hundredths)

1.53%

5.60%

1.16%

Debt instrument maturity date

11-Dec-17

31-Dec-15

31-Dec-21

Line of Credit Facility [Line Items]

Debt instrument variable rate basis

bear an interest rate at the latest base-lending rate published by the Peoplebs Bank of China

Borrowings under the Credit Agreement bear interest, at the Companybs option, at LIBOR or Base Rate as defined by the Credit Agreement, plus a variable premium. LIBOR advances may be based upon the one, three, or six-month LIBOR.

Basis spread on variable rate (in hundredths)

1.38%

0.38%

1.13%

0.13%

1.63%

0.63%

Credit facility commitment fee (in hundredths)

0.25%

0.38%

Outstanding letters of credit

10,500,000

0

Terms of the letters of credit

1 year

Line of credit facility maximum borrowing capacity

37,100,000

230,000,000

350,000,000

62,200,000

40,000,000

Line of credit facility, current borrowing capacity

200,000,000

Maturity date

24-Sep-14

Initial term of the Invoice Facility

2 years

2 years

Trade accounts receivable

275,065,000

271,847,000

57,900,000

Range of period at maturity date

9 months

Total borrowings

0

35,200,000

Aggregate annual maturities of debt [Abstract]

2015

36,194,000

2016

1,000,000

2017

201,000,000

2018

1,000,000

2019

1,000,000

Thereafter

1,250,000

Long-term debt

241,444,000

235,333,000

200,000,000

200,000,000

29,968,000

28,033,000

6,250,000

7,250,000

5,226,000

50,000

Net interest expense [Abstract]

Interest expense

6,393,000

5,147,000

6,890,000

Capitalized interest

-653,000

-1,157,000

0

Net interest expense

5,740,000

3,990,000

6,890,000

Interest Paid

$5,700,000

$4,900,000

$8,400,000

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	1 Months Ended	12 Months Ended			36 Months Ended
In Millions, except Per Share data, unless otherwise specified	Oct. 31, 2012	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012	Dec. 27, 2014	Dec. 25, 2010	Jun. 21, 2011
Site Contingency [Line Items]
Environmental expense		$1.20	$1	$3.10
Environmental reserves		22.7	23.6		22.7
Expected environmental expenditures for 2015		0.7			0.7
Expected environmental expenditures for 2016		0.8			0.8
Expected environmental expenditures for 2017		0.7			0.7
Expected environmental expenditures for 2018		0.7			0.7
Expected environmental expenditures for 2019		0.8			0.8
Expected environmental expenditures after 2019		9.4			9.4
Gain Contingencies [Line Items]
Proceeds from legal settlements	5.8
Consulting Agreement [Member]
Long-term Purchase Commitment [Line Items]
Consulting agreement term (in years)		6 years
Initial period of the consulting agreement		4 years
Initial period rate of pay based on final base compensation (in hundredths)		two-thirds
Final period of the consulting agreement		2 years
Final period rate of pay of based on final base compensation (in hundredths)		one-third
Remaining amount payable under the Consulting agreement		2.7			2.7
Facilities Vehicles and Equipment [Member]
Operating Leased Assets [Line Items]
Lease payments scheduled for 2015		6.2			6.2
Lease payments scheduled for 2016		3.9			3.9
Lease payments scheduled for 2017		2.6			2.6
Lease payments scheduled for 2018		2.1			2.1
Lease payments scheduled for 2019		0.4			0.4
Lease expense		9.8	9.1	8.5
Insurance Settlement [Member] | Fulton, Mississippi [Member]
Gain Contingencies [Line Items]
Pre-tax gain from settlement				1.5		1.5
Insurance Settlement [Member] | Wynne, Arkansas [Member]
Gain Contingencies [Line Items]
Insurance settlement proceeds			127.3
Insurance claim deductible amount			0.5
Pre-tax gain from settlement			106.3
Pre-tax gain from settlement (in dollars per share)			$1.17
Proceeds from insurance company received			62.3	55
United States Department of Commerce Antidumping Review [Member]
Loss Contingencies [Line Items]
Assignment of antidumping duty rate on U.S. imports by Company subsidiaries (in hundredths)							19.80%
Reserve established		1.1			1.1
Operating Properties [Member] | Mueller Copper Tube Products, Inc. [Member]
Site Contingency [Line Items]
Mitigation estimates minimum		0.8
Mitigation estimates maximum		1.3
Estimated number of years until mitigation resolution		10 years
Non-Operating Properties [Member] | Southeast Kansas Sites [Member]
Site Contingency [Line Items]
Environmental reserves		9.5			9.5
Number of parties involved in settlement negotiations		2			2
Non-Operating Properties [Member] | Shasta Area Mine Sites [Member]
Site Contingency [Line Items]
Environmental spending					1.7
Period of permit, implementation of Best Management Practices		10 years
Mitigation estimates minimum		10.5
Mitigation estimates maximum		13
Estimated number of years until mitigation resolution		20 years
Non-Operating Properties [Member] | Lead Refinery Site [Member]
Site Contingency [Line Items]
Environmental expense		0.1	0.1	0.1
Number of parties involved in settlement negotiations		3			3
Mitigation estimates minimum		1.9
Mitigation estimates maximum		3.6
Estimated number of years until mitigation resolution		20 years
Lead Refinery Site [Abstract]
EPA's estimated cost of site remediation		$26
Number of surrounding properties		300

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Income Taxes [Abstract]
Domestic	$135,445,000	$262,220,000	$105,945,000
Foreign	12,568,000	9,178,000	14,409,000
Income before income taxes	148,013,000	271,398,000	120,354,000
Current tax expense [Abstract]
Federal	45,723,000	69,565,000	33,152,000
Foreign	2,346,000	2,608,000	1,764,000
State and local	3,905,000	6,723,000	3,049,000
Current tax expense	51,974,000	78,896,000	37,965,000
Deferred tax (benefit) expense [Abstract]
Federal	-2,469,000	17,694,000	570,000
Foreign	890,000	-376,000	-2,015,000
State and local	-4,916,000	1,895,000	161,000
Deferred tax (benefit) expense	-6,495,000	19,213,000	-1,284,000
Income tax expense	45,479,000	98,109,000	36,681,000
Undistributed earnings of foreign subsidiaries	75,000,000
Income Tax Reconciliation [Abstract]
Expected income tax expense	51,805,000	94,989,000	42,124,000
State and local income tax, net of federal benefit	3,355,000	6,405,000	3,178,000
Effect of foreign statutory rate different from U.S. and other foreign adjustments	-1,094,000	-1,026,000	-2,637,000
Valuation allowance changes	-5,732,000	0	-1,224,000
U.S. production activities deduction	-4,025,000	-4,445,000	-2,975,000
Goodwill disposition	0	1,790,000	0
Tax contingency changes	0	-140,000	-3,224,000
Other, net	1,170,000	536,000	1,439,000
Income tax expense	45,479,000	98,109,000	36,681,000
Unrecognized Tax Benefits Reconciliation [Roll Forward]
Beginning balance	2,828,000	3,259,000
Increases related to prior year tax positions	0	0
Increases related to current year tax positions	0	0
Decreases related to prior year tax positions	-2,828,000	0
Decreases related to settlements with taxing authorities	0	-431,000
Decreases due to lapses in the statute of limitations	0	0
Ending balance	0	2,828,000	3,259,000
Unrecognized tax benefits that would impact effective tax rate	0
Deferred tax assets [Abstract]
Inventories	12,815,000	11,136,000
Other postretirement benefits and accrued items	14,550,000	13,548,000
Pension	4,792,000	0
Other reserves	10,262,000	12,931,000
Federal and foreign tax attributes	6,451,000	5,913,000
State tax attributes, net of federal benefit	22,928,000	24,663,000
Share-based compensation	3,016,000	2,486,000
Total deferred tax assets	74,814,000	70,677,000
Less valuation allowance	-17,119,000	-22,544,000
Deferred tax assets, net of valuation allowance	57,695,000	48,133,000
Deferred tax liabilities [Abstract]
Property, plant, and equipment	57,089,000	60,425,000
Pension	0	4,507,000
Other	1,721,000	2,209,000
Total deferred tax liabilities	58,810,000	67,141,000
Net deferred tax liability	-1,115,000	-19,008,000
State income tax credit carryforwards with expiration	4,100,000
Other state income tax credit carryforwards with unlimited life	11,100,000
State net operating loss carryforwards with potential tax benefits	7,800,000
Valuation allowances	11,800,000
Federal and foreign tax attributes with potential tax benefits	6,400,000
Federal and foreign tax attributes with potential tax benefits with unlimited life	4,500,000
Federal and foreign tax attributes with potential tax benefits with expiration	1,900,000
Valuation allowances	3,400,000
Additional valuation allowance per diluted share, State tax attributes (in dollars per share)	$0.10		$0.02
Income taxes paid	$47,300,000	$80,100,000	$38,400,000

Equity_Details

Equity (Details) (USD $)	0 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 24, 2012	Dec. 27, 2014
Equity, Class of Treasury Stock [Line Items]
Authorization to repurchase shares of common stock (in shares)		20,000,000
Shares repurchased (shares)		4,700,000
Leucadia [Member]
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (in shares)	20,800,000
Total cost of stock repurchased	$427,300

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 27, 2014	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$6,300,000	$5,700,000	$4,000,000
Severance	4,200,000	7,296,000	0	3,369,000
Related tax benefit to stock based compensation		800,000	700,000	2,600,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period		5 years
Number of years vesting starts after the grant date		1 year
Stock options expirations		10 years
Weighted average grant-date fair value of options granted (in dollars per share)		$9	$8.77	$7.45
Estimated forfeiture rate (in hundredths)		16.40%		16.50%
Weighted average key assumptions [Abstract]
Expected term (in years)		5 years 7 months 6 days	5 years 10 months 24 days	6 years 6 months
Expected price volatility (in hundredths)		34.30%	39.70%	37.50%
Risk-free interest rate (in hundredths)		1.70%	0.70%	0.70%
Dividend yield (in hundredths)		1.00%	0.90%	0.90%
Options outstanding [Roll Forward]
Beginning balance (in shares)		1,177,000
Granted (in shares)		202,000
Exercised (in shares)		-231,000
Forfeited (in shares)		-21,000
Ending balance (in shares)	1,127,000	1,127,000	1,177,000
Weighted average exercise price [Roll Forward]
Beginning balance (in dollars per share)		$14.67
Granted (in dollars per share)		$28.79
Exercised (in dollars per share)		$13.20
Forfeited (in dollars per share)		$21.22
Ending balance (in dollars per share)	$17.38	$17.38	$14.67
Weighted Average Grant Date Fair Value [Abstract]
Granted (in dollars per share)		$9	$8.77	$7.45
Aggregate intrinsic value of all outstanding options	18,200,000	18,200,000
Weighted average remaining contractual term of all outstanding options (in years)		5 years 1 month 6 days
Outstanding options, exercisable (in shares)	795,000	795,000
Aggregate intrinsic value of current exercisable shares	15,100,000	15,100,000
Weighted average exercise price (in dollars per share)	$15.07	$15.07
Weighted average remaining contractual term		4 years
Total intrinsic value of options exercised		3,500,000	2,900,000	12,100,000
Fair value of options vested		1,000,000	1,100,000	1,700,000
Stock option compensation not yet recognized	1,400,000	1,400,000
Average stock option expense recognition period		3 years
Shares available for future issuance (in shares)	1,600,000	1,600,000
Stock Options [Member] | Former Chief Financial Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Severance				2,100,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value		24,700,000
Compensation for stock awards not yet recognized	13,300,000	13,300,000
Compensation recognition period		3 years 7 months 6 days
Weighted average grant-date fair value of options granted (in dollars per share)		$28.80	$28.32	$21.42
Restricted Stock [Roll Forward]
Beginning Balance (in shares)		732,000
Granted (in shares)		197,000
Exercised (in shares)		-200,000
Forfeited (in shares)		-2,000
Ending Balance (in shares)	727,000	727,000	732,000
Weighted Average Grant Date Fair Value [Abstract]
Beginning Balance (in dollars per share)		$21.75
Granted (in dollars per share)		$28.80	$28.32	$21.42
Exercised (in dollars per share)		$21
Forfeited (in dollars per share)		$28.28
Ending Balance (in dollars per share)	$25.21	$25.21	$21.75
Fair value of options vested		$4,200,000	$1,800,000	$1,700,000
2014 Incentive Plan [Member] | Common Stock [Member]
Weighted Average Grant Date Fair Value [Abstract]
Shares available for future issuance (in shares)	1,500,000	1,500,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013		Dec. 29, 2012
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	($10,819)		($42,623)
Other comprehensive income (loss) before reclassifications	-38,839		25,471
Amounts reclassified from AOCI	6,735		6,333
Ending balance	-42,923		-10,819		-42,623
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Abstract]
Cost of goods sold	-2,043,719		-1,862,089		-1,904,463
Net change with respect to derivative instruments and hedging activities	-2,499	[1]	1,713	[1]	255	[1]
Selling, general, and administrative expense	-131,740		-134,914		-129,456
Cumulative Translation Adjustment [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	-462		-3,032
Other comprehensive income (loss) before reclassifications	-12,613		2,570
Amounts reclassified from AOCI	5,999		0
Ending balance	-7,076		-462
Unrealized (Losses)/Gains on Derivatives [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,546		-167
Other comprehensive income (loss) before reclassifications	-2,766		-2,102
Amounts reclassified from AOCI	267		3,815
Ending balance	-953		1,546
Unrealized (Losses)/Gains on Derivatives [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Abstract]
Cost of goods sold	328		5,618		763
Depreciation expense	0		54		0
Income tax expense	-61		-1,857		-294
Net of tax	267		3,815		469
Noncontrolling interest	0		0		0
Net change with respect to derivative instruments and hedging activities	267		3,815		469
Minimum Pension/OPEB Liability Adjustment [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	-12,158		-39,527
Other comprehensive income (loss) before reclassifications	-23,475		24,851
Amounts reclassified from AOCI	469		2,518
Ending balance	-35,164		-12,158
Minimum Pension/OPEB Liability Adjustment [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Abstract]
Selling, general, and administrative expense	541		3,844		3,809
Income tax expense	-72		-1,326		-1,308
Net of tax	469		2,518		2,501
Noncontrolling interest	0		0		0
Net of tax and noncontrolling interest	469		2,518		2,501
Unrealized Gains on Equity Investments [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	255		103
Other comprehensive income (loss) before reclassifications	15		152
Amounts reclassified from AOCI	0		0
Ending balance	270		255
Loss Recognized Upon Sale of Business [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Abstract]
Gain on sale of assets	5,999		0		0
Income tax benefit	0		0		0
Net of tax	5,999		0		0
Noncontrolling interest	0		0		0
Net of tax and noncontrolling interest	$5,999		$0		$0
[1]	Net of taxes of $1,362 in 2014, $(962) in 2013, and $(162) in 2012

Benefit_Plans_Details

Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 27, 2014		Dec. 28, 2013		Dec. 29, 2012
	Agreement
Change in fair value of plan assets [Roll Forward]
Payable maximum period to be considered current	12 months
Long-term liability	($20,070,000)		($10,645,000)
Weighted average assumptions in net periodic benefit calculations [Abstract]
Minimum annual assumed rate of increase in the per capita cost of covered benefits (in hundredths)	7.00%
Maximum annual assumed rate of increase in the per capita cost of covered benefits (in hundredths)	9.00%
Ultimate health care cost trend rate (in hundredths)	4.50%
One percent change assumptions [Abstract]
Increase in the accumulated postretirement benefit obligation	2,000,000
Increase in the service and interest cost components of net periodic postretirement benefit costs	100,000
Decrease in the accumulated postretirement benefit obligation	1,700,000
Decrease in the service and interest cost components of net periodic postretirement benefit costs	100,000
Defined Benefit Plan Disclosure [Line Items]
Plan assets	190,016,000		188,870,000
Approximate percentage of common stock invested in major industry (in hundredths)	51.00%		84.00%
Approximate percentage of mutual funds actively managed (in hundredths)	40.00%		32.00%
Approximate percentage of indexed mutual funds	60.00%		68.00%
Percentage of mutual funds' assets that are invested in U.S equities (in hundredths)	23.00%		33.00%
Percent of mutual funds' assets that are invested in non-U.S. equities (in hundredths)	67.00%		58.00%
Percent of mutual funds' assets that are invested in non-U.S. fixed income securities (in hundredths)	10.00%		9.00%
I.A.M Plan Trusts [Abstract]
Number of collective bargaining agreements	2
Pension contributions under the I.A.M. pension plan trusts	1,000,000		900,000		1,000,000
Percentage of employer contributions (in hundredths)	Less than 5.00%
Maximum percentage funded in the red zone, under the Pension Protection act of 2006 (in hundredths)	65.00%
Maximum percentage funded in the yellow zone, under the Pension Protection act of 2006 (in hundredths)	80.00%
Minimum percentage funded in the green zone, under the Pension Protection act of 2006 (in hundredths)	80.00%
401 (k) Plan [Abstract]
Compensation expense for the Company's matching contribution	4,100,000		3,200,000		2,900,000
Contributions to UMWA 1992 Benefit Plan	249,000		290,000		315,000
Limited Partnerships [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	4,780,000
Redemptions	-401,000
Subscriptions	401,000
Net appreciation in fair value	290,000
Ending balance	5,070,000
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	121,879,000		120,655,000
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	63,067,000		63,435,000
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	5,070,000		4,780,000
Cash and Money Market Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	84,377,000		13,992,000
Cash and Money Market Funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	84,377,000		13,992,000
Cash and Money Market Funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0		0
Cash and Money Market Funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0		0
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	26,105,000	[1]	79,497,000	[2]
Common Stock [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	26,105,000	[1]	79,497,000	[2]
Common Stock [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	[1]	0	[2]
Common Stock [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	[1]	0	[2]
Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	74,464,000	[3]	90,601,000	[4]
Mutual Funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	11,397,000	[3]	27,166,000	[4]
Mutual Funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	63,067,000	[3]	63,435,000	[4]
Mutual Funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	[3]	0	[4]
Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	5,070,000		4,780,000
Limited Partnerships [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0		0
Limited Partnerships [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0		0
Limited Partnerships [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	5,070,000		4,780,000
Pension Benefits [Member]
Change in benefit obligation [Roll Forward]
Obligation at beginning of year	184,058,000		196,167,000
Service cost	973,000		948,000
Interest cost	8,590,000		7,774,000
Actuarial loss (gain)	30,138,000		-11,635,000
Benefit payments	-11,064,000		-10,668,000
Foreign currency translation adjustment	-4,957,000		1,472,000
Obligation at end of year	207,738,000		184,058,000		196,167,000
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets at beginning of year	188,870,000		160,980,000
Actual return on plan assets	12,716,000		35,578,000
Employer contributions	3,275,000		1,551,000
Benefit payments	-11,064,000		-10,668,000
Foreign currency translation adjustment	-3,781,000		1,429,000
Fair value of plan assets at end of year	190,016,000		188,870,000		160,980,000
(Underfunded) funded status at end of year	-17,722,000		4,812,000
Unrecognized net actuarial loss (gain)	49,830,000		21,128,000
Unrecognized prior service cost	0		1,000
Long-term asset	2,348,000		15,457,000
Current liability	0		0
Long-term liability	-20,070,000		-10,645,000
Total (underfunded) funded status	-17,722,000		4,812,000
Service cost	973,000		948,000		884,000
Interest cost	8,590,000		7,774,000		8,472,000
Expected return on plan assets	-13,669,000		-11,059,000		-10,263,000
Amortization of prior service cost (credit)	1,000		1,000		1,000
Amortization of net (gain) loss	752,000		4,005,000		3,883,000
Net periodic benefit (income) cost	-3,353,000		1,669,000		2,977,000
Weighted average assumptions in benefit obligations calculations [Abstract]
Discount rate (in hundredths)	4.03%		4.82%
Expected long-term return on plan assets (in hundredths)	5.58%		7.40%
Rate of inflation (in hundredths)	3.10%		3.40%
Weighted average assumptions in net periodic benefit calculations [Abstract]
Discount rate (in hundredths)	4.82%		4.13%		4.80%
Expected long-term return on plan assets (in hundredths)	7.40%		7.15%		7.11%
Rate of inflation (in hundredths)	3.40%		2.70%		3.00%
Asset category [Abstract]
Total plan assets (in hundredths)	100.00%		100.00%
Expected long-term rate of return on plan assets (in hundredths)	5.58%		7.40%
Future expected benefit payments [Abstract]
2015	11,303,000
2016	11,492,000
2017	11,671,000
2018	11,878,000
2019	12,116,000
2020-2024	64,358,000
Total	122,818,000
Company's expected contribution to benefit plans in next fiscal year	1,500,000
Pension Benefits [Member] | Equity Securities [Member]
Asset category [Abstract]
Total plan assets (in hundredths)	49.00%		86.00%
Pension Benefits [Member] | Equity Securities [Member] | Maximum [Member]
Asset category [Abstract]
Total plan assets (in hundredths)	30.00%
Pension Benefits [Member] | Fixed Income Securities [Member]
Asset category [Abstract]
Total plan assets (in hundredths)	4.00%		4.00%
Pension Benefits [Member] | Fixed Income Securities [Member] | Minimum [Member]
Asset category [Abstract]
Total plan assets (in hundredths)	60.00%
Pension Benefits [Member] | Cash and Money Market Funds [Member]
Asset category [Abstract]
Total plan assets (in hundredths)	44.00%		7.00%
Pension Benefits [Member] | Alternative Investments [Member]
Asset category [Abstract]
Total plan assets (in hundredths)	3.00%		3.00%
Pension Benefits [Member] | Alternative Investments [Member] | Maximum [Member]
Asset category [Abstract]
Total plan assets (in hundredths)	5.00%
Other Benefits [Member]
Change in benefit obligation [Roll Forward]
Obligation at beginning of year	15,381,000		18,096,000
Service cost	348,000		413,000
Interest cost	685,000		647,000
Actuarial loss (gain)	4,272,000		-2,554,000
Benefit payments	-1,142,000		-1,211,000
Foreign currency translation adjustment	-237,000		-10,000
Obligation at end of year	19,307,000		15,381,000		18,096,000
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets at beginning of year	0		0
Actual return on plan assets	0		0
Employer contributions	1,142,000		1,211,000
Benefit payments	-1,142,000		-1,211,000
Foreign currency translation adjustment	0		0
Fair value of plan assets at end of year	0		0		0
(Underfunded) funded status at end of year	-19,307,000		-15,381,000
Unrecognized net actuarial loss (gain)	473,000		-4,016,000
Unrecognized prior service cost	14,000		20,000
Long-term asset	0		0
Current liability	-1,251,000		-1,033,000
Long-term liability	-18,056,000		-14,348,000
Total (underfunded) funded status	-19,307,000		-15,381,000
Service cost	348,000		413,000		380,000
Interest cost	685,000		647,000		635,000
Amortization of prior service cost (credit)	6,000		-2,000		-2,000
Amortization of net (gain) loss	-218,000		-160,000		-73,000
Net periodic benefit (income) cost	821,000		898,000		940,000
Weighted average assumptions in benefit obligations calculations [Abstract]
Discount rate (in hundredths)	4.33%		4.89%
Rate of compensation increases (in hundredths)	5.00%		5.50%
Weighted average assumptions in net periodic benefit calculations [Abstract]
Discount rate (in hundredths)	4.89%		4.06%		4.97%
Rate of compensation increases (in hundredths)	5.50%		5.04%		5.04%
Future expected benefit payments [Abstract]
2015	1,251,000
2016	1,137,000
2017	1,133,000
2018	1,203,000
2019	1,171,000
2020-2024	6,488,000
Total	12,383,000
Company's expected contribution to benefit plans in next fiscal year	1,300,000
U.K Plan [Member]
Change in fair value of plan assets [Roll Forward]
Percent of above benefit obligation on company sponsored UK pension plan (in hundredths)	40.00%		40.00%
Percent above plan assets on company sponsored UK pension plan (in hundredths)	34.00%		34.00%
Actuarial net loss to be recognized as components of net periodic benefit cost in 2015	$2,900,000
[1]	Approximately 51 percent of common stock represents investments in U.S. companies primarily in the health care, utilities, financials, consumer staples, industrials, and information technology sectors. All investments in common stock are listed on U.S. stock exchanges.
[2]	Approximately 84 percent of common stock represents investments in U.S. companies primarily in the health care, utilities, financials, consumer staples, industrials, and information technology sectors. All investments in common stock are listed on U.S. stock exchanges.
[3]	Approximately 40 percent of mutual funds are actively managed funds and approximately 60 percent of mutual funds are index funds. Additionally, 23 percent of the mutual funds assets are invested in U.S. equities, 67 percent in non-U.S. equities, and 10 percent in non-U.S. fixed income securities.
[4]	Approximately 32 percent of mutual funds are actively managed funds and approximately 68 percent of mutual funds are index funds. Additionally, 33 percent of the mutual funds assets are invested in U.S. equities, 58 percent in non-U.S. equities, and 9 percent in non-U.S. fixed income securities.

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities (Details) (USD $)	12 Months Ended
	Dec. 27, 2014		Dec. 28, 2013
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Assets fair value	$95,000	[1]	$2,598,000	[1]
Liabilities fair value	-1,825,000	[1]	-1,767,000	[1]
Commodity Contracts [Member] | Cash Flow Hedging [Member] | Long [Member]
Derivatives, Fair Value [Line Items]
Open future contracts to purchase copper	23,700,000
Time period for open copper future contract purchases	12 months
Fair value of future contracts with gain (loss) position	-809,000
Commodity Contracts [Member] | Fair Value Hedging [Member] | Short [Member]
Derivatives, Fair Value [Line Items]
Open future contracts to sell copper	1,600,000
Time period for open copper future contract sales	3 months
Fair value of future contracts with gain (loss) position	87,000
Other Current Asset [Member] | Commodity Contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Other current assets: Gain positions	99,000		448,000
Other current assets: Loss positions	-4,000		-10,000
Other Current Asset [Member] | Foreign Currency Contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Other current assets: Gain positions	0		836,000
Other Assets [Member] | Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Other assets: Gain positions	0		1,324,000
Other Current Liabilities [Member] | Commodity Contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Other current liability: Gain positions	15,000		340,000
Other current liability: Loss positions	-832,000		-2,107,000
Other Current Liabilities [Member] | Foreign Currency Contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Other current liability: Gain positions			0
Other current liability: Loss positions	-81,000
Other Liabilities [Member] | Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Other liabilities: Loss positions	($927,000)		$0
[1]	Does not include the impact of cash collateral provided to counterparties.

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities Part 2 (Details)

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 27, 2014

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

Feb. 20, 2013

Dec. 27, 2014

Dec. 27, 2014

Dec. 28, 2013

Dec. 27, 2014

Dec. 28, 2013

USD ($)

USD ($)

Commodity Contracts [Member]

Commodity Contracts [Member]

Commodity Contracts [Member]

Commodity Contracts [Member]

Commodity Contracts [Member]

Commodity Contracts [Member]

Commodity Contracts [Member]

Commodity Contracts [Member]

Commodity Contracts [Member]

Foreign Currency Contracts [Member]

Foreign Currency Contracts [Member]

Foreign Currency Contracts [Member]

Foreign Currency Contracts [Member]

Foreign Currency Contracts [Member]

Foreign Currency Contracts [Member]

Inventory [Member]

Inventory [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

USD ($)

Not Designated as Hedging Instrument [Member]

Not Designated as Hedging Instrument [Member]

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Fair Value Hedging [Member]

Fair Value Hedging [Member]

USD ($)

EUR (€)

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Fair Value Hedging [Member]

Fair Value Hedging [Member]

USD ($)

USD ($)

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Cash Flow Hedging [Member]

Cost of Goods Sold [Member]

Cost of Goods Sold [Member]

USD ($)

USD ($)

Cost of Goods Sold [Member]

Cost of Goods Sold [Member]

Cost of Goods Sold [Member]

Cost of Goods Sold [Member]

USD ($)

USD ($)

Property, plant, and equipment, net [Member]

Property, plant, and equipment, net [Member]

Cost of Goods Sold [Member]

Cost of Goods Sold [Member]

USD ($)

USD ($)

Interest Expense [Member]

Interest Expense [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Derivative Instruments, Gain (Loss) [Line Items]

(Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax

($1,088,000)

($3,337,000)

($275,000)

$401,000

($1,435,000)

$834,000

(Gain) Loss Reclassified from AOCI (Effective Portion), Net of Tax

267,000

3,781,000

0

34,000

0

0

Gain (loss) on the derivatives in designated and qualifying fair value hedges

6,783,000

5,115,000

-5,958,000

-4,827,000

Gain (loss) on undesignated derivatives

1,466,000

-611,000

Notional amount

1,500,000

200,000,000

Time period for open forward contracts to purchase

3 months

3 months

Period of interest rate swap

2 years

Interest rate swap, fixed interest rate (in hundredths)

1.40%

Term loan facility, all-in fixed interest rate (in hundredths)

2.70%

Interest rate swap maturity date

11-Dec-17

Deferred net gains (losses), net of tax, included in AOCI

-538,000

157,000

-601,000

Offsetting Assets [Line Items]

Restricted cash in other current assets as collateral related to open derivative contracts

$500,000

$2,100,000

Industry_Segments_Details

Industry Segments (Details) (USD $)	3 Months Ended		12 Months Ended
	Dec. 27, 2014	Sep. 28, 2013	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Segment Reporting Information [Line Items]
Percentage of net consolidated sales threshold constituting a major customer (in hundredths)			10.00%	10.00%	10.00%
Proforma net sales			$2,364,227,000	$2,158,541,000	$2,189,938,000
Long-lived assets	386,883,000		386,883,000	373,050,000	356,961,000
Summary of segment information [Abstract]
Proforma net sales			2,364,227,000	2,158,541,000	2,189,938,000
Cost of goods sold			2,043,719,000	1,862,089,000	1,904,463,000
Depreciation and amortization			33,735,000	32,394,000	31,495,000
Selling, general, and administrative expense			131,740,000	134,914,000	129,456,000
Litigation settlement					-4,050,000
Insurance settlement			0	-106,332,000	-1,500,000
(Gain) loss on disposal of assets	-4,800,000	-39,800,000	-6,259,000	-39,765,000	0
Impairment charges			0	4,304,000	0
Severance	4,200,000		7,296,000	0	3,369,000
Operating income			153,996,000	270,937,000	126,705,000
Interest expense			-5,740,000	-3,990,000	-6,890,000
Other (expense) income, net			-243,000	4,451,000	539,000
Income before income taxes			148,013,000	271,398,000	120,354,000
Expenditures for long-lived assets			66,286,000	65,320,000	65,457,000
Segment assets	1,328,096,000		1,328,096,000	1,247,767,000	1,104,155,000
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Proforma net sales			-12,388,000	-14,549,000	-22,898,000
Summary of segment information [Abstract]
Proforma net sales			-12,388,000	-14,549,000	-22,898,000
Cost of goods sold			-12,386,000	-14,488,000	-22,696,000
Depreciation and amortization			2,203,000	2,252,000	1,547,000
Selling, general, and administrative expense			22,743,000	24,964,000	26,328,000
Litigation settlement					-4,050,000
Insurance settlement				-2,437,000	0
(Gain) loss on disposal of assets			0	0
Impairment charges				0
Severance			0		3,369,000
Operating income			-24,948,000	-24,840,000	-27,396,000
United States [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Proforma net sales			1,752,548,000	1,676,385,000	1,696,589,000
Long-lived assets	322,178,000		322,178,000	325,667,000	306,023,000
Summary of segment information [Abstract]
Proforma net sales			1,752,548,000	1,676,385,000	1,696,589,000
United Kingdom [Member]
Segment Reporting Information [Line Items]
Net assets of foreign operations	112,600,000		112,600,000
United Kingdom [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Proforma net sales			326,832,000	229,659,000	234,684,000
Long-lived assets	43,064,000		43,064,000	22,159,000	23,496,000
Summary of segment information [Abstract]
Proforma net sales			326,832,000	229,659,000	234,684,000
Other [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Proforma net sales			284,847,000	252,497,000	258,665,000
Long-lived assets	21,641,000		21,641,000	25,224,000	27,442,000
Summary of segment information [Abstract]
Proforma net sales			284,847,000	252,497,000	258,665,000
Mexico [Member]
Segment Reporting Information [Line Items]
Net assets of foreign operations	50,400,000		50,400,000
Luxembourg [Member]
Segment Reporting Information [Line Items]
Net assets of foreign operations	45,700,000		45,700,000
China [Member]
Segment Reporting Information [Line Items]
Net assets of foreign operations	23,900,000		23,900,000
Tube and Fittings [Member]
Segment Reporting Information [Line Items]
Proforma net sales			1,143,164,000	972,107,000	986,825,000
Summary of segment information [Abstract]
Proforma net sales			1,143,164,000	972,107,000	986,825,000
Brass Rod and Forgings [Member]
Segment Reporting Information [Line Items]
Proforma net sales			556,985,000	553,896,000	583,940,000
Summary of segment information [Abstract]
Proforma net sales			556,985,000	553,896,000	583,940,000
OEM Components, Tube & Assemblies [Member]
Segment Reporting Information [Line Items]
Proforma net sales			345,991,000	337,772,000	335,461,000
Summary of segment information [Abstract]
Proforma net sales			345,991,000	337,772,000	335,461,000
Valves and Plumbing Specialties [Member]
Segment Reporting Information [Line Items]
Proforma net sales			262,504,000	239,822,000	231,278,000
Summary of segment information [Abstract]
Proforma net sales			262,504,000	239,822,000	231,278,000
Other [Member]
Segment Reporting Information [Line Items]
Proforma net sales			55,583,000	54,944,000	52,434,000
Summary of segment information [Abstract]
Proforma net sales			55,583,000	54,944,000	52,434,000
Plumbing and Refrigeration Segment [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Proforma net sales			1,416,701,000	1,225,306,000	1,238,230,000
Summary of segment information [Abstract]
Proforma net sales			1,416,701,000	1,225,306,000	1,238,230,000
Cost of goods sold			1,215,282,000	1,043,059,000	1,060,755,000
Depreciation and amortization			19,613,000	17,117,000	16,513,000
Selling, general, and administrative expense			87,539,000	85,471,000	75,448,000
Litigation settlement					0
Insurance settlement				-103,895,000	-1,500,000
(Gain) loss on disposal of assets			-6,259,000	-39,765,000
Impairment charges				4,173,000
Severance			7,296,000		0
Operating income			93,230,000	219,146,000	87,014,000
Expenditures for long-lived assets			55,098,000	47,222,000	24,030,000
Segment assets	664,784,000		664,784,000	625,371,000	531,429,000
OEM Segment [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Proforma net sales			959,914,000	947,784,000	974,606,000
Summary of segment information [Abstract]
Proforma net sales			959,914,000	947,784,000	974,606,000
Cost of goods sold			840,823,000	833,518,000	866,404,000
Depreciation and amortization			11,919,000	13,025,000	13,435,000
Selling, general, and administrative expense			21,458,000	24,479,000	27,680,000
Litigation settlement					0
Insurance settlement				0	0
(Gain) loss on disposal of assets			0	0
Impairment charges				131,000
Severance			0		0
Operating income			85,714,000	76,631,000	67,087,000
Expenditures for long-lived assets			10,788,000	14,845,000	24,137,000
Segment assets	313,245,000		313,245,000	305,052,000	290,058,000
General Corporate [Member]
Summary of segment information [Abstract]
Expenditures for long-lived assets			400,000	3,253,000	17,290,000
Segment assets	$350,067,000		$350,067,000	$317,344,000	$282,668,000

Quarterly_Financial_Informatio2

Quarterly Financial Information (Unaudited) (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 27, 2014		Sep. 27, 2014		Jun. 28, 2014		Mar. 29, 2014		Dec. 28, 2013		Sep. 28, 2013		Jun. 29, 2013		Mar. 30, 2013		Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Quarterly Financial Information (Unaudited) [Abstract]
Net sales	$537,342,000	[1]	$602,820,000	[1]	$649,691,000	[1]	$574,374,000	[1]	$487,715,000	[1]	$528,854,000	[1]	$582,282,000	[1]	$559,690,000	[1]
Gross profit	68,453,000	[1],[2]	81,542,000	[1],[2]	91,916,000	[1],[2]	78,597,000	[1],[2]	65,903,000	[1],[2]	72,552,000	[1],[2]	81,157,000	[1],[2]	76,840,000	[1],[2]
Consolidated net income	18,049,000	[1],[3],[4]	24,322,000	[1],[3]	35,209,000	[1],[3]	24,954,000	[1],[3]	15,020,000	[1]	39,993,000	[1],[5]	91,842,000	[1],[6]	26,434,000	[1]	102,534,000	173,289,000	83,673,000
Net income attributable to Mueller Industries, Inc.	17,987,000	[1]	23,823,000	[1]	35,045,000	[1]	24,706,000	[1]	15,384,000	[1]	39,864,000	[1]	91,150,000	[1]	26,202,000	[1]	101,560,000	172,600,000	82,395,000
Basic earnings per share (in dollars per share)	$0.32	[1]	$0.42	[1]	$0.63	[1]	$0.44	[1]	$0.28	[1]	$0.71	[1]	$1.64	[1]	$0.47	[1]	$1.81	$3.10	$1.17
Diluted earnings per share (in dollars per share)	$0.32	[1]	$0.42	[1]	$0.62	[1]	$0.44	[1]	$0.27	[1]	$0.71	[1]	$1.62	[1]	$0.46	[1]	$1.79	$3.06	$1.15
Dividends per share (in dollars per share)	$0.08	[1]	$0.08	[1]	$0.08	[1]	$0.08	[1]	$0.06	[1]	$0.06	[1]	$0.06	[1]	$0.06	[1]	$0.30	$0.25	$0.21
Pre-tax charges related to severance	4,200,000																7,296,000	0	3,369,000
Gain on insurance settlement													106,300,000
Gain on sale of manufacturing assets	4,800,000										39,800,000						6,259,000	39,765,000	0
Pre-tax impairment charges related to real property											$4,300,000
[1]	The sum of quarterly amounts may not equal the annual amounts reported due to rounding. In addition, the earnings per share amounts are computed independently for each quarter while the full year is based on the weighted average shares outstanding.
[2]	Gross profit is net sales less cost of goods sold, which excludes depreciation and amortization.
[3]	Includes income earned by Howell, acquired during Q4 2013, and losses incurred by Yorkshire, acquired during Q1 2014
[4]	Includes $4.8 million pre-tax gain on sale of assets and $4.2 million of pre-tax charges related to severance
[5]	Includes $39.8 million pre-tax gain on sale of manufacturing assets and pre-tax impairment charges of $4.3 million primarily related to real property associated with the aforementioned plastics sale transaction.
[6]	Includes $106.3 million pre-tax gain from settlement of insurance claims.

SCHEDULE_IIVALUATION_AND_QUALI1

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013		Dec. 29, 2012
Allowance for Doubtful Accounts [Member]
Valuation Allowances and Reserves (Roll Forward)
Balance	$2,391		$1,644		$1,564
Charged to costs and expenses	-500		273		867
Other additions	18	[1]	812	[1]	109	[1]
Deductions	1,243		338		896
Balance	666		2,391		1,644
Environmental Reserves [Member]
Valuation Allowances and Reserves (Roll Forward)
Balance	23,637		24,635		22,892
Charged to costs and expenses	1,187		986		3,056
Other additions	0		0		0
Deductions	2,163		1,984		1,313
Balance	22,661		23,637		24,635
Valuation Allowance of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Roll Forward)
Balance	22,544		30,394		29,705
Charged to costs and expenses	-5,630		332		-1,224
Other additions	2,282		0		1,913
Deductions	2,077		8,182		0
Balance	$17,119		$22,544		$30,394
[1]	Other consists primarily of bad debt recoveries as well as the effect of fluctuating foreign currency exchange rates in all years presented.