Commitments and Contingencies	6 Months Ended
Mar. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies We are involved in various legal proceedings that have arisen in the normal course of operations, including the proceedings summarized below. The effect of the outcome of these matters on our future results of operations cannot be predicted with certainty as any such effect depends on future results of operations and the amount and timing of the resolution of such matters. Other than the litigation described below, we do not believe that any of our outstanding litigation would have a material adverse effect on our businesses, operations or prospects. Environmental. We are subject to a wide variety of laws and regulations concerning the protection of the environment, both with respect to the operations at many of our properties and with respect to remediating environmental conditions that may exist at our own or other properties. We strive to comply with federal, state and local environmental laws and regulations. We accrue for environmental expenses resulting from existing conditions that relate to past operations when the costs are probable and reasonably estimable. In September 1987, U.S. Pipe implemented an Administrative Consent Order (“ACO”) for its Burlington, New Jersey property, which was required under the New Jersey Environmental Cleanup Responsibility Act (now known as the Industrial Site Recovery Act). We retained this property and did not sell it to the buyer of our U.S. Pipe business when it was sold on April 1, 2012 (see Note 3. Discontinued Operations and Assets Held for Sale). The ACO required soil and ground-water cleanup, and U.S. Pipe completed, and received final approval on, the soil cleanup required by the ACO. We expect ground-water issues as well as issues associated with the demolition of former manufacturing facilities at this site will continue and remediation by us could be required. Long-term ground-water monitoring may also be required, but we do not know how long such monitoring would be required and do not believe monitoring or further remediation costs, if any, will have a material adverse effect on our financial condition or results of operations. On July 13, 2010, Rohcan Investments Limited (“Rohcan”), the former owner of property leased by Mueller Canada Ltd. and located in Milton, Ontario, filed suit against Mueller Canada Ltd. and its directors seeking C$10 million in damages arising from the defendants' alleged environmental contamination of the property and breach of lease. Mueller Canada Ltd. leased the property from 1988 through 2008. We are pursuing indemnification from a former owner for certain potential liabilities that are alleged in this lawsuit, and we have accrued for other liabilities not covered by indemnification. On December 7, 2011, the Court denied the plaintiff's motion for summary judgment. In the acquisition agreement pursuant to which a predecessor to Tyco sold our Mueller Co. and Anvil businesses to the prior owners of these businesses in August 1999, Tyco agreed to indemnify us and our affiliates, among other things, for all “Excluded Liabilities.” Excluded Liabilities include, among other things, substantially all liabilities relating to the time prior to August 1999, including environmental liabilities. The indemnity survives indefinitely. Tyco's indemnity does not cover liabilities to the extent caused by us or the operation of our businesses after August 1999, nor does it cover liabilities arising with respect to businesses or sites acquired after August 1999. In June 2007, Tyco was separated into three separate publicly traded companies. In September 2011, Tyco International Ltd., one of the companies that was separated in the June 2007 split, announced it would split into three separate companies. Should Tyco's successors become financially unable or fail to comply with the terms of the indemnity, we may be responsible for such obligations or liabilities. Walter Energy-related Income Taxes. Each member of a consolidated group for federal income tax purposes is severally liable for the federal income tax liability of each other member of the consolidated group for any year in which it is a member of the group at any time during such year. Each member of the Walter Energy consolidated group, which included us and U.S. Pipe through December 14, 2006, is also jointly and severally liable for pension and benefit funding and termination liabilities of other group members, as well as certain benefit plan taxes. Accordingly, we could be liable under such provisions in the event any such liability is incurred, and not discharged, by any other member of the Walter Energy consolidated group for any period during which we were included in the Walter Energy consolidated group. The sale of our U.S. Pipe business does not affect our exposure to Walter Energy-related income taxes, and we have no right of indemnification from U.S. Pipe. A dispute exists with regard to federal income taxes for 1980 through 1994 allegedly owed by the Walter Energy consolidated group, which included U.S. Pipe during these periods. According to Walter Energy's last available public filing on the matter, Walter Energy's management estimated that the amount of tax claimed by the IRS was approximately $34.0 million for issues currently in dispute in bankruptcy court for matters unrelated to us. This amount is subject to interest and penalties. Of the $34.0 million in claimed tax, $21.0 million represents issues in which the IRS is not challenging the deductibility of the particular expense but only whether such expense is deductible in a particular year. Walter Energy's management believes that Walter Energy's financial exposure should be limited to interest and possible penalties and the amount of any tax claimed will be offset by favorable adjustments in other years. In addition, the IRS previously issued a Notice of Proposed Deficiency assessing additional tax of $82.2 million for the fiscal years ended May 31, 2000 through December 31, 2005. Walter Energy filed a formal protest with the IRS, but had not reached a final resolution with the Appeals Division at March 31, 2012. The unresolved issues relate primarily to Walter Energy's method of recognizing revenue on the sale of homes and related interest on the installment notes receivable. The items at issue relate primarily to the timing of revenue recognition and consequently, should the IRS prevail on its positions, Walter Energy's financial exposure should be limited to interest and penalties. As a matter of law, we are jointly and severally liable for any final tax determination for any year in which any of our subsidiaries were members of the Walter Energy consolidated group, which means that we would be liable in the event Walter Energy is unable to pay any amounts owed. Walter Energy has disclosed that it believes its filing positions have substantial merit and that it intends to defend vigorously any claims asserted. Walter Energy effectively controlled all of our tax decisions for periods during which we were a member of the Walter Energy consolidated group for federal income tax purposes and certain combined, consolidated or unitary state and local income tax groups. Under the terms of the income tax allocation agreement between us and Walter Energy dated May 26, 2006, we generally compute our tax liability on a stand-alone basis, but Walter Energy has sole authority to respond to and conduct all tax proceedings (including tax audits) relating to our federal income and combined state returns, to file all such returns on our behalf and to determine the amount of our liability to (or entitlement to payment from) Walter Energy for such previous periods. This arrangement may result in conflicts between Walter Energy and us. The separation of the Company from Walter Energy on December 14, 2006 was intended to qualify as a tax-free spin-off under Section 355 of the Internal Revenue Code of 1986, as amended. In addition, the tax allocation agreement provides that if the spin-off is determined not to be tax-free pursuant to Section 355, we generally will be responsible for any taxes incurred by Walter Energy or its shareholders if such taxes result from certain of our actions or omissions and for a percentage of any such taxes that are not a result of our actions or omissions or Walter Energy's actions or omissions or taxes based upon our market value relative to Walter Energy's market value. Additionally, to the extent that Walter Energy was unable to pay taxes, if any, attributable to the spin-off and for which it is responsible under the tax allocation agreement, we could be liable for those taxes as a result of being a member of the Walter Energy consolidated group for the year in which the spin-off occurred. In accordance with the income tax allocation agreement, Walter Energy used certain tax assets of a predecessor to the Company in its calendar 2006 tax return for which payment to us is required. The income tax allocation agreement only requires Walter Energy to make the payment upon realization of the tax benefit by receiving a refund or otherwise offsetting taxes due. Walter Energy currently owes us $10.9 million that is payable pending completion of an IRS audit of Walter Energy's 2006 tax year and the related refund of tax from that year. We recorded this receivable in other noncurrent assets. Indemnifications. We are a party to contracts in which it is common for us to agree to indemnify third parties for certain liabilities that arise out of or relate to the subject matter of the contract. In some cases, this indemnity extends to related liabilities arising from the negligence of the indemnified parties, but usually excludes any liabilities caused by gross negligence or willful misconduct. We cannot estimate the potential amount of future payments under these indemnities until events arise that would trigger a liability under the indemnities. Additionally, in connection with the sale of assets and the divestiture of businesses, such as the divestiture of our U.S. Pipe business (see Note 3. Discontinued Operations and Assets Held for Sale), we may agree to indemnify buyers and related parties for certain losses or liabilities incurred by these parties with respect to: (i) the representations and warranties made by us to these parties in connection with the sale and (ii) liabilities related to the pre-closing operations of the assets or business sold. Indemnities related to pre-closing operations generally include certain environmental and tax liabilities and other liabilities not assumed by these parties in the transaction. Indemnities related to the pre-closing operations of sold assets or businesses normally do not represent additional liabilities to us, but simply serve to protect these parties from potential liability associated with our obligations existing at the time of the sale. As with any liability, we have accrued for those pre-closing obligations that are considered probable and reasonably estimable. Should circumstances change, increasing the likelihood of payments related to a specific indemnity, we will accrue a liability when future payment is probable and the amount is reasonably estimable. Other Matters. We are party to a number of other lawsuits arising in the ordinary course of our businesses, including product liability cases for products manufactured by us or third parties. We provide for costs relating to these matters when a loss is probable and the amount is reasonably estimable. Administrative costs related to these matters are expensed as incurred. The effect of the outcome of these matters on our future results of operations cannot be predicted with certainty as any such effect depends on future results of operations and the amount and timing of the resolution of such matters. While the results of litigation cannot be predicted with certainty, we believe that the final outcome of such other litigation is not likely to have a materially adverse effect on our consolidated financial statements.

Commitments and Contingencies

We are involved in various legal proceedings that have arisen in the normal course of operations, including the proceedings summarized below. The effect of the outcome of these matters on our future results of operations cannot be predicted with certainty as any such effect depends on future results of operations and the amount and timing of the resolution of such matters. Other than the litigation described below, we do not believe that any of our outstanding litigation would have a material adverse effect on our businesses, operations or prospects.

Environmental. We are subject to a wide variety of laws and regulations concerning the protection of the environment, both with respect to the operations at many of our properties and with respect to remediating environmental conditions that may exist at our own or other properties. We strive to comply with federal, state and local environmental laws and regulations. We accrue for environmental expenses resulting from existing conditions that relate to past operations when the costs are probable and reasonably estimable.

In September 1987, U.S. Pipe implemented an Administrative Consent Order (“ACO”) for its Burlington, New Jersey property, which was required under the New Jersey Environmental Cleanup Responsibility Act (now known as the Industrial Site Recovery Act). We retained this property and did not sell it to the buyer of our U.S. Pipe business when it was sold on April 1, 2012 (see Note 3. Discontinued Operations and Assets Held for Sale). The ACO required soil and ground-water cleanup, and U.S. Pipe completed, and received final approval on, the soil cleanup required by the ACO. We expect ground-water issues as well as issues associated with the demolition of former manufacturing facilities at this site will continue and remediation by us could be required. Long-term ground-water monitoring may also be required, but we do not know how long such monitoring would be required and do not believe monitoring or further remediation costs, if any, will have a material adverse effect on our financial condition or results of operations.

On July 13, 2010, Rohcan Investments Limited (“Rohcan”), the former owner of property leased by Mueller Canada Ltd. and located in Milton, Ontario, filed suit against Mueller Canada Ltd. and its directors seeking C$10 million in damages arising from the defendants' alleged environmental contamination of the property and breach of lease. Mueller Canada Ltd. leased the property from 1988 through 2008. We are pursuing indemnification from a former owner for certain potential liabilities that are alleged in this lawsuit, and we have accrued for other liabilities not covered by indemnification. On December 7, 2011, the Court denied the plaintiff's motion for summary judgment.

In the acquisition agreement pursuant to which a predecessor to Tyco sold our Mueller Co. and Anvil businesses to the prior owners of these businesses in August 1999, Tyco agreed to indemnify us and our affiliates, among other things, for all “Excluded Liabilities.” Excluded Liabilities include, among other things, substantially all liabilities relating to the time prior to August 1999, including environmental liabilities. The indemnity survives indefinitely. Tyco's indemnity does not cover liabilities to the extent caused by us or the operation of our businesses after August 1999, nor does it cover liabilities arising with respect to businesses or sites acquired after August 1999. In June 2007, Tyco was separated into three separate publicly traded companies. In September 2011, Tyco International Ltd., one of the companies that was separated in the June 2007 split, announced it would split into three separate companies. Should Tyco's successors become financially unable or fail to comply with the terms of the indemnity, we may be responsible for such obligations or liabilities.

Walter Energy-related Income Taxes. Each member of a consolidated group for federal income tax purposes is severally liable for the federal income tax liability of each other member of the consolidated group for any year in which it is a member of the group at any time during such year. Each member of the Walter Energy consolidated group, which included us and U.S. Pipe through December 14, 2006, is also jointly and severally liable for pension and benefit funding and termination liabilities of other group members, as well as certain benefit plan taxes. Accordingly, we could be liable under such provisions in the event any such liability is incurred, and not discharged, by any other member of the Walter Energy consolidated group for any period during which we were included in the Walter Energy consolidated group. The sale of our U.S. Pipe business does not affect our exposure to Walter Energy-related income taxes, and we have no right of indemnification from U.S. Pipe.

A dispute exists with regard to federal income taxes for 1980 through 1994 allegedly owed by the Walter Energy consolidated group, which included U.S. Pipe during these periods. According to Walter Energy's last available public filing on the matter, Walter Energy's management estimated that the amount of tax claimed by the IRS was approximately $34.0 million for issues currently in dispute in bankruptcy court for matters unrelated to us. This amount is subject to interest and penalties. Of the $34.0 million in claimed tax, $21.0 million represents issues in which the IRS is not challenging the deductibility of the particular expense but only whether such expense is deductible in a particular year. Walter Energy's management believes that Walter Energy's financial exposure should be limited to interest and possible penalties and the amount of any tax claimed will be offset by favorable adjustments in other years.

In addition, the IRS previously issued a Notice of Proposed Deficiency assessing additional tax of $82.2 million for the fiscal years ended May 31, 2000 through December 31, 2005. Walter Energy filed a formal protest with the IRS, but had not reached a final resolution with the Appeals Division at March 31, 2012. The unresolved issues relate primarily to Walter Energy's method of recognizing revenue on the sale of homes and related interest on the installment notes receivable. The items at issue relate primarily to the timing of revenue recognition and consequently, should the IRS prevail on its positions, Walter Energy's financial exposure should be limited to interest and penalties. As a matter of law, we are jointly and severally liable for any final tax determination for any year in which any of our subsidiaries were members of the Walter Energy consolidated group, which means that we would be liable in the event Walter Energy is unable to pay any amounts owed. Walter Energy has disclosed that it believes its filing positions have substantial merit and that it intends to defend vigorously any claims asserted.

Walter Energy effectively controlled all of our tax decisions for periods during which we were a member of the Walter Energy consolidated group for federal income tax purposes and certain combined, consolidated or unitary state and local income tax groups. Under the terms of the income tax allocation agreement between us and Walter Energy dated May 26, 2006, we generally compute our tax liability on a stand-alone basis, but Walter Energy has sole authority to respond to and conduct all tax proceedings (including tax audits) relating to our federal income and combined state returns, to file all such returns on our behalf and to determine the amount of our liability to (or entitlement to payment from) Walter Energy for such previous periods. This arrangement may result in conflicts between Walter Energy and us.

The separation of the Company from Walter Energy on December 14, 2006 was intended to qualify as a tax-free spin-off under Section 355 of the Internal Revenue Code of 1986, as amended. In addition, the tax allocation agreement provides that if the spin-off is determined not to be tax-free pursuant to Section 355, we generally will be responsible for any taxes incurred by Walter Energy or its shareholders if such taxes result from certain of our actions or omissions and for a percentage of any such taxes that are not a result of our actions or omissions or Walter Energy's actions or omissions or taxes based upon our market value relative to Walter Energy's market value. Additionally, to the extent that Walter Energy was unable to pay taxes, if any, attributable to the spin-off and for which it is responsible under the tax allocation agreement, we could be liable for those taxes as a result of being a member of the Walter Energy consolidated group for the year in which the spin-off occurred.

In accordance with the income tax allocation agreement, Walter Energy used certain tax assets of a predecessor to the Company in its calendar 2006 tax return for which payment to us is required. The income tax allocation agreement only requires Walter Energy to make the payment upon realization of the tax benefit by receiving a refund or otherwise offsetting taxes due. Walter Energy currently owes us $10.9 million that is payable pending completion of an IRS audit of Walter Energy's 2006 tax year and the related refund of tax from that year. We recorded this receivable in other noncurrent assets.

Indemnifications. We are a party to contracts in which it is common for us to agree to indemnify third parties for certain liabilities that arise out of or relate to the subject matter of the contract. In some cases, this indemnity extends to related liabilities arising from the negligence of the indemnified parties, but usually excludes any liabilities caused by gross negligence or willful misconduct. We cannot estimate the potential amount of future payments under these indemnities until events arise that would trigger a liability under the indemnities.

Additionally, in connection with the sale of assets and the divestiture of businesses, such as the divestiture of our U.S. Pipe business (see Note 3. Discontinued Operations and Assets Held for Sale), we may agree to indemnify buyers and related parties for certain losses or liabilities incurred by these parties with respect to: (i) the representations and warranties made by us to these parties in connection with the sale and (ii) liabilities related to the pre-closing operations of the assets or business sold. Indemnities related to pre-closing operations generally include certain environmental and tax liabilities and other liabilities not assumed by these parties in the transaction.

Indemnities related to the pre-closing operations of sold assets or businesses normally do not represent additional liabilities to us, but simply serve to protect these parties from potential liability associated with our obligations existing at the time of the sale. As with any liability, we have accrued for those pre-closing obligations that are considered probable and reasonably estimable. Should circumstances change, increasing the likelihood of payments related to a specific indemnity, we will accrue a liability when future payment is probable and the amount is reasonably estimable.

Other Matters. We are party to a number of other lawsuits arising in the ordinary course of our businesses, including product liability cases for products manufactured by us or third parties. We provide for costs relating to these matters when a loss is probable and the amount is reasonably estimable. Administrative costs related to these matters are expensed as incurred. The effect of the outcome of these matters on our future results of operations cannot be predicted with certainty as any such effect depends on future results of operations and the amount and timing of the resolution of such matters. While the results of litigation cannot be predicted with certainty, we believe that the final outcome of such other litigation is not likely to have a materially adverse effect on our consolidated financial statements.