Summary of Significant Accounting Policies (Policies)	12 Months Ended
Sep. 30, 2014
Accounting Policies [Abstract]
Inventory Supplies, Policy	-Other current assets include maintenance supplies and tooling costs. Costs for perishable tools and maintenance items are expensed when put into service. Costs for more durable items are amortized over their estimated useful lives, ranging from 3 to 10 years.
Revenue Recognition	Revenue Recognition-Revenue is recognized when delivery of products has occurred or services have been rendered and there is persuasive evidence of a sales arrangement, selling prices are fixed or determinable and collectibility is reasonably assured. Revenue is reported net of estimated discounts, returns and rebates as “net sales.”
Shipping and Handling	Shipping and Handling-Costs to ship products to customers are included in cost of sales. Amounts billed to customers, if any, to cover shipping and handling costs are included in net sales.
Share-based Compensation	Stock-based Compensation-Compensation expense for stock-based awards granted to employees and directors is based on the fair value at the grant dates for most of our outstanding stock-based compensation awards, and is based on the fair value at each reporting date for our Phantom Plan and cash-settled performance share awards. See Note 10 for more information regarding our stock-based compensation. Stock-based compensation expense is a component of selling, general and administrative expenses.
Cash and Cash Equivalents	Cash and Cash Equivalents-All highly liquid investments with remaining maturities of 90 days or less when purchased are classified as cash equivalents. Where there is no right of offset against cash balances, outstanding checks are included in accounts payable.
Receivables	Receivables-Receivables are amounts due from customers. To reduce credit risk, credit investigations are generally performed prior to accepting orders from new customers and, when necessary, letters of credit, bonds or other instruments are required to ensure payment. The estimated allowance for doubtful receivables is based upon judgments and estimates of expected losses and specific identification of problem accounts. Significantly weaker than anticipated industry or economic conditions could impact customers' ability to pay such that actual losses may be greater than the amounts provided for in this allowance. The periodic evaluation of the adequacy of the allowance for doubtful receivables is based on an analysis of prior collection experience, specific customer creditworthiness and current economic trends within the industries served. In circumstances where we expect a specific customer's inability to meet its financial obligations (e.g., bankruptcy filings or substantial downgrading of credit ratings), we record a specific allowance to reduce the receivable to the amount management reasonably believes will be collected.
Inventories	Inventories-Inventories are recorded at the lower of first-in, first-out method cost or market value. We evaluate our inventory in terms of excess and obsolete exposures. This evaluation includes such factors as anticipated usage, inventory turnover, inventory levels and ultimate product sales value. Inventory cost includes an overhead component that is affected by levels of production and actual costs incurred. Management periodically evaluates the effects of production levels and costs capitalized as part of inventory.
Property, Plant and Equipment	Property, Plant and Equipment-Property, plant and equipment is recorded at cost, less accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets. Estimated useful lives are 10 to 20 years for land improvements, 10 to 40 years for buildings and 3 to 15 years for machinery and equipment. Leasehold improvements and capitalized leases are depreciated using the straight-line method over the lesser of the useful life of the asset or the remaining lease term. Gains and losses upon disposition are reflected in operating results in the period of disposition. Direct internal and external costs to implement computer systems and internal-use software are capitalized. Capitalized costs are depreciated over the estimated useful life of the system or software, generally 3 to 6 years, beginning when site installation or module development is complete and ready for use. Liabilities are recognized at fair value for asset retirement obligations related to plant and landfill closures in the period in which they are incurred and the carrying amounts of the related long-lived assets are correspondingly increased. Over time, the liabilities are accreted to their estimated future values. At September 30, 2014 and 2013, asset retirement obligations were $3.2 million and $3.6 million, respectively.
Accounting for the Impairment of Long-Lived Assets	Accounting for the Impairment of Long-Lived Assets-We test intangible assets that have an indefinite life and goodwill for impairment annually (or more frequently if events or circumstances indicate possible impairment.) We perform our annual impairment testing at September 1. We amortize finite-lived intangible assets over their respective estimated useful lives and review for impairment if events or circumstances indicate possible impairment.
Workers Compensation	Workers Compensation-Our exposure to workers compensation claims is generally limited to $1 million per incident. Liabilities, including those related to claims incurred but not reported, are recorded principally using annual valuations based on discounted future expected payments and using historical data combined with insurance industry data when historical data is limited. We are indemnified under an agreement with a predecessor to Tyco for all Mueller Co. and Anvil workers compensation liabilities related to incidents that occurred prior to August 16, 1999. See Note 16. We retained U.S. Pipe workers compensation liabilities related to incidents that occurred prior to April 1, 2012, but the Purchaser has agreed to reimburse us for up to $11.8 million in payments we make related to these liabilities. At September 30, 2014, the remaining reimbursements may be up to $6.5 million, which we have recorded on a discounted basis as $1.6 million in other current assets and $4.0 million in other noncurrent assets. See Note 5. On an undiscounted basis, workers compensation liabilities were $17.0 million and $20.0 million at September 30, 2014 and 2013, respectively. On a discounted basis, workers compensation liabilities were $14.7 million and $17.2 million at September 30, 2014 and 2013, respectively. We apply a discount rate at a risk-free interest rate, generally a U.S. Treasury bill rate, for each policy period. The rate used is one with a duration that corresponds to the weighted average expected payout period for each policy period. Once a discount rate is applied to a policy period, it remains the discount rate for that policy period until al
Warranty Costs	Warranty Costs-We accrue for warranty expenses that can include customer costs of repair and/or replacement, including labor, materials, equipment, freight and reasonable overhead costs. We accrue for the estimated cost of product warranties at the time of sale if such costs are determined to be reasonably estimable at that time. Warranty cost estimates are revised throughout applicable warranty periods as better information regarding warranty costs becomes available.
Deferred Financing Fees	Deferred Financing Fees-Costs of debt financing are charged to expense over the lives of the related financing agreements, which ranged from 5 to 10 years. Remaining costs and the future period over which they would be charged to expense are reassessed when amendments to the related financing agreements or prepayments occur. Deferred financing fees of $6.7 million at September 30, 2014 were scheduled to amortize as follows: $2.1 million related to the ABL Agreement amortizes on a straight-line basis; $2.8 million related to the Senior Unsecured Notes amortizes using the effective-interest rate method; and $1.8 million related to the Senior Subordinated Notes amortizes using the effective-interest rate method. All such amortization would have been over the remaining term of the respective debt.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities-Changes in the fair value of derivative instruments accounted for as effective cash-flow hedges were recorded to accumulated other comprehensive loss. Gains and losses on derivative instruments not qualifying as effective cash-flow hedges, representing hedge ineffectiveness and hedge components excluded from the assessment of effectiveness, were recognized in earnings in the periods in which they occurred. Our ongoing business operations expose us to commodity price risk and interest rate risk, which we had previously managed to some extent using derivative instruments. We used natural gas swap contracts at U.S. Pipe to manage the price risk associated with purchases of natural gas used in certain of our manufacturing processes and interest rate swap contracts to manage interest rate risk associated with our variable-rate borrowings. During 2010, we terminated all of our remaining interest rate swap contracts and we reclassified expense related to these swap contracts from accumulated other comprehensive loss to interest expense in 2012. We have not initiated any new interest rate swap contracts since then. During 2012, we terminated our remaining natural gas swap contract and have not initiated any new natural gas swap contracts since then. We had designated our natural gas swap contracts and interest rate swap contracts as cash flow hedges of our purchases of natural gas and our interest payments, respectively. As a result, to the extent the hedges were effective, the changes in the fair value of these contracts prior to settlement were reported as a component of accumulated other comprehensive loss and reclassified into earnings in the periods during which the hedged transactions affected, or were expected to affect, earnings.
Income Taxes	Income Taxes-Deferred tax liabilities and deferred tax assets are recognized for the expected future tax consequences of events that have been included in the financial statements or tax returns. Such liabilities and assets are determined based on the differences between the financial statement basis and the tax basis of assets and liabilities, using tax rates in effect for the years in which the differences are expected to reverse. A valuation allowance is provided when, based upon the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. We only record tax benefits for positions that management believes are more likely than not of being sustained under audit based solely on the technical merits of the associated tax position. The amount of tax benefit recognized for any position that meets the more likely than not threshold is the largest amount of the tax benefit that we believe is greater than 50% likely of being realized.
Environmental Expenditures	Environmental Expenditures-We capitalize environmental expenditures that increase the life or efficiency of noncurrent assets or that reduce or prevent environmental contamination. We accrue for environmental expenses resulting from existing conditions that relate to past operations when the costs are probable and reasonably estimable. We are indemnified under an agreement with a predecessor to Tyco for certain environmental liabilities that existed at August 16, 1999. See Note 16.
Research and Development	Research and Development-Research and development costs are expensed as incurred.
Advertising	Advertising-Advertising costs are expensed as incurred.
Translation of Foreign Currency	Translation of Foreign Currency-Assets and liabilities of our businesses whose functional currency is other than the U.S. dollar are translated into U.S. dollars using currency exchange rates at the balance sheet date. Revenues and expenses are translated at average currency exchange rates during the period. Foreign currency translation gains and losses are reported as a component of accumulated other comprehensive loss. Gains and losses resulting from foreign currency transactions are included in operating results as incurred.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Sep. 30, 2014

-Other current assets include maintenance supplies and tooling costs. Costs for perishable tools and maintenance items are expensed when put into service. Costs for more durable items are amortized over their estimated useful lives, ranging from 3 to 10 years.

Revenue Recognition

Revenue Recognition-Revenue is recognized when delivery of products has occurred or services have been rendered and there is persuasive evidence of a sales arrangement, selling prices are fixed or determinable and collectibility is reasonably assured. Revenue is reported net of estimated discounts, returns and rebates as “net sales.”

Shipping and Handling

Shipping and Handling-Costs to ship products to customers are included in cost of sales. Amounts billed to customers, if any, to cover shipping and handling costs are included in net sales.

Share-based Compensation

Stock-based Compensation-Compensation expense for stock-based awards granted to employees and directors is based on the fair value at the grant dates for most of our outstanding stock-based compensation awards, and is based on the fair value at each reporting date for our Phantom Plan and cash-settled performance share awards. See Note 10 for more information regarding our stock-based compensation. Stock-based compensation expense is a component of selling, general and administrative expenses.

Cash and Cash Equivalents

Cash and Cash Equivalents-All highly liquid investments with remaining maturities of 90 days or less when purchased are classified as cash equivalents. Where there is no right of offset against cash balances, outstanding checks are included in accounts payable.

Receivables

Receivables-Receivables are amounts due from customers. To reduce credit risk, credit investigations are generally performed prior to accepting orders from new customers and, when necessary, letters of credit, bonds or other instruments are required to ensure payment.

The estimated allowance for doubtful receivables is based upon judgments and estimates of expected losses and specific identification of problem accounts. Significantly weaker than anticipated industry or economic conditions could impact customers' ability to pay such that actual losses may be greater than the amounts provided for in this allowance. The periodic evaluation of the adequacy of the allowance for doubtful receivables is based on an analysis of prior collection experience, specific customer creditworthiness and current economic trends within the industries served. In circumstances where we expect a specific customer's inability to meet its financial obligations (e.g., bankruptcy filings or substantial downgrading of credit ratings), we record a specific allowance to reduce the receivable to the amount management reasonably believes will be collected.

Inventories

Inventories-Inventories are recorded at the lower of first-in, first-out method cost or market value. We evaluate our inventory in terms of excess and obsolete exposures. This evaluation includes such factors as anticipated usage, inventory turnover, inventory levels and ultimate product sales value. Inventory cost includes an overhead component that is affected by levels of production and actual costs incurred. Management periodically evaluates the effects of production levels and costs capitalized as part of inventory.

Property, Plant and Equipment

Property, Plant and Equipment-Property, plant and equipment is recorded at cost, less accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets. Estimated useful lives are 10 to 20 years for land improvements, 10 to 40 years for buildings and 3 to 15 years for machinery and equipment. Leasehold improvements and capitalized leases are depreciated using the straight-line method over the lesser of the useful life of the asset or the remaining lease term. Gains and losses upon disposition are reflected in operating results in the period of disposition.

Direct internal and external costs to implement computer systems and internal-use software are capitalized. Capitalized costs are depreciated over the estimated useful life of the system or software, generally 3 to 6 years, beginning when site installation or module development is complete and ready for use.

Liabilities are recognized at fair value for asset retirement obligations related to plant and landfill closures in the period in which they are incurred and the carrying amounts of the related long-lived assets are correspondingly increased. Over time, the liabilities are accreted to their estimated future values. At September 30, 2014 and 2013, asset retirement obligations were $3.2 million and $3.6 million, respectively.

Accounting for the Impairment of Long-Lived Assets

Accounting for the Impairment of Long-Lived Assets-We test intangible assets that have an indefinite life and goodwill for impairment annually (or more frequently if events or circumstances indicate possible impairment.) We perform our annual impairment testing at September 1. We amortize finite-lived intangible assets over their respective estimated useful lives and review for impairment if events or circumstances indicate possible impairment.

Workers Compensation

Workers Compensation-Our exposure to workers compensation claims is generally limited to $1 million per incident. Liabilities, including those related to claims incurred but not reported, are recorded principally using annual valuations based on discounted future expected payments and using historical data combined with insurance industry data when historical data is limited. We are indemnified under an agreement with a predecessor to Tyco for all Mueller Co. and Anvil workers compensation liabilities related to incidents that occurred prior to August 16, 1999. See Note 16. We retained U.S. Pipe workers compensation liabilities related to incidents that occurred prior to April 1, 2012, but the Purchaser has agreed to reimburse us for up to $11.8 million in payments we make related to these liabilities. At September 30, 2014, the remaining reimbursements may be up to $6.5 million, which we have recorded on a discounted basis as $1.6 million in other current assets and $4.0 million in other noncurrent assets. See Note 5. On an undiscounted basis, workers compensation liabilities were $17.0 million and $20.0 million at September 30, 2014 and 2013, respectively. On a discounted basis, workers compensation liabilities were $14.7 million and $17.2 million at September 30, 2014 and 2013, respectively.

We apply a discount rate at a risk-free interest rate, generally a U.S. Treasury bill rate, for each policy period. The rate used is one with a duration that corresponds to the weighted average expected payout period for each policy period. Once a discount rate is applied to a policy period, it remains the discount rate for that policy period until al

Warranty Costs

Warranty Costs-We accrue for warranty expenses that can include customer costs of repair and/or replacement, including labor, materials, equipment, freight and reasonable overhead costs. We accrue for the estimated cost of product warranties at the time of sale if such costs are determined to be reasonably estimable at that time. Warranty cost estimates are revised throughout applicable warranty periods as better information regarding warranty costs becomes available.

Deferred Financing Fees

Deferred Financing Fees-Costs of debt financing are charged to expense over the lives of the related financing agreements, which ranged from 5 to 10 years. Remaining costs and the future period over which they would be charged to expense are reassessed when amendments to the related financing agreements or prepayments occur.

Deferred financing fees of $6.7 million at September 30, 2014 were scheduled to amortize as follows: $2.1 million related to the ABL Agreement amortizes on a straight-line basis; $2.8 million related to the Senior Unsecured Notes amortizes using the effective-interest rate method; and $1.8 million related to the Senior Subordinated Notes amortizes using the effective-interest rate method. All such amortization would have been over the remaining term of the respective debt.

Derivative Instruments and Hedging Activities

Derivative Instruments and Hedging Activities-Changes in the fair value of derivative instruments accounted for as effective cash-flow hedges were recorded to accumulated other comprehensive loss. Gains and losses on derivative instruments not qualifying as effective cash-flow hedges, representing hedge ineffectiveness and hedge components excluded from the assessment of effectiveness, were recognized in earnings in the periods in which they occurred.

Our ongoing business operations expose us to commodity price risk and interest rate risk, which we had previously managed to some extent using derivative instruments. We used natural gas swap contracts at U.S. Pipe to manage the price risk associated with purchases of natural gas used in certain of our manufacturing processes and interest rate swap contracts to manage interest rate risk associated with our variable-rate borrowings. During 2010, we terminated all of our remaining interest rate swap contracts and we reclassified expense related to these swap contracts from accumulated other comprehensive loss to interest expense in 2012. We have not initiated any new interest rate swap contracts since then. During 2012, we terminated our remaining natural gas swap contract and have not initiated any new natural gas swap contracts since then.

We had designated our natural gas swap contracts and interest rate swap contracts as cash flow hedges of our purchases of natural gas and our interest payments, respectively. As a result, to the extent the hedges were effective, the changes in the fair value of these contracts prior to settlement were reported as a component of accumulated other comprehensive loss and reclassified into earnings in the periods during which the hedged transactions affected, or were expected to affect, earnings.

Income Taxes

Income Taxes-Deferred tax liabilities and deferred tax assets are recognized for the expected future tax consequences of events that have been included in the financial statements or tax returns. Such liabilities and assets are determined based on the differences between the financial statement basis and the tax basis of assets and liabilities, using tax rates in effect for the years in which the differences are expected to reverse. A valuation allowance is provided when, based upon the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

We only record tax benefits for positions that management believes are more likely than not of being sustained under audit based solely on the technical merits of the associated tax position. The amount of tax benefit recognized for any position that meets the more likely than not threshold is the largest amount of the tax benefit that we believe is greater than 50% likely of being realized.

Environmental Expenditures

Environmental Expenditures-We capitalize environmental expenditures that increase the life or efficiency of noncurrent assets or that reduce or prevent environmental contamination. We accrue for environmental expenses resulting from existing conditions that relate to past operations when the costs are probable and reasonably estimable. We are indemnified under an agreement with a predecessor to Tyco for certain environmental liabilities that existed at August 16, 1999. See Note 16.

Research and Development

Research and Development-Research and development costs are expensed as incurred.

Advertising

Advertising-Advertising costs are expensed as incurred.

Translation of Foreign Currency

Translation of Foreign Currency-Assets and liabilities of our businesses whose functional currency is other than the U.S. dollar are translated into U.S. dollars using currency exchange rates at the balance sheet date. Revenues and expenses are translated at average currency exchange rates during the period. Foreign currency translation gains and losses are reported as a component of accumulated other comprehensive loss. Gains and losses resulting from foreign currency transactions are included in operating results as incurred.