Mueller Water Products (MWA) 10-K 22 Nov 16 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2016	Nov. 11, 2016	Mar. 31, 2016	Sep. 30, 2015
Document Information [Line Items]
Document Fiscal Period Focus	FY
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Entity Well-known Seasoned Issuer	No
Entity Registrant Name	Mueller Water Products, Inc.
Entity Central Index Key	1,350,593
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Property, plant and equipment, net	$ 155,100,000			$ 148,900,000
Intangible Assets, Net (Including Goodwill)	$ 486,000,000			$ 507,300,000
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Amendment Flag	false
Entity Common Stock, Shares Outstanding		161,732,282
Entity Public Float			$ 1,575,896,511

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Assets:
Cash and cash equivalents	$ 195	$ 113.1
Receivables, net	186.7	175.3
Inventories	213.8	219.1
Deferred income taxes	0	28.3
Other current assets	16.8	13.7
Total current assets	612.3	549.5
Property, plant and equipment, net	155.1	148.9
Intangible Assets, Net (Including Goodwill)	486	507.3
Other noncurrent assets	27.2	24.1
Total assets	1,280.6	1,229.8
Liabilities and equity:
Current portion of long-term debt	5.9	6.1
Accounts payable	100.8	98.7
Other current liabilities	79.1	63.2
Total current liabilities	185.8	168
Long-term debt, excluding current maturities	479.2	482.9
Deferred income taxes	109.9	145.3
Other noncurrent liabilities	86.2	65.8
Total liabilities	861.1	862
Common Stock	1.6	1.6
Additional paid-in capital	1,563.9	1,574.8
Accumulated deficit	(1,078.9)	(1,142.8)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(68.3)	(67.3)
Stockholders' Equity Attributable to Parent	418.3	366.3
Equity Attributable to Noncontrolling Interest	1.2	1.5
Equity	419.5	367.8
Total liabilities and equity	$ 1,280.6	$ 1,229.8

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - shares	Sep. 30, 2016	Sep. 30, 2015
Statement of Financial Position [Abstract]
Series A common stock, shares authorized	600,000,000	600,000,000
Series A common stock, shares outstanding	161,693,051	160,497,841

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Revenue, Net	$ 1,138.9	$ 1,164.5	$ 1,184.7
Cost of sales	774.6	817.2	836.8
Gross profit	364.3	347.3	347.9
Operating expenses:
Selling, general and administrative	218.8	216.4	220.7
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	16.6	(0.5)	0
Balances written off, net of recoveries	0	0.2	0.1
Other Cost and Expense, Operating	8.3	9.2	3.1
Total operating expenses	243.7	237.7	223.8
Operating income	120.6	109.6	124.1
Interest expense, net	23.6	27.6	49.6
Net Income Before Income Tax	97	50.7	73.5
Income tax expense (benefit)	33.1	19.8	18
Net Income (Loss) Attributable to Parent	$ 63.9	$ 30.9	$ 55.5
Net loss per basic share:
Net income (loss) per basic share	$ 0.40	$ 0.19	$ 0.35
Net loss per diluted share:
Net income (loss) per diluted share	$ 0.39	$ 0.19	$ 0.34
Weighted average shares outstanding:
Basic, in shares	161.3	160.5	159.2
Diluted, in shares	163.4	163.2	162.2
Dividends declared per share, in dollars per share	$ 0.100	$ 0.075	$ 0.070
Loss on early extinguishment of debt	$ 0	$ 31.3	$ 1
WalterEnergy [Member]
Operating expenses:
Balances written off, net of recoveries	$ 0	$ 11.6	$ 0

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income Statement - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Net Income (Loss) Attributable to Parent	$ 63.9	$ 30.9	$ 55.5
Other comprehensive income (loss):
Minimum pension liability	(2.8)	(6.3)	45.1
Income tax effects	(1.1)	(2.6)	17.4
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	0.2	(8.7)	(4.4)
Amortization of interest expense on terminated swap contracts	(4.7)	(2.6)	0
Income tax effects	1.8	1	0
Other Comprehensive Income (Loss), Net of Tax	(1)	(6.6)	(32.1)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 62.9	$ 24.3	$ 23.4

Consolidated Statement Of Stock

Consolidated Statement Of Stockholders' Equity - USD ($) $ in Millions	Total	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive income (loss)	Noncontrolling Interest [Member]	Stock-based Compensation Related [Member]	Stock-based Compensation Related [Member]Common stock	Stock-based Compensation Related [Member]Additional paid-in capital	Stock-based Compensation Related [Member]Accumulated deficit	Stock-based Compensation Related [Member]Accumulated other comprehensive income (loss)	Stock-based Compensation Related [Member]Noncontrolling Interest [Member]	Stock Repurchase Program [Member]	Stock Repurchase Program [Member]Common stock	Stock Repurchase Program [Member]Additional paid-in capital	Stock Repurchase Program [Member]Accumulated deficit	Stock Repurchase Program [Member]Accumulated other comprehensive income (loss)	Stock Repurchase Program [Member]Noncontrolling Interest [Member]
Balance at Sep. 30, 2013	$ 328.2	$ 1.6	$ 1,584.4	$ (1,229.2)	$ (28.6)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	55.4
Net Income (Loss) Attributable to Noncontrolling Interest						(0.1)
Net Income (Loss) Attributable to Parent	55.5	0	0	55.5	0
Dividends declared	(11.2)	0	(11.2)	0	0	0
Stock-based compensation	8.5	0	8.5	0	0	0
Shares retained for employee taxes							$ (3.1)	$ 0	$ (3.1)	$ 0	$ 0	$ 0
Stock issued under stock compensation plans	4.2	0	4.2	0	0	0
Other Comprehensive Income (Loss), Net of Tax	(32.1)	0	0	0	(32.1)	0
Balance at Sep. 30, 2014	351.6	1.6	1,582.8	(1,173.7)	(60.7)	1.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	30.8
Net Income (Loss) Attributable to Noncontrolling Interest						(0.1)
Net Income (Loss) Attributable to Parent	30.9	0	0	30.9	0
Dividends declared	(12)	0	(12)	0	0	0
Stock-based compensation	4.9	0	4.9	0	0	0
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	3.2	0	3.2	0	0	0
Shares retained for employee taxes							(2.4)	0	$ (2.4)	0	0	0	$ (5)	$ 0	$ (5)	$ 0	$ 0	$ 0
Stock issued under stock compensation plans	3.3	0	3.3	0	0	0
Other Comprehensive Income (Loss), Net of Tax	(6.6)	0	0	0	(6.6)	0
Balance at Sep. 30, 2015	367.8	1.6	1,574.8	(1,142.8)	(67.3)	1.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	63.6
Net Income (Loss) Attributable to Noncontrolling Interest						(0.3)
Net Income (Loss) Attributable to Parent	63.9	0	0		0
Dividends declared	(16.1)	0	(16.1)	0	0	0
Stock-based compensation	5.2	0	5.2	0	0	0
Shares retained for employee taxes							$ (3.3)	$ 0		$ 0	$ 0	$ 0
Stock issued under stock compensation plans	3.3	0	3.3	0	0	0
Payments to Acquire Interest in Joint Venture	1.7
Other Comprehensive Income (Loss), Net of Tax	(1)	0	0	0	(1)	0
Balance at Sep. 30, 2016	$ 419.5	$ 1.6	$ 1,563.9	$ (1,078.9)	$ (68.3)	$ 1.2

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Net Income (Loss) Attributable to Parent	$ 63.9	$ 30.9	$ 55.5
Adjustments to reconcile net income (loss) to income (loss) from continuing operations:
Depreciation	28.3	28.7	27.3
Amortization	24.3	29.4	29.4
Defined Benefit Plan, Net Periodic Benefit Cost	21	1.1	1.5
Asset Impairment Charges	0	11.6	0
Stock-based compensation expense	5.2	4.8	8.6
Deferred income taxes	(7.5)	6.9	15.6
Loss on early extinguishment of debt	0	31.3	1
Other, net	3.9	4.7	0.7
Changes in assets and liabilities, net of acquisitions:
Receivables	(11.1)	3.5	(16.9)
Inventories	5.5	(24.6)	11
Other current assets and other noncurrent assets	(5.7)	(0.7)	3.6
Accounts payable and other liabilities	17.3	(39.8)	10.3
Net cash provided by (used in) operating activities	145.1	87.8	147.6
Investing activities:
Capital expenditures	(39.4)	(37.5)	(36.9)
Acquisitions, net of cash acquired	0	0.3	(10)
Proceeds from sales of assets	0.3	5.6	4.7
Net cash provided by (used in) investing activities	(39.1)	(31.6)	(42.2)
Financing activities:
Repayment of debt	5	589	55.7
Proceeds from Issuance of Long-term Debt	0	512.5	0
Dividends paid	(16.1)	(12)	(11.2)
Excess Tax Benefit from Share-based Compensation, Financing Activities	0	3.2	0
Common stock issued	3.3	3.3	4.2
Payments for Repurchase of Common Stock	0	(5)	0
Shares retained for employee taxes	(3.3)	(2.4)	(3.1)
Payment of deferred financing fees	(1.2)	(8.5)	0
Sale of noncontrolling interest	0	0	1.7
Other	(1.4)	(1.1)	(1.1)
Net cash used in financing activities	(23.7)	(99)	(65.2)
Effect of currency exchange rate changes on cash	(0.4)	(5.2)	(2.7)
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Net change in cash and cash equivalents	81.9	(48)	37.5
Cash and cash equivalents at beginning of period	113.1	161.1	123.6
Cash and cash equivalents at end of period	$ 195	$ 113.1	$ 161.1

Summary of Significant Accounti

Summary of Significant Accounting Policies All (Notes)	12 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies 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.” In May 2014, the Financial Accounting Standards Board (“FASB”) issued new guidance for the recognition of revenue. This new guidance applies to us beginning with our first quarter of 2019 and we do not anticipate adopting early. We are in the early stages of evaluating the impact of the adoption of this guidance on our financial statements and related disclosures and we have not yet reached any conclusions. 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 our outstanding stock-settled share awards and is based on the fair value at each reporting date for our cash-settled 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. At March 31, 2016, we adopted FASB Accounting Standards Update 2016-09 Improvements to Employee Share-Based Payment Accounting. Most significantly, this update changes the accounting for “excess tax benefits” related to stock-based compensation awards by requiring such benefits be included in earnings, rather than recorded directly to additional paid-in capital. 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 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 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. The following table summarizes information concerning our allowance for doubtful receivables. 2016 2015 2014 (in millions) Balance at beginning of year $ 5.2 $ 5.3 $ 5.3 Provision charged to expense 0.6 0.1 — Balances written off, net of recoveries — (0.2 ) (0.1 ) Other (0.1 ) — 0.1 Balance at end of year $ 5.7 $ 5.2 $ 5.3 Inventories- Inventories are recorded at the lower of first-in, first-out method cost or estimated net realizable 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. The following table summarizes information concerning our inventory valuation reserves. 2016 2015 2014 (in millions) Balance at beginning of year $ 7.8 $ 8.5 $ 10.6 Provision charged to expense 2.1 2.1 2.8 Inventory disposed (1.5 ) (2.9 ) (4.3 ) Other 0.2 0.1 (0.6 ) Balance at end of year $ 8.6 $ 7.8 $ 8.5 Other Current Assets- 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. 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, 2016 and 2015 , asset retirement obligations were $7.5 million and $2.9 million , respectively. During the quarter ended March 31, 2016, FASB issued Accounting Standards Update 2016-02 Leases , which will require us to recognize lease assets and lease liabilities for those leases currently referred to as operating leases. This requirement is effective for 2020, although early adoption is permitted. The update allows for several different methods of application and adoption of the requirement. We are currently evaluating these methods, in what period we will adopt the requirement, and the impact of this requirement, which we do not believe will be material to our consolidated financial statements as a whole. Accounting for the Impairment of Long-Lived Assets- We test indefinite-lived intangible assets 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- 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 the segment's April 1, 2012 sale date , but the purchaser agreed to reimburse us for up to $11.8 million in payments we make related to these liabilities. At September 30, 2016 , the remaining reimbursements may be up to $4.9 million , which we have recorded on a discounted basis as $0.6 million in other current assets and $4.1 million in other noncurrent assets. On an undiscounted basis, workers compensation liabilities were $13.7 million and $15.3 million at September 30, 2016 and 2015 , respectively. On a discounted basis, workers compensation liabilities were $11.8 million and $13.1 million at September 30, 2016 and 2015 , 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 all claims are paid. 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. Activity in accrued warranty, reported as part of other current liabilities, is presented below. 2016 2015 2014 (in millions) Balance at beginning of year $ 2.9 $ 2.6 $ 2.8 Warranty expense 5.3 5.2 4.1 Warranty payments (6.2 ) (4.9 ) (4.3 ) Balance at end of year $ 2.0 $ 2.9 $ 2.6 Deferred Financing Costs- Costs of debt financing are charged to expense over the lives of the related financing agreements. 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. ABL Agreement-related deferred financing costs are included in other noncurrent assets and remaining deferred financing costs are offset against long-term debt in the accompanying consolidated balance sheets. Deferred financing costs of $8.1 million at September 30, 2016 are scheduled to amortize as follows: $1.8 million related to the ABL Agreement amortizes on a straight-line basis; $6.3 million related to the Term Loan amortizes using the effective-interest rate method. All such amortization will be over the remaining term of the respective debt. See Note 6. Derivative Instruments and Hedging Activities- We manage interest rate risk to some extent using derivative instruments. We designated our interest rate swap contracts as cash flow hedges of interest payments. As a result, the changes in the fair value of these contracts prior to settlement are reported as a component of accumulated other comprehensive loss and are reclassified into earnings in the periods during which the hedged transactions affect earnings. 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. At December 31, 2015, we adopted FASB Accounting Standards Update 2015-17 Balance Sheet Classification of Deferred Taxes , which requires that all deferred tax assets and deferred tax liabilities, netted by tax jurisdiction, be classified as noncurrent on the balance sheet. The prior period consolidated balance sheet has not been reclassified. 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 costs are expensed as incurred. Advertising- Advertising costs are expensed as incurred. 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.

Identifiable Intangible Assets

Identifiable Intangible Assets	12 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Identifiable Intangible Assets	Intangible Assets Direct internal and external costs to develop external-use software are capitalized. Capitalized costs are amortized over the estimated useful life of the software, beginning when the software is complete and ready for sale. During 2014, we revised our estimate of the useful life of the software to 6 years from 3 years. At September 30, 2016 , the remaining weighted-average amortization period for external-use software was 3.6 years. Amortization expense related to such software assets was $1.9 million , $1.6 million and $1.1 million for 2016 , 2015 and 2014 , respectively. Amortization expense for each of the next five years is scheduled to be $2.8 million in 2017 , $2.6 million in 2018 , $2.4 million in 2019 , $2.1 million in 2020 and $1.3 million in 2021 . At September 30, 2016 , the remaining weighted-average amortization period for the business combination-related finite-lived intangible assets was 7.2 years. Amortization expense related to these assets was $22.4 million , $27.8 million and $28.3 million for 2016 , 2015 and 2014 , respectively. Amortization expense for each of the next five years is scheduled to be $22.3 million in 2017 , $22.5 million in 2018 , $22.3 million in 2019 , $22.2 million in 2020 and $21.9 million in 2021 . Intangible assets are presented below. September 30, 2016 2015 (in millions) Capitalized external-use software: Cost $ 20.9 $ 17.9 Accumulated amortization (8.9 ) (7.0 ) Net book value 12.0 10.9 Business combination-related: Cost: Finite-lived intangible assets: Technology 80.3 80.3 Customer relationships and other 400.2 400.2 Indefinite-lived intangible assets: Trade names and trademarks 299.6 299.6 Goodwill 5.4 5.4 785.5 785.5 Accumulated amortization: Technology (75.0 ) (74.2 ) Customer relationships and other (236.5 ) (214.9 ) (311.5 ) (289.1 ) Net book value 474.0 496.4 Total intangible assets net book value $ 486.0 $ 507.3

Discontinued Operations, Assets

Discontinued Operations, Assets Held for Sale and Divestitures	12 Months Ended
	Sep. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations, Assets Held for Sale and Divestitures	Other Charges During the quarter ended June 30, 2016, we initiated certain demolition and related activities for our Statesboro, Georgia property, some of the costs of which are indemnified by Tyco as explained in Note 16. We have recorded a receivable from Tyco for our estimated recovery under the indemnification and a net charge of $4.1 million under the caption other charges for our Corporate segment through September 30, 2016. In 2015, Mueller Co. sold certain assets related to its municipal casting operations in Canada and closed the associated facility. These actions resulted in restructuring expense of $7.2 million under the caption other charges, which was comprised of a $2.5 million impairment charge, $2.3 million of environmental remediation costs and $2.4 million of severance and other costs. These operations generated net sales of $11.5 million during 2014. In 2014, Anvil sold the production equipment and certain inventory at its Bloomington, Minnesota location for an immaterial gain. Anvil also signed a supply agreement with the buyer and terminated the employment of all employees at that location, which resulted in the withdrawal from the only multi-employer pension plan in which the Company had participated. Anvil recorded a related withdrawal liability of $0.9 million as restructuring expense under the caption other charges. Also in 2014, Anvil sold the land and buildings at this location, which resulted in a net a gain of $2.5 million included in selling, general and administrative expenses.

Income Taxes

Income Taxes	12 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income before income taxes are presented below. 2016 2015 2014 (in millions) U.S. $ 96.8 $ 55.4 $ 71.6 Non-U.S. 0.2 (4.7 ) 1.9 Income before income taxes $ 97.0 $ 50.7 $ 73.5 The cumulative amount of undistributed earnings of foreign subsidiaries that we consider to be indefinitely reinvested, and thus for which United States income taxes have not been provided, was $54.7 million at September 30, 2016 . It is not currently practical to estimate the amount of unrecognized United States income taxes that might be payable on the repatriation of these earnings. The components of income tax expense are presented below. 2016 2015 2014 (in millions) Current: U.S. federal $ 37.4 $ 12.4 $ 0.1 U.S. state and local 3.1 0.7 1.6 Non-U.S. 0.1 (0.2 ) 0.7 40.6 12.9 2.4 Deferred: U.S. federal (10.5 ) 4.5 28.7 U.S. state and local 3.2 2.9 (12.8 ) Non-U.S. (0.2 ) (0.5 ) (0.3 ) (7.5 ) 6.9 15.6 Income tax expense $ 33.1 $ 19.8 $ 18.0 The reconciliation between income tax expense at the U.S. federal statutory income tax rate and reported income tax expense from continuing operations is presented below. 2016 2015 2014 (in millions) Expense at U.S. federal statutory income tax rate of 35% $ 34.0 $ 17.7 $ 25.7 Adjustments to reconcile to income tax expense: State income taxes, net of federal benefit 3.8 2.4 3.6 Domestic production activities deduction (3.9 ) (1.5 ) — Tax credits (2.2 ) (1.3 ) (0.1 ) Nondeductible expenses, other than compensation 0.9 0.7 0.9 Federal valuation allowance (0.2 ) 0.6 (1.2 ) Foreign income taxes 0.1 0.4 (0.2 ) Nondeductible compensation 0.4 0.3 0.8 State valuation allowance, net of federal benefit — (0.1 ) (8.4 ) State tax rate change 0.4 — (2.5 ) Other (0.2 ) 0.6 (0.6 ) Income tax expense $ 33.1 $ 19.8 $ 18.0 Deferred income tax balances are presented below. September 30, 2016 2015 (in millions) Deferred income tax assets: Inventory reserves $ 14.8 $ 15.5 Accrued expenses 15.0 13.6 Pension and other postretirement benefits 25.0 17.8 Stock-based compensation 7.7 8.9 State net operating losses 5.0 8.1 Federal credit carryovers 0.6 0.5 Other 4.8 3.0 72.9 67.4 Valuation allowance (0.9 ) (1.3 ) Total deferred income tax assets, net of valuation allowance 72.0 66.1 Deferred income tax liabilities: Intangible assets 177.0 182.3 Other 3.8 0.8 Total deferred income tax liabilities 180.8 183.1 Net deferred income tax liabilities $ 108.8 $ 117.0 We reevaluate the need for a valuation allowance against the U.S. deferred tax assets each quarter, considering results to date, projections of taxable income, tax planning strategies and reversing taxable temporary differences. After inclusion of the tax effect of the loss on the sale of U.S. Pipe in 2012, our net reversing deferred tax credits were insufficient to fully support our deferred tax assets, which included net operating loss carryforwards, and we concluded that a valuation allowance was necessary to reduce our U.S. net reversing deferred tax assets to zero. Accordingly, we recorded income tax expense in 2012 to establish valuation allowances related to deferred tax assets. In the 2014 fourth quarter, we credited to income substantially all of the deferred tax valuation allowance based on our expectation of future taxable income. In the 2015 fourth quarter, we credited to income the remaining state net operating loss valuation allowance based on utilization. Our state net operating loss carryforwards, which expire between calendar years 2016 and 2033 , remain available to offset future taxable earnings. The following table summarizes information concerning our gross unrecognized tax benefits. 2016 2015 (in millions) Balance at beginning of year $ 2.6 $ 2.7 Increases related to prior year positions 0.3 0.3 Increases related to current year positions 0.2 — Decreases due to lapse in statute of limitations (0.3 ) (0.4 ) Balance at end of year $ 2.8 $ 2.6 Substantially all unrecognized tax benefits would, if recognized, impact the effective tax rate. We recognize interest related to uncertain tax positions as interest expense and recognize any penalties incurred as a component of selling, general and administrative expenses. At September 30, 2016 and 2015 , we had $0.5 million and $0.6 million , respectively, of accrued interest expense related to unrecognized tax benefits. We expect to settle certain state income tax audits within the next 12 months and believe it is reasonably possible that these audit settlements will reduce the gross unrecognized tax benefits by $0.8 million . The federal income tax returns for Mueller Co. and Anvil are closed for years prior to 2005 and for Mueller Water Products, Inc. for 2007 and 2008. Our 2009 through 2012 returns are closed except to the extent net operating losses from those years have been utilized on subsequent years’ returns. Tax years 1980 to 1994 and 1999 to 2001 remain open for our predecessor company, U.S. Pipe, which was a subsidiary of Walter Energy in those years. See Note 16. We also remain liable for any taxes related to periods prior to the sale of U.S. Pipe in 2012 pursuant to the terms of the sale agreement with the purchaser of the segment. Our state income tax returns are generally closed for years prior to 2012, except to the extent of our state net operating loss carryforwards. Our Canadian income tax returns are generally closed for years prior to 2009. We are currently under audit by several jurisdictions, including Canada Revenue Agency for the year ended September 30, 2014, at various levels of completion. We do not have any material unpaid assessments.

Borrowing Arrangements

Borrowing Arrangements	12 Months Ended
	Sep. 30, 2016
Long-term Debt and Capital Lease Obligations [Abstract]
Borrowing Arrangements	Borrowing Arrangements The components of our long-term debt are presented below. September 30, 2016 2015 (in millions) ABL Agreement $ — $ — Term Loan 489.4 494.0 Other 2.0 2.4 491.4 496.4 Deferred financing costs (6.3 ) (7.4 ) Less current portion (5.9 ) (6.1 ) Long-term debt $ 479.2 $ 482.9 ABL Agreement . Our asset based lending agreement (“ABL Agreement”) consists of a revolving credit facility for up to $225 million of revolving credit borrowings, swing line loans and letters of credit. The ABL Agreement also permits us to increase the size of the credit facility by an additional $150 million in certain circumstances subject to adequate borrowing base availability. We may borrow up to $25 million through swing line loans and may have up to $60 million of letters of credit outstanding. Borrowings under the ABL Agreement bear interest at a floating rate equal to LIBOR plus a margin ranging from 125 to 150 basis points, or a base rate, as defined in the ABL Agreement, plus a margin ranging from 25 to 50 basis points. At September 30, 2016 the applicable rate was LIBOR plus 125 basis points. The ABL Agreement terminates on July 13, 2021 . We pay a commitment fee for any unused borrowing capacity under the ABL Agreement of 25 basis points per annum. Borrowings are not subject to any financial maintenance covenants unless excess availability is less than the greater of $17.5 million and 10% of the Loan Cap as defined in the ABL Agreement. Excess availability based on September 30, 2016 data, as reduced by outstanding letters of credit, swap contract liabilities and accrued fees and expenses of $30.4 million , was approximately $169 million . Term Loan . On November 25, 2014 , we entered into a $500.0 million senior secured term loan (“Term Loan”). We capitalized $8.5 million of financing costs, which are being amortized over the term of the Term Loan using the effective interest rate method. The proceeds from the Term Loan, along with other cash, were used to prepay our 7.375% Senior Subordinated Notes (“Senior Subordinated Notes”) and 8.75% Senior Unsecured Notes (“Senior Unsecured Notes”) and to satisfy and discharge our obligations under the respective indentures. We recorded a loss on early extinguishment of debt of $31.3 million , which consisted of $25.2 million of tender and call premiums, $4.4 million of deferred financing costs and $1.7 million of unamortized discount written off. The Term Loan accrues interest at a floating rate equal to LIBOR, subject to a floor of 0.75% , plus 325 basis points. At September 30, 2016 , the weighted-average effective interest rate, including amortization of deferred finance costs and original issue discount and the effect of interest rate swaps, was 4.54% . We may voluntarily repay amounts borrowed under the Term Loan at any time. The principal amount of the Term Loan is required to be repaid in quarterly installments of $1.25 million , with any remaining principal due on November 25, 2021 . The Term Loan is guaranteed by substantially all of our U.S. subsidiaries and is secured by essentially all of our assets, although the ABL Agreement has a senior claim on certain collateral securing borrowings thereunder. The Term Loan is reported net of unamortized discount of $1.8 million . Based on quoted market prices, the outstanding Term Loan had a fair value of $496.2 million at September 30, 2016 . The Term Loan contains affirmative and negative operating covenants applicable to us and our restricted subsidiaries. We believe we were compliant with these covenants at September 30, 2016 and expect to remain in compliance through September 30, 2017 . The scheduled maturities of all borrowings outstanding at September 30, 2016 for each of the following years are $5.9 million for 2017 , $5.6 million for 2018 , $5.4 million for 2019 , $5.1 million for 2020 , $5.0 million for 2021 and $466.2 million after 2021 .

Derivative Financial Instrument

Derivative Financial Instruments (Notes)	12 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivative Financial Instruments We are exposed to interest rate risk that we manage to some extent using derivative instruments. Under our April 2015 interest rate swap contracts, we receive interest calculated using 3-month LIBOR, subject to a floor of 0.750% , and pay fixed interest at 2.341% , on an aggregate notional amount of $150.0 million . These swap contracts effectively fix the cash interest rate on $150.0 million of our borrowings under the Term Loan at 5.591% from September 30, 2016 through September 30, 2021 . We have designated our interest rate swap contracts as cash flow hedges of our future interest payments and elected to apply the “shortcut” method of assessing hedge effectiveness. As a result, the gains and losses on the swap contracts are reported as a component of other comprehensive loss and are reclassified into interest expense as the related interest payments are made. The fair values of the swap contracts are presented below. September 30, 2016 2015 (in millions) Other current liabilities $ 2.0 $ — Other noncurrent liabilities 5.3 2.6 $ 7.3 $ 2.6 The fair values and the classification of the fair values between current and noncurrent portions are based on calculated cash flows using publicly available interest rate forward rate yield curve information, but amounts due at the actual settlement dates are dependent on actual rates in effect at the settlement dates and may differ significantly from amounts shown above.

Retirement Plans

Retirement Plans	12 Months Ended
	Sep. 30, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Pension and Other Postretirement Benefits Disclosure	Retirement Plans We have various pension plans (“Pension Plans”), which we fund in accordance with their requirements and, where applicable, in amounts sufficient to satisfy the minimum funding requirements of applicable laws. The Pension Plans provide benefits based on years of service and compensation or at stated amounts for each year of service. The measurement date for all Pension Plans was September 30. During 2016, our U.S. pension plan (“Plan”) completed a pension obligation settlement program targeting vested, terminated participants not yet receiving benefits. Approximately 75% of eligible participants accepted settlement offers. The Plan distributed assets totaling $58.5 million . We incurred a non-cash pension settlement charge of $16.6 million as a result of the program, which had an immaterial impact on the Plan’s funded ratio. During 2015, we contributed $1.2 million to fully fund two of our Canadian plans and recorded a pension settlement charge of $0.5 million . We were not required to make, and we did not make, any contributions to our U.S. pension plan in 2016 , and we currently plan to make $1.3 million of contributions to a Canadian pension plan in 2017 . Our U.S. plan comprised 98% of the Pension Plans’ obligations and 98% of the Pension Plans’ assets at September 30, 2016 . The components of net periodic benefit cost are presented below. 2016 2015 2014 (in millions) Service cost $ 1.7 $ 1.9 $ 1.7 Interest cost 18.9 20.1 19.9 Expected return on plan assets (19.7 ) (24.6 ) (23.8 ) Amortization of net loss 3.4 3.2 3.5 Curtailment / special settlement loss 16.6 0.5 0.2 Other 0.1 — — Net periodic benefit cost $ 21.0 $ 1.1 $ 1.5 Balance sheet information for Pension Plans with accumulated benefit obligations in excess of plan assets is presented below. September 30, 2016 2015 (in millions) Projected benefit obligations $ 402.0 $ 427.0 Accumulated benefit obligations 402.0 427.0 Fair value of plan assets 337.9 381.3 Balance sheet information for Pension Plans with accumulated benefit obligations less than plan assets is presented below. September 30, 2016 2015 (in millions) Projected benefit obligations $ 1.1 $ 1.2 Accumulated benefit obligations 1.1 1.2 Fair value of plan assets 2.1 2.1 Pension Plan activity in accumulated other comprehensive loss, before tax, in 2016 is presented below, in millions. Balance at beginning of year $ 113.5 Actuarial loss 17.3 Prior year actuarial loss amortization to net periodic cost, including effect of pension settlement (20.0 ) Balance at end of year $ 110.8 Beginning in 2015, we amortized amounts in accumulated other comprehensive loss representing unrecognized prior year service cost and unrecognized loss related to our U.S. pension plan over the weighted average life expectancy of the plan’s inactive participants instead of the weighted average remaining service period for active participants, as we did through 2014. The effect of this change was not material to our consolidated financial statements. The components of accumulated other comprehensive loss related to pension that we expect to amortize into net periodic benefit cost in 2017 are presented below, in millions. Amortization of unrecognized prior year service cost $ — Amortization of unrecognized loss 4.0 $ 4.0 Amounts recognized for our Pension Plans and other postretirement benefit plans are presented below. Pension Plans 2016 2015 (in millions) Projected benefit obligations: Beginning of year $ 428.2 $ 461.5 Service cost 1.7 1.9 Interest cost 18.9 20.1 Actuarial loss (gain) 37.7 (25.9 ) Benefits paid (25.1 ) (26.0 ) Currency translation 0.2 (1.6 ) Decrease in obligation due to curtailment / settlement (58.5 ) (1.8 ) End of year $ 403.1 $ 428.2 Accumulated benefit obligations at end of year $ 403.1 $ 428.2 Plan assets: Beginning of year $ 383.4 $ 410.5 Actual return on plan assets 40.1 1.3 Employer contributions — 1.2 Settlement (58.5 ) (1.9 ) Currency translation 0.1 (1.7 ) Benefits paid (25.1 ) (26.0 ) End of year $ 340.0 $ 383.4 Accrued benefit cost at end of year: Unfunded status $ (63.1 ) $ (44.8 ) Recognized on balance sheet: Other noncurrent assets $ 1.0 $ 0.9 Other current liabilities (1.2 ) — Other noncurrent liabilities (62.9 ) (45.7 ) $ (63.1 ) $ (44.8 ) Recognized in accumulated other comprehensive loss, before tax: Prior year service cost $ — $ — Net actuarial loss 110.8 113.5 $ 110.8 $ 113.5 The discount rates for determining the present value of pension obligations were selected using a “bond settlement” approach, which constructs a hypothetical bond portfolio that could be purchased such that the coupon payments and maturity values could be used to satisfy the projected benefit payments. The discount rate is the equivalent rate that results in the present value of the projected benefit payments equaling the market value of this bond portfolio. Only high quality (AA graded or higher), non-callable corporate bonds are included in this bond portfolio. We rely on the Pension Plans’ actuaries to assist in the development of the discount rate model. The actuarial loss in 2016 was primarily due to the decrease in the discount rate at September 30, 2016 compared to September 30, 2015. The actuarial gain in 2015 was primarily due to the increase in the discount rate at September 30, 2015 compared to September 30, 2014. Management’s expected returns on plan assets were determined with the assistance of the Pension Plans’ actuaries and investment consultants. Expected returns on plan assets were developed using forward looking returns over a time horizon of 10 to 15 years for major asset classes along with projected risk and historical correlations. A summary of key assumptions for our pension plans is below. Pension Plans 2016 2015 2014 Weighted average used to determine benefit obligations: Discount rate 3.68 % 4.84 % 4.49 % Weighted average used to determine net periodic cost: Discount rate 3.92 % 4.49 % 5.16 % Expected return on plan assets 5.50 6.21 6.24 We maintain a single trust to hold the assets of the U.S. pension plan. Throughout 2014, 2015, and most of 2016, the strategic asset allocation was about 40% equity investments. Near the end of 2016, we directed our investment manager to adjust the asset allocation to about 30% equity investments. This trust’s strategic asset allocations, tactical range at September 30, 2016 and actual asset allocations are presented below. Strategic asset allocation Actual asset allocations at September 30, Tactical range 2016 2015 2014 Equity investments: Large capitalization stocks 19 % Small capitalization stocks 4 International stocks 7 30 30 - 50 % 29 % 39 % 40 % Fixed income investments 70 50 - 70 69 60 59 Cash — 0 - 5 2 1 1 100 % 100 % 100 % 100 % Assets of the Pension Plans are allocated to various investments to attain diversification and reasonable risk-adjusted returns while also managing the exposure to asset and liability volatility. These ranges are targets and deviations may occur from time to time due to market fluctuations. Portfolio assets are typically rebalanced to the allocation targets at least annually. The valuation methodologies used to measure the assets of the Pension Plans at fair value are: • Equity investments are valued at the closing price reported on the active market when reliable market quotations are readily available. When market quotations are not readily available, assets of the Pension Plans are valued by a method the trustees of the Pension Plans believe accurately reflects fair value; • Fixed income fund investments are valued using the closing price reported in the active market in which the investment is traded or based on yields currently available on comparable securities of issuers with similar credit ratings; and • Other investments are valued as determined by the trustees of the Pension Plans based on their net asset values and supported by the value of the underlying securities and by the unit prices of actual purchase and sale transactions occurring at or close to the financial statement date. The assets of the Pension Plans by level within the fair value hierarchy are presented below. September 30, 2016 Level 1 Level 2 Total (in millions) Equity: Large cap stocks: Large cap growth funds $ — $ 7.3 $ 7.3 Large cap index funds — 38.2 38.2 Large cap value funds — 7.2 7.2 Small cap stocks: Small cap growth funds — 15.1 15.1 International stocks: Mutual funds 13.5 — 13.5 International funds — 18.1 18.1 Total equity 13.5 85.9 99.4 Fixed income — 233.3 233.3 Cash and cash equivalents 7.3 — 7.3 $ 20.8 $ 319.2 $ 340.0 September 30, 2015 Level 1 Level 2 Total (in millions) Equity: Large cap stocks: Large cap growth funds $ — $ 32.7 $ 32.7 Large cap index funds — 27.1 27.1 Large cap value funds — 15.7 15.7 Small cap stocks: Small cap growth funds — 18.5 18.5 International stocks: Mutual funds 42.1 — 42.1 International funds — 13.9 13.9 Total equity 42.1 107.9 150.0 Fixed income — 229.4 229.4 Cash and cash equivalents 4.0 — 4.0 $ 46.1 $ 337.3 $ 383.4 Our estimated future pension benefit payments are presented below in millions. 2017 $ 32.6 2018 25.7 2019 25.6 2020 25.5 2021 25.4 2022-2026 122.9 Defined Contribution Retirement Plans- Certain of our employees participate in defined contribution 401(k) plans or similar non-U.S plans. We make matching contributions as a function of employee contributions. Matching contributions were $5.9 million , $6.2 million and $5.6 million during 2016 , 2015 and 2014 , respectively.

Capital Stock

Capital Stock	12 Months Ended
	Sep. 30, 2016
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Stockholders' Equity Note Disclosure	Capital Stock Common stock share activity is presented below. Shares outstanding at September 30, 2013 158,234,300 Vesting of restricted stock units, net of shares withheld for taxes 734,047 Exercise of stock options 587,964 Exercise of employee stock purchase plan instruments 204,360 Shares outstanding at September 30, 2014 159,760,671 Vesting of restricted stock units, net of shares withheld for taxes 541,839 Exercise of stock options 506,632 Exercise of employee stock purchase plan instruments 212,550 Stock repurchased under buyback program (523,851 ) Shares outstanding at September 30, 2015 160,497,841 Vesting of restricted stock units, net of shares withheld for taxes 370,138 Settlement of performance-based restricted stock units, net of shares withheld for taxes 335,998 Exercise of stock options 270,599 Exercise of employee stock purchase plan instruments 218,475 Shares outstanding at September 30, 2016 161,693,051

Stock-based Compensation Plans

Stock-based Compensation Plans	12 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	Stock-based Compensation Plans The effect of stock-based compensation on our statements of operations is presented below. 2016 2015 2014 (in millions, except per share data) Decrease in operating income $ 9.1 $ 7.0 $ 13.2 Decrease in net income 5.8 4.4 8.1 Decrease in earnings per basic share 0.04 0.03 0.05 Decrease in earnings per diluted share 0.04 0.03 0.05 We excluded 867,065 , 1,165,414 and 1,103,845 instruments from the calculation of diluted earnings per share for 2016 , 2015 and 2014 , respectively, because the effect of including them would have been antidilutive. At September 30, 2016 , there was approximately $4.6 million of unrecognized compensation expense related to stock-based awards not yet vested. We expect to recognize this expense over a weighted average life of approximately 1.3 years. The Mueller Water Products, Inc. 2006 Stock Incentive Plan (“2006 Plan”) authorizes an aggregate of 20,500,000 shares of common stock that may be granted through the issuance of stock-based awards. Any awards canceled are available for reissuance. Generally, all of our employees and members of our board of directors are eligible to participate in the 2006 Plan. At September 30, 2016 , 7,319,621 shares of common stock were available for future grants of awards under the 2006 Plan. This total assumes that the maximum number of shares will be earned for awards for which the final number of shares to be earned has not yet been determined. An award granted under the 2006 Plan vests at such times and in such installments as set by the Compensation and Human Resources Committee of the board of directors, but no award will be exercisable after the ten -year anniversary of the date on which it is granted. Management expects some instruments will be forfeited prior to vesting. Grants to members of our board of the directors are expected to vest fully. Based on historical forfeitures, we expect grants to others to be forfeited at an annual rate of 2% . Restricted Stock Units. Depending on the specific terms of each award, restricted stock units generally vest on the three -year anniversary of the grant date, or ratably over the life of the award, usually three years, on each anniversary date of the original grant. Compensation expense for restricted stock units is recognized between the grant date and the vesting date (or the date on which a participant becomes Retirement-eligible, if sooner) on a straight-line basis for each tranche of each award. Fair values of restricted stock units are determined using the closing price of our common stock on the respective dates of grant. Restricted stock unit activity under the 2006 Plan is summarized below. Restricted stock units Weighted average grant date fair value per unit Weighted average remaining contractual term (years) Aggregate intrinsic value (millions) Outstanding at September 30, 2013 1,925,340 $ 4.30 0.9 Granted 381,012 8.51 Vested (1,099,591 ) 4.94 $ 9.4 Cancelled — — Outstanding at September 30, 2014 1,206,761 5.04 0.7 Granted 459,659 9.70 Vested (793,630 ) 3.99 7.7 Cancelled — — Outstanding at September 30, 2015 872,790 8.45 0.8 Granted 360,255 9.33 Vested (510,535 ) 7.94 4.7 Cancelled (59,062 ) 8.23 Outstanding at September 30, 2016 663,448 $ 9.34 1.0 Performance Shares. Performance-based restricted stock units (“PRSUs”) represent a target number of units that may be paid out at the end of a multi-year award cycle consisting of annual performance periods coinciding with our fiscal years. As determined at the date of award, PRSUs may settle in cash-value equivalent of, or directly in, shares of our common stock. Settlement will range from zero to two times the number of PRSUs granted, depending on our financial performance against predetermined targets. The Compensation and Human Resources Committee of our board of directors (“Committee”) establishes performance goals within 90 days of the beginning of each performance period, with such date referred to as the “grant date”. At the end of each annual performance period, the Committee confirms performance against the applicable performance targets. PRSUs do not convey voting rights or earn dividends. PRSUs vest on the last day of an award cycle, unless vested sooner due to a “Change of Control” of the Company, or the death, disability or Retirement of a participant. There were 243,992 cash-settled PRSUs awarded in the quarter ended December 31, 2012 that settled in the quarter ended December 31, 2014 for $4.0 million . Compensation expense for cash-settled PRSUs was recognized over the applicable performance periods based on the estimated performance factor and the closing price of our common stock at each balance sheet date. We recognize compensation expense for stock-settled PRSUs starting on the first day of the applicable performance period and ending on the respective vesting dates. We base the recognized compensation expense upon the number of units awarded for each performance period, the closing price of our common stock on the grant date and the estimated performance factor. In 2016, we issued 542,212 shares to settle the PRSUs awarded November 27, 2012. Stock-settled PRSUs activity under the 2006 Plan is summarized below. Award date Settlement year Performance period Grant date per unit fair value Units awarded Units forfeited Net units Performance factor Shares earned November 27, 2012 2016 2013 $ 5.22 135,553 — 135,553 2.000 271,106 2014 $ 8.52 135,553 — 135,553 2.000 271,106 2015 $ 9.78 135,552 — 135,552 0.000 — December 3, 2013 2017 2014 $ 8.52 90,841 (5,401 ) 85,440 2.000 170,880 2015 $ 9.78 90,841 (5,401 ) 85,440 0.000 — 2016 $ 9.38 90,849 (5,402 ) 85,447 1.021 87,241 December 2, 2014 2018 2015 $ 9.78 80,233 (7,318 ) 72,915 0.000 — 2016 $ 9.38 80,229 (7,318 ) 72,911 1.021 74,442 2017 80,229 (7,319 ) 72,910 December 1, 2015 2019 2016 $ 9.38 77,821 (3,997 ) 73,824 1.021 75,374 2017 77,821 (3,997 ) 73,824 2018 77,829 (3,999 ) 73,830 Stock Options. Stock options generally vest ratably over three years on each anniversary date of the original grant. Stock options granted since November 2007 also vest upon the Retirement of a participant. Compensation expense for stock options is recognized between the grant date and the vesting date (or the date on which a participant becomes Retirement-eligible, if sooner) on a straight-line basis for each tranche of each award. Stock option activity under the 2006 Plan is summarized below. Options Weighted average exercise price per option Weighted average remaining contractual term (years) Aggregate intrinsic value (millions) Outstanding at September 30, 2013 5,124,706 $ 6.22 5.9 $ 14.6 Granted 86,904 8.58 Exercised (587,964 ) 4.61 — Cancelled (71,411 ) 12.92 Outstanding at September 30, 2014 4,552,235 6.37 5.0 13.6 Granted 97,119 9.97 Exercised (506,632 ) 3.42 3.2 Cancelled (150,056 ) 13.90 Outstanding at September 30, 2015 3,992,666 6.54 4.2 9.3 Granted — — Exercised (270,599 ) 6.83 0.8 Cancelled (167,759 ) 17.82 Outstanding at September 30, 2016 3,554,308 $ 5.99 3.4 $ 23.8 Exercisable at September 30, 2016 3,471,004 $ 5.90 3.3 $ 23.5 Expected to vest after September 30, 2016 83,304 $ 9.54 8.0 $ 0.3 Stock option exercise prices are equal to the closing price of our common stock on the relevant grant date. The ranges of exercise prices for stock options outstanding at September 30, 2016 are summarized below. Exercise price Options Weighted average exercise price Weighted average remaining contractual term (years) Exercisable options Weighted average exercise price $ 0.00 - $ 4.99 1,343,036 $ 3.34 4.4 1,343,036 $ 3.34 $ 5.00 - $ 9.99 1,644,230 6.03 3.4 1,560,926 5.84 $ 10.00 - $ 14.99 440,984 11.31 1.0 440,984 11.31 $ 15.00 - $ 20.99 126,058 15.09 0.2 126,058 15.09 3,554,308 $ 5.99 3.4 3,471,004 $ 5.90 Compensation expense attributed to stock options is based on the fair value of the awards on their respective grant dates, as determined using a Black-Scholes model. The weighted average grant-date fair values of stock options granted and the weighted average assumptions used to determine these fair values are indicated below. 2015 2014 Grant-date fair value $ 5.93 $ 5.13 Risk-free interest rate 1.74 % 2.44 % Dividend yield 0.80 % 1.10 % Expected life (years) 8.0 8.0 Expected annual volatility 0.6199 0.6386 The risk-free interest rate is based on the U.S. Treasury zero-coupon yield in effect at the grant date with a term equal to the expected life. The expected dividend yield is based on our estimated annual dividend and stock price history at the grant date. The expected term represents the period of time the awards are expected to be outstanding. Employee Stock Purchase Plan. The Mueller Water Products, Inc. 2006 Employee Stock Purchase Plan (“ESPP”) authorizes the sale of up to 5,800,000 shares of our common stock to employees. Generally, all full-time, active employees are eligible to participate in the ESPP, subject to certain restrictions. Employee purchases are funded through payroll deductions, and any excess payroll withholdings are returned to the employee. The price for shares purchased under the ESPP is 85% of the lower of the closing price on the first day or the last day of the offering period. At September 30, 2016 , 3,051,778 shares were available for issuance under the ESPP. Phantom Plan. Under the Mueller Water Products, Inc. Phantom Plan we adopted in 2012 (“Phantom Plan”), we have awarded “phantom shares” to certain non-officer employees. A phantom share settles in cash equal to the price of one share of our common stock on the vesting date. Phantom shares vest ratably over three years on each anniversary date of the original grant. We recognize compensation expense for phantom shares on a straight-line basis for each tranche of each award based on the closing price of our common stock at each balance sheet date. The outstanding phantom shares had a fair value of $12.55 per award at September 30, 2016 and our accrued liability for such awards was $4.1 million . Phantom Plan activity is summarized below. Phantom Plan units Weighted average grant date fair value per unit Weighted average remaining contractual term (years) Aggregate intrinsic value (millions) Outstanding at September 30, 2013 608,982 $ 4.03 1.0 Granted 304,815 8.52 Vested (240,739 ) $ 2.1 Cancelled (29,770 ) 5.29 Outstanding at September 30, 2014 643,288 6.22 0.8 Granted 289,524 9.78 Vested (317,409 ) 3.1 Cancelled (56,525 ) 8.29 Outstanding at September 30, 2015 558,878 8.49 0.8 Granted 302,875 9.84 Vested (270,822 ) 2.5 Cancelled (56,905 ) 9.28 Outstanding at September 30, 2016 534,026 $ 9.60 0.9

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	12 Months Ended
	Sep. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Supplemental Balance Sheet Information	Supplemental Balance Sheet Information Selected supplemental balance sheet information is presented below. September 30, 2016 2015 (in millions) Inventories: Purchased components and raw material $ 77.8 $ 77.8 Work in process 39.0 40.7 Finished goods 97.0 100.6 $ 213.8 $ 219.1 Other current assets: Maintenance and repair tooling $ 5.1 $ 5.0 Income taxes 1.5 1.5 Other 10.2 7.2 $ 16.8 $ 13.7 Property, plant and equipment: Land $ 9.8 $ 9.4 Buildings 81.7 79.3 Machinery and equipment 375.2 350.7 Construction in progress 20.6 20.1 $ 487.3 $ 459.5 Accumulated depreciation (332.2 ) (310.6 ) $ 155.1 $ 148.9 Other current liabilities: Compensation and benefits $ 36.1 $ 30.5 Customer rebates 17.3 15.4 Taxes other than income taxes 4.1 4.0 Warranty 2.0 2.9 Environmental 5.0 1.9 Income taxes 4.6 0.8 Interest 0.5 0.5 Restructuring 0.7 0.1 Other 8.8 7.1 $ 79.1 $ 63.2

Supplemental Statement of Opera

Supplemental Statement of Operations Information	12 Months Ended
	Sep. 30, 2016
Supplemental Income Statement Elements [Abstract]
Statement of Operations, Supplemental Disclosures [Text Block]	Supplemental Statement of Operations Information Selected supplemental statement of operations information is presented below. 2016 2015 2014 (in millions) Included in selling, general and administrative expenses: Research and development $ 12.9 $ 14.9 $ 14.4 Advertising $ 5.0 $ 5.2 $ 4.7 Interest expense, net: Term Loan $ 20.5 $ 17.5 $ — Deferred financing costs amortization 1.9 2.0 2.0 ABL Agreement 1.1 1.7 1.2 7.375% Senior Subordinated Notes — 4.0 30.6 8.75% Senior Unsecured Notes — 2.4 16.0 Other interest expense 0.5 0.3 0.2 24.0 27.9 50.0 Interest income (0.4 ) (0.3 ) (0.4 ) $ 23.6 $ 27.6 $ 49.6

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss) Note [Text Block]	Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is presented below. Foreign currency translation Minimum pension liability, net of tax Derivative instruments, net of tax Total (in millions) Balance at September 30, 2015 $ (6.3 ) $ (59.4 ) $ (1.6 ) $ (67.3 ) Other comprehensive income (loss) before reclassifications 0.2 (10.6 ) (2.9 ) Amounts reclassified out of accumulated other comprehensive loss — 12.3 — Other comprehensive income (loss) 0.2 1.7 (2.9 ) (1.0 ) Balance at September 30, 2016 $ (6.1 ) $ (57.7 ) $ (4.5 ) $ (68.3 )

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Sep. 30, 2016
Supplemental Cash Flow Information [Abstract]
Cash Flow, Supplemental Disclosures [Text Block]	Supplemental Cash Flow Information Supplemental cash flow information is presented below. September 30, 2016 2015 2014 (in millions) Cash paid, net: Interest $ 21.1 $ 36.8 $ 48.7 Income taxes $ 36.9 $ 13.3 $ 2.6

Segment Information

Segment Information	12 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	Segment Information Our operations consist of three business segments: Mueller Co., Anvil and Mueller Technologies. These segments are organized primarily based on products sold and customers served and are consistent with how the segments are managed, how resources are allocated and how information is used by the chief operating decision maker. Mueller Co. manufactures valves for water and gas systems including butterfly, iron gate, tapping, check, knife, plug and ball valves and dry-barrel and wet-barrel fire hydrants. Anvil manufactures and sources a broad range of products including a variety of fittings, couplings, hangers and related products. The Mueller Technologies businesses offer metering, leak detection, pipe condition assessment and other products and services for the water infrastructure industry. Segment results are not reflective of their results on a stand-alone basis. Intersegment sales and transfers are made at selling prices generally intended to cover costs. Mueller Co. personnel provide certain administrative services, including management of accounts payable and accounts receivable, without any allocation of cost to Mueller Technologies. We do not believe the costs of such administrative services are material to the segments’ results. The determination of segment results excludes certain corporate expenses designated as Corporate because they are not directly attributable to segment operations. Interest expense, loss on early extinguishment of debt and income taxes are not allocated to the segments. Corporate expenses include those costs incurred by our corporate function, such as accounting, treasury, risk management, human resources, legal, tax and other administrative functions and also costs associated with assets and liabilities retained following the sale of U.S. Pipe. Corporate assets principally consist of cash and assets related to the sale of U.S. Pipe. Segment assets consist primarily of receivables, inventories, property, plant and equipment, intangible assets and other noncurrent assets. Geographical area information is presented below. United States Canada Other Total (in millions) Net sales: 2016 $ 1,020.7 $ 73.8 $ 44.4 $ 1,138.9 2015 1,037.7 82.7 44.1 1,164.5 2014 1,040.6 101.1 43.0 1,184.7 Property, plant and equipment, net: September 30, 2016 $ 149.3 $ 2.5 $ 3.3 $ 155.1 September 30, 2015 142.9 2.7 3.3 148.9 Net sales in Canada declined in 2015 compared with 2014 due primarily to the sale of Mueller Co.’s municipal castings business in December 2014. Approximately 43% of our 2016 gross sales were to our 10 largest customers, and approximately 28% of our 2016 gross sales were to our two largest customers, Ferguson Enterprises, Inc. (“Ferguson Enterprises”) and HD Supply, Inc. (“HD Supply”). Sales to Ferguson Enterprises comprised approximately 15% , 13% and 13% of our total gross sales during 2016 , 2015 and 2014 , respectively. In 2016 , Ferguson Enterprises accounted for approximately 17% , 9% and 17% of gross sales for Mueller Co., Anvil and Mueller Technologies, respectively. Receivables from Ferguson Enterprises totaled $30.7 million and $28.2 million at September 30, 2016 and 2015 , respectively. Sales to HD Supply comprised approximately 13% , 12% and 11% of our total gross sales during 2016 , 2015 , and 2014 , respectively. In 2016 , HD Supply accounted for approximately 18% and 6% of gross sales for Mueller Co. and Anvil, respectively. Receivables from HD Supply totaled $27.6 million and $17.4 million at September 30, 2016 and 2015 , respectively. Summarized financial information for our segments is presented below. Mueller Co. Anvil Mueller Technologies Corporate Total (in millions) Net sales, excluding intercompany: 2016 $ 715.7 $ 338.3 $ 84.9 $ — $ 1,138.9 2015 702.2 371.1 91.2 — 1,164.5 2014 679.1 401.4 104.2 — 1,184.7 Intercompany sales: 2016 $ 5.8 $ 0.1 $ — $ — $ 5.9 2015 7.2 0.1 — — 7.3 2014 6.7 0.1 — — 6.8 Operating income (loss): 2016 $ 159.3 $ 26.8 $ (11.1 ) $ (54.4 ) $ 120.6 2015 136.9 30.0 (12.9 ) (44.4 ) 109.6 2014 126.7 41.3 (4.4 ) (39.5 ) 124.1 Depreciation and amortization: 2016 $ 34.2 $ 13.1 $ 4.8 $ 0.5 $ 52.6 2015 38.8 14.7 4.2 0.4 58.1 2014 38.0 14.2 4.1 0.4 56.7 Total pension settlement, loss on Walter receivable and other charges: 2016 $ 3.0 $ 2.3 $ 0.9 $ 18.7 $ 24.9 2015 8.4 0.7 0.1 12.1 21.3 2014 2.1 0.9 0.1 — 3.1 Capital expenditures: 2016 $ 24.3 $ 7.9 $ 7.0 $ 0.2 $ 39.4 2015 20.5 10.3 6.5 0.2 37.5 2014 18.8 11.6 6.1 0.4 36.9 Total assets: September 30, 2016 $ 750.4 $ 243.5 $ 86.1 $ 200.6 $ 1,280.6 September 30, 2015 757.7 255.3 77.2 139.6 1,229.8 Intangible assets, net: September 30, 2016 $ 416.9 $ 51.4 $ 17.7 $ — $ 486.0 September 30, 2015 435.5 54.5 17.3 — 507.3

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Sep. 30, 2016
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 financial statements cannot be predicted with certainty as any such effect depends on 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 business 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 accrue for environmental expenses resulting from existing conditions that relate to past operations when the costs are probable and reasonably estimable. In the acquisition agreement pursuant to which a predecessor to Tyco sold our businesses to a previous owner 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. Since 2007, Tyco has engaged in multiple corporate restructurings, split-offs and divestitures. While none of these transactions directly affects the indemnification obligations of the Tyco indemnitors under the 1999 acquisition agreement, the result of such transactions is that the assets of, and control over, such Tyco indemnitors has changed. Should any of these Tyco indemnitors become financially unable or fail to comply with the terms of the indemnity, we may be responsible for such obligations or liabilities. In September 1987, we implemented an Administrative Consent Order (“ACO”) for our Burlington, New Jersey property, which was required under the New Jersey Environmental Cleanup Responsibility Act (now known as the Industrial Site Recovery Act). The ACO required soil and ground-water cleanup, and we completed, and received final approval on, the soil cleanup required by the ACO. We retained this property related to the sale of our former U.S. Pipe segment. 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 any of our financial statements. On July 13, 2010, Rohcan Investments Limited, 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$10.0 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. The purchaser of U.S. Pipe has been identified as a “potentially responsible party” (“PRP”) under the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”) in connection with a former manufacturing facility operated by U.S. Pipe that was in the vicinity of a proposed Superfund site located in North Birmingham, Alabama. Under the terms of the acquisition agreement relating to our sale of U.S. Pipe, we agreed to indemnify the purchaser for certain environmental liabilities, including those arising out of the former manufacturing site in North Birmingham. Accordingly, the purchaser tendered the matter to us for indemnification, which we accepted. Ultimate liability for the site will depend on many factors that have not yet been determined, including the determination of EPA’s remediation costs, the number and financial viability of the other PRPs (there are four other PRPs currently) and the determination of the final allocation of the costs among the PRPs, if any. Accordingly, because the amount of such costs cannot be reasonably estimated at this time, no amounts had been accrued for this matter at September 30, 2016 . Walter Energy . Each member of the Walter Energy consolidated group, which included us through December 14, 2006, is jointly and 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. Accordingly, we could be liable in the event any such federal income tax 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. 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 an 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 tax returns, to file all such tax returns on our behalf and to determine the amount of our liability to (or entitlement to payment from) Walter Energy for such previous periods. According to Walter Energy's quarterly report on Form 10-Q filed with the SEC on November 5, 2015 (“Walter November 2015 Filing”), at September 30, 2015, a dispute exists with the IRS regarding federal income taxes for years 1980 to 1994 and 1999 to 2001 allegedly owed by the Walter Energy consolidated group, which included U.S. Pipe during these periods. As a matter of law, we are jointly and severally liable for any final tax determination, which means we would be liable in the event Walter Energy is unable to pay any amounts owed. According to the Walter November 2015 Filing, Walter Energy had $33.0 million of accruals for unrecognized tax benefits on the matters subject to disposition. In the Walter November 2015 Filing, Walter Energy stated that it believed that it had sufficient accruals to address any claims, including interest and penalties, and did not believe that any potential difference between the final settlements and the amounts accrued would have a material effect on Walter Energy's financial position, but such potential difference could be material to results of its operations in a future reporting period. Walter Energy filed a petition for reorganization under Chapter 11 of the U.S. Bankruptcy Code in July 2015, which is pending before the Bankruptcy Court for the Northern District of Alabama (“Bankruptcy Case”). We continue to monitor the progress of the Bankruptcy Case to determine whether we could be liable for all or a portion for all or a portion of this federal income tax liability if it is incurred, and not discharged, for any period during which we were included in the Walter Energy consolidated group. On January 11, 2016, the IRS filed a proof of claim in the Bankruptcy Case, alleging that Walter Energy owes amounts for prior taxable periods (specifically, 1983-1994, 2000-2002 and 2005) in an aggregate amount of $554.3 million ( $229.1 million of which the IRS claims is entitled to priority status in the Bankruptcy Case). The IRS asserts that its claim is based on an alleged settlement of Walter Energy’s tax liability for the 1983-1995 taxable periods in connection with Walter Energy’s prior bankruptcy proceeding in the United States Bankruptcy Court for the Middle District of Florida. In the proof of claim, the IRS included an alternative calculation in the event the alleged settlement of the prior bankruptcy court is found to be non-binding, which provides for a claim by the IRS in an aggregate amount of $860.4 million ( $535.3 million of which the IRS claims is entitled to priority status in the Bankruptcy Case). According to a current report on Form 8-K filed by Walter Energy with the SEC on April 1, 2016 (“Walter April 2016 Filing”), on March 31, 2016, Walter Energy closed on the sale of substantially all of Walter Energy’s Alabama assets pursuant to the provisions of Sections 105, 363 and 365 of the Bankruptcy Code. The Walter April 2016 Filing further stated that Walter Energy would have no further material business operations after April 1, 2016 and Walter Energy was evaluating its options with respect to the wind down of its remaining assets. The asset sale did not impact the IRS’ proof of claim filed in the Bankruptcy Case and the proof of claim, as well as the alleged tax liability thereunder, remain unresolved. We cannot predict whether or to what extent we may become liable for the tax-related amounts of the Walter Energy consolidated group asserted in the IRS’ proof of claim filed in the Bankruptcy Case, in part, because: (i) the amounts owed by the Walter Energy consolidated group for certain of the taxable periods from 1980 through 2006 remain unresolved; (ii) it is unclear whether Walter Energy will be obligated to pay any or all of such amounts owed; and (iii) in the event Walter Energy does not discharge all tax obligations for the consolidated group, it is unclear whether and to what extent the IRS will seek to enforce claims against us and any other member of the Walter Energy consolidated group. Walter Energy stated in the Walter November 2015 Filing that it believes its tax filing positions have substantial merit and it intends to vigorously defend the claims asserted by the IRS. We also intend to vigorously assert any and all available defenses against any liability we may have as a member of the Walter Energy consolidated group. However, we cannot currently estimate our liability, if any, relating to the tax-related liabilities of Walter Energy’s consolidated tax group for tax years prior to 2007, and such liability could have a material adverse effect on our business, financial condition, liquidity or results of operations. In accordance with the income tax allocation agreement entered into in connection with our spin-off from Walter Energy, Walter Energy used certain tax assets of one of our predecessors 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 this tax benefit by receiving a refund or otherwise offsetting taxes due. Walter Energy currently owes us $11.6 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. As a result of the aforementioned Chapter 11 petition, we wrote off this receivable during the quarter ended September 30, 2015. 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 segment, 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. At September 30, 2016, Anvil was in a dispute with Victaulic Company (“Victaulic”) regarding two patents held by Victaulic, U.S. Patent 7,086,131 (the “131 Patent”) and U.S. Patent 7,712,796 (the “796 Patent” and collectively with the 131 Patent, the “U.S. Patents”), which Anvil believed were invalid. The U.S. Patents potentially related to a coupling product currently manufactured and marketed by Anvil. During the course of this dispute, Anvil filed multiple reexamination requests with the U.S. Patent and Trademark Office (the “PTO”) regarding the U.S. Patents, and the PTO granted the requests. Although the PTO examiner initially invalidated most of the claims of the 796 Patent, the PTO examiner affirmed the validity of the 796 Patent in September 2014. In April 2015, the PTO examiner invalidated the original claim of the 131 Patent but found several claims added during reexamination that appear substantially similar to those included in the 796 Patent patentable. The PTO examiners’ decisions with respect to the U.S. Patents were appealed to the Patent Trial and Appeal Board by Anvil and Victaulic. In July 2016, the Patent Trial and Appeal Board rejected as unpatentable all claims of the 131 Patent. Relatedly, at September 30, 2016, Anvil and Victaulic were also engaged in lawsuits with respect to these patent matters in the U.S. District Court for the Northern District of Georgia and in the Federal Court of Toronto, Ontario, Canada. In October 2016, we entered into a settlement and license agreement with Victaulic, which amicably resolved all of these lawsuits and patent matters. We are party to a number of other lawsuits arising in the ordinary course of business, 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 financial statements cannot be predicted with certainty as any such effect depends on 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 business or prospects. Operating Leases. We maintain operating leases primarily for equipment and facilities. Rent expense was $10.2 million , $10.4 million and $9.3 million for 2016 , 2015 and 2014 , respectively. Future minimum payments under non-cancellable operating leases are $7.1 million , $4.8 million , $3.3 million , $2.1 million and $2.0 million during 2017 , 2018 , 2019 , 2020 and 2021 , respectively. Total minimum payments due beyond 2021 are $5.1 million .

Subsequent Events

Subsequent Events	12 Months Ended
	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 26, 2016 , our board of directors declared a dividend of $0.03 per share on our common stock, payable on or about November 21, 2016 to stockholders of record at the close of business on November 10, 2016 .

Quarterly Consolidated Financia

Quarterly Consolidated Financial Information (Unaudited)	12 Months Ended
	Sep. 30, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Quarterly Consolidated Financial Information (Unaudited) Quarter Fourth Third Second First (in millions, except per share amounts) 2016 Net sales $ 302.5 $ 310.1 $ 283.6 $ 242.7 Gross profit 103.6 107.1 84.9 68.7 Operating income 46.7 29.7 29.3 14.9 Net income 26.5 15.5 15.7 6.2 Net income per share (1) Basic 0.16 0.10 0.10 0.04 Diluted 0.16 0.09 0.10 0.04 2015 Net sales $ 311.4 $ 301.0 $ 290.3 $ 261.8 Gross profit 97.7 96.2 82.1 71.3 Operating income 44.4 31.5 25.6 8.1 Net income (loss) 22.3 16.5 12.3 (20.2 ) Net income (loss) per share (1): Basic 0.14 0.10 0.08 (0.13 ) Diluted 0.14 0.10 0.08 (0.13 ) (1) The sum of the quarterly amounts may not equal the full year amount due to rounding.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
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.” In May 2014, the Financial Accounting Standards Board (“FASB”) issued new guidance for the recognition of revenue. This new guidance applies to us beginning with our first quarter of 2019 and we do not anticipate adopting early. We are in the early stages of evaluating the impact of the adoption of this guidance on our financial statements and related disclosures and we have not yet reached any conclusions.
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 our outstanding stock-settled share awards and is based on the fair value at each reporting date for our cash-settled 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. At March 31, 2016, we adopted FASB Accounting Standards Update 2016-09 Improvements to Employee Share-Based Payment Accounting. Most significantly, this update changes the accounting for “excess tax benefits” related to stock-based compensation awards by requiring such benefits be included in earnings, rather than recorded directly to additional paid-in capital.
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 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.
Inventory Supplies, Policy	Other Current Assets- 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.
Inventories	Inventories- Inventories are recorded at the lower of first-in, first-out method cost or estimated net realizable 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, 2016 and 2015 , asset retirement obligations were $7.5 million and $2.9 million , respectively. During the quarter ended March 31, 2016, FASB issued Accounting Standards Update 2016-02 Leases , which will require us to recognize lease assets and lease liabilities for those leases currently referred to as operating leases. This requirement is effective for 2020, although early adoption is permitted. The update allows for several different methods of application and adoption of the requirement. We are currently evaluating these methods, in what period we will adopt the requirement, and the impact of this requirement, which we do not believe will be material to our consolidated financial statements as a whole.
Accounting for the Impairment of Long-Lived Assets	Accounting for the Impairment of Long-Lived Assets- We test indefinite-lived intangible assets 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 the segment's April 1, 2012 sale date , but the purchaser agreed to reimburse us for up to $11.8 million in payments we make related to these liabilities. At September 30, 2016 , the remaining reimbursements may be up to $4.9 million , which we have recorded on a discounted basis as $0.6 million in other current assets and $4.1 million in other noncurrent assets. On an undiscounted basis, workers compensation liabilities were $13.7 million and $15.3 million at September 30, 2016 and 2015 , respectively. On a discounted basis, workers compensation liabilities were $11.8 million and $13.1 million at September 30, 2016 and 2015 , 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 all claims are paid.
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 Costs- Costs of debt financing are charged to expense over the lives of the related financing agreements. 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. ABL Agreement-related deferred financing costs are included in other noncurrent assets and remaining deferred financing costs are offset against long-term debt in the accompanying consolidated balance sheets. Deferred financing costs of $8.1 million at September 30, 2016 are scheduled to amortize as follows: $1.8 million related to the ABL Agreement amortizes on a straight-line basis; $6.3 million related to the Term Loan amortizes using the effective-interest rate method. All such amortization will be over the remaining term of the respective debt.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities- We manage interest rate risk to some extent using derivative instruments. We designated our interest rate swap contracts as cash flow hedges of interest payments. As a result, the changes in the fair value of these contracts prior to settlement are reported as a component of accumulated other comprehensive loss and are reclassified into earnings in the periods during which the hedged transactions 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. At December 31, 2015, we adopted FASB Accounting Standards Update 2015-17 Balance Sheet Classification of Deferred Taxes , which requires that all deferred tax assets and deferred tax liabilities, netted by tax jurisdiction, be classified as noncurrent on the balance sheet. The prior period consolidated balance sheet has not been reclassified.
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 Accoun26

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Schedule of Credit Losses for Financing Receivables, Current [Table Text Block]	The following table summarizes information concerning our allowance for doubtful receivables. 2016 2015 2014 (in millions) Balance at beginning of year $ 5.2 $ 5.3 $ 5.3 Provision charged to expense 0.6 0.1 — Balances written off, net of recoveries — (0.2 ) (0.1 ) Other (0.1 ) — 0.1 Balance at end of year $ 5.7 $ 5.2 $ 5.3
Schedule of Reserves for Excess and Obsolete Inventory	The following table summarizes information concerning our inventory valuation reserves. 2016 2015 2014 (in millions) Balance at beginning of year $ 7.8 $ 8.5 $ 10.6 Provision charged to expense 2.1 2.1 2.8 Inventory disposed (1.5 ) (2.9 ) (4.3 ) Other 0.2 0.1 (0.6 ) Balance at end of year $ 8.6 $ 7.8 $ 8.5
Schedule of Product Warranty Liability	Activity in accrued warranty, reported as part of other current liabilities, is presented below. 2016 2015 2014 (in millions) Balance at beginning of year $ 2.9 $ 2.6 $ 2.8 Warranty expense 5.3 5.2 4.1 Warranty payments (6.2 ) (4.9 ) (4.3 ) Balance at end of year $ 2.0 $ 2.9 $ 2.6

Identifiable Intangible Assets

Identifiable Intangible Assets (Tables)	12 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill [Table Text Block]	Intangible assets are presented below. September 30, 2016 2015 (in millions) Capitalized external-use software: Cost $ 20.9 $ 17.9 Accumulated amortization (8.9 ) (7.0 ) Net book value 12.0 10.9 Business combination-related: Cost: Finite-lived intangible assets: Technology 80.3 80.3 Customer relationships and other 400.2 400.2 Indefinite-lived intangible assets: Trade names and trademarks 299.6 299.6 Goodwill 5.4 5.4 785.5 785.5 Accumulated amortization: Technology (75.0 ) (74.2 ) Customer relationships and other (236.5 ) (214.9 ) (311.5 ) (289.1 ) Net book value 474.0 496.4 Total intangible assets net book value $ 486.0 $ 507.3

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The components of income before income taxes are presented below. 2016 2015 2014 (in millions) U.S. $ 96.8 $ 55.4 $ 71.6 Non-U.S. 0.2 (4.7 ) 1.9 Income before income taxes $ 97.0 $ 50.7 $ 73.5
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The components of income tax expense are presented below. 2016 2015 2014 (in millions) Current: U.S. federal $ 37.4 $ 12.4 $ 0.1 U.S. state and local 3.1 0.7 1.6 Non-U.S. 0.1 (0.2 ) 0.7 40.6 12.9 2.4 Deferred: U.S. federal (10.5 ) 4.5 28.7 U.S. state and local 3.2 2.9 (12.8 ) Non-U.S. (0.2 ) (0.5 ) (0.3 ) (7.5 ) 6.9 15.6 Income tax expense $ 33.1 $ 19.8 $ 18.0
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The reconciliation between income tax expense at the U.S. federal statutory income tax rate and reported income tax expense from continuing operations is presented below. 2016 2015 2014 (in millions) Expense at U.S. federal statutory income tax rate of 35% $ 34.0 $ 17.7 $ 25.7 Adjustments to reconcile to income tax expense: State income taxes, net of federal benefit 3.8 2.4 3.6 Domestic production activities deduction (3.9 ) (1.5 ) — Tax credits (2.2 ) (1.3 ) (0.1 ) Nondeductible expenses, other than compensation 0.9 0.7 0.9 Federal valuation allowance (0.2 ) 0.6 (1.2 ) Foreign income taxes 0.1 0.4 (0.2 ) Nondeductible compensation 0.4 0.3 0.8 State valuation allowance, net of federal benefit — (0.1 ) (8.4 ) State tax rate change 0.4 — (2.5 ) Other (0.2 ) 0.6 (0.6 ) Income tax expense $ 33.1 $ 19.8 $ 18.0
Schedule of Deferred Tax Assets and Liabilities	Deferred income tax balances are presented below. September 30, 2016 2015 (in millions) Deferred income tax assets: Inventory reserves $ 14.8 $ 15.5 Accrued expenses 15.0 13.6 Pension and other postretirement benefits 25.0 17.8 Stock-based compensation 7.7 8.9 State net operating losses 5.0 8.1 Federal credit carryovers 0.6 0.5 Other 4.8 3.0 72.9 67.4 Valuation allowance (0.9 ) (1.3 ) Total deferred income tax assets, net of valuation allowance 72.0 66.1 Deferred income tax liabilities: Intangible assets 177.0 182.3 Other 3.8 0.8 Total deferred income tax liabilities 180.8 183.1 Net deferred income tax liabilities $ 108.8 $ 117.0
Summary of Unrecognized Tax Benefits	The following table summarizes information concerning our gross unrecognized tax benefits. 2016 2015 (in millions) Balance at beginning of year $ 2.6 $ 2.7 Increases related to prior year positions 0.3 0.3 Increases related to current year positions 0.2 — Decreases due to lapse in statute of limitations (0.3 ) (0.4 ) Balance at end of year $ 2.8 $ 2.6

Borrowing Arrangements (Tables)

Borrowing Arrangements (Tables)	12 Months Ended
	Sep. 30, 2016
Long-term Debt and Capital Lease Obligations [Abstract]
Components of Long-Term Debt	The components of our long-term debt are presented below. September 30, 2016 2015 (in millions) ABL Agreement $ — $ — Term Loan 489.4 494.0 Other 2.0 2.4 491.4 496.4 Deferred financing costs (6.3 ) (7.4 ) Less current portion (5.9 ) (6.1 ) Long-term debt $ 479.2 $ 482.9

Derivative Financial Instrume30

Derivative Financial Instruments (Tables)	12 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The fair values of the swap contracts are presented below. September 30, 2016 2015 (in millions) Other current liabilities $ 2.0 $ — Other noncurrent liabilities 5.3 2.6 $ 7.3 $ 2.6

Derivative Financial Instrume31

Derivative Financial Instruments Fair Vale of Derivatives Table (Tables)	12 Months Ended
	Sep. 30, 2016
Derivatives, Fair Value [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The fair values of the swap contracts are presented below. September 30, 2016 2015 (in millions) Other current liabilities $ 2.0 $ — Other noncurrent liabilities 5.3 2.6 $ 7.3 $ 2.6

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Sep. 30, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Schedule of Net Periodic Benefit Cost	The components of net periodic benefit cost are presented below. 2016 2015 2014 (in millions) Service cost $ 1.7 $ 1.9 $ 1.7 Interest cost 18.9 20.1 19.9 Expected return on plan assets (19.7 ) (24.6 ) (23.8 ) Amortization of net loss 3.4 3.2 3.5 Curtailment / special settlement loss 16.6 0.5 0.2 Other 0.1 — — Net periodic benefit cost $ 21.0 $ 1.1 $ 1.5
Schedule of Accumulated and Projected Benefit Obligations	Balance sheet information for Pension Plans with accumulated benefit obligations in excess of plan assets is presented below. September 30, 2016 2015 (in millions) Projected benefit obligations $ 402.0 $ 427.0 Accumulated benefit obligations 402.0 427.0 Fair value of plan assets 337.9 381.3 Balance sheet information for Pension Plans with accumulated benefit obligations less than plan assets is presented below. September 30, 2016 2015 (in millions) Projected benefit obligations $ 1.1 $ 1.2 Accumulated benefit obligations 1.1 1.2 Fair value of plan assets 2.1 2.1
Schedule Of Defined Benefit Plans Disclosures	Amounts recognized for our Pension Plans and other postretirement benefit plans are presented below. Pension Plans 2016 2015 (in millions) Projected benefit obligations: Beginning of year $ 428.2 $ 461.5 Service cost 1.7 1.9 Interest cost 18.9 20.1 Actuarial loss (gain) 37.7 (25.9 ) Benefits paid (25.1 ) (26.0 ) Currency translation 0.2 (1.6 ) Decrease in obligation due to curtailment / settlement (58.5 ) (1.8 ) End of year $ 403.1 $ 428.2 Accumulated benefit obligations at end of year $ 403.1 $ 428.2 Plan assets: Beginning of year $ 383.4 $ 410.5 Actual return on plan assets 40.1 1.3 Employer contributions — 1.2 Settlement (58.5 ) (1.9 ) Currency translation 0.1 (1.7 ) Benefits paid (25.1 ) (26.0 ) End of year $ 340.0 $ 383.4 Accrued benefit cost at end of year: Unfunded status $ (63.1 ) $ (44.8 ) Recognized on balance sheet: Other noncurrent assets $ 1.0 $ 0.9 Other current liabilities (1.2 ) — Other noncurrent liabilities (62.9 ) (45.7 ) $ (63.1 ) $ (44.8 ) Recognized in accumulated other comprehensive loss, before tax: Prior year service cost $ — $ — Net actuarial loss 110.8 113.5 $ 110.8 $ 113.5
Schedule of Pension and Other Postretirement Benefits Activity in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Pension Plan activity in accumulated other comprehensive loss, before tax, in 2016 is presented below, in millions. Balance at beginning of year $ 113.5 Actuarial loss 17.3 Prior year actuarial loss amortization to net periodic cost, including effect of pension settlement (20.0 ) Balance at end of year $ 110.8
Schedule of Components of Accumulated Other Comprehensive Income (Loss) Related to Pension and Other Postretirement Benefits Expected to be Amortized	The components of accumulated other comprehensive loss related to pension that we expect to amortize into net periodic benefit cost in 2017 are presented below, in millions. Amortization of unrecognized prior year service cost $ — Amortization of unrecognized loss 4.0 $ 4.0
Schedule of Assumptions Used	A summary of key assumptions for our pension plans is below. Pension Plans 2016 2015 2014 Weighted average used to determine benefit obligations: Discount rate 3.68 % 4.84 % 4.49 % Weighted average used to determine net periodic cost: Discount rate 3.92 % 4.49 % 5.16 % Expected return on plan assets 5.50 6.21 6.24
Schedule of Strategic Allocation of Plan Assets [Table Text Block]	This trust’s strategic asset allocations, tactical range at September 30, 2016 and actual asset allocations are presented below. Strategic asset allocation Actual asset allocations at September 30, Tactical range 2016 2015 2014 Equity investments: Large capitalization stocks 19 % Small capitalization stocks 4 International stocks 7 30 30 - 50 % 29 % 39 % 40 % Fixed income investments 70 50 - 70 69 60 59 Cash — 0 - 5 2 1 1 100 % 100 % 100 % 100 %
Schedule of Allocation of Plan Assets	The assets of the Pension Plans by level within the fair value hierarchy are presented below. September 30, 2016 Level 1 Level 2 Total (in millions) Equity: Large cap stocks: Large cap growth funds $ — $ 7.3 $ 7.3 Large cap index funds — 38.2 38.2 Large cap value funds — 7.2 7.2 Small cap stocks: Small cap growth funds — 15.1 15.1 International stocks: Mutual funds 13.5 — 13.5 International funds — 18.1 18.1 Total equity 13.5 85.9 99.4 Fixed income — 233.3 233.3 Cash and cash equivalents 7.3 — 7.3 $ 20.8 $ 319.2 $ 340.0 September 30, 2015 Level 1 Level 2 Total (in millions) Equity: Large cap stocks: Large cap growth funds $ — $ 32.7 $ 32.7 Large cap index funds — 27.1 27.1 Large cap value funds — 15.7 15.7 Small cap stocks: Small cap growth funds — 18.5 18.5 International stocks: Mutual funds 42.1 — 42.1 International funds — 13.9 13.9 Total equity 42.1 107.9 150.0 Fixed income — 229.4 229.4 Cash and cash equivalents 4.0 — 4.0 $ 46.1 $ 337.3 $ 383.4
Schedule of Expected Benefit Payments	Our estimated future pension benefit payments are presented below in millions. 2017 $ 32.6 2018 25.7 2019 25.6 2020 25.5 2021 25.4 2022-2026 122.9

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Sep. 30, 2016
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Schedule of Common Stock Outstanding Roll Forward [Table Text Block]	Common stock share activity is presented below. Shares outstanding at September 30, 2013 158,234,300 Vesting of restricted stock units, net of shares withheld for taxes 734,047 Exercise of stock options 587,964 Exercise of employee stock purchase plan instruments 204,360 Shares outstanding at September 30, 2014 159,760,671 Vesting of restricted stock units, net of shares withheld for taxes 541,839 Exercise of stock options 506,632 Exercise of employee stock purchase plan instruments 212,550 Stock repurchased under buyback program (523,851 ) Shares outstanding at September 30, 2015 160,497,841 Vesting of restricted stock units, net of shares withheld for taxes 370,138 Settlement of performance-based restricted stock units, net of shares withheld for taxes 335,998 Exercise of stock options 270,599 Exercise of employee stock purchase plan instruments 218,475 Shares outstanding at September 30, 2016 161,693,051

Stock-based Compensation Plans

Stock-based Compensation Plans (Tables)	12 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	The effect of stock-based compensation on our statements of operations is presented below. 2016 2015 2014 (in millions, except per share data) Decrease in operating income $ 9.1 $ 7.0 $ 13.2 Decrease in net income 5.8 4.4 8.1 Decrease in earnings per basic share 0.04 0.03 0.05 Decrease in earnings per diluted share 0.04 0.03 0.05
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	Restricted stock unit activity under the 2006 Plan is summarized below. Restricted stock units Weighted average grant date fair value per unit Weighted average remaining contractual term (years) Aggregate intrinsic value (millions) Outstanding at September 30, 2013 1,925,340 $ 4.30 0.9 Granted 381,012 8.51 Vested (1,099,591 ) 4.94 $ 9.4 Cancelled — — Outstanding at September 30, 2014 1,206,761 5.04 0.7 Granted 459,659 9.70 Vested (793,630 ) 3.99 7.7 Cancelled — — Outstanding at September 30, 2015 872,790 8.45 0.8 Granted 360,255 9.33 Vested (510,535 ) 7.94 4.7 Cancelled (59,062 ) 8.23 Outstanding at September 30, 2016 663,448 $ 9.34 1.0
Schedule of Nonvested Performance-based Units Activity [Table Text Block]	Stock-settled PRSUs activity under the 2006 Plan is summarized below. Award date Settlement year Performance period Grant date per unit fair value Units awarded Units forfeited Net units Performance factor Shares earned November 27, 2012 2016 2013 $ 5.22 135,553 — 135,553 2.000 271,106 2014 $ 8.52 135,553 — 135,553 2.000 271,106 2015 $ 9.78 135,552 — 135,552 0.000 — December 3, 2013 2017 2014 $ 8.52 90,841 (5,401 ) 85,440 2.000 170,880 2015 $ 9.78 90,841 (5,401 ) 85,440 0.000 — 2016 $ 9.38 90,849 (5,402 ) 85,447 1.021 87,241 December 2, 2014 2018 2015 $ 9.78 80,233 (7,318 ) 72,915 0.000 — 2016 $ 9.38 80,229 (7,318 ) 72,911 1.021 74,442 2017 80,229 (7,319 ) 72,910 December 1, 2015 2019 2016 $ 9.38 77,821 (3,997 ) 73,824 1.021 75,374 2017 77,821 (3,997 ) 73,824 2018 77,829 (3,999 ) 73,830
Schedule of Share-based Compensation. Options	Stock option activity under the 2006 Plan is summarized below. Options Weighted average exercise price per option Weighted average remaining contractual term (years) Aggregate intrinsic value (millions) Outstanding at September 30, 2013 5,124,706 $ 6.22 5.9 $ 14.6 Granted 86,904 8.58 Exercised (587,964 ) 4.61 — Cancelled (71,411 ) 12.92 Outstanding at September 30, 2014 4,552,235 6.37 5.0 13.6 Granted 97,119 9.97 Exercised (506,632 ) 3.42 3.2 Cancelled (150,056 ) 13.90 Outstanding at September 30, 2015 3,992,666 6.54 4.2 9.3 Granted — — Exercised (270,599 ) 6.83 0.8 Cancelled (167,759 ) 17.82 Outstanding at September 30, 2016 3,554,308 $ 5.99 3.4 $ 23.8 Exercisable at September 30, 2016 3,471,004 $ 5.90 3.3 $ 23.5 Expected to vest after September 30, 2016 83,304 $ 9.54 8.0 $ 0.3
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]	The ranges of exercise prices for stock options outstanding at September 30, 2016 are summarized below. Exercise price Options Weighted average exercise price Weighted average remaining contractual term (years) Exercisable options Weighted average exercise price $ 0.00 - $ 4.99 1,343,036 $ 3.34 4.4 1,343,036 $ 3.34 $ 5.00 - $ 9.99 1,644,230 6.03 3.4 1,560,926 5.84 $ 10.00 - $ 14.99 440,984 11.31 1.0 440,984 11.31 $ 15.00 - $ 20.99 126,058 15.09 0.2 126,058 15.09 3,554,308 $ 5.99 3.4 3,471,004 $ 5.90
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The weighted average grant-date fair values of stock options granted and the weighted average assumptions used to determine these fair values are indicated below. 2015 2014 Grant-date fair value $ 5.93 $ 5.13 Risk-free interest rate 1.74 % 2.44 % Dividend yield 0.80 % 1.10 % Expected life (years) 8.0 8.0 Expected annual volatility 0.6199 0.6386
Schedule of Share-based Compensation, Phantom Award, Activity	Phantom Plan activity is summarized below. Phantom Plan units Weighted average grant date fair value per unit Weighted average remaining contractual term (years) Aggregate intrinsic value (millions) Outstanding at September 30, 2013 608,982 $ 4.03 1.0 Granted 304,815 8.52 Vested (240,739 ) $ 2.1 Cancelled (29,770 ) 5.29 Outstanding at September 30, 2014 643,288 6.22 0.8 Granted 289,524 9.78 Vested (317,409 ) 3.1 Cancelled (56,525 ) 8.29 Outstanding at September 30, 2015 558,878 8.49 0.8 Granted 302,875 9.84 Vested (270,822 ) 2.5 Cancelled (56,905 ) 9.28 Outstanding at September 30, 2016 534,026 $ 9.60 0.9

Supplemental Balance Sheet In35

Supplemental Balance Sheet Information (Tables)	12 Months Ended
	Sep. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Schedule Of Selected Supplemental Balance Sheet Information [Table Text Block]	Selected supplemental balance sheet information is presented below. September 30, 2016 2015 (in millions) Inventories: Purchased components and raw material $ 77.8 $ 77.8 Work in process 39.0 40.7 Finished goods 97.0 100.6 $ 213.8 $ 219.1 Other current assets: Maintenance and repair tooling $ 5.1 $ 5.0 Income taxes 1.5 1.5 Other 10.2 7.2 $ 16.8 $ 13.7 Property, plant and equipment: Land $ 9.8 $ 9.4 Buildings 81.7 79.3 Machinery and equipment 375.2 350.7 Construction in progress 20.6 20.1 $ 487.3 $ 459.5 Accumulated depreciation (332.2 ) (310.6 ) $ 155.1 $ 148.9 Other current liabilities: Compensation and benefits $ 36.1 $ 30.5 Customer rebates 17.3 15.4 Taxes other than income taxes 4.1 4.0 Warranty 2.0 2.9 Environmental 5.0 1.9 Income taxes 4.6 0.8 Interest 0.5 0.5 Restructuring 0.7 0.1 Other 8.8 7.1 $ 79.1 $ 63.2

Supplemental Statement of Ope36

Supplemental Statement of Operations Information (Tables) (Tables)	12 Months Ended
	Sep. 30, 2016
Supplemental Income Statement Elements [Abstract]
Schedule of Operations, Supplemental Disclosures [Table Text Block]	Selected supplemental statement of operations information is presented below. 2016 2015 2014 (in millions) Included in selling, general and administrative expenses: Research and development $ 12.9 $ 14.9 $ 14.4 Advertising $ 5.0 $ 5.2 $ 4.7 Interest expense, net: Term Loan $ 20.5 $ 17.5 $ — Deferred financing costs amortization 1.9 2.0 2.0 ABL Agreement 1.1 1.7 1.2 7.375% Senior Subordinated Notes — 4.0 30.6 8.75% Senior Unsecured Notes — 2.4 16.0 Other interest expense 0.5 0.3 0.2 24.0 27.9 50.0 Interest income (0.4 ) (0.3 ) (0.4 ) $ 23.6 $ 27.6 $ 49.6

Accumulated Other Comprehensi37

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Accumulated other comprehensive loss is presented below. Foreign currency translation Minimum pension liability, net of tax Derivative instruments, net of tax Total (in millions) Balance at September 30, 2015 $ (6.3 ) $ (59.4 ) $ (1.6 ) $ (67.3 ) Other comprehensive income (loss) before reclassifications 0.2 (10.6 ) (2.9 ) Amounts reclassified out of accumulated other comprehensive loss — 12.3 — Other comprehensive income (loss) 0.2 1.7 (2.9 ) (1.0 ) Balance at September 30, 2016 $ (6.1 ) $ (57.7 ) $ (4.5 ) $ (68.3 )

Supplemental Cash Flow Inform38

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Sep. 30, 2016
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Supplemental cash flow information is presented below. September 30, 2016 2015 2014 (in millions) Cash paid, net: Interest $ 21.1 $ 36.8 $ 48.7 Income taxes $ 36.9 $ 13.3 $ 2.6

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	Geographical area information is presented below. United States Canada Other Total (in millions) Net sales: 2016 $ 1,020.7 $ 73.8 $ 44.4 $ 1,138.9 2015 1,037.7 82.7 44.1 1,164.5 2014 1,040.6 101.1 43.0 1,184.7 Property, plant and equipment, net: September 30, 2016 $ 149.3 $ 2.5 $ 3.3 $ 155.1 September 30, 2015 142.9 2.7 3.3 148.9
Schedule Of Selected Supplemental Balance Sheet Information	Summarized financial information for our segments is presented below. Mueller Co. Anvil Mueller Technologies Corporate Total (in millions) Net sales, excluding intercompany: 2016 $ 715.7 $ 338.3 $ 84.9 $ — $ 1,138.9 2015 702.2 371.1 91.2 — 1,164.5 2014 679.1 401.4 104.2 — 1,184.7 Intercompany sales: 2016 $ 5.8 $ 0.1 $ — $ — $ 5.9 2015 7.2 0.1 — — 7.3 2014 6.7 0.1 — — 6.8 Operating income (loss): 2016 $ 159.3 $ 26.8 $ (11.1 ) $ (54.4 ) $ 120.6 2015 136.9 30.0 (12.9 ) (44.4 ) 109.6 2014 126.7 41.3 (4.4 ) (39.5 ) 124.1 Depreciation and amortization: 2016 $ 34.2 $ 13.1 $ 4.8 $ 0.5 $ 52.6 2015 38.8 14.7 4.2 0.4 58.1 2014 38.0 14.2 4.1 0.4 56.7 Total pension settlement, loss on Walter receivable and other charges: 2016 $ 3.0 $ 2.3 $ 0.9 $ 18.7 $ 24.9 2015 8.4 0.7 0.1 12.1 21.3 2014 2.1 0.9 0.1 — 3.1 Capital expenditures: 2016 $ 24.3 $ 7.9 $ 7.0 $ 0.2 $ 39.4 2015 20.5 10.3 6.5 0.2 37.5 2014 18.8 11.6 6.1 0.4 36.9 Total assets: September 30, 2016 $ 750.4 $ 243.5 $ 86.1 $ 200.6 $ 1,280.6 September 30, 2015 757.7 255.3 77.2 139.6 1,229.8 Intangible assets, net: September 30, 2016 $ 416.9 $ 51.4 $ 17.7 $ — $ 486.0 September 30, 2015 435.5 54.5 17.3 — 507.3

Quarterly Consolidated Financ40

Quarterly Consolidated Financial Information (Unaudited) (Tables)	12 Months Ended
	Sep. 30, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Quarter Fourth Third Second First (in millions, except per share amounts) 2016 Net sales $ 302.5 $ 310.1 $ 283.6 $ 242.7 Gross profit 103.6 107.1 84.9 68.7 Operating income 46.7 29.7 29.3 14.9 Net income 26.5 15.5 15.7 6.2 Net income per share (1) Basic 0.16 0.10 0.10 0.04 Diluted 0.16 0.09 0.10 0.04 2015 Net sales $ 311.4 $ 301.0 $ 290.3 $ 261.8 Gross profit 97.7 96.2 82.1 71.3 Operating income 44.4 31.5 25.6 8.1 Net income (loss) 22.3 16.5 12.3 (20.2 ) Net income (loss) per share (1): Basic 0.14 0.10 0.08 (0.13 ) Diluted 0.14 0.10 0.08 (0.13 ) (1) The sum of the quarterly amounts may not equal the full year amount due to rounding.

Organization (Details)

Organization (Details) $ in Millions	Jul. 31, 2014	Sep. 30, 2016USD ($)business_segments
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization		Organization Mueller Water Products, Inc., a Delaware corporation, together with its consolidated subsidiaries, operates in three business segments: Mueller Co., Anvil and Mueller Technologies. Mueller Co. manufactures valves for water and gas systems, including butterfly, iron gate, tapping, check, knife, plug and ball valves, as well as dry-barrel and wet-barrel fire hydrants. Anvil manufactures and sources a broad range of products, including a variety of fittings, couplings, hangers and related products. Mueller Technologies offers metering systems, leak detection, pipe condition assessment and other products and services for the water infrastructure industry. The “Company,” “we,” “us” or “our” refer to Mueller Water Products, Inc. and its subsidiaries. With regard to the Company’s segments, “we,” “us” or “our” may also refer to the segment being discussed. In July 2014 , Mueller Co. acquired a 49% ownership in an industrial valve joint-venture for $1.7 million . Due to substantive control features in the joint-venture agreement, all of the joint venture’s assets, liabilities and results of operations are included in our consolidated financial statements. We included an adjustment for the loss attributable to noncontrolling interest in selling, general and administrative expenses. Noncontrolling interest is recorded at its carrying value, which approximates fair value. Our consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), which require us to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, sales and expenses and the disclosure of contingent assets and liabilities for the reporting periods. Actual results could differ from those estimates. All significant intercompany balances and transactions have been eliminated. Certain reclassifications have been made to previously reported amounts to conform to the current presentation. Unless the context indicates otherwise, whenever we refer to a particular year, we mean our fiscal year ended or ending September 30 in that particular calendar year.
Number of Reportable Segments | business_segments		3
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	49.00%
Payments to Acquire Interest in Joint Venture | $		$ 1.7

Summary of Significant Accoun42

Summary of Significant Accounting Policies (Schedule of Allowance for Doubtful Receivables) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of year	$ 5.2	$ 5.3	$ 5.3
Provision for Doubtful Accounts	0.6	0.1	0
Balances written off, net of recoveries	0	(0.2)	(0.1)
Reclassifications	(0.1)	0	0.1
Balance at end of year	$ 5.7	$ 5.2	$ 5.3

Summary of Significant Accoun43

Summary of Significant Accounting Policies (Schedule of Reserves for Excess and Obsolete Inventory) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	$ 7.8	$ 8.5	$ 10.6
Provision charged to expense	(2.1)	(2.1)	(2.8)
Inventory disposed	(1.5)	(2.9)	(4.3)
Valuation Allowances and Reserves, Adjustments	0.2	0.1	(0.6)
Balance at end of year	$ 8.6	$ 7.8	$ 8.5

Summary of Significant Accoun44

Summary of Significant Accounting Policies (Schedule of Product Warranty Liability) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of year	$ 2.9	$ 2.6	$ 2.8
Warranty expense	5.3	5.2	4.1
Warranty payments	(6.2)	(4.9)	(4.3)
Balance at end of year	$ 2	$ 2.9	$ 2.6

Summary of Significant Accoun45

Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2013
Asset Retirement Obligation	$ 7.5	$ 2.9
Exposure to Workers Compensation Claims, Per Incident	1
Discontinued Operations, Receivable from Buyer of Discontinued Operation			$ 11.8
Workers Compensation Undiscounted Basis Liability	13.7	15.3
Workers' Compensation Liability	$ 11.8	13.1
Income Tax Benefit, Likelihood of Realization Threshold	50.00%
Deferred Finance Costs, Net	$ 8.1
Minimum [Member]
Finite-Lived Tangible Asset, Useful Life, Maximum	3 years
Maximum [Member]
Finite-Lived Tangible Asset, Useful Life, Maximum	10 years
Land Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life, Minimum	10 years
Land Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life, Minimum	20 years
Building [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life, Minimum	10 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life, Minimum	40 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life, Minimum	3 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life, Minimum	15 years
Software and Software Development Costs [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life, Minimum	3 years
Software and Software Development Costs [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life, Minimum	6 years
U.S. Pipe [Member] | Maximum [Member]
Discontinued Operations, Receivable from Buyer of Discontinued Operation	$ 4.9
Other Current Assets [Member] | U.S. Pipe [Member]
Discontinued Operations, Receivable from Buyer of Discontinued Operation	0.6
Other Noncurrent Assets [Member] | U.S. Pipe [Member]
Discontinued Operations, Receivable from Buyer of Discontinued Operation	4.1
Revolving Credit Facility [Member]
Deferred Finance Costs, Net	1.8
Secured Debt [Member]
Deferred Finance Costs, Net	$ 6.3	$ 7.4

Identifiable Intangible Asset46

Identifiable Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Amortization		$ 24.3	$ 29.4	$ 29.4
Software and Software Development Costs [Member]
Finite-Lived Intangible Asset, Useful Life	3 years	6 years
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		3 years 7 months 3 days
Amortization		$ 1.9	1.6	1.1
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		2.8
Finite-Lived Intangible Assets, Amortization Expense, Year Two		2.6
Finite-Lived Intangible Assets, Amortization Expense, Year Three		2.4
Finite-Lived Intangible Assets, Amortization Expense, Year Four		2.1
Finite-Lived Intangible Assets, Amortization Expense, Year Five		$ 1.3
Business Combination-Related Identifiable Intangible [Member]
Finite-Lived Intangible Asset, Useful Life		7 years 2 months 2 days
Amortization		$ 22.4	$ 27.8	$ 28.3
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		22.3
Finite-Lived Intangible Assets, Amortization Expense, Year Two		22.5
Finite-Lived Intangible Assets, Amortization Expense, Year Three		22.3
Finite-Lived Intangible Assets, Amortization Expense, Year Four		22.2
Finite-Lived Intangible Assets, Amortization Expense, Year Five		$ 21.9

Identifiable Intangible Asset47

Identifiable Intangible Assets Schedule of Intangible Assets and Goodwill (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Indefinite-lived intangible assets:
Goodwill	$ 5.4	$ 5.4
Intangible Assets, Gross (Excluding Goodwill)	785.5	785.5
Accumulated amortization:
Accumulated Amortization	311.5	289.1
Intangible Assets, Net (Including Goodwill)	486	507.3
Business Combination-Related Identifiable Intangible [Member]
Accumulated amortization:
Net book value	474	496.4
Trademarks and Trade Names [Member]
Indefinite-lived intangible assets:
Trade names and trademarks	299.6	299.6
Software and Software Development Costs [Member]
Capitalized external-use software:
Capitalized Computer Software, Gross	20.9	17.9
Accumulated amortization	8.9	7
Net book value	12	10.9
Technology-Based Intangible Assets [Member]
Finite-lived intangible assets:
Technology	80.3	80.3
Accumulated amortization:
Accumulated Amortization	75	74.2
Customer Relationships [Member]
Finite-lived intangible assets:
Customer relationships and other	400.2	400.2
Accumulated amortization:
Accumulated Amortization	$ 236.5	$ 214.9

Business Combination Schedule o

Business Combination Schedule of Business Acquisitions, by Acquisition (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Assets acquired:
Goodwill	$ 5.4	$ 5.4

Discontinued Operations, Asse49

Discontinued Operations, Assets Held for Sale and Divestitures (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Other Cost and Expense, Operating									$ 8.3	$ 9.2	$ 3.1
Asset Impairment Charges									0	11.6	0
Revenue, Net	$ 302.5	$ 310.1	$ 283.6	$ 242.7	$ 311.4	$ 301	$ 290.3	$ 261.8	1,138.9	1,164.5	$ 1,184.7
Multiemployer Plans, Withdrawal Obligation	$ 0.9								0.9
Gain (Loss) on Sale of Assets and Asset Impairment Charges									2.5
Statesboro [Member]
Other Cost and Expense, Operating									4.1
QUEBEC
Restructuring Charges									7.2
Asset Impairment Charges									2.5
Environmental Remediation Expense									2.3
Severance Costs									$ 2.4
Revenue, Net										$ 11.5

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 0.5	$ 0.6
Income tax expense (benefit)	33.1	$ 19.8	$ 18
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	0.8
Undistributed foreign earnings	$ 54.7
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2016
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2033

Income Taxes (Income before Inc

Income Taxes (Income before Income Tax, Domestic and Foreign) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Loss before income taxes, U.S.	$ 96.8	$ 55.4	$ 71.6
Loss before income taxes, Non-U.S.	0.2	(4.7)	1.9
Net Income Before Income Tax	$ 97	$ 50.7	$ 73.5

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Current:
Current Federal Tax Expense (Benefit)	$ 37.4	$ 12.4	$ 0.1
Current State and Local Tax Expense (Benefit)	3.1	0.7	1.6
Current Foreign Tax Expense (Benefit)	0.1	(0.2)	0.7
Current Income Tax Expense (Benefit)	40.6	12.9	2.4
Deferred:
Deferred Federal Income Tax Expense (Benefit)	(10.5)	4.5	28.7
Deferred State and Local Income Tax Expense (Benefit)	3.2	2.9	(12.8)
Deferred Foreign Income Tax Expense (Benefit)	(0.2)	(0.5)	(0.3)
Deferred Income Tax Expense (Benefit)	(7.5)	6.9	15.6
Income tax expense (benefit)	$ 33.1	$ 19.8	$ 18

Income Taxes (Disposal Groups,

Income Taxes (Disposal Groups, including Discontinued Operations) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense (benefit)	$ 33.1	$ 19.8	$ 18

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Statutory Taxes to Effective Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Tax at U.S. federal statutory income tax rate of 35%	$ 34	$ 17.7	$ 25.7
Adjustments to reconcile to income tax expense (benefit):
Federal Valuation Allowance	(0.2)	0.6	(1.2)
State income taxes, net of federal benefit	3.8	2.4	3.6
Domestic production activities deduction	(3.9)	(1.5)	0
State tax rate change	0.4	0	(2.5)
Effective Income Tax Rate Reconciliation, Change in State Deferred TAx Assets Valuation Allowance, Amount.	0	(0.1)	(8.4)
Tax Credits	(2.2)	(1.3)	(0.1)
Other nondeductible expenses	0.9	0.7	0.9
Foreign income taxes	0.1	0.4	(0.2)
Nondeductible compensation	0.4	0.3	0.8
Other income tax	(0.2)	0.6	(0.6)
Income tax expense (benefit)	$ 33.1	$ 19.8	$ 18

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Deferred income tax assets:
Inventory reserves	$ 14.8	$ 15.5
Accrued expenses	15	13.6
Pension and other postretirement benefits	25	17.8
Stock-based compensation	7.7	8.9
State net operating losses	5	8.1
Federal net operating losses and credit carryovers	0.6	0.5
All other	4.8	3
Deferred income tax assets	72.9	67.4
Valuation allowance	(0.9)	(1.3)
Total deferred income tax assets	72	66.1
Deferred income tax liabilities:
Identifiable intangible assets	(177)	(182.3)
Other	(3.8)	(0.8)
Total deferred income tax liabilities	180.8	183.1
Net deferred income tax liabilities	$ 108.8	$ 117

Income Taxes (Gross Unrecognize

Income Taxes (Gross Unrecognized Tax Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of year	$ 2.6	$ 2.7
Increases related to prior year positions	0.3	0.3
Increases related to current year positions	0.2	0
Decreases due to lapse in statute of limitations	(0.3)	(0.4)
Balance at end of year	$ 2.8	$ 2.6

Income Taxes (Summary of Valuat

Income Taxes (Summary of Valuation Allowance) (Details) $ in Millions	Sep. 30, 2016USD ($)
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 1.3
Balance at end of year	$ 0.9

Borrowing Arrangements (Narrati

Borrowing Arrangements (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended			84 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Nov. 25, 2021
Agreement termination date	Jul. 13, 2021
Loss on early extinguishment of debt	$ 0	$ 31,300	$ 1,000
Gain (Loss) on Repurchase of Debt Instrument	25,200
Write off of Deferred Debt Issuance Cost	4,400
Debtor Reorganization Items, Write-off of Deferred Financing Costs and Debt Discounts	1,700
Future maturities of outstanding borrowings
CY plus 1	5,900
CY plus 2	5,600
CY plus 3	5,400
CY plus 4	5,100
CY plus 5	5,000
CY plus 6 and more	466,200
Payments of Financing Costs	1,200	$ 8,500	$ 0
Revolving Credit Facility [Member]
Revolving credit facility amount	225,000
Potential increase size of the credit facility by an additional amount	$ 150,000
Line of Credit Facility, Interest Rate at Period End	12500.00%
Aggregate commitments availability	$ 17,500
Aggregate commitments availability, percentage	10.00%
Outstanding letter of credit accrued fees and expenses	$ 30,400
Excess availability reduced by outstanding borrowings, outstanding letters of credit and accrued fees and expenses	$ 169,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	2500.00%
Swing Line Loans [Member]
Revolving credit facility amount	$ 25,000
Letter Of Credit [Member]
Revolving credit facility amount	60,000
Secured Debt [Member]
Deferred Finance Costs, Noncurrent, Gross	$ 8,500
Borrowing rate in addition to LIBOR	32500.00%
Debt Instrument, Interest Rate, Effective Percentage	4.54%
Debt Instrument, Periodic Payment, Principal	$ 1,250
Long-term Debt, Gross	500,000
Future maturities of outstanding borrowings
Debt Instrument, Unamortized Discount	1,800
Financial Liabilities Fair Value Disclosure	$ 496,200
London Interbank Offered Rate (LIBOR) [Member] | Secured Debt [Member]
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	0.75%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR	12500.00%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR	15000.00%
Base Rate [Member] | Minimum [Member] | Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR	2500.00%
Base Rate [Member] | Maximum [Member] | Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR	5000.00%
Scenario, Forecast [Member] | Secured Debt [Member]
Agreement termination date				Nov. 25, 2021

Borrowing Arrangements (Compone

Borrowing Arrangements (Components Of Long-Term Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Debt	$ 491.4	$ 496.4
Deferred Finance Costs, Net	(8.1)
Current portion of long-term debt	(5.9)	(6.1)
Long-term debt, excluding current maturities	479.2	482.9
Revolving Credit Facility [Member]
Debt	0	0
Deferred Finance Costs, Net	(1.8)
Secured Debt [Member]
Debt	489.4	494
Deferred Finance Costs, Net	(6.3)	(7.4)
Other [Member]
Debt	$ 2	$ 2.4

Derivative Financial Instrume60

Derivative Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities	$ 2	$ 0
HedgePeriodStart	Sep. 30, 2016
Derivative, Maturity Date	Sep. 30, 2021
Derivative, Cap Interest Rate	0.75%
Derivative, Fixed Interest Rate	2.341%
Derivative, Notional Amount	$ 150
Other noncurrent liabilities	5.3	2.6
Derivative Liability	$ 7.3	$ 2.6
Secured Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	4.54%
Derivative, Amount of Hedged Item	$ 150
Cash Flow Hedging [Member] | Secured Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	5.591%

Derivative Financial Instrume61

Derivative Financial Instruments Narrative (Details)	12 Months Ended
	Sep. 30, 2016
Derivative [Line Items]
Derivative, Inception Date	Apr. 7, 2015

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Jun. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements			$ 16.6	$ (0.5)	$ 0
Defined Benefit Plan, Other Information	0.75
Defined Benefit Plan, Settlements, Plan Assets			58.5
Defined Benefit Plan, Contributions by Employer			$ 0	1.2
Percentage of Obligations Related to U.S. Plan			98.00%
Defined Benefit Plan, Target Plan Asset Allocations			100.00%
Defined Contribution Plan, Cost Recognized			$ 5.9	6.2	5.6
Percentage of Assets Related to U.S. Plan			98.00%
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Expected Return on Plan Assets Major Asset Classes Time Horizon			10
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Expected Return on Plan Assets Major Asset Classes Time Horizon			15
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Settlements, Plan Assets			$ 58.5	1.9
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments			$ (16.6)	$ (0.5)	$ (0.2)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			3.68%	4.84%	4.49%
Discount rate			3.92%	4.49%	5.16%
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations			30.00%	40.00%
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Contributions		$ 1.3

Retirement Plans (Net Periodic

Retirement Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan, Net Periodic Benefit Cost	$ 21	$ 1.1	$ 1.5
Pension Plan, Defined Benefit [Member]
Other	0.1	0	0
Service cost	1.7	1.9	1.7
Interest cost	18.9	20.1	19.9
Expected return on plan assets	(19.7)	(24.6)	(23.8)
Amortization of net loss (gain)	3.4	3.2	3.5
Curtailment / special settlement loss (gain)	16.6	0.5	0.2
Defined Benefit Plan, Net Periodic Benefit Cost	$ 21	$ 1.1	$ 1.5

Retirement Plans (Accumulated a

Retirement Plans (Accumulated and Projected Benefit Obligations) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Pension Plans with accumulated benefit obligations in excess of plan assets
Projected benefit obligation	$ 402	$ 427
Accumulated benefit obligation	402	427
Fair value of plan assets	337.9	381.3
Pension plans with plan assets in excess of accumulated benefit obligations
Projected benefit obligation	1.1	1.2
Accumulated benefit obligation	1.1	1.2
Fair value of plan assets	$ 2.1	$ 2.1

Retirement Plans (Amounts Recog

Retirement Plans (Amounts Recognized for Pension and Other Postretirement Benefit Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Plan assets:
Beginning of year	$ 383.4
Defined Benefit Plan, Contributions by Employer	0	$ 1.2
Settlement	(58.5)
End of year	340	383.4
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other current liabilities	(1.2)	0
Projected benefit obligations:
Beginning of year	428.2	461.5
Service cost	1.7	1.9	$ 1.7
Interest cost	18.9	20.1	19.9
Actuarial loss (gain)	37.7	(25.9)
Benefits paid	(25.1)	(26)
Currency translation	0.2	(1.6)
Decrease in obligation due to curtailment / settlement	58.5	1.8
End of year	403.1	428.2	461.5
Accumulated benefit obligation at end of year	403.1	428.2
Plan assets:
Beginning of year	383.4	410.5
Actual return on plan assets	40.1	1.3
Settlement	(58.5)	(1.9)
Currency translation	0.1	(1.7)
Benefits paid	(25.1)	(26)
End of year	340	383.4	$ 410.5
Accrued benefit cost at end of year:
Unfunded status	(63.1)	(44.8)
Recognized on balance sheet:
Other noncurrent assets	1	0.9
Other noncurrent liabilities	(62.9)	(45.7)
Amount recognized on balance sheet	(63.1)	(44.8)
Recognized in accumulated other comprehensive loss, before tax:
Prior year service cost (gain)	0	0
Net actuarial loss (gain)	110.8	113.5
Recognized in accumulated other comprehensive loss, before tax	$ 110.8	$ 113.5

Retirement Plans (Pension and O

Retirement Plans (Pension and Other Postretirement Benefits Activity in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ 16.6	$ (0.5)	$ 0
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Balance at beginning of year	113.5
Actuarial gain	(17.3)
Prior year service loss amortization to net periodic cost	(20)
Balance at end of year	$ 110.8	$ 113.5

Retirement Plans (Components of

Retirement Plans (Components of Accumulated Other Comprehensive Income (Loss) Related to Pension and Other Postretirement Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Amortization of Gains (Losses)		$ 3.4	$ 3.2	$ 3.5
Scenario, Forecast [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	$ 0
Defined Benefit Plan, Amortization of Gains (Losses)	4
Defined Benefit Plans, Expected Future Amortization Into Net Periodic Benefit Cost in Year One	$ 4

Retirement Plans (Assumptions U

Retirement Plans (Assumptions Used) (Details) - Pension Plan, Defined Benefit [Member]	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Weighted average used to determine benefit obligations:
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.68%	4.84%	4.49%
Weighted average used to determine net periodic cost:
Discount rate	3.92%	4.49%	5.16%
Expected return on plan assets	5.50%	6.21%	6.24%

Retirement Plans (Strategic All

Retirement Plans (Strategic Allocation of Plan Assets) (Details)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Strategic asset allocation
Defined Benefit Plan, Target Plan Asset Allocations	100.00%
Actual asset allocations
Actual plan asset allocations	100.00%	100.00%	100.00%
Equity Securities [Member]
Strategic asset allocation
Defined Benefit Plan, Target Plan Asset Allocations	30.00%	40.00%
Equity investments tactical range, minimum	30.00%
Equity investments tactical range, maximum	50.00%
Actual asset allocations
Actual plan asset allocations	29.00%	39.00%	40.00%
Large Capitalization Stocks [Member]
Strategic asset allocation
Defined Benefit Plan, Target Plan Asset Allocations	19.00%
Small Capitalization Stocks [Member]
Strategic asset allocation
Defined Benefit Plan, Target Plan Asset Allocations	4.00%
International Stocks [Member]
Strategic asset allocation
Defined Benefit Plan, Target Plan Asset Allocations	7.00%
Fixed Income Securities [Member]
Strategic asset allocation
Defined Benefit Plan, Target Plan Asset Allocations	70.00%
Fixed Income Funds [Member]
Strategic asset allocation
Equity investments tactical range, minimum	50.00%
Equity investments tactical range, maximum	70.00%
Actual asset allocations
Actual plan asset allocations	69.00%	60.00%	59.00%
Cash and Cash Equivalents [Member]
Strategic asset allocation
Defined Benefit Plan, Target Plan Asset Allocations	0.00%
Equity investments tactical range, minimum	0.00%
Equity investments tactical range, maximum	5.00%
Actual asset allocations
Actual plan asset allocations	2.00%	1.00%	1.00%

Retirement Plans (Fair Value As

Retirement Plans (Fair Value Asset Allocation) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 340	$ 383.4
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	20.8	46.1
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	319.2	337.3
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	99.4	150
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13.5	42.1
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	85.9	107.9
Large Cap Growth Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.3	32.7
Large Cap Growth Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large Cap Growth Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.3	32.7
Large Cap Index Funds [Member] [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38.2	27.1
Large Cap Index Funds [Member] [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large Cap Index Funds [Member] [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38.2	27.1
Large Cap Value Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.2	15.7
Large Cap Value Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large Cap Value Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.2	15.7
Small Cap Growth Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15.1	18.5
Small Cap Growth Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small Cap Growth Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15.1	18.5
Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13.5	42.1
Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13.5	42.1
Mutual Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International Stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18.1	13.9
International Stocks [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International Stocks [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18.1	13.9
Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	233.3	229.4
Fixed Income Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fixed Income Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	233.3	229.4
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.3	4
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.3	4
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

Retirement Plans (Expected Bene

Retirement Plans (Expected Benefit Payments) (Details) $ in Millions	Sep. 30, 2016USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated benefit payments, CY plus 1	$ 32.6
Estimated benefit payments, CY plus 2	25.7
Estimated benefit payments, CY plus 3	25.6
Estimated benefit payments, CY plus 4	25.5
Estimated benefit payments, CY plus 5	25.4
Estimated benefit payments, CY plus 6 and up	$ 122.9

Retirement Plans Schedule of Am

Retirement Plans Schedule of Amounts Expected to Amortize from AOCI to net income in the coming year (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amortization of Gains (Losses)		$ (3.4)	$ (3.2)	$ (3.5)
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	$ 0
Defined Benefit Plan, Amortization of Gains (Losses)	(4)
Defined Benefit Plans, Expected Future Amortization Into Net Periodic Benefit Cost in Year One	$ 4

Capital Stock (Details)

Capital Stock (Details) - shares	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Outstanding Shares [Roll Forward]
Shares outstanding	160,497,841	159,760,671	158,234,300
Exercised stock options	270,599	506,632	587,964
Exercise of employee stock purchase plan	218,475	212,550	204,360
Vesting of restricted stock units, net of shares withheld	370,138	541,839	734,047
Treasury Stock, Shares, Acquired		(523,851)
Shares outstanding	161,693,051	160,497,841	159,760,671
Performance Shares [Member]
Outstanding Shares [Roll Forward]
Vesting of restricted stock units, net of shares withheld	335,998

Stock-based Compensation Plan74

Stock-based Compensation Plans (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares	Sep. 30, 2016USD ($)$ / sharesshares	Sep. 30, 2015$ / sharesshares	Sep. 30, 2014$ / sharesshares	Sep. 30, 2013$ / shares	Dec. 14, 2011shares
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		867,065	1,165,414	1,103,845
Weighted-average recognition period, Compensation expense related to stock awards not yet vested		1 year 3 months 19 days
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 4.6	$ 4.6
Number of shares authorized under a Plan						20,500,000
Shares available for future grants under a Plan	7,319,621	7,319,621
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years
Share-based Compensation, Expected Forfeiture Rate		2.00%
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		302,875	289,524	304,815
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares	$ 9.60	$ 9.60	$ 8.49	$ 6.22	$ 4.03
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Intrinsic Value, Amount Per Share | $ / shares	$ 12.55	$ 12.55
Share-based compensation liability | $	$ 4.1	$ 4.1
Employee Stock [Member]
Number of shares authorized under a Plan	5,800,000	5,800,000
Shares available for future grants under a Plan	3,051,778	3,051,778
Price for shares offered under ESPP, as a percentage of closing price on the first or last day of the offering period	85.00%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares	$ 9.38	$ 9.38	$ 9.78	$ 8.52
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period		542,212
Performance Shares [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				90,841
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		360,255	459,659	381,012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares	$ 9.34	$ 9.34	$ 8.45	$ 5.04	$ 4.30
Cash-settled Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		243,992
Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards | $		$ 4
Minimum [Member] | Performance Shares [Member]
Performance Factor		0
Maximum [Member] | Performance Shares [Member]
Performance Factor		2

Stock-based Compensation Plan75

Stock-based Compensation Plans (Schedule of Share-based Compensation, Effect on Statement of Operations) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Decrease in operating income	$ 9.1	$ 7	$ 13.2
Effect on net income or loss	$ (5.8)	$ (4.4)	$ (8.1)
Effect on earnings or loss per basic share	$ (0.04)	$ (0.03)	$ (0.05)
Effect on earnings or loss per diluted share	$ (0.04)	$ (0.03)	$ (0.05)

Stock-based Compensation Plan76

Stock-based Compensation Plans (Schedule of Share-based Compensation, Restricted Stock Units Activity) (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs, Outstanding, Number	663,448	663,448	872,790	1,206,761	1,925,340
Outstanding, Weighted average grant date fair value per share	$ 9.34	$ 9.34	$ 8.45	$ 5.04	$ 4.30
Outstanding, Weighted average remaining contractual term	1 year		9 months	8 months	11 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		360,255	459,659	381,012
Granted, Weighted average grant date fair value per share		$ 9.33	$ 9.70	$ 8.51
Vested, shares		(510,535)	(793,630)	(1,099,591)
RSUs, Vested in Period, Weighted Average Grant Date Fair Value		$ 7.94	$ 3.99	$ 4.94
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value		$ 4.7	$ 7.7	$ 9.4
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period		(59,062)	0	0
Canceled, Weighted average grant date fair value per share		$ 8.23	$ 0	$ 0

Stock-based Compensation Plan77

Stock-based Compensation Plans (Schedule of Shared-Based Compensation, Performance Units (Details) - Performance Shares [Member]	12 Months Ended
	Sep. 30, 2016$ / sharesshares	Sep. 30, 2015$ / sharesshares	Sep. 30, 2014$ / sharesshares	Sep. 30, 2013$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares	$ 9.38	$ 9.78	$ 8.52
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	542,212
Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			90,841
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(5,401)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	85,440
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	87,241		170,880
Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			90,841
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(5,401)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	85,440
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		0
Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			90,849
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	85,447
2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares		$ 9.78	$ 8.52	$ 5.22
2013 [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				135,553
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	135,553
Performance Factor				2
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period				271,106
2013 [Member] | Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				135,553
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	135,553
Performance Factor			2
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			271,106
2013 [Member] | Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				135,552
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	135,552
Performance Factor		0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		0
2014 [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance Factor			2
2014 [Member] | Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance Factor		0
2014 [Member] | Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(5,402)
Performance Factor	1.021
2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares	$ 9.38	$ 9.78
2015 [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		80,233
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(7,318)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	72,915
Performance Factor		0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	74,442	0
2015 [Member] | Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		80,229
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(7,318)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	72,911
Performance Factor	1.021
2015 [Member] | Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		80,229
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(7,319)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	72,910
2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares	$ 9.38
2016 [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	77,821
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(3,997)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	73,824
Performance Factor	1.021
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	75,374
2016 [Member] | Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	77,821
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(3,997)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	73,824
2016 [Member] | Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	77,829
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(3,999)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	73,830

Stock-based Compensation Plan78

Stock-based Compensation Plans (Schedule of Share-based Compensation. Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, shares	3,992,666	4,552,235	5,124,706
Outstanding, Weighted average exercise price (per share)	$ 5.99	$ 6.54	$ 6.37	$ 6.22
Outstanding, Weighted average remaining contractual term, years	3 years 5 months	4 years 2 months	5 years	5 years 11 months
Outstanding, Aggregate intrinsic value	$ 23.8	$ 9.3	$ 13.6	$ 14.6
Granted, shares	0	97,119	86,904
Granted, Weighted average exercise price (per share)	$ 0	$ 9.97	$ 8.58
Exercised, shares	(270,599)	(506,632)	(587,964)
Exercised, Weighted average exercise price (per share)	$ 6.83	$ 3.42	$ 4.61
Exercised, Aggregate intrinsic value	$ 0.8	$ 3.2	$ 0
Canceled, shares	(167,759)	(150,056)	(71,411)
Canceled, Weighted average exercise price (per share)	$ 17.82	$ 13.90	$ 12.92
Stock Options, Exercisable, Number	3,471,004
Exercisable, Weighted average exercise price (per share)	$ 5.90
Exercisable, Weighted average remaining contractual term, years	3 years 3 months
Exercisable, Aggregate intrinsic value	$ 23.5
Expected to vest in subsequent periods, shares	83,304
Expected to vest in subsequent periods, Weighted average exercise price (per share)	$ 9.54
Expected to vest in subsequent periods, Weighted average remaining contractual term, years	8 years
Expected to vest in subsequent periods, Aggregate intrinsic value	$ 0.3
Outstanding, shares	3,554,308	3,992,666	4,552,235	5,124,706

Stock-based Compensation Plan79

Stock-based Compensation Plans Schedule of Share-based Compensation, Option Disclosures by Ranges of Exercise Prices (Details)	12 Months Ended
	Sep. 30, 2016$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock Options, Exercise Price Range, Number of Outstanding Options | shares	3,554,308
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 5.99
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	3 years 5 months
Stock Options, Exercisable, Number | shares	3,471,004
Stock Options, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 5.90
Exercise Price Range 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock Options, Exercise Price Range, Lower Range Limit	0
Stock Options, Exercise Price Range, Upper Range Limit	$ 4.99
Stock Options, Exercise Price Range, Number of Outstanding Options | shares	1,343,036
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 3.34
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	4 years 4 months 11 days
Stock Options, Exercisable, Number | shares	1,343,036
Stock Options, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 3.34
Exercise Price Range 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock Options, Exercise Price Range, Lower Range Limit	5
Stock Options, Exercise Price Range, Upper Range Limit	$ 9.99
Stock Options, Exercise Price Range, Number of Outstanding Options | shares	1,644,230
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 6.03
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	3 years 4 months 22 days
Stock Options, Exercisable, Number | shares	1,560,926
Stock Options, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 5.84
Exercise Price Range 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock Options, Exercise Price Range, Lower Range Limit	10
Stock Options, Exercise Price Range, Upper Range Limit	$ 14.99
Stock Options, Exercise Price Range, Number of Outstanding Options | shares	440,984
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 11.31
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	1 year 7 days
Stock Options, Exercisable, Number | shares	440,984
Stock Options, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 11.31
Exercise Price Range 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock Options, Exercise Price Range, Lower Range Limit	15
Stock Options, Exercise Price Range, Upper Range Limit	$ 20.99
Exercise Price Range 4 [Domain]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock Options, Exercise Price Range, Number of Outstanding Options | shares	126,058
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 15.09
Stock Options, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	2 months 2 days
Stock Options, Exercisable, Number | shares	126,058
Stock Options, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 15.09

Stock-based Compensation Plan80

Stock-based Compensation Plans (Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions) (Details) - Employee Stock Option [Member] - $ / shares	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant-date fair value, in dollars per share	$ 5.93	$ 5.13
Risk-free interest rate	1.74%	2.44%
Dividend yield	0.80%	1.10%
Expected life (years)	8 years	8 years
Expected annual volatility	61.99%	63.86%

Stock-based Compensation Plan81

Stock-based Compensation Plans (Schedule of Share-based Compensation, Phantom Award Activity) (Details) - Phantom Share Units (PSUs) [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, shares	558,878	643,288	608,982
Outstanding, Weighted average grant date fair value per share	$ 9.60	$ 8.49	$ 6.22	$ 4.03
Outstanding, Weighted average remaining contractual term	11 months	9 months 7 days	9 months 7 days	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	302,875	289,524	304,815
Granted, Weighted average grant date fair value per share	$ 9.84	$ 9.78	$ 8.52
Vested, shares	(270,822)	(317,409)	(240,739)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 2.5	$ 3.1	$ 2.1
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(56,905)	(56,525)	(29,770)
Canceled, Weighted average grant date fair value per share	$ 9.28	$ 8.29	$ 5.29
Outstanding, shares	534,026	558,878	643,288	608,982

Supplemental Balance Sheet In82

Supplemental Balance Sheet Information (Schedule Of Selected Supplemental Balance Sheet Information) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Inventories:
Purchased components and raw material	$ 77.8	$ 77.8
Work in process	39	40.7
Finished goods	97	100.6
Inventories, net	213.8	219.1
Other current assets:
Maintenance and repair tooling	5.1	5
Prepaid income taxes	1.5	1.5
Other	10.2	7.2
Other current assets	16.8	13.7
Property, plant and equipment:
Land	9.8	9.4
Buildings	81.7	79.3
Machinery and equipment	375.2	350.7
Construction in progress	20.6	20.1
Property, plant and equipment, gross	487.3	459.5
Accumulated depreciation	(332.2)	(310.6)
Property, plant and equipment, net	155.1	148.9
Other current liabilities:
Compensation and benefits	36.1	30.5
Customer rebates	17.3	15.4
Interest	0.5	0.5
Taxes other than income taxes	4.1	4
Warranty	2	2.9	$ 2.6	$ 2.8
Income taxes	4.6	0.8
Restructuring	0.7	0.1
Environmental	5	1.9
Other	8.8	7.1
Other current liabilities	$ 79.1	$ 63.2

Supplemental Statement of Ope83

Supplemental Statement of Operations Information (Details) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Included in selling, general and administrative expenses:
Research and development	$ 12.9	$ 14.9	$ 14.4
Advertising	5	5.2	4.7
Interest expense, net:
Deferred financing fees amortization	1.9	2	2
Other interest expense	0.5	0.3	0.2
Interest Expense	24	27.9	50
Interest income	(0.4)	(0.3)	(0.4)
Interest expense, net	(23.6)	(27.6)	(49.6)
Secured Debt [Member]
Interest expense, net:
Debt instrument interest expense	20.5	17.5	0
Seven Point Three Seven Five Senior Subordinated Notes [Member]
Interest expense, net:
Debt instrument interest expense	0	4	30.6
Eight Point Seven Five Senior Unsecured Notes [Member]
Interest expense, net:
Debt instrument interest expense	0	2.4	16
ABL Agreement [Member]
Interest expense, net:
Debt instrument interest expense	$ 1.1	$ 1.7	$ 1.2

Accumulated Other Comprehensi84

Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	$ 0.2
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(6.3)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(59.4)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(1.6)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(67.3)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(6.1)	$ (6.3)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(57.7)	(59.4)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(4.5)	(1.6)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(68.3)	(67.3)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	10.6
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(2.9)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	12.3
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	1.8	1	$ 0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	0.2	(8.7)	(4.4)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax	1.7
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(2.9)
Other Comprehensive Income (Loss), Net of Tax	$ (1)	$ (6.6)	$ (32.1)

Supplemental Cash Flow Inform85

Supplemental Cash Flow Information (Schedule of Cash Flow, Supplemental Disclosures) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Cash paid, net:
Interest	$ 21.1	$ 36.8	$ 48.7
Income taxes	$ 36.9	$ 13.3	$ 2.6

Segment Information (Revenue an

Segment Information (Revenue and Long-Lived Assets by Geographical Areas) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net	$ 302.5	$ 310.1	$ 283.6	$ 242.7	$ 311.4	$ 301	$ 290.3	$ 261.8	$ 1,138.9	$ 1,164.5	$ 1,184.7
Intangible Assets, Net (Including Goodwill)	486				507.3				486	507.3
Total assets	1,280.6				1,229.8				$ 1,280.6	1,229.8
Document Period End Date									Sep. 30, 2016
Property, plant and equipment, net	155.1				148.9				$ 155.1	148.9
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net									1,020.7	1,037.7	1,040.6
Property, plant and equipment, net	149.3				142.9				149.3	142.9
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net									73.8	82.7	101.1
Property, plant and equipment, net	2.5				2.7				2.5	2.7
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net									44.4	44.1	$ 43
Property, plant and equipment, net	$ 3.3				$ 3.3				$ 3.3	$ 3.3

Segment Information (Narrative)

Segment Information (Narrative) (Details) $ in Millions	12 Months Ended
	Sep. 30, 2016USD ($)business_segmentscustomer	Sep. 30, 2015USD ($)	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting [Abstract]
Number of Reportable Segments | business_segments	3
Revenue, Major Customer [Line Items]
Receivables, net	$ 186.7	$ 175.3
Intangible Assets, Net (Including Goodwill)	486	507.3
Total assets	$ 1,280.6	1,229.8
Document Period End Date	Sep. 30, 2016
Mueller Co. [Member]
Revenue, Major Customer [Line Items]
Intangible Assets, Net (Including Goodwill)	$ 416.9	435.5
Total assets	750.4	757.7
Anvil [Member]
Revenue, Major Customer [Line Items]
Intangible Assets, Net (Including Goodwill)	51.4	54.5
Total assets	243.5	255.3
Mueller Technologies [Member]
Revenue, Major Customer [Line Items]
Intangible Assets, Net (Including Goodwill)	17.7	17.3
Total assets	$ 86.1	$ 77.2
Customer Concentration Risk [Member] | Major Customers, Group One
Revenue, Major Customer [Line Items]
Number of major customers | customer	10
Customer Concentration Risk [Member] | Major Customers, Group One | Sales Revenue, Goods, Gross [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	43.00%
Customer Concentration Risk [Member] | Major Customers, Group Two
Revenue, Major Customer [Line Items]
Number of major customers | customer	2
Customer Concentration Risk [Member] | Major Customers, Group Two | Sales Revenue, Goods, Gross [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	28.00%
Customer Concentration Risk [Member] | Ferguson Enterprises | Sales Revenue, Goods, Gross [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	15.00%	13.00%	13.00%
Customer Concentration Risk [Member] | Ferguson Enterprises | Sales Revenue, Goods, Gross [Member] | Mueller Co. [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	17.00%
Customer Concentration Risk [Member] | Ferguson Enterprises | Sales Revenue, Goods, Gross [Member] | Anvil [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	9.00%
Customer Concentration Risk [Member] | Ferguson Enterprises | Sales Revenue, Goods, Gross [Member] | Mueller Technologies [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	17.00%
Customer Concentration Risk [Member] | Ferguson Enterprises | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Receivables, net	$ 30.7	$ 28.2
Customer Concentration Risk [Member] | HD Supply | Sales Revenue, Goods, Gross [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	13.00%	12.00%		11.00%
Customer Concentration Risk [Member] | HD Supply | Sales Revenue, Goods, Gross [Member] | Mueller Co. [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	18.00%
Customer Concentration Risk [Member] | HD Supply | Sales Revenue, Goods, Gross [Member] | Anvil [Member]
Revenue, Major Customer [Line Items]
Concentration risk, percentage of benchmark	6.00%
Customer Concentration Risk [Member] | HD Supply | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Receivables, net	$ 27.6	$ 17.4

Segment Information (Schedule O

Segment Information (Schedule Of Selected Supplemental Balance Sheet Information) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Net sales, excluding intercompany	$ 302.5	$ 310.1	$ 283.6	$ 242.7	$ 311.4	$ 301	$ 290.3	$ 261.8	$ 1,138.9	$ 1,164.5	$ 1,184.7
Operating income	46.7	$ 29.7	$ 29.3	$ 14.9	44.4	$ 31.5	$ 25.6	$ 8.1	120.6	109.6	124.1
Depreciation and amortization									52.6	58.1	56.7
2,016									24.9	21.3	3.1
Capital expenditures									(39.4)	(37.5)	(36.9)
Property, plant and equipment, net	155.1				148.9				155.1	148.9
Total assets	1,280.6				1,229.8				$ 1,280.6	1,229.8
Document Period End Date									Sep. 30, 2016
Intangible Assets, Net (Including Goodwill)	486				507.3				$ 486	507.3
Mueller Co. [Member]
Segment Reporting Information [Line Items]
Net sales, excluding intercompany									715.7	702.2	679.1
Operating income									159.3	136.9	126.7
Depreciation and amortization									34.2	38.8	38
2,016									3	8.4	2.1
Capital expenditures									(24.3)	(20.5)	(18.8)
Total assets	750.4				757.7				750.4	757.7
Intangible Assets, Net (Including Goodwill)	416.9				435.5				416.9	435.5
Anvil [Member]
Segment Reporting Information [Line Items]
Net sales, excluding intercompany									338.3	371.1	401.4
Operating income									26.8	30	41.3
Depreciation and amortization									13.1	14.7	14.2
2,016									2.3	0.7	0.9
Capital expenditures									(7.9)	(10.3)	(11.6)
Total assets	243.5				255.3				243.5	255.3
Intangible Assets, Net (Including Goodwill)	51.4				54.5				51.4	54.5
Mueller Technologies [Member]
Segment Reporting Information [Line Items]
Net sales, excluding intercompany									84.9	91.2	104.2
Operating income									(11.1)	(12.9)	(4.4)
Depreciation and amortization									4.8	4.2	4.1
2,016									0.9	0.1	0.1
Capital expenditures									(7)	(6.5)	(6.1)
Total assets	86.1				77.2				86.1	77.2
Intangible Assets, Net (Including Goodwill)	17.7				17.3				17.7	17.3
Corporate [Member]
Segment Reporting Information [Line Items]
Net sales, excluding intercompany									0	0	0
Operating income									(54.4)	(44.4)	(39.5)
Depreciation and amortization									0.5	0.4	0.4
2,016									18.7	12.1	0
Capital expenditures									(0.2)	(0.2)	(0.4)
Total assets	200.6				139.6				200.6	139.6
Intangible Assets, Net (Including Goodwill)	$ 0				$ 0				0	0
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intercompany sales									5.9	7.3	6.8
Intersegment Eliminations [Member] | Mueller Co. [Member]
Segment Reporting Information [Line Items]
Intercompany sales									5.8	7.2	6.7
Intersegment Eliminations [Member] | Anvil [Member]
Segment Reporting Information [Line Items]
Intercompany sales									0.1	0.1	0.1
Intersegment Eliminations [Member] | Mueller Technologies [Member]
Segment Reporting Information [Line Items]
Intercompany sales									0	0	0
Intersegment Eliminations [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Intercompany sales									$ 0	$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) CAD in Millions, $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2016CAD	Mar. 31, 2016USD ($)
Loss Contingency, Damages Sought, Value | CAD				CAD 10
Document Period End Date			Sep. 30, 2016	Sep. 30, 2016
Walter Energy tax assessment			$ 33
Amount receivable pending completion of an IRS audit			11.6
Operating Leases
Rent expense	$ 10.4	$ 9.3	10.2
Future minimum payment under non-cancelable operating leases, CY Plus 1			7.1
Future minimum payment under non-cancelable operating leases, CY Plus 2			4.8
Future minimum payment under non-cancelable operating leases, CY Plus 3			3.3
Future minimum payment under non-cancelable operating leases, CY Plus 4			2.1
Future minimum payment under non-cancelable operating leases, CY Plus 5			2
Future minimum payment under non-cancelable operating leases, CY plus 6 and up			$ 5.1
IRS-Walter Energy Claim 1 Total [Member]
Loss Contingency, Range of Possible Loss, Maximum					$ 554.3
IRS-Walter Energy Claim 1 Priority [Member]
Loss Contingency, Range of Possible Loss, Maximum					229.1
IRS-Walter Energy Claim 2 [Member]
Loss Contingency, Range of Possible Loss, Maximum					860.4
IRS-Walter Energy Claim 2 Priority [Member]
Loss Contingency, Range of Possible Loss, Maximum					$ 535.3

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Subsequent Event [Line Items]
Dividends declared, in dollars per share		$ 0.100	$ 0.075	$ 0.070
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends Payable, Date Declared	Oct. 26, 2016
Dividends declared, in dollars per share	$ 0.03
Dividends Payable, Date to be Paid	Nov. 21, 2016
Dividends Payable, Date of Record	Nov. 10, 2016

Quarterly Consolidated Financ91

Quarterly Consolidated Financial Information (Unaudited) (Quarterly Financial Information Disclosure)(Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenue, Net	$ 302.5	$ 310.1	$ 283.6	$ 242.7	$ 311.4	$ 301	$ 290.3	$ 261.8	$ 1,138.9	$ 1,164.5	$ 1,184.7
Gross profit	103.6	107.1	84.9	68.7	97.7	96.2	82.1	71.3	364.3	347.3	347.9
Operating income	46.7	29.7	29.3	14.9	44.4	31.5	25.6	8.1	120.6	109.6	124.1
Net Income (Loss) Attributable to Parent	$ 26.5	$ 15.5	$ 15.7	$ 6.2	$ 22.3	$ 16.5	$ 12.3	$ (20.2)	$ 63.9	$ 30.9	$ 55.5
Net income (loss) per share(1)
Net income (loss) per basic share	$ 0.16	$ 0.10	$ 0.10	$ 0.04	$ 0.14	$ 0.10	$ 0.08	$ (0.13)	$ 0.40	$ 0.19	$ 0.35
Net income (loss) per diluted share	$ 0.16	$ 0.09	$ 0.10	$ 0.04	$ 0.14	$ 0.10	$ 0.08	$ (0.13)	$ 0.39	$ 0.19	$ 0.34