Mueller Water Products (MWA) 10-Q 8 Feb 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	3 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Mar. 31, 2017
Document And Entity Information [Abstract]
Document Fiscal Period Focus	Q1
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,018
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-Q
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Amendment Flag	false
Entity Common Stock, Shares Outstanding		158,754,223
Entity Public Float			$ 1,856,526,077

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2017	Sep. 30, 2017
Assets:
Cash and cash equivalents	$ 348.3	$ 361.7
Receivables, net	107.4	145.3
Inventories	155.2	138.9
Other current assets	26.5	24.4
Total current assets	637.4	670.3
Property, plant and equipment, net	122.3	122.3
Identifiable intangible assets	434.6	439.3
Other noncurrent assets	25.9	26.4
Total assets	1,220.2	1,258.3
Liabilities and stockholders' equity:
Current portion of long-term debt	5.6	5.6
Accounts payable	51.3	82.5
Other current liabilities	46.1	53.5
Total current liabilities	103	141.6
Long-term debt	474.3	475
Deferred income taxes	76.2	115.1
Other noncurrent liabilities	32.4	37.1
Total liabilities	685.9	768.8
Common Stock	1.6	1.6
Additional paid-in capital	1,482.4	1,494.2
Accumulated deficit	(900.5)	(955.6)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(50.2)	(51.8)
Total stockholders' equity	533.3	488.4
Noncontrolling interest	1	1.1
Total equity	534.3	489.5
Total liabilities and stockholders' equity	$ 1,220.2	$ 1,258.3

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - shares	Dec. 31, 2015	Sep. 30, 2014
Statement of Financial Position [Abstract]
Series A common stock, shares authorized	600,000,000	600,000,000
Series A common stock, shares outstanding	0	161,693,051

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Revenue, Net	$ 178.3	$ 167.2
Cost of sales	122.9	115.4
Gross profit	55.4	51.8
Operating expenses:
Selling, general and administrative	39.8	36.3
Gain on sale of idle property	(9)	0
Restructuring	3.9	1.3
Total operating expenses	34.7	37.6
Operating income	20.7	14.2
Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost	0.2	0.3
Interest expense, net	5.2	6.4
Income (loss) before income taxes	15.3	7.5
Income tax expense (benefit)	(39.8)	2.1
Income (loss) from continuing operations	55.1	5.4
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	1.3
Net Income (Loss) Attributable to Parent	$ 55.1	$ 6.7
Continuing operations	$ 0.35	$ 0.03
Discontinued operations	0	0.01
Net loss per basic share:
Net income (loss) per basic share	0.35	0.04
Continuing operations	0.34	0.03
Discontinued operations	0	0.01
Net loss per diluted share:
Net income (loss) per diluted share	$ 0.34	$ 0.04
Weighted average shares outstanding:
Basic, in shares	158.5	161.8
Diluted, in shares	160	164.6
Dividends declared per share, in dollars per share	$ 0.04	$ 0.03

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income Statement - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Net Income (Loss) Attributable to Parent	$ 55.1	$ 6.7
Other comprehensive income (loss):
Minimum pension liability	0.8	1
Income tax effects	(0.3)	(0.4)
Foreign currency translation	0.1	(1.5)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	1.6	4.7
Income tax effects	(0.6)	(1.8)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1.6	2
Other Comprehensive Income (Loss), Net of Tax	1.6
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 56.7	$ 8.7

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]
Balance at Sep. 30, 2016	$ 489.5	$ 1.6	$ 1,494.2	$ (955.6)	$ (51.8)	$ 1.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	6.7
Balance at Dec. 31, 2016	534.3	1.6	1,482.4	(900.5)	(50.2)	1
Balance at Sep. 30, 2017	489.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared	(6.3)	0	(6.3)	0	0	0
Stock repurchased under buyback program	10	0	10	0	0	0
Stock-based compensation	2	0	2	0	0	0
Shares retained for employee taxes	(1.8)	0		0	0	0
Stock issued under stock compensation plans	4.3	0	4.3	0	0	0
Other Comprehensive Income (Loss), Net of Tax	1.6	0	0	$ 0	1.6	0
Net Income (Loss) Attributable to Parent	55.1	$ 0	$ 0		$ 0
Net Income (Loss) Attributable to Noncontrolling Interest						$ (0.1)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	55
Balance at Dec. 31, 2017	$ 534.3

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Stock repurchased under buyback program	$ 10	$ 0
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Income (Loss) Attributable to Parent	55.1	6.7
Less: income (loss) from discontinued operations	0	(1.3)
Income (loss) from continuing operations	55.1	5.4
Adjustments to reconcile net income (loss) to income (loss) from continuing operations:
Depreciation	4.9	4.9
Amortization	5.7	5.4
Stock-based compensation expense	2	1.8
Deferred income taxes	(39.7)	(2.1)
Gain on sale of idle property	9	0
Retirement plans	0.7	0.8
Other, net	0.7	0.3
Changes in assets and liabilities, net of acquisitions:
Receivables	38.4	27.4
Inventories	(16.3)	(12.2)
Other current assets and other noncurrent assets	(0.8)	(0.8)
Accounts payable and other liabilities	(41.2)	(50.8)
Net cash provided by (used in) operating activities	0.5	(19.9)
Investing activities:
Capital expenditures	(6.4)	(4.2)
Net cash provided by (used in) investing activities	1	(4.2)
Repayments of debt	1.2	1.3
Financing activities:
Dividends paid	(6.3)	(4.8)
Common stock issued	4.3	0.4
Shares retained for employee taxes	(1.8)	(2.5)
Other	0	0.1
Net cash used in financing activities	(15)	(8.1)
Operating activities	0	12.4
Investing activities	0	(2.1)
Financing activities	0	(0.1)
Net cash provided by (used in) discontinued operations	0	10.2
Effect of currency exchange rate changes on cash	0.1	(0.7)
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Net change in cash and cash equivalents	(13.4)	(22.7)
Cash and cash equivalents at beginning of period	361.7
Cash and cash equivalents at end of period	348.3	348.3
Proceeds from sales of assets	$ 7.4	$ 0

Discontinued Operations, Assets

Discontinued Operations, Assets Held for Sale and Divestitures	3 Months Ended
	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	Discontinued Operations and Divestitures On December 4, 2017, we sold an idle property in Burlington, New Jersey that had previously been a plant in our former U.S. Pipe segment and recorded a gain of $9.0 million on our Corporate segment. We received $7.4 million in cash, recorded net current assets of $0.8 million and conveyed plant, property and equipment with a net carrying value of $0.4 million , and the buyer assumed related environmental liabilities with a carrying value of $1.2 million . On January 6, 2017 , we sold our former Anvil segment to affiliates of One Equity Partners. The table below presents a summary of the operating results for the Anvil discontinued operations during the quarter ended December 31, 2016 . These operating results do not reflect what they would have been had Anvil not been sold. Three months ended December 31, 2016 (in millions) Net sales $ 83.1 Cost of sales 62.8 Gross profit 20.3 Operating expenses: Selling, general and administrative 18.3 Other charges 0.2 Total operating expenses 18.5 Operating income 1.8 Income tax expense 0.5 Income from discontinued operations $ 1.3

Organization

Organization	3 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Mueller Water Products, Inc., a Delaware corporation, together with its consolidated subsidiaries, operates in two business segments: Infrastructure and Technologies. Infrastructure 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. Technologies offers metering systems, leak detection, pipe condition assessment and other related products and services. 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. On January 6, 2017, we sold our former Anvil segment. Amounts applicable to Anvil have been classified as discontinued operations. Infrastructure owns a 49% ownership interest in an industrial valve joint venture. Due to substantive control features in the operating agreement, all of the joint venture's assets, liabilities and results of operations are included in our consolidated financial statements. The net loss attributable to noncontrolling interest is included in selling, general and administrative expenses. Noncontrolling interest is recorded at its carrying value, which approximates fair value. 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. 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. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements included in our Annual Report on Form 10-K for the year ended September 30, 2017 . In our opinion, all normal and recurring adjustments that we consider necessary for a fair financial statement presentation have been made. Certain reclassifications have been made to previously reported amounts to conform to the current presentation. The condensed consolidated balance sheet data at September 30, 2017 was derived from audited financial statements, but does not include all disclosures required by GAAP. On October 1, 2017, we adopted Financial Accountings Standards Board Accounting Standards Update No. 2017-07, which requires us to exclude from operating income the components of net periodic benefit cost other than service cost. Accordingly, in the Condensed Consolidated Statement of Operations for the three months ended December 31, 2016, we have reclassified $0.2 million from selling, general and administrative expenses and $0.1 million from cost of sales to pension costs other than service. On February 15, 2017, we acquired Singer Valve. Singer had net sales of $3.7 million in the quarter ended December 31, 2017 and is included in Infrastructure. HR-1, formerly referred to as the Tax Cuts and Jobs Act, was enacted on December 22, 2017 and made significant revisions to federal income tax laws, including lowering the corporate income tax rate to 21% from 35% , effective January 1, 2018. The effects of these revisions are discussed in Note 3. In May 2014, the Financial Accounting Standards Board (“FASB”) issued new guidance for the recognition of revenue and requiring additional financial statement disclosures. We plan to adopt this guidance using the modified retrospective transition method beginning in the first quarter of fiscal 2019. We have completed our initial scoping and are implementing a project plan to evaluate revenue recognition practices for each revenue stream against the new requirements, to consider changes to the terms of our sales contracts, and to design and implement processes to quantify the effects of necessary changes. This work is ongoing, but at this time, we do not expect the new guidance to materially impact our stockholders' equity, net sales or operating income. On September 7, 2017, we announced a strategic reorganization plan designed to accelerate our product innovation and revenue growth. We have adopted a matrix management structure, where business teams have line and cross-functional responsibility for managing distinct product portfolios, and engineering, operations, sales and marketing and other functions are centralized to better align with business needs and generate greater efficiencies. Costs and expenses in the quarter ended December 31, 2017 for this plan, included in strategic reorganization and other charges, were primarily personnel-related. Activity in accrued restructuring, reported as part of other current liabilities, is presented below. Three months ended December 31, 2017 (in millions) Beginning balance $ 3.3 Expense 2.3 Payments (1.4 ) Ending balance $ 4.2

Income Taxes

Income Taxes	3 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes On December 22, 2017, HR-1, formerly referred to as the Tax Cuts and Jobs Act (“Act”), was enacted, which made significant revisions to federal income tax laws, including lowering the corporate income tax rate to 21% from 35% effective January 1, 2018, overhauling the taxation of income earned outside the United States and eliminating or limiting certain deductions. Our deferred tax assets and liabilities are provided at the enacted tax rates in effect when we expect to recognize the related tax expenses or benefits. The average of these rates varies slightly from year to year but historically has been approximately 39% . With the legislation changing enacted rates taking place in the current quarter, we have remeasured our deferred tax items at an average rate of approximately 25% . This resulted in a provisional income tax benefit of $42.6 million , which is subject to change, if necessary, as we continue to analyze certain aspects of the Act and refine our calculations. We do not expect changes to this amount to be material. The Act also imposes a one-time transition tax on the undistributed, non-previously taxed, post-1986 foreign “earnings and profits” (as defined by the IRS) of certain U.S.-owned corporations. Determination of our transition tax liability requires us to calculate foreign earnings and profits going back to 1992, which in many cases requires information that is not readily available, and then to assess our historical overall foreign loss position and the applicability of certain foreign tax credits. We are gathering this information and completing these calculations, but we are unable at this time to reasonably estimate our transition tax liability, and therefore we have not recorded any amount for this tax at December 31, 2017 . In addition to the deferred tax remeasurement item discussed above, our income tax benefit includes federal income tax expense on our current period earnings at a full-year blended rate of 24.5% , since the rate reduction in the Act is effective on January 1, 2018. The reconciliation between the U.S. federal statutory income tax rate and the effective tax rate is presented below. Three months ended December 31, 2017 2016 U.S. federal statutory income tax rate 24.5 % 35.0 % Adjustments to reconcile to the effective tax rate: State income taxes, net of federal benefit 4.3 3.9 Valuation allowance adjustment related to stock compensation (5.7 ) — Excess tax benefits related to stock compensation (2.8 ) (7.6 ) Domestic production activities deduction (1.6 ) (3.3 ) Tax credits (0.9 ) (0.8 ) Other 0.5 0.8 18.3 % 28.0 % Remeasurement of deferred taxes for change in rates (278.4 ) — Effective income tax rate (260.1 )% 28.0 % At December 31, 2017 and September 30, 2017 , the gross liabilities for unrecognized income tax benefits were $3.1 million and $3.0 million , respectively.
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The reconciliation between the U.S. federal statutory income tax rate and the effective tax rate is presented below. Three months ended December 31, 2017 2016 U.S. federal statutory income tax rate 24.5 % 35.0 % Adjustments to reconcile to the effective tax rate: State income taxes, net of federal benefit 4.3 3.9 Valuation allowance adjustment related to stock compensation (5.7 ) — Excess tax benefits related to stock compensation (2.8 ) (7.6 ) Domestic production activities deduction (1.6 ) (3.3 ) Tax credits (0.9 ) (0.8 ) Other 0.5 0.8 18.3 % 28.0 % Remeasurement of deferred taxes for change in rates (278.4 ) — Effective income tax rate (260.1 )% 28.0 %

Borrowing Arrangements

Borrowing Arrangements	3 Months Ended
	Dec. 31, 2017
Long-term Debt and Capital Lease Obligations [Abstract]
Borrowing Arrangements	Borrowing Arrangements The components of our long-term debt are presented below. December 31, September 30, 2017 2017 (in millions) ABL Agreement $ — $ — Term Loan 483.7 484.8 Other 1.7 1.7 485.4 486.5 Less deferred financing costs 5.5 5.9 Less current portion 5.6 5.6 Long-term debt $ 474.3 $ 475.0 ABL Agreement . At December 31, 2017 , our asset based lending agreement (“ABL Agreement”) consisted of a revolving credit facility for up to $225 million of revolving credit borrowings, swing line loans and letters of credit. The ABL Agreement 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 December 31, 2017 , 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. Our obligations under the ABL Agreement are secured by a first-priority perfected lien on all of our U.S. receivables and inventories, certain cash and other supporting obligations. 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 December 31, 2017 data, as reduced by outstanding letters of credit, swap contract liabilities and accrued fees and expenses of $19.8 million , was $96.3 million . Term Loan . On November 25, 2014 , we entered into a $500.0 million senior secured term loan (“Term Loan”). The proceeds from the Term Loan, along with other cash, were used to prepay our 7.375% Senior Subordinated Notes and 8.75% Senior Unsecured Notes and to satisfy and discharge our obligations under the respective indentures. The Term Loan accrues interest at a floating rate equal to LIBOR, subject to a floor of 0.75% , plus 250 basis points. At December 31, 2017 , the weighted-average effective interest rate was 4.60% . 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 $1.225 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, which was $1.4 million at December 31, 2017 . Based on quoted market prices, the outstanding Term Loan had a fair value of $490 million at December 31, 2017 . 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 December 31, 2017 and expect to remain in compliance through December 31, 2018 .

Derivative Financial Instrument

Derivative Financial Instruments (Notes)	3 Months Ended
	Dec. 31, 2017
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 0.75% , 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 4.841% 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. During the quarters ended December 31, 2017 and December 31, 2016 , we included $0.4 million and $0.6 million of such interest expense in income from continuing operations, respectively. The fair values of the swap contracts are presented below. December 31, September 30, 2017 2017 (in millions) Interest rate swap contracts, designated as cash flow hedges: Other current liabilities $ 0.7 $ 1.2 Other noncurrent liabilities 0.2 1.3 $ 0.9 $ 2.5 Currency swap contracts, not designated as hedges: Other noncurrent liabilities $ 1.3 $ 1.3 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	3 Months Ended
	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Retirement Plans	Retirement Plans The components of net periodic benefit cost for our pension plans are presented below. Three months ended December 31, 2017 2016 (in millions) Service cost $ 0.5 $ 0.5 Pension costs other than service: Interest cost 3.6 3.6 Expected return on plan assets (4.2 ) (4.3 ) Amortization of actuarial net loss 0.8 1.0 0.2 0.3 Net periodic benefit cost $ 0.7 $ 0.8 The amortization of actuarial losses, net of tax, is recorded as a component of other comprehensive loss.

Stock-based Compensation Plans

Stock-based Compensation Plans	3 Months Ended
	Dec. 31, 2017
Share-based Compensation [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	Stock-based Compensation Plans We have granted various forms of stock-based compensation, including stock options, restricted stock units and both cash-settled and stock-settled performance-based restricted stock units (“PRSUs”) under our Amended and Restated 2006 Mueller Water Products, Inc. Stock Incentive Plan (the “2006 Stock Plan”). A PRSU award represents a target number of units that may be paid out at the end of a multi-year award cycle consisting of a series of annual performance periods coinciding with our fiscal years. After we determine the financial performance targets related to PRSUs for a given performance period, typically during the first quarter of that fiscal year, we consider that portion of a PRSU award to be granted. Thus, each award consists of a grant in the year of award and grants in the designated following years. Settlement will range from zero to two times the number of PRSUs granted, depending on our financial performance against the targets. As determined at the date of award, PRSUs may settle in cash-value equivalent of, or directly in, shares of our common stock. We awarded 171,288 stock-settled PRSUs in the quarter ended December 31, 2017 scheduled to settle in three years. We issued 146,061 shares and 263,410 shares of common stock during the quarters ended December 31, 2017 and 2016, respectively, to settle PRSUs. In addition to the PRSU activity, 213,532 restricted stock units vested during the quarter ended December 31, 2017 . We have granted cash-settled Phantom Plan instruments under the Mueller Water Products, Inc. Phantom Plan (“Phantom Plan”). At December 31, 2017 , the outstanding Phantom Plan instruments had a fair value of $12.53 per instrument and our liability for Phantom Plan instruments was $1.2 million . We granted stock-based compensation awards under the 2006 Stock Plan, the Mueller Water Products, Inc. 2006 Employee Stock Purchase Plan and the Phantom Plan during the three months ended December 31, 2017 as follows. Number granted Weighted average grant date fair value per instrument Total grant date fair value (in millions) Restricted stock units 171,288 $ 12.41 $ 2.1 Employee stock purchase plan instruments 35,099 2.28 0.1 Phantom Plan awards 160,672 12.41 2.0 PRSUs: 2018 award 57,092 12.41 0.7 2017 award 71,070 12.41 0.9 2016 award 71,072 12.41 0.9 $ 6.7 Income from continuing operations included stock-based compensation expense of $2.4 million and $2.7 million during the three months ended December 31, 2017 and 2016 , respectively. At December 31, 2017 , there was approximately $8.9 million of unrecognized compensation expense related to stock-based compensation arrangements, and 185,270 PRSUs that have been awarded for the 2019 and 2020 performance periods, for which performance goals have not been set. We excluded 70,996 and 323,010 of stock-based compensation instruments from the calculations of diluted earnings per share for the quarters ended December 31, 2017 and 2016 , respectively, since their inclusion would have been antidilutive.

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	3 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Supplemental Balance Sheet Information	Selected supplemental balance sheet information is presented below. December 31, September 30, 2017 2017 (in millions) Inventories: Purchased components and raw material $ 74.3 $ 67.7 Work in process 37.8 35.6 Finished goods 43.1 35.6 $ 155.2 $ 138.9 Other current assets: Maintenance and repair tooling $ 3.2 $ 3.3 Income taxes 11.9 10.9 Other 11.4 10.2 $ 26.5 $ 24.4 Property, plant and equipment: Land $ 5.5 $ 5.6 Buildings 51.4 53.4 Machinery and equipment 270.0 266.7 Construction in progress 25.2 24.7 352.1 350.4 Accumulated depreciation (229.8 ) (228.1 ) $ 122.3 $ 122.3 Other current liabilities: Compensation and benefits $ 18.2 $ 26.9 Customer rebates 8.1 6.5 Taxes other than income taxes 2.4 3.2 Warranty 3.7 3.5 Income taxes 0.8 0.9 Environmental 1.2 1.3 Interest 0.7 0.6 Restructuring 4.2 3.3 Other 6.8 7.3 $ 46.1 $ 53.5

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Dec. 31, 2017
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. Pension, net of tax Foreign currency translation Derivative instruments, net of tax Total Balance at September 30, 2017 $ (47.0 ) $ (3.3 ) $ (1.5 ) $ (51.8 ) Current period other comprehensive income (loss) 0.5 0.1 1.0 1.6 Balance at December 31, 2017 $ (46.5 ) $ (3.2 ) $ (0.5 ) $ (50.2 ) Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is presented below. Pension, net of tax Foreign currency translation Derivative instruments, net of tax Total Balance at September 30, 2017 $ (47.0 ) $ (3.3 ) $ (1.5 ) $ (51.8 ) Current period other comprehensive income (loss) 0.5 0.1 1.0 1.6 Balance at December 31, 2017 $ (46.5 ) $ (3.2 ) $ (0.5 ) $ (50.2 )

Segment Information

Segment Information	3 Months Ended
	Dec. 31, 2017
Segment Reporting, Measurement Disclosures [Abstract]
Segment Reporting Disclosure [Text Block]	Segment Information Summarized financial information for our segments is presented below. Three months ended December 31, 2017 2016 (in millions) Net sales, excluding intercompany: Infrastructure $ 160.1 $ 146.3 Technologies 18.2 20.9 $ 178.3 $ 167.2 Intercompany sales: Infrastructure $ — $ 1.1 Technologies — — $ — $ 1.1 Operating income (loss): Infrastructure $ 28.1 $ 26.2 Technologies (4.7 ) (2.2 ) Corporate (2.7 ) (9.8 ) $ 20.7 $ 14.2 Depreciation and amortization: Infrastructure $ 9.1 $ 9.0 Technologies 1.4 1.2 Corporate 0.1 0.1 $ 10.6 $ 10.3 Strategic reorganization and other charges: Infrastructure $ — $ 0.1 Technologies 0.1 — Corporate 3.8 1.2 $ 3.9 $ 1.3 Capital expenditures: Infrastructure $ 4.8 $ 3.0 Technologies 1.5 1.1 Corporate 0.1 0.1 $ 6.4 $ 4.2

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Dec. 31, 2017
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. 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. Accordingly, because the amount of such costs cannot be reasonably estimated at this time, no amounts had been accrued for this matter at December 31, 2017 . 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. As described further below, the IRS is currently alleging that Walter Energy owes substantial amounts for prior taxable periods (specifically, 1983-1994, 2000-2002 and 2005). 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. In July 2015, Walter Energy filed a petition for reorganization under Chapter 11 of the U.S. Bankruptcy Code before the Bankruptcy Court for the Northern District of Alabama (“Chapter 11 Case”). During the pendency of the Chapter 11 Case, we monitored the proceeding to determine whether we could be liable 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 Chapter 11 Case, alleging that Walter Energy owes taxes, interest and penalties for the years 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 Chapter 11 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 Chapter 11 Case). According to a quarterly report on Form 10-Q filed by Walter Energy with the SEC on November 5, 2015 (“Walter November 2015 Filing”), at September 30, 2015, Walter Energy had $33.0 million of accruals for unrecognized tax benefits in connection with the matters subject to the IRS claims. In the Walter November 2015 Filing, Walter Energy stated it believed it had sufficient accruals to address any claims, including interest and penalties, and did not believe that any potential difference between any final settlements and amounts accrued would have a material effect on Walter Energy’s financial position, but such potential difference could be material to its results of operations in a future reporting period. According to a 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 cases and the proof of claim, as well as the alleged tax liability thereunder, remain unresolved. On February 2, 2017, at the request of Walter Energy, the Bankruptcy Court for the Northern District of Alabama signed an order converting the Chapter 11 Case to a liquidation proceeding under Chapter 7 of the U.S. Bankruptcy Code, pursuant to which Walter Energy will be wound-down and liquidated (“Chapter 7 Case”). In its objection contesting such conversion, the IRS indicated its intent to pursue collection of amounts included in the Proof of Claim from former members of the Walter Energy consolidated group. 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 cases, 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 what priority, if any, the IRS will receive in the Chapter 7 Case with respect to its claims against Walter Energy, and whether and to what extent funds will be available in the Chapter 7 Case to pay priority tax claims. 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. 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 divestitures of U.S. Pipe and Anvil, we may agree to indemnify buyers and related parties for certain losses or liabilities incurred by these parties with respect to: (i) the representations and warranties made by us to these parties in connection with the sale and (ii) liabilities related to the pre-closing operations of the assets or business sold. Indemnities related to pre-closing operations generally include certain environmental and tax liabilities and other liabilities not assumed by these parties in the transaction. Indemnities related to the pre-closing operations of sold assets or businesses normally do not represent additional liabilities to us, but simply serve to protect these parties from potential liability associated with our obligations existing at the time of the sale. As with any liability, we have accrued for those pre-closing obligations that are considered probable and reasonably estimable. Should circumstances change, increasing the likelihood of payments related to a specific indemnity, we will accrue a liability when future payment is probable and the amount is reasonably estimable. Other Matters. We are party to a number of 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.

Subsequent Events

Subsequent Events	3 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 24, 2018 , our board of directors declared a dividend of $0.05 per share on our common stock, payable on or about February 20, 2018 to stockholders of record at the close of business on February 9, 2018 .

Discontinued Operations, Asse20

Discontinued Operations, Assets Held for Sale and Divestitures (Tables)	3 Months Ended
	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Groups, Including Discontinued Operations [Table Text Block]	The table below presents a summary of the operating results for the Anvil discontinued operations during the quarter ended December 31, 2016 . These operating results do not reflect what they would have been had Anvil not been sold. Three months ended December 31, 2016 (in millions) Net sales $ 83.1 Cost of sales 62.8 Gross profit 20.3 Operating expenses: Selling, general and administrative 18.3 Other charges 0.2 Total operating expenses 18.5 Operating income 1.8 Income tax expense 0.5 Income from discontinued operations $ 1.3

Organization Restructuring Roll

Organization Restructuring Rollforward (Tables)	3 Months Ended
	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Costs [Table Text Block]	Activity in accrued restructuring, reported as part of other current liabilities, is presented below. Three months ended December 31, 2017 (in millions) Beginning balance $ 3.3 Expense 2.3 Payments (1.4 ) Ending balance $ 4.2

Income Taxes Rate Reconciliatio

Income Taxes Rate Reconciliation (Tables)	3 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The reconciliation between the U.S. federal statutory income tax rate and the effective tax rate is presented below. Three months ended December 31, 2017 2016 U.S. federal statutory income tax rate 24.5 % 35.0 % Adjustments to reconcile to the effective tax rate: State income taxes, net of federal benefit 4.3 3.9 Valuation allowance adjustment related to stock compensation (5.7 ) — Excess tax benefits related to stock compensation (2.8 ) (7.6 ) Domestic production activities deduction (1.6 ) (3.3 ) Tax credits (0.9 ) (0.8 ) Other 0.5 0.8 18.3 % 28.0 % Remeasurement of deferred taxes for change in rates (278.4 ) — Effective income tax rate (260.1 )% 28.0 %

Borrowing Arrangements (Tables)

Borrowing Arrangements (Tables)	3 Months Ended
	Dec. 31, 2017
Long-term Debt and Capital Lease Obligations [Abstract]
Components of Long-Term Debt	The components of our long-term debt are presented below. December 31, September 30, 2017 2017 (in millions) ABL Agreement $ — $ — Term Loan 483.7 484.8 Other 1.7 1.7 485.4 486.5 Less deferred financing costs 5.5 5.9 Less current portion 5.6 5.6 Long-term debt $ 474.3 $ 475.0

Derivative Financial Instrume24

Derivative Financial Instruments (Tables)	3 Months Ended
	Dec. 31, 2017
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. December 31, September 30, 2017 2017 (in millions) Interest rate swap contracts, designated as cash flow hedges: Other current liabilities $ 0.7 $ 1.2 Other noncurrent liabilities 0.2 1.3 $ 0.9 $ 2.5 Currency swap contracts, not designated as hedges: Other noncurrent liabilities $ 1.3 $ 1.3

Retirement Plans (Tables)

Retirement Plans (Tables)	3 Months Ended
	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Schedule of Net Periodic Benefit Cost	The components of net periodic benefit cost for our pension plans are presented below. Three months ended December 31, 2017 2016 (in millions) Service cost $ 0.5 $ 0.5 Pension costs other than service: Interest cost 3.6 3.6 Expected return on plan assets (4.2 ) (4.3 ) Amortization of actuarial net loss 0.8 1.0 0.2 0.3 Net periodic benefit cost $ 0.7 $ 0.8

Stock-based Compensation Plans

Stock-based Compensation Plans (Tables)	3 Months Ended
	Dec. 31, 2017
Share-based Compensation [Abstract]
Share-based Compensation, Activity [Table Text Block]	Number granted Weighted average grant date fair value per instrument Total grant date fair value (in millions) Restricted stock units 171,288 $ 12.41 $ 2.1 Employee stock purchase plan instruments 35,099 2.28 0.1 Phantom Plan awards 160,672 12.41 2.0 PRSUs: 2018 award 57,092 12.41 0.7 2017 award 71,070 12.41 0.9 2016 award 71,072 12.41 0.9 $ 6.7

Supplemental Balance Sheet In27

Supplemental Balance Sheet Information (Tables)	3 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Schedule Of Selected Supplemental Balance Sheet Information [Table Text Block]	ental balance sheet information is presented below. December 31, September 30, 2017 2017 (in millions) Inventories: Purchased components and raw material $ 74.3 $ 67.7 Work in process 37.8 35.6 Finished goods 43.1 35.6 $ 155.2 $ 138.9 Other current assets: Maintenance and repair tooling $ 3.2 $ 3.3 Income taxes 11.9 10.9 Other 11.4 10.2 $ 26.5 $ 24.4 Property, plant and equipment: Land $ 5.5 $ 5.6 Buildings 51.4 53.4 Machinery and equipment 270.0 266.7 Construction in progress 25.2 24.7 352.1 350.4 Accumulated depreciation (229.8 ) (228.1 ) $ 122.3 $ 122.3 Other current liabilities: Compensation and benefits $ 18.2 $ 26.9 Customer rebates 8.1 6.5 Taxes other than income taxes 2.4 3.2 Warranty 3.7 3.5 Income taxes 0.8 0.9 Environmental 1.2 1.3 Interest 0.7 0.6 Restructuring 4.2 3.3 Other 6.8 7.3 $ 46.1 $ 53.5

Accumulated Other Comprehensi28

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule Of Accumulated Other Comprehensive Loss	Accumulated other comprehensive loss is presented below. Pension, net of tax Foreign currency translation Derivative instruments, net of tax Total Balance at September 30, 2017 $ (47.0 ) $ (3.3 ) $ (1.5 ) $ (51.8 ) Current period other comprehensive income (loss) 0.5 0.1 1.0 1.6 Balance at December 31, 2017 $ (46.5 ) $ (3.2 ) $ (0.5 ) $ (50.2 ) Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is presented below. Pension, net of tax Foreign currency translation Derivative instruments, net of tax Total Balance at September 30, 2017 $ (47.0 ) $ (3.3 ) $ (1.5 ) $ (51.8 ) Current period other comprehensive income (loss) 0.5 0.1 1.0 1.6 Balance at December 31, 2017 $ (46.5 ) $ (3.2 ) $ (0.5 ) $ (50.2 )

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Dec. 31, 2017
Segment Reporting, Measurement Disclosures [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas
Schedule Of Selected Supplemental Balance Sheet Information	Summarized financial information for our segments is presented below. Three months ended December 31, 2017 2016 (in millions) Net sales, excluding intercompany: Infrastructure $ 160.1 $ 146.3 Technologies 18.2 20.9 $ 178.3 $ 167.2 Intercompany sales: Infrastructure $ — $ 1.1 Technologies — — $ — $ 1.1 Operating income (loss): Infrastructure $ 28.1 $ 26.2 Technologies (4.7 ) (2.2 ) Corporate (2.7 ) (9.8 ) $ 20.7 $ 14.2 Depreciation and amortization: Infrastructure $ 9.1 $ 9.0 Technologies 1.4 1.2 Corporate 0.1 0.1 $ 10.6 $ 10.3 Strategic reorganization and other charges: Infrastructure $ — $ 0.1 Technologies 0.1 — Corporate 3.8 1.2 $ 3.9 $ 1.3 Capital expenditures: Infrastructure $ 4.8 $ 3.0 Technologies 1.5 1.1 Corporate 0.1 0.1 $ 6.4 $ 4.2

Discontinued Operations, Asse30

Discontinued Operations, Assets Held for Sale and Divestitures (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of idle property	$ 9		$ 0
Disposal Date		Jan. 6, 2017
Restructuring	3.9		1.3
Revenue, Net	178.3		$ 167.2
Cash [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration	7.4
Prepaid Expenses and Other Current Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration	$ 0.8

Organization (Details)

Organization (Details) - USD ($) $ in Millions	Jul. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2019	Sep. 30, 2017
Segment Reporting Information [Line Items]
Beginning balance		$ 3.3
Restructuring		3.9	$ 1.3
Payments		$ 1.4
Number of Reportable Segments		2
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	49.00%
Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost		$ 0.2	0.3
Revenue, Net		$ 178.3	$ 167.2
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		24.50%	35.00%		35.00%
Mueller Co. [Member]
Segment Reporting Information [Line Items]
Restructuring		$ 0	$ 0.1
Revenue, Net		160.1	146.3
General and Administrative Expense [Member] | Mueller Co. [Member]
Segment Reporting Information [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost			0.2
Cost of Sales [Member] | Mueller Co. [Member]
Segment Reporting Information [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost			$ 0.1
Product [Member]
Segment Reporting Information [Line Items]
Revenue, Net		$ 3.7
Scenario, Forecast [Member]
Segment Reporting Information [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent				21.00%

Discontinued Operations, Asse32

Discontinued Operations, Assets Held for Sale and Divestitures (Schedule of Disposal Groups, Including Discontinued Operations - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales		$ 83.1
Cost of sales		62.8
Gross profit		20.3
Operating expenses:
Selling, general and administrative		18.3
Other charges		0.2
Total operating expenses		18.5
Operating income		1.8
Income tax expense		0.5
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	$ 0	$ 1.3

Organization Restructuring (Det

Organization Restructuring (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Beginning balance	$ 3.3
Restructuring	3.9	$ 1.3
Payments	(1.4)
Mueller One Project [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 2.3

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	24.50%	35.00%	35.00%
Weighted Average Deferred Income Tax Provision Rate	25.00%		39.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	$ (42.6)

Income Taxes Income Tax Rate Re

Income Taxes Income Tax Rate Reconciliation (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	24.50%	35.00%	35.00%
Adjustments to reconcile to the effective tax rate:
State income taxes, net of federal benefit	4.30%	3.90%
Valuation allowance adjustment related to stock compensation	(5.70%)	0.00%
Tax benefits from stock compensation	2.80%	7.60%
U.S. manufacturing deduction	1.60%	3.30%
Tax credits	0.90%	0.80%
Other	(0.50%)	0.80%
Change in rate for deferred taxes	(278.40%)	0.00%
Effective income tax rate	(260.10%)	28.00%

Borrowing Arrangements (Narrati

Borrowing Arrangements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017	Dec. 31, 2015	Sep. 30, 2015
Cash and cash equivalents	$ 348,300	$ 348,300	$ 361,700	$ 172,300	$ 195,000
Future maturities of outstanding borrowings
Debt Instrument, Unamortized Discount	1,400
Domestic Line of Credit [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%
Agreement termination date	Jul. 13, 2021
Aggregate commitments availability	$ 17,500
Aggregate commitments availability, percentage	10.00%
Outstanding letter of credit accrued fees and expenses	$ 19,800
Excess availability reduced by outstanding borrowings, outstanding letters of credit and accrued fees and expenses	96,300
Swing Line Loans [Member]
Revolving credit facility amount	(25,000)
Letters Of Credit Outstanding [Member]
Revolving credit facility amount	(60,000)
Secured Debt [Member]
Long-term Debt, Gross	$ 500,000
Debt Instrument, Basis Spread on Variable Rate	25000.00%
Debt Instrument, Interest Rate, Effective Percentage	4.60%
Debt Instrument, Periodic Payment, Principal	$ 1,225
Agreement termination date	Nov. 25, 2021
Future maturities of outstanding borrowings
Financial Liabilities Fair Value Disclosure	$ 490,000
Minimum [Member] | Domestic Line of Credit [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	2500.00%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Long-term Debt [Member]
Debt Instrument, Basis Spread on Variable Rate	2500.00%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Domestic Line of Credit [Member]
Debt Instrument, Basis Spread on Variable Rate		12500.00%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Secured Debt [Member]
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum (Deprecated 2016-01-31)	0.75%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Domestic Line of Credit [Member]
Debt Instrument, Basis Spread on Variable Rate	15000.00%
Base Rate [Member] | Maximum [Member] | Domestic Line of Credit [Member]
Debt Instrument, Basis Spread on Variable Rate	5000.00%

Borrowing Arrangements (Compone

Borrowing Arrangements (Components Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Sep. 30, 2017
Debt instrument	$ 485.4	$ 486.5
Deferred financing costs	5.5	5.9
Current portion of long-term debt	5.6	5.6
Long-term debt	474.3	475
Domestic Line of Credit [Member]
Debt instrument	0	0
Secured Debt [Member]
Debt instrument	483.7	484.8
Other [Member]
Debt instrument	$ 1.7	$ 1.7

Derivative Financial Instrume38

Derivative Financial Instruments (Details) - USD ($) $ in Millions	3 Months Ended		60 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2021	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
Other current liabilities	$ 0.7			$ 1.2
Derivative, Cap Interest Rate					0.75%
Derivative, Fixed Interest Rate	2.341%
Derivative, Amount of Hedged Item	$ 150
Other noncurrent liabilities	0.2			1.3
Interest Rate Derivatives, at Fair Value, Net	0.9			2.5
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	0.4	$ 0.6
Other noncurrent liabilities	1.3			$ 1.3
Secured Debt [Member]
Derivative [Line Items]
Long-term Debt, Gross	$ 500
Debt Instrument, Interest Rate, Effective Percentage	4.60%
Debt Instrument, Basis Spread on Variable Rate	25000.00%
Scenario, Forecast [Member]
Derivative [Line Items]
HedgePeriodStart			Sep. 30, 2016
Derivative, Maturity Date			Sep. 30, 2021
Cash Flow Hedging [Member] | Secured Debt [Member]
Derivative [Line Items]
Long-term Debt, Gross	$ 150
Debt Instrument, Interest Rate, Effective Percentage	4.841%

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) $ in Millions	3 Months Ended
	Dec. 31, 2017USD ($)
Decrease in accumulated other comprehensive loss net of tax	$ 0.5

Retirement Plans (Net Periodic

Retirement Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Service Cost	$ 0.5	$ 0.5
Defined Benefit Plan, Interest Cost	3.6	3.6
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(4.2)	(4.3)
Amortization of actuarial net loss	0.8	1
Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost	0.2	0.3
Net periodic benefit cost	$ 0.7	$ 0.8

Stock-based Compensation Plan41

Stock-based Compensation Plans (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)shares
Allocated Share-based Compensation Expense | $	$ 2.4	$ 2.7
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 8.9
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	70,996	323,010
Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Intrinsic Value, Amount Per Share | $ / shares	$ 12.53
Share-based compensation liability | $	$ 1.2
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	146,061	263,410
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	171,288
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based compensation, units awarded but not yet granted	185,270
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	213,532
Minimum [Member] | Performance Shares [Member]
Performance Factor		0
Maximum [Member] | Performance Shares [Member]
Performance Factor		2

Stock-based Compensation Plan42

Stock-based Compensation Plans Grants Table $ / shares in Units, $ in Millions	3 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Granted, Value, Share-based Compensation, Gross	$ 6.7
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares | shares	171,288
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	$ 12.41
Stock Granted, Value, Share-based Compensation, Gross	$ 2.1
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares | shares	35,099
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	$ 2.28
Stock Granted, Value, Share-based Compensation, Gross	$ 0.1
Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares | shares	160,672
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	$ 12.41
Stock Granted, Value, Share-based Compensation, Gross	$ 2
Share-based Compensation Award, Tranche One [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares | shares	57,092
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	$ 12.41
Stock Granted, Value, Share-based Compensation, Gross	$ 0.7
Share-based Compensation Award, Tranche Two [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares | shares	71,070
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	$ 12.41
Stock Granted, Value, Share-based Compensation, Gross	$ 0.9
Share-based Compensation Award, Tranche Three [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares | shares	71,072
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	$ 12.41
Stock Granted, Value, Share-based Compensation, Gross	$ 0.9

Supplemental Balance Sheet In43

Supplemental Balance Sheet Information (Schedule Of Selected Supplemental Balance Sheet Information) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Sep. 30, 2017
Inventories:
Purchased components and raw material	$ 74.3	$ 67.7
Work in process	37.8	35.6
Finished goods	43.1	35.6
Inventories, net	155.2	138.9
Maintenance and repair tooling	3.2	3.3
Income taxes	11.9	10.9
Other	11.4	10.2
Other	26.5	24.4
Property, plant and equipment:
Land	5.5	5.6
Buildings	51.4	53.4
Machinery and equipment	270	266.7
Construction in progress	25.2	24.7
Property, plant and equipment, gross	352.1	350.4
Accumulated depreciation	(229.8)	(228.1)
Property, plant and equipment net	122.3	122.3
Other current liabilities:
Compensation and benefits	18.2	26.9
Customer rebates	8.1	6.5
Interest	0.7	0.6
Taxes other than income taxes	2.4	3.2
Warranty	3.7	3.5
Environmental	1.2	1.3
Income taxes	0.8	0.9
Restructuring	4.2	3.3
Other	6.8	7.3
Other current liabilities	$ 46.1	$ 53.5

Accumulated Other Comprehensi44

Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	$ (47)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(3.3)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(1.5)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(50.2)		$ (51.8)
Minimum pension liability, net of tax	0.5
Foreign currency translation	0.1	$ (1.5)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	1
Other Comprehensive Income (Loss), Net of Tax	1.6
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	(46.5)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(3.2)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(0.5)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (50.2)

Segment Information (Narrative)

Segment Information (Narrative) (Details)	3 Months Ended
	Dec. 31, 2017
Segment Reporting Information [Line Items]
Number of Reportable Segments	2

Segment Information (Schedule O

Segment Information (Schedule Of Selected Supplemental Balance Sheet Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Segment Reporting Information [Line Items]
Net sales, excluding intercompany	$ 178.3	$ 167.2
2,013	0	1.1
Operating income	20.7	14.2
Depreciation and amortization	10.6	10.3
Restructuring	3.9	1.3
Payments to Acquire Productive Assets	6.4	4.2
Total assets	1,220.2		$ 1,258.3
Intangible intangible assets, net	434.6		$ 439.3
Mueller Co. [Member]
Segment Reporting Information [Line Items]
Net sales, excluding intercompany	160.1	146.3
2,013	0	1.1
Operating income	28.1	26.2
Depreciation and amortization	9.1	9
Restructuring	0	0.1
Payments to Acquire Productive Assets	4.8	3
Mueller Technologies [Member]
Segment Reporting Information [Line Items]
Net sales, excluding intercompany	18.2	20.9
2,013	0	0
Operating income	(4.7)	(2.2)
Depreciation and amortization	1.4	1.2
Restructuring	0.1	0
Payments to Acquire Productive Assets	1.5	1.1
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income	(2.7)	(9.8)
Depreciation and amortization	0.1	0.1
Restructuring	3.8	1.2
Payments to Acquire Productive Assets	$ 0.1	$ 0.1

Commitments and Contingencies (

Commitments and Contingencies (Details) CAD in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2017CAD	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2014USD ($)
Loss Contingency, Damages Sought, Value | CAD	CAD 10
Prior To 1995 [member]
Walter Energy tax assessment				$ 33
IRS-Walter Energy Claim 1 [Member]
Loss Contingency, Estimate of Possible Loss			$ 554.3
IRS-Walter Energy Claim 1 Priority [Member]
Loss Contingency, Estimate of Possible Loss		$ 229.1
IRS-Walter Energy Claim 2 [Member]
Loss Contingency, Estimate of Possible Loss		860.4
IRS-Walter Energy Claim 2 Priority [Member]
Loss Contingency, Estimate of Possible Loss		$ 535.3

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	Feb. 20, 2018	Feb. 09, 2018	Jan. 24, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Dividends declared, in dollars per share				$ 0.04	$ 0.03
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends Payable, Date Declared			Jan. 24, 2018
Dividends declared, in dollars per share			$ 0.0500
Dividends Payable, Date to be Paid	Feb. 20, 2018
Dividends Payable, Date of Record		Feb. 9, 2018