Cover Page - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Nov. 14, 2025	Mar. 31, 2025
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Sep. 30, 2025
Current Fiscal Year End Date	--09-30
Document Transition Report	false
Entity File Number	001-32892
Entity Registrant Name	MUELLER WATER PRODUCTS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-3547095
Entity Address, Address Line One	1200 Abernathy Road N.E.
Entity Address, Address Line Two	Suite 1200
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30328
City Area Code	(770)
Local Phone Number	206-4200
Title of 12(b) Security	Common Stock, par value $0.01
Trading Symbol	MWA
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		156,349,160
Entity Public Float			$ 3,951.5
Documents Incorporated by Reference [Text Block]	Applicable portions of the Proxy Statement for our upcoming 2026 Annual Meeting of Stockholders of the Company are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0001350593
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Amendment Flag	false