Cover Page Document - shares	3 Months Ended
	Dec. 31, 2020	Jan. 31, 2021
Cover Page [Abstract]
Entity Incorporation, State or Country Code	DE
Document Type	10-Q
Document Type	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	001-32892
Entity Registrant Name	MUELLER WATER PRODUCTS, INC.
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
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		158,435,893
Trading Symbol	MWA
Security Exchange Name	NYSE