Document and Entity Information - USD ($)	6 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document And Entity Information [Abstract]
Document Fiscal Period Focus	Q2
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Entity Registrant Name	Mueller Water Products, Inc.
Entity Central Index Key	0001350593
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Entity Emerging Growth Company	false
Amendment Flag	false
Entity Common Stock, Shares Outstanding		158,362,740
Entity Small Business	false
Entity Public Float	$ 1,856,526,077