XML 13 R1.htm IDEA: XBRL DOCUMENT v3.10.0.1
Document and Entity Information - USD ($)
 3 Months Ended
Dec. 31, 2018
Jan. 31, 2019
Mar. 31, 2017
Document And Entity Information [Abstract]      
Document Fiscal Period Focus Q1    
Document Period End Date Dec. 31, 2018    
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   158,211,464  
Entity Small Business false    
Entity Public Float     $ 1,856,526,077