Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Mar. 31, 2019	May 10, 2019	Sep. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Rexnord Corp
Entity Central Index Key	0001439288
Document Type	10-K
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		104,866,451
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 3.2