Document and Entity Information	6 Months Ended
	Mar. 31, 2017 shares
Document and Entity Information [Abstract]
Entity Registrant Name	ROCKWELL AUTOMATION INC.
Entity Central Index Key	0001024478
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	128,835,404