Document and Entity Information	3 Months Ended
	Dec. 31, 2014	Jan. 20, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	OSHKOSH CORP
Entity Central Index Key	0000775158
Document Type	10-Q
Document Period End Date	Dec. 31, 2014
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		78,140,407
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1