Document and Entity Information	3 Months Ended
	Oct. 31, 2017 shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 31, 2017
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Trading Symbol	THO
Entity Registrant Name	THOR INDUSTRIES INC
Entity Central Index Key	0000730263
Current Fiscal Year End Date	--07-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	52,694,365