Document and Entity Information	3 Months Ended
	Oct. 31, 2018 shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 31, 2018
Document Fiscal Year Focus	2019
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
Smaller reporting company	false
Emerging growth company	false
Entity Common Stock, Shares Outstanding	52,806,981