Acquisitions - Pro Forma Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Business Combinations [Abstract]
Net sales	$ 3,875,018	$ 2,943,733	$ 7,880,700	$ 5,756,969
Net income attributable to THOR Industries, Inc.	$ 266,568	$ 148,448	$ 515,623	$ 266,584
Basic earnings per common share (in dollars per share)	$ 4.80	$ 2.68	$ 9.30	$ 4.82
Diluted earnings per common share (in dollars per share)	$ 4.79	$ 2.67	$ 9.25	$ 4.80