Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]	Stockholders' Equity Attributable to Thor [Member]	Non-controlling Interests [Member]
Balance (in shares) at Jul. 31, 2016		62,439,795				9,957,180
Balance at Jul. 31, 2016	$ 1,265,222	$ 6,244	$ 224,496	$ 1,365,981		$ (331,499)	$ 1,265,222
Net income	374,254			374,254			374,254
Restricted stock unit activity (in shares)		157,315				53,889
Restricted stock unit activity	(6,027)	$ 16	(1,471)			$ (4,572)	(6,027)
Cash dividends	(69,409)			(69,409)			(69,409)
Stock compensation expense	12,500		12,500				12,500
Balance (in shares) at Jul. 31, 2017		62,597,110				10,011,069
Balance at Jul. 31, 2017	1,576,540	$ 6,260	235,525	1,670,826		$ (336,071)	1,576,540
Net income	430,151			430,151			430,151
Restricted stock unit activity (in shares)		168,714				59,390
Restricted stock unit activity	(7,961)	$ 17	(321)			$ (7,657)	(7,961)
Cash dividends	(77,989)			(77,989)			(77,989)
Stock compensation expense	17,000		17,000				17,000
Balance (in shares) at Jul. 31, 2018		62,765,824				10,070,459
Balance at Jul. 31, 2018	1,937,741	$ 6,277	252,204	2,022,988		$ (343,728)	1,937,741
Net income	132,465			133,275			133,275	$ (810)
Restricted stock unit activity (in shares)		167,591				55,975
Restricted stock unit activity	(3,116)	$ 16	1,286			$ (4,418)	(3,116)
Cash dividends	(84,139)			(84,139)			(84,139)
Stock compensation expense	18,950		18,950				18,950
Other comprehensive income (loss)	(57,598)				$ (57,004)		(57,004)	(594)
Cumulative effect of adoption of ASU no. 2014-09, net of tax	(5,450)			(5,450)			(5,450)
Acquisitions (in shares)		2,256,492
Acquisitions	156,375	$ 226	143,942				144,168	12,207
Balance (in shares) at Jul. 31, 2019		65,189,907				10,126,434
Balance at Jul. 31, 2019	$ 2,095,228	$ 6,519	$ 416,382	$ 2,066,674	$ (57,004)	$ (348,146)	$ 2,084,425	$ 10,803