Business Segments - Schedule of Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020	Jul. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 3,459,264	$ 1,681,735	$ 8,724,412	$ 5,843,653
Income (loss) from continuing operations before income taxes	232,679	21,229	542,957	124,726
Total assets	6,713,967		6,713,967		$ 5,771,460
Depreciation and amortization expense, total	58,689	45,459	169,643	144,611
Capital acquisitions	33,140	23,870	81,201	75,027
Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	3,395,735	1,652,771
Operating segments | Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	3,395,735	1,652,771	8,567,761	5,727,257
Income (loss) from continuing operations before income taxes	266,466	59,934	645,223	236,039
Total assets	6,157,426		6,157,426		5,112,209
Depreciation and amortization expense, total	55,163	42,345	159,323	135,558
Capital acquisitions	31,355	23,232	76,367	72,533
Operating segments | Recreational vehicles | North America
Segment Reporting Information [Line Items]
Net sales	2,501,495	1,037,428	6,337,570	3,981,792
Income (loss) from continuing operations before income taxes	222,473	60,176	596,520	254,615
Total assets	2,951,205		2,951,205		2,010,138
Depreciation and amortization expense, total	23,912	20,296	65,141	60,006
Capital acquisitions	16,466	7,352	38,262	34,476
Operating segments | Recreational vehicles | North America | North American Towables
Segment Reporting Information [Line Items]
Net sales	1,726,102	773,391	4,491,327	2,958,186
Income (loss) from continuing operations before income taxes	167,693	49,261	456,752	207,009
Total assets	1,802,162		1,802,162		1,529,913
Depreciation and amortization expense, total	16,904	16,696	49,029	49,398
Capital acquisitions	9,750	5,192	26,071	23,888
Operating segments | Recreational vehicles | North America | North American Motorized
Segment Reporting Information [Line Items]
Net sales	775,393	264,037	1,846,243	1,023,606
Income (loss) from continuing operations before income taxes	54,780	10,915	139,768	47,606
Total assets	1,149,043		1,149,043		480,225
Depreciation and amortization expense, total	7,008	3,600	16,112	10,608
Capital acquisitions	6,716	2,160	12,191	10,588
Operating segments | Recreational vehicles | Europe
Segment Reporting Information [Line Items]
Net sales	894,240	615,343	2,230,191	1,745,465
Income (loss) from continuing operations before income taxes	43,993	(242)	48,703	(18,576)
Total assets	3,206,221		3,206,221		3,102,071
Depreciation and amortization expense, total	31,251	22,049	94,182	75,552
Capital acquisitions	14,889	15,880	38,105	38,057
Other, net
Segment Reporting Information [Line Items]
Net sales	106,960	45,632	262,381	176,943
Income (loss) from continuing operations before income taxes	16,667	3,996	37,801	24,356
Total assets	258,531		258,531		212,378
Depreciation and amortization expense, total	3,108	2,676	9,058	7,710
Capital acquisitions	1,427	517	4,087	1,445
Corporate
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	(50,454)	(42,701)	(140,067)	(135,669)
Total assets	298,010		298,010		$ 446,873
Depreciation and amortization expense, total	418	438	1,262	1,343
Capital acquisitions	358	121	747	1,049
Intercompany eliminations
Segment Reporting Information [Line Items]
Net sales	$ (43,431)	$ (16,668)	$ (105,730)	$ (60,547)