Business Segments - Schedule of Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020	Jul. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 2,727,788	$ 2,003,133	$ 5,265,148	$ 4,161,918
Income (loss) from continuing operations before income taxes	163,959	34,863	310,278	103,497
Total assets	6,369,546		6,369,546		$ 5,771,460
Depreciation and amortization expense, total	56,715	48,945	110,954	99,152
Capital acquisitions	25,209	21,134	48,061	51,157
Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	2,683,639	1,964,702
Operating segments | Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	2,683,639	1,964,702	5,172,026	4,074,486
Income (loss) from continuing operations before income taxes	201,517	73,032	378,757	176,105
Total assets	5,819,651		5,819,651		5,112,209
Depreciation and amortization expense, total	53,260	45,965	104,160	93,213
Capital acquisitions	23,965	20,431	45,012	49,301
Operating segments | Recreational vehicles | North America
Segment Reporting Information [Line Items]
Net sales	1,950,176	1,327,587	3,836,075	2,944,364
Income (loss) from continuing operations before income taxes	191,301	68,342	374,047	194,439
Total assets	2,788,122		2,788,122		2,010,138
Depreciation and amortization expense, total	21,652	19,945	41,229	39,710
Capital acquisitions	10,643	13,281	21,796	27,124
Operating segments | Recreational vehicles | North America | North American Towables
Segment Reporting Information [Line Items]
Net sales	1,373,181	983,907	2,765,225	2,184,795
Income (loss) from continuing operations before income taxes	147,880	53,426	289,059	157,748
Total assets	1,721,615		1,721,615		1,529,913
Depreciation and amortization expense, total	16,318	16,431	32,125	32,702
Capital acquisitions	6,913	7,421	16,321	18,696
Operating segments | Recreational vehicles | North America | North American Motorized
Segment Reporting Information [Line Items]
Net sales	576,995	343,680	1,070,850	759,569
Income (loss) from continuing operations before income taxes	43,421	14,916	84,988	36,691
Total assets	1,066,507		1,066,507		480,225
Depreciation and amortization expense, total	5,334	3,514	9,104	7,008
Capital acquisitions	3,730	5,860	5,475	8,428
Operating segments | Recreational vehicles | Europe
Segment Reporting Information [Line Items]
Net sales	733,463	637,115	1,335,951	1,130,122
Income (loss) from continuing operations before income taxes	10,216	4,690	4,710	(18,334)
Total assets	3,031,529		3,031,529		3,102,071
Depreciation and amortization expense, total	31,608	26,020	62,931	53,503
Capital acquisitions	13,322	7,150	23,216	22,177
Other, net
Segment Reporting Information [Line Items]
Net sales	74,714	57,745	155,421	131,311
Income (loss) from continuing operations before income taxes	9,644	8,609	21,134	20,360
Total assets	245,299		245,299		212,378
Depreciation and amortization expense, total	3,039	2,523	5,950	5,034
Capital acquisitions	1,216	273	2,660	928
Corporate
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	(47,202)	(46,778)	(89,613)	(92,968)
Total assets	304,596		304,596		$ 446,873
Depreciation and amortization expense, total	416	457	844	905
Capital acquisitions	28	430	389	928
Intercompany eliminations
Segment Reporting Information [Line Items]
Net sales	$ (30,565)	$ (19,314)	$ (62,299)	$ (43,879)