Business Segments - Schedule of Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019	Jul. 31, 2019
Segment Reporting Information [Line Items]
Net sales	$ 2,003,133	$ 1,290,576	$ 4,161,918	$ 3,046,552
Income (loss) from continuing operations before income taxes	34,863	1,873	103,497	33,390
Total assets	5,628,477		5,628,477		$ 5,660,446
Depreciation and amortization expense, total	48,945	23,522	99,152	46,580
Capital acquisitions	21,134	17,776	51,157	49,917
Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	1,964,702	1,253,059
Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	1,964,702	1,253,059	4,074,486	2,963,355
Income (loss) from continuing operations before income taxes	73,032	51,265	176,105	147,527
Total assets	5,150,403		5,150,403		5,040,949
Depreciation and amortization expense, total	45,965	20,414	93,213	40,481
Capital acquisitions	20,431	17,064	49,301	46,725
Operating Segments | Recreational vehicles | North American
Segment Reporting Information [Line Items]
Net sales	1,327,587	1,253,059	2,944,364	2,963,355
Income (loss) from continuing operations before income taxes	68,342	51,265	194,439	147,527
Total assets	2,043,549		2,043,549		1,963,145
Depreciation and amortization expense, total	19,945	20,414	39,710	40,481
Capital acquisitions	13,281	17,064	27,124	46,725
Operating Segments | Recreational vehicles | North American | Towables
Segment Reporting Information [Line Items]
Net sales	983,907	881,564	2,184,795	2,160,662
Income (loss) from continuing operations before income taxes	53,426	34,060	157,748	108,610
Total assets	1,565,409		1,565,409		1,516,519
Depreciation and amortization expense, total	16,431	16,971	32,702	33,602
Capital acquisitions	7,421	14,255	18,696	36,497
Operating Segments | Recreational vehicles | North American | Motorized
Segment Reporting Information [Line Items]
Net sales	343,680	371,495	759,569	802,693
Income (loss) from continuing operations before income taxes	14,916	17,205	36,691	38,917
Total assets	478,140		478,140		446,626
Depreciation and amortization expense, total	3,514	3,443	7,008	6,879
Capital acquisitions	5,860	2,809	8,428	10,228
Operating Segments | Recreational vehicles | European
Segment Reporting Information [Line Items]
Net sales	637,115	0	1,130,122	0
Income (loss) from continuing operations before income taxes	4,690	0	(18,334)	0
Total assets	3,106,854		3,106,854		3,077,804
Depreciation and amortization expense, total	26,020	0	53,503	0
Capital acquisitions	7,150	0	22,177	0
Other, net
Segment Reporting Information [Line Items]
Net sales	57,745	55,114	131,311	128,962
Income (loss) from continuing operations before income taxes	8,609	5,950	20,360	11,860
Total assets	162,326		162,326		163,897
Depreciation and amortization expense, total	2,523	2,693	5,034	5,267
Capital acquisitions	273	287	928	2,731
Corporate
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	(46,778)	(55,342)	(92,968)	(125,997)
Total assets	315,748		315,748		$ 455,600
Depreciation and amortization expense, total	457	415	905	832
Capital acquisitions	430	425	928	461
Intercompany eliminations
Segment Reporting Information [Line Items]
Net sales	$ (19,314)	$ (17,597)	$ (43,879)	$ (45,765)