Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016
Segment Reporting Information [Line Items]
Net sales	$ 1,588,525	$ 975,071	$ 3,297,056	$ 2,005,422
Income (loss) from continuing operations before income taxes	98,365	65,888	214,165	143,579
Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	106,488	73,588	229,584	158,465
Operating Segments | Recreational vehicles | Towables
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	78,000	53,069	172,173	116,293
Operating Segments | Recreational vehicles | Motorized
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	28,488	20,519	57,411	42,172
Operating Segments | Other
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	5,696	3,010	12,074	5,666
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	(13,819)	(10,710)	(27,493)	(20,552)
Continuing Operations
Segment Reporting Information [Line Items]
Net sales	1,588,525	975,071	3,297,056	2,005,422
Continuing Operations | Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	1,557,221	941,185	3,229,548	1,936,963
Continuing Operations | Operating Segments | Recreational vehicles | Towables
Segment Reporting Information [Line Items]
Net sales	1,082,249	698,318	2,293,122	1,442,997
Continuing Operations | Operating Segments | Recreational vehicles | Motorized
Segment Reporting Information [Line Items]
Net sales	474,972	242,867	936,426	493,966
Continuing Operations | Operating Segments | Other
Segment Reporting Information [Line Items]
Net sales	53,891	48,011	112,887	98,393
Continuing Operations | Intercompany Eliminations
Segment Reporting Information [Line Items]
Net sales	$ (22,587)	$ (14,125)	$ (45,379)	$ (29,934)