Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Segment Reporting Information [Line Items]
Net sales	$ 2,231,668	$ 1,708,531
Income (loss) before income taxes	187,091	115,800
Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Income (loss) before income taxes	196,437	123,096
Operating Segments | Recreational vehicles | Towables
Segment Reporting Information [Line Items]
Income (loss) before income taxes	158,851	94,173
Operating Segments | Recreational vehicles | Motorized
Segment Reporting Information [Line Items]
Income (loss) before income taxes	37,586	28,923
Operating Segments | Other
Segment Reporting Information [Line Items]
Income (loss) before income taxes	8,483	6,378
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Income (loss) before income taxes	(17,829)	(13,674)
Continuing Operations
Segment Reporting Information [Line Items]
Net sales	2,231,668	1,708,531
Continuing Operations | Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	2,185,112	1,672,327
Continuing Operations | Operating Segments | Recreational vehicles | Towables
Segment Reporting Information [Line Items]
Net sales	1,618,501	1,210,873
Continuing Operations | Operating Segments | Recreational vehicles | Motorized
Segment Reporting Information [Line Items]
Net sales	566,611	461,454
Continuing Operations | Operating Segments | Other
Segment Reporting Information [Line Items]
Net sales	82,919	58,996
Continuing Operations | Intercompany Eliminations
Segment Reporting Information [Line Items]
Net sales	$ (36,363)	$ (22,792)