Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Segment Reporting Information [Line Items]
Net sales	$ 8,328,909	$ 7,246,952	$ 4,582,112
Income (loss) from continuing operations before income taxes	633,029	556,386	383,313
Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	8,155,015	7,098,957	4,432,909
Income (loss) from continuing operations before income taxes	667,442	584,238	410,397
Operating Segments | Recreational vehicles | Towables
Segment Reporting Information [Line Items]
Net sales	6,008,700	5,127,491	3,338,659
Income (loss) from continuing operations before income taxes	532,657	458,915	321,874
Operating Segments | Recreational vehicles | Motorized
Segment Reporting Information [Line Items]
Net sales	2,146,315	1,971,466	1,094,250
Income (loss) from continuing operations before income taxes	134,785	125,323	88,523
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	305,947	253,557	218,673
Income (loss) from continuing operations before income taxes	32,973	28,909	18,547
Intercompany Eliminations
Segment Reporting Information [Line Items]
Net sales	(132,053)	(105,562)	(69,470)
Income (loss) from continuing operations before income taxes	(306)	(195)	(23)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	$ (67,080)	$ (56,566)	$ (45,608)