Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 7,246,952	$ 4,582,112	$ 4,006,819
Income (loss) from continuing operations before income taxes	556,386	383,313	292,895
Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	584,238	410,397	325,838
Operating Segments | Recreational vehicles | Towables
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	458,915	321,874	259,092
Operating Segments | Recreational vehicles | Motorized
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	125,323	88,523	66,746
Operating Segments | Other
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	28,909	18,547	1,424
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	(56,566)	(45,608)	(33,813)
Intercompany Eliminations
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	(195)	(23)	(554)
Continuing Operations
Segment Reporting Information [Line Items]
Net sales	7,246,952	4,582,112	4,006,819
Continuing Operations | Operating Segments | Recreational vehicles
Segment Reporting Information [Line Items]
Net sales	7,098,957	4,432,909	3,967,204
Continuing Operations | Operating Segments | Recreational vehicles | Towables
Segment Reporting Information [Line Items]
Net sales	5,127,491	3,338,659	3,096,405
Continuing Operations | Operating Segments | Recreational vehicles | Motorized
Segment Reporting Information [Line Items]
Net sales	1,971,466	1,094,250	870,799
Continuing Operations | Operating Segments | Other
Segment Reporting Information [Line Items]
Net sales	253,557	218,673	56,594
Continuing Operations | Intercompany Eliminations
Segment Reporting Information [Line Items]
Net sales	$ (105,562)	$ (69,470)	$ (16,979)