Changes in Carrying Amount of Goodwill by Reportable Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 377,693	$ 377,693
No activity	0	0
Goodwill, Ending Balance	377,693	377,693
Towables
Goodwill [Line Items]
Goodwill, Beginning Balance	334,822	334,822
No activity	0	0
Goodwill, Ending Balance	334,822	334,822
Motorized
Goodwill [Line Items]
No activity	0	0
Other
Goodwill [Line Items]
Goodwill, Beginning Balance	42,871	42,871
No activity	0	0
Goodwill, Ending Balance	$ 42,871	$ 42,871