Changes in Carrying Amount of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified													12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2012 Towables	Jul. 31, 2011 Towables	Jul. 31, 2010 Towables	Jul. 31, 2012 Motorized	Jul. 31, 2011 Motorized	Jul. 31, 2010 Motorized	Jul. 31, 2012 Buses	Jul. 31, 2011 Buses	Jul. 31, 2010 Buses	Jul. 31, 2012 Heartland	Jul. 31, 2011 Heartland	Jul. 31, 2012 Heartland Towables	Jul. 31, 2011 Heartland Towables
Goodwill [Line Items]
Goodwill	$ 262,461	$ 261,704	$ 168,153	$ 238,103	$ 237,346	$ 143,795	$ 17,252	$ 17,252	$ 17,252	$ 7,106	$ 7,106	$ 7,106
Accumulated impairment charges	(17,252)	(17,252)	(17,252)				(17,252)	(17,252)	(17,252)
Goodwill, Beginning Balance	245,209	244,452	150,901	238,103	237,346	143,795				7,106	7,106	7,106
Goodwill acquired													757	93,551	757	93,551
Goodwill	262,461	261,704	168,153	238,103	237,346	143,795	17,252	17,252	17,252	7,106	7,106	7,106
Accumulated impairment charges	(17,252)	(17,252)	(17,252)				(17,252)	(17,252)	(17,252)
Goodwill, Ending Balance	$ 245,209	$ 244,452	$ 150,901	$ 238,103	$ 237,346	$ 143,795				$ 7,106	$ 7,106	$ 7,106