Summary of Fair Value Assigned to Net Assets Acquired (Detail) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Jan. 05, 2015	Jul. 31, 2015	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Business Acquisition [Line Items]
Goodwill		$ 312,622	$ 312,622	$ 256,579	$ 238,103
Total cash consideration for acquisition, less cash acquired			194,486	$ 86,092	$ 10,718
Cruiser RV, LLC and DRV, LLC
Business Acquisition [Line Items]
Cash	$ 1,062	1,062	$ 1,062
Other current assets	22,175
Property, plant and equipment	4,533
Goodwill	13,172
Current liabilities	(12,507)
Total fair value of net assets acquired	48,585
Less cash acquired	(1,062)
Total cash consideration for acquisition, less cash acquired	47,523	$ 47,523
Cruiser RV, LLC and DRV, LLC | Dealer Networks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset	14,300
Cruiser RV, LLC and DRV, LLC | Trademarks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset	5,400
Cruiser RV, LLC and DRV, LLC | Backlog
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset	$ 450