Summary of Final Fair Value Assigned to Net Assets Acquired (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended							0 Months Ended							0 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Jul. 31, 2014	Oct. 31, 2013 Bison	Oct. 31, 2013 Bison Dealer Networks	Oct. 31, 2013 Bison Trademarks	Oct. 31, 2013 Bison Backlog	Aug. 30, 2013 Livin' Lite	Aug. 30, 2013 Livin' Lite	Aug. 30, 2013 Livin' Lite Dealer Networks	Aug. 30, 2013 Livin' Lite Trademarks	Aug. 30, 2013 Livin' Lite Backlog	Aug. 30, 2013 Livin' Lite Design Technology Assets	Aug. 30, 2013 Livin' Lite Non-Compete Agreements	May 01, 2014 K.Z. Inc.	May 01, 2014 K.Z. Inc.	May 01, 2014 K.Z. Inc. Dealer Networks	May 01, 2014 K.Z. Inc. Trademarks	May 01, 2014 K.Z. Inc. Backlog	May 01, 2014 K.Z. Inc. Non-Compete Agreements
Business Acquisition [Line Items]
Cash									$ 247							$ 996
Current assets				4,050
Other current assets									3,626							34,121
Property, plant and equipment				625					137							15,057
Business acquisition allocated to amortizing intangible asset					7,400	1,800	140			3,200	1,500	110	1,100	130			13,160	5,540	420	450
Goodwill	256,579		256,579	6,660					9,113							2,703
Current liabilities				(3,761)					(2,147)							(16,127)
Total fair value of net assets acquired				16,914					17,016							56,320
Less cash acquired								(247)							(996)
Total cash consideration for acquisition, less cash acquired	$ 2,915	$ 33,774						$ 16,769							$ 55,324