Summary of Final Fair Value Assigned to Net Assets Acquired (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended		0 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Aug. 30, 2013	May 01, 2014	Jul. 31, 2014	Oct. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 269,651				$ 256,579
Total cash consideration for acquisition, less cash acquired	49,265	33,683
Bison
Business Acquisition [Line Items]
Current assets						4,050
Property, plant and equipment						625
Goodwill						6,660
Current liabilities						(3,761)
Total fair value of net assets acquired						16,914
Bison | Dealer Networks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset						7,400
Bison | Trademarks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset						1,800
Bison | Backlog
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset						140
Livin' Lite
Business Acquisition [Line Items]
Cash			247
Other current assets			3,626
Property, plant and equipment			137
Goodwill			9,113
Current liabilities			(2,147)
Total fair value of net assets acquired			17,016
Less cash acquired			(247)
Total cash consideration for acquisition, less cash acquired			16,769
Livin' Lite | Dealer Networks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset			3,200
Livin' Lite | Trademarks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset			1,500
Livin' Lite | Backlog
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset			110
Livin' Lite | Design Technology Assets
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset			1,100
Livin' Lite | Non-Compete Agreements
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset			130
K.Z. Inc.
Business Acquisition [Line Items]
Cash				996
Other current assets				34,121
Property, plant and equipment				15,057
Goodwill				2,703
Current liabilities				(16,127)
Total fair value of net assets acquired				56,320
Less cash acquired				(996)
Total cash consideration for acquisition, less cash acquired				55,324
K.Z. Inc. | Dealer Networks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset				13,160
K.Z. Inc. | Trademarks
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset				5,540
K.Z. Inc. | Backlog
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset				420
K.Z. Inc. | Non-Compete Agreements
Business Acquisition [Line Items]
Business acquisition allocated to amortizing intangible asset				$ 450