Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Jul. 31, 2018 USD ($) Segment shares	Jul. 31, 2017 USD ($) shares	Jul. 31, 2016 USD ($) shares	Jul. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | Segment	2
Cash and cash equivalents	$ 275,249	$ 223,258	$ 209,902	$ 183,478
Depreciation	38,105	34,333	24,613
Excess liability insurance	50,000
Advertising costs	$ 26,874	$ 24,997	$ 14,472
Maximum percentage of tax benefits realized upon ultimate settlement	50.00%
Antidilutive stock options, restricted stock units and unvested restricted stock outstanding | shares	0	0	0
Trademarks
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	17 years
Non-Compete Agreements
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	1 year
Any occurrence after March 31,2015
Summary Of Significant Accounting Policies [Line Items]
Self-insured retention for products liability and personal injury matters	$ 500
Any occurrence after March 31, 2014 and through March 31, 2015
Summary Of Significant Accounting Policies [Line Items]
Self-insured retention for products liability and personal injury matters	1,000
Continuing Operations | Selling, General and Administrative Expenses
Summary Of Significant Accounting Policies [Line Items]
Depreciation	$ 5,035	$ 5,710	$ 3,812
Restricted Stock Units (RSUs)
Summary Of Significant Accounting Policies [Line Items]
Stock-based Compensation, requisite service period	3 years
Minimum
Summary Of Significant Accounting Policies [Line Items]
Self-insured retention for products liability and personal injury matters	$ 500
Minimum | Trademarks
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	15 years
Minimum | Dealer Network
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	12 years
Minimum | Design Technology Assets
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	2 years
Minimum | Non-Compete Agreements
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	2 years
Minimum | Building and Building Improvements
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	10 years
Minimum | Machinery and Equipment
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Cash equivalents maturity period	3 months	3 months
Self-insured retention for products liability and personal injury matters	$ 7,500
Maximum | Trademarks
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	25 years
Maximum | Dealer Network
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	20 years
Maximum | Design Technology Assets
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	15 years
Maximum | Non-Compete Agreements
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	15 years
Maximum | Backlog
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortization period	3 months
Maximum | Building and Building Improvements
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	39 years
Maximum | Machinery and Equipment
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	10 years
Held By One Financial Institution
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 254,701	$ 211,408