Goodwill and Intangible Assets - Other Intangibles Assets (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Apr. 30, 2020	Oct. 31, 2019	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019	Jul. 31, 2019
Other Intangible Assets [Line Items]
Gross Carrying Amount	$ 56,594			$ 56,594		$ 65,466
Accumulated Amortization	(33,150)			(33,150)		(29,343)
Net Book Value	23,444			23,444		36,123
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Intangible Assets	1,290		$ 1,443	3,872	$ 4,314
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	5,218			5,218
Finite-Lived Intangible Assets, Amortization Expense, Year Two	5,384			5,384
Finite-Lived Intangible Assets, Amortization Expense, Year Three	5,109			5,109
Finite-Lived Intangible Assets, Amortization Expense, Year Four	2,191			2,191
Finite-Lived Intangible Assets, Amortization Expense, Year Five	0			$ 0
Customer relationships and other
Other Intangible Assets [Line Items]
Weighted Average Amortization Period		9 years		8 years
Gross Carrying Amount	47,180			$ 47,180		46,595
Accumulated Amortization	(33,150)			(33,150)		(29,343)
Net Book Value	14,030			14,030		17,252
Tradenames
Other Intangible Assets [Line Items]
Gross Carrying Amount	9,414			9,414		18,871
Accumulated Amortization	0			0		0
Net Book Value	$ 9,414			$ 9,414		$ 18,871