Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Income Tax [Line Items]
Net current deferred tax assets		$ 59,864
Net long-term deferred income tax liabilities		20,563
Unrecognized tax benefits that, if recognized, would affect the company's income tax rate	$ 8,886	8,764	$ 13,679
Tax positions related to prior years: Reductions	920	7,695	9,281
Accrued interest and penalties	1,547	1,895	5,200
Total amount of interest and penalties expense (benefit) recognized	(231)	$ (2,552)	(3,418)
Expected decrease in unrecognized tax benefits due to resolution of uncertain tax positions	5,193
Expected decrease in interest due to resolution of uncertain tax positions	857
Discontinued Operations
Income Tax [Line Items]
Tax positions related to prior years: Reductions			$ 1,378
ASU 2015-17 | Reclassification adjustment
Income Tax [Line Items]
Net current deferred tax assets	67,344
Net long-term deferred income tax liabilities	13,927
State and Local Jurisdiction
Income Tax [Line Items]
Tax credit carry forward	2,649
Gross state tax Net Operating Loss carry forwards	45,500
Deferred tax asset, Net Operating Loss carry forwards	$ 973
State and Local Jurisdiction | Earliest Tax Year
Income Tax [Line Items]
Tax credit carry forward expiration year	2022
Gross state tax Net Operating Loss carry forwards, expiration year	2017
State and Local Jurisdiction | Latest Tax Year
Income Tax [Line Items]
Tax credit carry forward expiration year	2026
Gross state tax Net Operating Loss carry forwards, expiration year	2036