Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Income Taxes [Line Items]
Change in valuation allowance	$ 9,700,000
Stockholder owning ownership on corporation's securities percentage	5.00%
Stockholder owning ownership on corporation's securities rolling period	3 years
Tax Benefit Preservation Plan, adoption date	2011-10-17
Any person acquiring shares of the Company's securities holding percentage as amended by Tax Plan which protects Tax Benefits	4.99%
Net operating loss carryforwards for federal tax	2,000,000,000
Net operating loss carryforwards for state tax	451,900,000
Foreign net operating loss carryforward	60,100,000
Deferred tax liability	19,392,000	18,061,000
U.S. federal income tax rate	35.00%	35.00%	35.00%
Unrecognized tax benefits, including interest, related to federal, state and foreign taxes	1,000,000	1,300,000	2,400,000
Liabilities for interest expense related to uncertain tax positions	10,000	78,000	130,000
Foreign Subsidiaries
Income Taxes [Line Items]
Undistributed earnings from foreign subsidiaries	62,800,000
Undistributed earnings reinvested	11,300,000
Amount of taxes attributable to the permanently undistributed earnings	4,400,000
Deferred tax liability	18,000,000
Undistributed earnings that are not considered to be permanently reinvested	51,500,000
Federal
Income Taxes [Line Items]
Net operating losses expire date	2021 through 2033
Capital loss carryforwards	16,300,000
Capital losses expiration year	2015
State
Income Taxes [Line Items]
Net operating losses expire date	2014 through 2033
Capital loss carryforwards	16,300,000
Capital losses expiration year	2016
Indefinite Carryforward
Income Taxes [Line Items]
Foreign net operating loss carryforward	$ 47,000,000