Provision for Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014	Apr. 30, 2013
Income Tax [Line Items]
Maximum percentage of tax benefits realized upon ultimate settlement			50.00%
Effective income tax rate	33.40%	31.00%	32.50%	30.70%
Decreases in unrecognized tax benefits resulting from settlement	$ 760		$ 6,443
Income tax benefit related to gross uncertain tax benefit releases, net	694		3,326
Interest and penalties related to uncertain tax benefits	281		868
Expected decrease in unrecognized tax benefits due to resolution of uncertain tax positions			3,262
Expected decrease in interest and penalties due to resolution of uncertain tax positions			798
Minimum
Income Tax [Line Items]
Expected gross unrecognized tax benefits decrease			900
Expected decrease in interest and penalties			400
Maximum
Income Tax [Line Items]
Expected gross unrecognized tax benefits decrease			6,300
Expected decrease in interest and penalties			$ 3,800