Provision for Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Income Tax [Line Items]
Effective income tax rate	32.80%	33.40%	31.90%	32.50%
Decreases in unrecognized tax benefits resulting from effective settlement	$ 2,862		$ 7,368
Income tax benefit related to gross uncertain tax benefit releases, net	1,375		3,762
Accrued an additional uncertain tax benefit related to prior tax periods			90
Interest and penalties related to uncertain tax benefits	92		385
Expected decrease in unrecognized tax benefits due to resolution of uncertain tax positions			3,640
Expected decrease in interest and penalties due to resolution of uncertain tax positions			690
Expected gross unrecognized tax benefits decrease			540
Expected decrease in interest and penalties			$ 410