Assets and Liabilities Carried at Fair Value Measured on Recurring Basis (Parenthetical) (Detail) (Fair Value, Measurements, Recurring)	3 Months Ended
	Oct. 31, 2012
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, Discount rate	22.10%