Loan Transactions and Related Notes Receivable - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified			6 Months Ended
	Jan. 31, 2009 First Credit Agreement	Jan. 31, 2009 Second Credit Agreement	Jan. 31, 2014 Third Credit Agreement	Dec. 31, 2009 Third Credit Agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	$ 10,000	$ 10,000		$ 10,000
Original principal amount outstanding			$ 7,400
Notes receivable, maturity			Aug. 30, 2015