Summary Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net change	$ 20,000	$ 27,000
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at September 30, 2011	57,000
Balance at September 30, 2012	7,000
Net change	$ 50,000