Investment in Historic Tax Credit Entity (Additional Information) (Detail) - USD ($) $ in Thousands	Oct. 15, 2014	Jun. 30, 2015	Sep. 30, 2014
Committed To Invest Into Limited Liability	$ 4,200
Percentage Of Received Equity Interest	99.00%
Percentage Of Receive Operating Profit And Losses	99.00%
Investment Credit Available To Be Estimated	$ 4,600
Other Assets		$ 7,369	$ 2,567
Description Of Investment In Credit	The Bank invested $417,000 on October 15, 2014 and has committed to invest an additional $417,000 when the project is 50% completed and the remaining $3.3 million when the project is fully completed and the certificate of occupancy is received. The project is expected to be fully completed in April 2016.
Investment In Credit [Member]
Other Assets		4,200
Other Liabilities		$ 3,800