Loans Receivable - Additional Information (Detail) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Receivables [Line Items]
Carrying value of Purchased loans	$ 5,100,000
Unpaid Principal Balance	40,658,000	41,084,000
Estimated fair value	7,300,000
Contractual cash flows	13,900,000
Preliminary estimate of expected cash flows	8,800,000
Non-accretable discount	5,100,000
Cash flows in excess of estimated fair value	1,400,000
Reclassifications of nonaccretable discounts	872,000
Allowance for loan losses recorded for acquired loans	157,000	0
Mortgage loans	104,810,000	80,986,000
Non Accrual loans	21,912,000	23,279,000	23,707,000
Additional interest income under loan agreements	1,054,000	883,000	592,000
Criteria in internal rating system	Ten point
Categories considered as not criticized	Six
Days past due over which loans are considered as substandard	90 days
Minimum internal review amount	500,000
Minimum external review amount	1,000,000
First Star Bank Member
Receivables [Line Items]
Unpaid Principal Balance	$ 12,900,000