Loans Receivable (excluding Covered Loans) - Loan Modifications (Details) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2015 USD ($) contract	Jun. 30, 2014 USD ($) contract	Jun. 30, 2015 USD ($) contract	Jun. 30, 2014 USD ($) contract
Financing Receivable, Modifications [Line Items]
Number of contracts (in contracts) \| contract	11	19	26	47
Recorded investment	$ 1,895	$ 3,327	$ 4,320	$ 9,821
Single-Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts (in contracts) \| contract	9	17	19	42
Recorded investment	$ 1,594	$ 3,088	$ 3,329	$ 9,206
Land - Consumer Lot Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts (in contracts) \| contract	2	1	7	4
Recorded investment	$ 301	$ 69	$ 991	$ 445
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts (in contracts) \| contract	0	1	0	1
Recorded investment	$ 0	$ 170	$ 0	$ 170