Subordinated Debentures and Subordinated Notes Payable - Narrative (Details)	9 Months Ended	12 Months Ended	60 Months Ended
	Jun. 30, 2016 USD ($) trust $ / shares shares	Sep. 30, 2015 USD ($)	Aug. 15, 2025
Debt Instrument [Line Items]
Maximum interest payment deferral period	5 years
Total subordinated debentures and subordinated notes payable	$ 111,827,000	$ 90,727,000
Junior Subordinated Debt
Debt Instrument [Line Items]
Total subordinated debentures and subordinated notes payable	77,128,000	56,083,000
Common shares held in other assets	2,520,000	1,683,000
Subordinated Debt
Debt Instrument [Line Items]
Total subordinated debentures and subordinated notes payable	$ 34,699,000	34,644,000
Face amount of debt issued		$ 35,000,000
Stated interest rate, percentage		4.875%
Redemption price, percentage of principal		100.00%
Trust Preferred Securities Subject to Mandatory Redemption
Debt Instrument [Line Items]
Number of trusts | trust	7
Number of shares caused to be issued | shares	78,400
Par value per shares issued (in USD per share) | $ / shares	$ 1,000
Trust Preferred Securities Subject to Mandatory Redemption | Minimum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	1.48%
Trust Preferred Securities Subject to Mandatory Redemption | Maximum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	3.35%
Scenario, Forecast | Subordinated Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			3.15%