FDIC Indemnification Asset - Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of year	$ 14,722	$ 26,678	$ 45,690
Amortization	(3,836)	(7,552)	(14,604)
Changes in expected reimbursements from FDIC for changes in expected credit losses	(278)	(305)	2,148
Changes in reimbursable expenses	(791)	(1,972)	2,358
Payments (reimbursements) of covered losses from the FDIC	960	(2,127)	(8,914)
Balance at end of year	$ 10,777	$ 14,722	$ 26,678