Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Deferred tax assets:
Allowance for loan and lease losses	$ 27,005	$ 23,412
Compensation	6,306	3,989
Net operating loss carryforward	17	68
Securities available for sale	0	0
Other real estate owned	1,231	3,223
Core deposit intangible and other fair value adjustments	7,303	11,068
Excess tax basis of FDIC indemnification asset and clawback liability	2,514	611
Excess tax basis of loans acquired over carrying value	12,896	5,004
Other	4,580	2,232
Total deferred tax assets	61,852	49,607
Deferred tax liabilities:
Goodwill and other intangibles	(11,555)	(10,504)
Securities available for sale	(3,398)	(1,436)
Premises and equipment	(7,758)	(3,908)
Excess carrying value of FDIC indemnification asset and clawback liability	0	0
Other	(795)	(1,289)
Total deferred tax liabilities	(23,506)	(17,137)
Net deferred tax assets	$ 38,346	$ 32,470