Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Premises and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 416,920	$ 390,291
Less accumulated depreciation and amortization	(148,925)	(126,597)
Premises and equipment, net	267,995	263,694
Future minimum payments due, 2019	5,582
Future minimum payments due, 2020	5,316
Future minimum payments due, 2021	4,758
Future minimum payments due, 2022	4,172
Future minimum payments due, 2023	3,689
Future minimum payments due, thereafter	13,778
Rental expense	6,477	5,500	$ 5,346
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	110,251	102,381
Buildings
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	156,803	149,805
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	22,887	18,587
Furniture, software and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 126,979	$ 119,518
Minimum \| Buildings
Property, Plant and Equipment [Line Items]
Estimated Useful Life	25 years
Minimum \| Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Minimum \| Furniture, software and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	2 years
Maximum \| Buildings
Property, Plant and Equipment [Line Items]
Estimated Useful Life	40 years
Maximum \| Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated Useful Life	15 years
Maximum \| Furniture, software and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	10 years