Accounting for Certain Loans Acquired with Deteriorated Credit Quality - Schedule of Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	$ 193,864	$ 238,106
Recorded Investment	92,595	129,531
Carrying Value	91,602	127,852
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	110,797	129,615
Recorded Investment	30,099	44,448
Carrying Value	29,417	43,676
Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	10,463	19,174
Recorded Investment	7,174	15,254
Carrying Value	7,059	15,254
Commercial non-real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	9,825	11,588
Recorded Investment	1,920	3,196
Carrying Value	1,920	3,196
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	61,981	76,696
Recorded Investment	52,736	65,737
Carrying Value	52,540	64,830
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	798	1,033
Recorded Investment	666	896
Carrying Value	$ 666	$ 896

Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Recorded Investment

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

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- Definition

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

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