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Investment Securities (Narrative) (Details)	3 Months Ended
	Dec. 31, 2019 USD ($) security	Dec. 31, 2018 USD ($)
Schedule of Investments [Line Items]
Available-for-sale Securities Pledged as Collateral	$ 147,283,000	$ 214,239,000
Debt Securities, Available-for-sale, Restriction Type [Extensible List]	us-gaap:CollateralPledgedMember	us-gaap:CollateralPledgedMember
FHLB [Member]
Schedule of Investments [Line Items]
Letter of credit outstanding, amount	$ 169,051,000	$ 36,850,000
ASU 2019-04 [Member]
Schedule of Investments [Line Items]
Debt securities, held-to-maturity with an aggregate amortized cost	67,096,000
Gain (loss) on sale of debt securities	$ 1,779,000
Number of held-to-maturity debt securities | security	113
Number of held-to-maturity debt securities sold | security	113

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- Definition

Number of held to maturity debt securities.

+ References

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- Definition

Number of held-to-maturity debt securities sold.

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- Definition

Amount of restricted investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

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- Definition

Indicates type of restriction on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(2)
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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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Amount, before other-than-temporary impairment (OTTI) accretion, of investment in debt securities measured at amortized cost (held-to-maturity).

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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