Derivative Instruments (Narrative) (Details) $ in Thousands	9 Months Ended	12 Months Ended
Jun. 30, 2020 USD ($)	Sep. 30, 2019 USD ($) contracts
Derivative [Line Items]
Estimated amount to be reclassed in the next 12 months as an increase to expense	$ 46,282
Not Designated as Hedging Instrument \| Forward Commitments For Sale Of Mortgage Loans
Derivative [Line Items]
Derivative, number of instruments held \| contracts		0
Not Designated as Hedging Instrument \| Interest Rate Lock Commitments
Derivative [Line Items]
Fair Value	$ 694	$ 44
Cash Flow Hedge \| Designated as Hedging Instrument \| Interest Rate Swap
Derivative [Line Items]
Derivative, weighted average terms	3 years 3 months 18 days	3 years 8 months 12 days
Derivative, weighted average fixed-rate interest payments	1.80%	1.92%
Fair Value	$ 0	$ 0

Derivative, Weighted Average Fixed Rate Paid On Swap

No definition available.

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- Definition

Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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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 number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

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- Definition

The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, net of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet.

+ References

No definition available.

+ Details

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