FAIR VALUE OF FINANCIAL INSTRUMENTS - Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Financial assets
Fair Value	$ 65,421	$ 93,745
Level 1
Financial assets
Cash and cash equivalents	720,243	427,367
Debt securities available for sale	0	0
Fair Value	0	0
Common equities and mutual funds	3,324	2,969
Non-marketable equity securities	0	0
Loans held for sale	0	0
Loans and leases receivable	0	0
Federal Reserve Bank and Federal Home Loan Bank stocks	0	0
Accrued interest receivable	16,230	16,628
Financial liabilities
Deposits	5,851,452	4,705,028
Other short- and long-term borrowings	0	0
Accrued interest payable	1,853	1,923
Level 2
Financial assets
Cash and cash equivalents	0	0
Debt securities available for sale	1,917,605	1,268,102
Fair Value	65,421	93,745
Common equities and mutual funds	0	0
Non-marketable equity securities	14,750	12,000
Loans held for sale	87,905	183,577
Loans and leases receivable	0	0
Federal Reserve Bank and Federal Home Loan Bank stocks	28,433	27,138
Accrued interest receivable	0	0
Financial liabilities
Deposits	37,519	275,045
Other short- and long-term borrowings	94,979	100,185
Accrued interest payable	0	0
Level 3
Financial assets
Cash and cash equivalents	0	0
Debt securities available for sale	0	0
Fair Value	0	0
Common equities and mutual funds	0	0
Non-marketable equity securities	0	0
Loans held for sale	0	0
Loans and leases receivable	3,498,673	3,307,037
Federal Reserve Bank and Federal Home Loan Bank stocks	0	0
Accrued interest receivable	0	0
Financial liabilities
Deposits	0	0
Other short- and long-term borrowings	0	0
Accrued interest payable	0	0
Carrying Amount
Financial assets
Cash and cash equivalents	720,243	427,367
Debt securities available for sale	1,917,605	1,268,102
Fair Value	64,247	92,610
Common equities and mutual funds	3,324	2,969
Non-marketable equity securities	19,474	14,784
Loans held for sale	87,905	183,577
Loans and leases receivable	3,495,239	3,314,140
Federal Reserve Bank and Federal Home Loan Bank stocks	28,433	27,138
Accrued interest receivable	16,230	16,628
Financial liabilities
Deposits	5,888,871	4,979,200
Other short- and long-term borrowings	93,634	98,224
Accrued interest payable	1,853	1,923
Estimated Fair Value
Financial assets
Cash and cash equivalents	720,243	427,367
Debt securities available for sale	1,917,605	1,268,102
Fair Value	65,421	93,745
Common equities and mutual funds	3,324	2,969
Non-marketable equity securities	19,474	14,784
Loans held for sale	87,905	183,577
Loans and leases receivable	3,498,673	3,307,037
Federal Reserve Bank and Federal Home Loan Bank stocks	28,433	27,138
Accrued interest receivable	16,230	16,628
Financial liabilities
Deposits	5,888,971	4,980,073
Other short- and long-term borrowings	94,979	100,185
Accrued interest payable	$ 1,853	$ 1,923

The fair value disclosure of accrued interest payable as of the balance sheet date.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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