FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS - Additional Information (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Advances from Federal Home Loan Banks	$ 0	$ 105,000,000.0
FHLB interest rate		3.20%
Prepaid FHLB advances	105,000,000.0
FHLB prepayment penalty	4,784,000
Short-term or overnight borrowings with FHLB	15,000,000	$ 128,100,000
Rate of overnight borrowings with FHLB		1.81%
FHLB advance	$ 15,000,000.0	$ 15,000,000.0
FHLB advance rate	0.34%	1.79%
Cash flow hedge, term	3 years
Unused commitments from FHLB	$ 1,800,000,000
Unused short-term or overnight borrowings from correspondent banks	22,000,000.0
Unused short-term or overnight borrowings from FRB	987,700,000,000
Borrowings from the federal reserve’s PPPLF	$ 177,086,000
Paycheck protection program liquidity facility interest rate	0.35%
Paycheck protection program liquidity facility term	2 years
Federal Reserve Bank of New York [Member]
Debt Instrument [Line Items]
Short-term or overnight borrowings with FHLB		$ 113,100,000
Residential Mortgage [Member] \| Fixed Rate Advances [Member]
Debt Instrument [Line Items]
Mortgages pledged as collateral for advances		347,500,000
Multifamily Mortgage [Member] \| Fixed Rate Advances [Member]
Debt Instrument [Line Items]
Mortgages pledged as collateral for advances		773,100,000
Securities [Member] \| Fixed Rate Advances [Member]
Debt Instrument [Line Items]
Mortgages pledged as collateral for advances		$ 154,300,000

Federal Home Loan Bank Advances Activity cash flow hedge, term.

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Federal home loan bank prepayment penalty.

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Amount of unused borrowing capacity under the short-term or overnight borrowings financing arrangement with correspondent banks.

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Amount of unused borrowing capacity under the short-term or overnight borrowings financing arrangement with Federal Reserve Bank.

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Paycheck protection program liquidity facility.

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Prepaid federal home loan bank advances.

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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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The calculated weighted average interest rate for Federal Home Loan Bank advances outstanding as of the Balance Sheet date.

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The calculated weighted average interest rate for Federal Home Loan Bank advances for the period ended as of the Balance Sheet date.

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The maximum balance outstanding at any month end during the period as of the Balance Sheet date.

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Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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