OFFSETTING ASSETS AND LIABILITIES - Offsetting of Assets (Details) $ in Thousands	Sep. 30, 2020 USD ($)
Offsetting Assets [Line Items]
Gross Amount Of Recognized Assets	$ 14,239
Gross Amount Of Assets Offset In The Balance Sheet	0
Net Amount Of Assets Presented In The Balance Sheet	14,239
Gross Amounts Of Financial Instruments Received Not Offset In Balance Sheet	0
Gross Amounts Of Cash Collateral Received Not Offset In Balance Sheet	(1,037)
Net Amount Of Assets	13,202
Payer Swaption [Member]
Offsetting Assets [Line Items]
Gross Amount Of Recognized Assets	14,048
Gross Amount Of Assets Offset In The Balance Sheet	0
Net Amount Of Assets Presented In The Balance Sheet	14,048
Gross Amounts Of Financial Instruments Received Not Offset In Balance Sheet	0
Gross Amounts Of Cash Collateral Received Not Offset In Balance Sheet	(1,037)
Net Amount Of Assets	13,011
TBA Contracts [Member]
Offsetting Assets [Line Items]
Gross Amount Of Recognized Assets	191
Gross Amount Of Assets Offset In The Balance Sheet	0
Net Amount Of Assets Presented In The Balance Sheet	191
Gross Amounts Of Financial Instruments Received Not Offset In Balance Sheet	0
Gross Amounts Of Cash Collateral Received Not Offset In Balance Sheet	0
Net Amount Of Assets	$ 191