OFFSETTING ASSETS AND LIABILITIES - Offsetting of Liabilties (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Offsetting Liabilities [Line Items]
Gross Amount Of Recognized Liabilties	$ 210,013,000	$ 201,334,000
Gross Amount Of Liabilties Offset In The Balance Sheet	0	0
Net Amount Of Liabilities Presented In The Balance Sheet	210,013,000	201,334,000
Gross Amount Of Financial Instruments Posted Not Offset in Balance Sheet	(206,176,000)	(200,166,000)
Gross Amounts Of Cash Posted Not Offset In Balance Sheet	(3,778,000)	(773,000)
Net Amount Of Liabilities	59,000	395,000
Repurchase Agreements [Member]
Offsetting Liabilities [Line Items]
Gross Amount Of Recognized Liabilties	209,954,000	200,396,000
Gross Amount Of Liabilties Offset In The Balance Sheet	0	0
Net Amount Of Liabilities Presented In The Balance Sheet	209,954,000	200,396,000
Gross Amount Of Financial Instruments Posted Not Offset in Balance Sheet	(206,176,000)	(200,166,000)
Gross Amounts Of Cash Posted Not Offset In Balance Sheet	(3,778,000)	(230,000)
Net Amount Of Liabilities	0	0
TBA Contracts [Member]
Offsetting Liabilities [Line Items]
Gross Amount Of Recognized Liabilties	59,000	938,000
Gross Amount Of Liabilties Offset In The Balance Sheet	0	0
Net Amount Of Liabilities Presented In The Balance Sheet	59,000	938,000
Gross Amount Of Financial Instruments Posted Not Offset in Balance Sheet	0	0
Gross Amounts Of Cash Posted Not Offset In Balance Sheet	0	(543,000)
Net Amount Of Liabilities	$ 59,000	$ 395,000