FAIR VALUE OF FINANCIAL INSTRUMENTS, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Securities available-for-sale [Abstract]
Loans held for sale	$ 1,430	$ 500
Recurring [Member]
Marketable equity securities (Registered Mutual Funds) [Abstract]
Domestic equity mutual funds	1,264	1,657
International equity mutual funds	331	420
Fixed income mutual funds	3,803	3,817
Securities available-for-sale [Abstract]
Agency Notes	10,036	19,935
Corporate Securities	47,032	28,596
Pass-through MBS issued by GSEs	238,634	247,483
Agency CMOs	262,123	254,981
Derivative - cash flow hedges		1,081
Derivative - freestanding derivatives	12,379	1,362
Financial Liabilities [Abstract]
Derivative - cash flow hedges	27,014	7,718
Derivative - freestanding derivatives	12,379	1,362
Recurring [Member] | Level 1 Inputs [Member]
Marketable equity securities (Registered Mutual Funds) [Abstract]
Domestic equity mutual funds	1,264	1,657
International equity mutual funds	331	420
Fixed income mutual funds	3,803	3,817
Securities available-for-sale [Abstract]
Agency Notes	0	0
Corporate Securities	0	0
Pass-through MBS issued by GSEs	0	0
Agency CMOs	0	0
Derivative - cash flow hedges		0
Derivative - freestanding derivatives	0	0
Financial Liabilities [Abstract]
Derivative - cash flow hedges	0	0
Derivative - freestanding derivatives	0	0
Recurring [Member] | Level 2 Inputs [Member]
Marketable equity securities (Registered Mutual Funds) [Abstract]
Domestic equity mutual funds	0	0
International equity mutual funds	0	0
Fixed income mutual funds	0	0
Securities available-for-sale [Abstract]
Agency Notes	10,036	19,935
Corporate Securities	47,032	28,596
Pass-through MBS issued by GSEs	238,634	247,483
Agency CMOs	262,123	254,981
Derivative - cash flow hedges		1,081
Derivative - freestanding derivatives	12,379	1,362
Financial Liabilities [Abstract]
Derivative - cash flow hedges	27,014	7,718
Derivative - freestanding derivatives	12,379	1,362
Recurring [Member] | Level 3 Inputs [Member]
Marketable equity securities (Registered Mutual Funds) [Abstract]
Domestic equity mutual funds	0	0
International equity mutual funds	0	0
Fixed income mutual funds	0	0
Securities available-for-sale [Abstract]
Agency Notes	0	0
Corporate Securities	0	0
Pass-through MBS issued by GSEs	0	0
Agency CMOs	0	0
Derivative - cash flow hedges		0
Derivative - freestanding derivatives	0	0
Financial Liabilities [Abstract]
Derivative - cash flow hedges	0	0
Derivative - freestanding derivatives	0	0
Nonrecurring [Member]
Impaired Loans [Abstract]
Fair value	$ 0	$ 0