LOANS, Impaired Real Estate Loans (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Unpaid Principal Balance [Abstract]
With no related allowance recorded		$ 4,380		$ 4,380		$ 213
With related allowance recorded		10,176		10,176		10,082
Total		14,556		14,556		10,295
Recorded Investment [Abstract]
With no related allowance recorded	[1]	4,380		4,380		213
With related allowance recorded	[1]	10,176		10,176		10,082
Total	[1]	14,556		14,556		10,295
Related Allowance [Abstract]
Related allowance		10,129		10,129		10,082
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	5,832	$ 7,408	3,958	$ 6,835
Total	[1]	15,961	7,524	14,071	7,016
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	0	100	7	211
Total	[2]	0	100	7	217
Real Estate Loans [Member]
Related Allowance [Abstract]
Related allowance		0		0		0
Real Estate Loans [Member] | One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member]
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	2,948	11	1,965	12
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	0	0	0	0
Real Estate Loans [Member] | Multifamily Residential and Residential Mixed-Use [Member]
Unpaid Principal Balance [Abstract]
With no related allowance recorded		1,377		1,377		153
Recorded Investment [Abstract]
With no related allowance recorded	[1]	1,377		1,377		153
Related Allowance [Abstract]
Related allowance		0		0		0
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	1,355	608	954	589
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	0	9	6	22
Real Estate Loans [Member] | Commercial Real Estate and Commercial Mixed-Use [Member]
Unpaid Principal Balance [Abstract]
With no related allowance recorded		3,003		3,003		60
Recorded Investment [Abstract]
With no related allowance recorded	[1]	3,003		3,003		60
Related Allowance [Abstract]
Related allowance		0		0		0
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	1,529	6,789	1,039	6,234
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	0	91	1	189
Commercial and Industrial ("C&I") Loans [Member]
Unpaid Principal Balance [Abstract]
With related allowance recorded		10,176		10,176		10,082
Recorded Investment [Abstract]
With related allowance recorded	[1]	10,176		10,176		10,082
Related Allowance [Abstract]
Related allowance		10,129		10,129		$ 10,082
Average Recorded Investment [Abstract]
With related allowance recorded	[1]	10,129	116	10,113	181
Interest Income Recognized [Abstract]
With related allowance recorded	[2]	$ 0	$ 0	$ 0	$ 6

[1] The recorded investment excludes accrued interest receivable and net deferred costs due to immateriality.

[2] Cash basis interest and interest income recognized on accrual basis approximate each other.