LOANS, Impaired Real Estate Loans (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Unpaid Principal Balance [Abstract]
With no related allowance recorded		$ 7,283		$ 213
With related allowance recorded		10,082		10,082
Total		17,365		10,295
Recorded Investment [Abstract]
With no related allowance recorded	[1]	7,283		213
With related allowance recorded	[1]	10,082		10,082
Total	[1]	17,365		10,295
Related Allowance [Abstract]
Related allowance		10,082		10,082
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	3,749	$ 7,252
Total	[1]	13,831	7,523
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	7	112
Total	[2]	7	118
Real Estate Loans [Member]
Related Allowance [Abstract]
Related allowance		0		0
Real Estate Loans [Member] | One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member]
Unpaid Principal Balance [Abstract]
With no related allowance recorded		5,895		0
Recorded Investment [Abstract]
With no related allowance recorded	[1]	5,895		0
Related Allowance [Abstract]
Related allowance		0		0
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	2,948	13
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	0	0
Real Estate Loans [Member] | Multifamily Residential and Residential Mixed-Use [Member]
Unpaid Principal Balance [Abstract]
With no related allowance recorded		1,332		153
Recorded Investment [Abstract]
With no related allowance recorded	[1]	1,332		153
Related Allowance [Abstract]
Related allowance		0		0
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	743	544
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	6	13
Real Estate Loans [Member] | Commercial Real Estate and Commercial Mixed-Use [Member]
Unpaid Principal Balance [Abstract]
With no related allowance recorded		56		60
Recorded Investment [Abstract]
With no related allowance recorded	[1]	56		60
Related Allowance [Abstract]
Related allowance		0		0
Average Recorded Investment [Abstract]
With no related allowance recorded	[1]	58	6,695
Interest Income Recognized [Abstract]
With no related allowance recorded	[2]	1	99
Commercial and Industrial ("C&I") Loans [Member]
Unpaid Principal Balance [Abstract]
With related allowance recorded		10,082		10,082
Recorded Investment [Abstract]
With related allowance recorded	[1]	10,082		10,082
Related Allowance [Abstract]
Related allowance		10,082		$ 10,082
Average Recorded Investment [Abstract]
With related allowance recorded	[1]	10,082	271
Interest Income Recognized [Abstract]
With related allowance recorded	[2]	$ 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.