ALLOWANCE FOR LOAN LOSSES, Impaired Real Estate Loans (Details) - Real Estate Loans [Member] - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Unpaid Principal Balance [Abstract]
With no allowance reserve		$ 11,305		$ 11,305		$ 11,913
Recorded Investment [Abstract]
With no allowance reserve	[1]	11,305		11,305		11,913
Related Allowance [Abstract]
Related allowance		0		0		0
Average Recorded Investment [Abstract]
With no allowance reserve		11,529	$ 10,621	11,658	$ 10,268
Interest Income Recognized [Abstract]
With no related allowance recorded		99	110	231	235
One- to Four-Family Residential, Including Condominium and Cooperative Apartment [Member]
Unpaid Principal Balance [Abstract]
With no allowance reserve		399		399		407
Recorded Investment [Abstract]
With no allowance reserve	[1]	399		399		407
Related Allowance [Abstract]
Related allowance		0		0		0
Average Recorded Investment [Abstract]
With no allowance reserve		400	399	402	465
Interest Income Recognized [Abstract]
With no related allowance recorded		7	7	14	41
Multifamily Residential And Residential Mixed Use Allowance [Member]
Unpaid Principal Balance [Abstract]
With no allowance reserve		3,257		3,257		3,333
Recorded Investment [Abstract]
With no allowance reserve	[1]	3,257		3,257		3,333
Related Allowance [Abstract]
Related allowance		0		0		0
Average Recorded Investment [Abstract]
With no allowance reserve		3,264	2,451	3,287	1,962
Interest Income Recognized [Abstract]
With no related allowance recorded		16	25	62	38
Commercial Mixed Use Real Estate [Member]
Unpaid Principal Balance [Abstract]
With no allowance reserve		4,319		4,319		4,810
Recorded Investment [Abstract]
With no allowance reserve	[1]	4,319		4,319		4,810
Related Allowance [Abstract]
Related allowance		0		0		0
Average Recorded Investment [Abstract]
With no allowance reserve		4,527	4,367	4,622	4,360
Interest Income Recognized [Abstract]
With no related allowance recorded		43	44	88	88
Commercial Real Estate [Member]
Unpaid Principal Balance [Abstract]
With no allowance reserve		3,330		3,330		3,363
Recorded Investment [Abstract]
With no allowance reserve	[1]	3,330		3,330		3,363
Related Allowance [Abstract]
Related allowance		0		0		$ 0
Average Recorded Investment [Abstract]
With no allowance reserve		3,338	3,404	3,347	3,481
Interest Income Recognized [Abstract]
With no related allowance recorded		$ 33	$ 34	$ 67	$ 68

[1] The recorded investment excludes accrued interest receivable and loan origination fees, net, due to immateriality.