LOANS (Schedule of Loans Outstanding, by Classification) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Total loans	$ 2,913,242	$ 2,250,267
Loans and Finance Receivables [Member]
Total loans (in percent)	100.00%	100.00%
Unallocated Financing Receivables [Member]
Total loans	$ 500	$ 1,838
Unallocated Financing Receivables [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	0.02%	0.08%
Residential Mortgage [Member] | Residential Portfolio Segment [Member]
Total loans	$ 470,869	$ 466,760
Residential Mortgage [Member] | Residential Portfolio Segment [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	16.16%	20.74%
Multifamily Property [Member] | Residential Portfolio Segment [Member]
Total loans	$ 1,416,775	$ 1,080,256
Multifamily Property [Member] | Residential Portfolio Segment [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	48.63%	48.00%
Commercial Mortgage [Member] | Commercial Real Estate Portfolio Segment [Member]
Total loans	$ 413,118	$ 308,491
Commercial Mortgage [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	14.18%	13.71%
Commercial Loans [Member] | Commercial Portfolio Segment [Member]
Total loans	$ 512,886	$ 308,743
Commercial Loans [Member] | Commercial Portfolio Segment [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	17.60%	13.72%
Construction Loans [Member]
Total loans	$ 1,401	$ 5,998
Construction Loans [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	0.05%	0.27%
Home Equity Lines of Credit [Member] | Residential Portfolio Segment [Member]
Total loans	$ 52,649	$ 50,141
Home Equity Lines of Credit [Member] | Residential Portfolio Segment [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	1.81%	2.23%
Consumer Loans, Including Home Equity Loans [Member] | Consumer and Other [Member]
Total loans	$ 45,044	$ 28,040
Consumer Loans, Including Home Equity Loans [Member] | Consumer and Other [Member] | Loans and Finance Receivables [Member]
Total loans (in percent)	1.55%	1.25%