FAIR VALUE OF FINANCIAL INSTRUMENTS, Balance Sheet Groupings (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Carrying (Reported) Amount, Fair Value Disclosure [Member]
ASSETS
Cash and due from banks	$ 74,073	$ 78,187
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	250
Investment securities held to maturity (TRUPS)	5,349	5,367
Loans, net (excluding impaired loans carried at fair value)	4,473,133	4,096,347
Accrued Interest Receivable	12,547	12,664
FHLBNY capital stock	54,348	58,407
Liabilities [Abstract]
Savings, money market and checking accounts	2,141,790	1,733,474
Certificates of Deposit (CDs)	887,707	926,318
Escrow and other deposits	131,132	91,921
FHLBNY advances	1,069,725	1,173,725
Trust preferred securities payable	70,680	70,680
Accrued Interest Payable	2,389	2,729
Estimate of Fair Value, Fair Value Disclosure [Member]
ASSETS
Cash and due from banks	74,073	78,187
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	250
Investment securities held to maturity (TRUPS)	7,478	6,315
Loans, net (excluding impaired loans carried at fair value)	4,521,373	4,188,137
Accrued Interest Receivable	12,547	12,664
FHLBNY capital stock	0	0
Liabilities [Abstract]
Savings, money market and checking accounts	2,141,790	1,733,474
Certificates of Deposit (CDs)	895,391	934,324
Escrow and other deposits	131,132	91,921
FHLBNY advances	1,079,707	1,186,069
Trust preferred securities payable	70,680	70,680
Accrued Interest Payable	2,389	2,729
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
ASSETS
Cash and due from banks	74,073	78,187
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	250
Investment securities held to maturity (TRUPS)	0	0
Loans, net (excluding impaired loans carried at fair value)	0	0
Accrued Interest Receivable	0	2
FHLBNY capital stock	0	0
Liabilities [Abstract]
Savings, money market and checking accounts	2,141,790	1,733,474
Certificates of Deposit (CDs)	0	0
Escrow and other deposits	131,132	91,921
FHLBNY advances	0	0
Trust preferred securities payable	0	0
Accrued Interest Payable	0	0
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
ASSETS
Cash and due from banks	0	0
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	0
Investment securities held to maturity (TRUPS)	7,478	0
Loans, net (excluding impaired loans carried at fair value)	0	0
Accrued Interest Receivable	28	104
FHLBNY capital stock	0	0
Liabilities [Abstract]
Savings, money market and checking accounts	0	0
Certificates of Deposit (CDs)	895,391	934,324
Escrow and other deposits	0	0
FHLBNY advances	1,079,707	1,186,069
Trust preferred securities payable	70,680	70,680
Accrued Interest Payable	2,389	2,729
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
ASSETS
Cash and due from banks	0	0
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	0
Investment securities held to maturity (TRUPS)	0	6,315
Loans, net (excluding impaired loans carried at fair value)	4,521,373	4,188,137
Accrued Interest Receivable	12,519	12,558
FHLBNY capital stock	0	0
Liabilities [Abstract]
Savings, money market and checking accounts	0	0
Certificates of Deposit (CDs)	0	0
Escrow and other deposits	0	0
FHLBNY advances	0	0
Trust preferred securities payable	0	0
Accrued Interest Payable	$ 0	$ 0