Loans and Allowance for Loan Losses (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		$ 3,282,005		$ 3,158,332
Less: Allowance for loan losses		45,149	$ 45,571	46,327	$ 46,512	$ 46,935	$ 47,714
Net loans		3,236,856		3,112,005
Real Estate Construction Loans [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		28,300		38,500
Residential Borrowers [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		12,000		17,600
Commercial Borrowers Residential Purpose [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		16,300		20,900
Commercial [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		208,794		223,382
Less: Allowance for loan losses		4,056	4,022	4,071	4,045	4,073	4,019
Commercial [Member] | Commercial Real Estate [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		185,919		194,124
Commercial [Member] | Other [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		22,875		29,258
Real Estate Mortgage - 1 to 4 Family [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		3,064,281		2,927,356
Less: Allowance for loan losses		40,647	41,087	42,088	42,340	42,752	43,597
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		2,648,221		2,517,567
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		59,723		57,655
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		356,337		352,134
Installment [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		8,930		7,594
Less: Allowance for loan losses		446	$ 462	168	$ 127	$ 110	$ 98
New York and Other States [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net	[1]	2,654,151		2,612,379
New York and Other States [Member] | Commercial [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		192,961		203,988
New York and Other States [Member] | Commercial [Member] | Commercial Real Estate [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net	[1]	170,185		174,788
New York and Other States [Member] | Commercial [Member] | Other [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net	[1]	22,776		29,200
New York and Other States [Member] | Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net	[1]	2,093,433		2,041,140
New York and Other States [Member] | Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net	[1]	51,852		51,713
New York and Other States [Member] | Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net	[1]	308,239		308,764
New York and Other States [Member] | Installment [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net	[1]	7,666		6,774
Florida [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		627,854		545,953
Florida [Member] | Commercial [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		15,833		19,394
Florida [Member] | Commercial [Member] | Commercial Real Estate [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		15,734		19,336
Florida [Member] | Commercial [Member] | Other [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		99		58
Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		554,788		476,427
Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		7,871		5,942
Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		48,098		43,370
Florida [Member] | Installment [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total loans, net		$ 1,264		$ 820

[1] Includes New York, New Jersey, Vermont and Massachusetts.