Loans and Allowance for Loan Losses, Past Due (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015		Dec. 31, 2014
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	$ 6,494		$ 5,737
60-89 Days Past Due	3,601		4,620
90+ Days Past Due	20,835		22,343
Total 30+ days Past Due	30,930		32,700
Current	3,162,695		3,125,632
Total loans	3,193,625		3,158,332
Loans that are 90 days past due and still accruing interest	0		0
Number of days past due	90 days		90 days
Commercial [Member]
Aging of the recorded investment in past due loans [Abstract]
Total loans	212,145		223,382
Commercial Real Estate [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	886		618
60-89 Days Past Due	527		52
90+ Days Past Due	1,231		2,627
Total 30+ days Past Due	2,644		3,297
Current	184,502		190,827
Total loans	187,146		194,124
Other [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	0		0
60-89 Days Past Due	0		0
90+ Days Past Due	0		0
Total 30+ days Past Due	0		0
Current	24,999		29,258
Total loans	24,999		29,258
Real Estate Mortgage - 1 to 4 Family [Member]
Aging of the recorded investment in past due loans [Abstract]
Total loans	2,973,477		2,927,356
First Mortgages [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	4,838		4,141
60-89 Days Past Due	2,342		4,157
90+ Days Past Due	18,065		18,007
Total 30+ days Past Due	25,245		26,305
Current	2,536,530		2,491,262
Total loans	2,561,775		2,517,567
Home Equity Loans [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	152		141
60-89 Days Past Due	0		59
90+ Days Past Due	272		337
Total 30+ days Past Due	424		537
Current	58,726		57,118
Total loans	59,150		57,655
Home Equity Lines of Credit [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	585		741
60-89 Days Past Due	641		342
90+ Days Past Due	1,218		1,314
Total 30+ days Past Due	2,444		2,397
Current	350,108		349,737
Total loans	352,552		352,134
Installment [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	33		96
60-89 Days Past Due	91		10
90+ Days Past Due	49		58
Total 30+ days Past Due	173		164
Current	7,830		7,430
Total loans	8,003		7,594
New York and Other States [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	5,713		4,746
60-89 Days Past Due	3,519		4,337
90+ Days Past Due	19,886		21,002
Total 30+ days Past Due	29,118		30,085
Current	2,593,432		2,582,294
Total loans	2,622,550	[1]	2,612,379	[1]
New York and Other States [Member] | Commercial [Member]
Aging of the recorded investment in past due loans [Abstract]
Total loans	196,128		203,988
New York and Other States [Member] | Commercial Real Estate [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	886		618
60-89 Days Past Due	527		52
90+ Days Past Due	1,231		2,627
Total 30+ days Past Due	2,644		3,297
Current	168,534		171,491
Total loans	171,178	[1]	174,788	[1]
New York and Other States [Member] | Other [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	0		0
60-89 Days Past Due	0		0
90+ Days Past Due	0		0
Total 30+ days Past Due	0		0
Current	24,950		29,200
Total loans	24,950	[1]	29,200	[1]
New York and Other States [Member] | First Mortgages [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	4,094		3,340
60-89 Days Past Due	2,260		3,874
90+ Days Past Due	17,216		16,782
Total 30+ days Past Due	23,570		23,996
Current	2,037,572		2,017,144
Total loans	2,061,142	[1]	2,041,140	[1]
New York and Other States [Member] | Home Equity Loans [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	152		141
60-89 Days Past Due	0		59
90+ Days Past Due	272		337
Total 30+ days Past Due	424		537
Current	51,429		51,176
Total loans	51,853	[1]	51,713	[1]
New York and Other States [Member] | Home Equity Lines of Credit [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	550		568
60-89 Days Past Due	641		342
90+ Days Past Due	1,118		1,198
Total 30+ days Past Due	2,309		2,108
Current	303,887		306,656
Total loans	306,196	[1]	308,764	[1]
New York and Other States [Member] | Installment [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	31		79
60-89 Days Past Due	91		10
90+ Days Past Due	49		58
Total 30+ days Past Due	171		147
Current	7,060		6,627
Total loans	7,231	[1]	6,774	[1]
Florida [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	781		991
60-89 Days Past Due	82		283
90+ Days Past Due	949		1,341
Total 30+ days Past Due	1,812		2,615
Current	569,263		543,338
Total loans	571,075		545,953
Florida [Member] | Commercial [Member]
Aging of the recorded investment in past due loans [Abstract]
Total loans	16,017		19,394
Florida [Member] | Commercial Real Estate [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	0		0
60-89 Days Past Due	0		0
90+ Days Past Due	0		0
Total 30+ days Past Due	0		0
Current	15,968		19,336
Total loans	15,968		19,336
Florida [Member] | Other [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	0		0
60-89 Days Past Due	0		0
90+ Days Past Due	0		0
Total 30+ days Past Due	0		0
Current	49		58
Total loans	49		58
Florida [Member] | First Mortgages [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	744		801
60-89 Days Past Due	82		283
90+ Days Past Due	849		1,225
Total 30+ days Past Due	1,675		2,309
Current	498,958		474,118
Total loans	500,633		476,427
Florida [Member] | Home Equity Loans [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	0		0
60-89 Days Past Due	0		0
90+ Days Past Due	0		0
Total 30+ days Past Due	0		0
Current	7,297		5,942
Total loans	7,297		5,942
Florida [Member] | Home Equity Lines of Credit [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	35		173
60-89 Days Past Due	0		0
90+ Days Past Due	100		116
Total 30+ days Past Due	135		289
Current	46,221		43,081
Total loans	46,356		43,370
Florida [Member] | Installment [Member]
Aging of the recorded investment in past due loans [Abstract]
30-59 Days Past Due	2		17
60-89 Days Past Due	0		0
90+ Days Past Due	0		0
Total 30+ days Past Due	2		17
Current	770		803
Total loans	$ 772		$ 820

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