Loans and Allowance for Loan Losses, Allowance for Loan Losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012	Dec. 31, 2012
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	$ 47,927		$ 48,717
Loans charged off [Abstract]
Total loan chargeoffs	2,411		3,432
Recoveries of loans previously charged off [Abstract]
Total recoveries	142		150
Net loans charged off	2,269		3,282
Provision for loan losses	2,000		3,100
Balance at end of period	47,658		48,535
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0
Collectively evaluated for impairment	47,658			47,927
Total ending allowance balance	47,658		48,535
Loans [Abstract]
Individually evaluated for impairment	26,591			26,073
Collectively evaluated for impairment	2,677,176			2,658,660
Total ending loans balance	2,703,767			2,684,733
Commercial [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	3,771		3,737
Loans charged off [Abstract]
Total loan chargeoffs	350		492
Recoveries of loans previously charged off [Abstract]
Total recoveries	3		11
Net loans charged off	347		481
Provision for loan losses	540		346
Balance at end of period	3,964		3,602
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0
Collectively evaluated for impairment	3,964			3,771
Total ending allowance balance	3,964		3,602
Loans [Abstract]
Individually evaluated for impairment	8,573			9,333
Collectively evaluated for impairment	204,064			210,244
Total ending loans balance	212,637			219,577
Real Estate Mortgage - 1 to 4 Family [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	44,069		44,882
Loans charged off [Abstract]
Total loan chargeoffs	2,042		2,932
Recoveries of loans previously charged off [Abstract]
Total recoveries	135		123
Net loans charged off	1,907		2,809
Provision for loan losses	1,433		2,778
Balance at end of period	43,595		44,851
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0
Collectively evaluated for impairment	43,595			44,069
Total ending allowance balance	43,595		44,851
Loans [Abstract]
Individually evaluated for impairment	18,018			16,740
Collectively evaluated for impairment	2,468,281			2,443,837
Total ending loans balance	2,486,299			2,460,577
Installment [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	87		98
Loans charged off [Abstract]
Total loan chargeoffs	19		8
Recoveries of loans previously charged off [Abstract]
Total recoveries	4		16
Net loans charged off	15		(8)
Provision for loan losses	27		(24)
Balance at end of period	99		82
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0
Collectively evaluated for impairment	99			87
Total ending allowance balance	99		82
Loans [Abstract]
Individually evaluated for impairment	0			0
Collectively evaluated for impairment	4,831			4,579
Total ending loans balance	4,831			4,579
New York and Other States [Member]
Loans charged off [Abstract]
Total loan chargeoffs	1,906		1,589
Recoveries of loans previously charged off [Abstract]
Total recoveries	80		140
Loans [Abstract]
Total ending loans balance	2,352,992	[1]		2,355,966	[1]
New York and Other States [Member] | Commercial [Member]
Loans charged off [Abstract]
Total loan chargeoffs	250		324
Recoveries of loans previously charged off [Abstract]
Total recoveries	2		3
Loans [Abstract]
Total ending loans balance	193,157			200,630
New York and Other States [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loans charged off [Abstract]
Total loan chargeoffs	1,637		1,257
Recoveries of loans previously charged off [Abstract]
Total recoveries	74		121
New York and Other States [Member] | Installment [Member]
Loans charged off [Abstract]
Total loan chargeoffs	19		8
Recoveries of loans previously charged off [Abstract]
Total recoveries	4		16
Loans [Abstract]
Total ending loans balance	4,354	[1]		4,183	[1]
Florida [Member]
Loans charged off [Abstract]
Total loan chargeoffs	505		1,843
Recoveries of loans previously charged off [Abstract]
Total recoveries	62		10
Loans [Abstract]
Total ending loans balance	350,775			328,767
Florida [Member] | Commercial [Member]
Loans charged off [Abstract]
Total loan chargeoffs	100		168
Recoveries of loans previously charged off [Abstract]
Total recoveries	1		8
Loans [Abstract]
Total ending loans balance	19,480			18,947
Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loans charged off [Abstract]
Total loan chargeoffs	405		1,675
Recoveries of loans previously charged off [Abstract]
Total recoveries	61		2
Florida [Member] | Installment [Member]
Loans charged off [Abstract]
Total loan chargeoffs	0		0
Recoveries of loans previously charged off [Abstract]
Total recoveries	0		0
Loans [Abstract]
Total ending loans balance	$ 477			$ 396

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