Loans and Allowance for Loan Losses, Allowance for Loan Losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011	Dec. 31, 2011
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	$ 48,018		$ 45,561	$ 48,717		$ 41,911
Loans charged off [Abstract]
Total loan chargeoffs	3,732		3,033	10,819		9,184
Recoveries of loans previously charged off [Abstract]
Total recoveries	178		154	466		505
Net loans charged off	3,554		2,879	10,353		8,679
Provision for loan losses	2,900		5,100	9,000		14,550
Balance at end of period	47,364		47,782	47,364		47,782
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0			0
Collectively evaluated for impairment	47,364			47,364			48,717
Total ending allowance balance	47,364		47,782	47,364		47,782
Loans [Abstract]
Individually evaluated for impairment	24,646			24,646			13,711
Collectively evaluated for impairment	2,581,295			2,581,295			2,507,592
Total ending loans balance	2,605,941			2,605,941			2,521,303
Commercial [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	3,792		4,164	4,140		4,227
Loans charged off [Abstract]
Total loan chargeoffs	770		1	2,265		670
Recoveries of loans previously charged off [Abstract]
Total recoveries	25		4	38		59
Net loans charged off	745		(3)	2,227		611
Provision for loan losses	813		(116)	1,947		435
Balance at end of period	3,860		4,051	3,860		4,051
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0			0
Collectively evaluated for impairment	3,860			3,860			4,140
Total ending allowance balance	3,860		4,051	3,860		4,051
Loans [Abstract]
Individually evaluated for impairment	8,578			8,578			9,981
Collectively evaluated for impairment	208,853			208,853			238,182
Total ending loans balance	217,431			217,431			248,163
Real Estate Mortgage - 1 to 4 Family [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	44,147		41,244	44,479		37,448
Loans charged off [Abstract]
Total loan chargeoffs	2,944		3,009	8,506		8,442
Recoveries of loans previously charged off [Abstract]
Total recoveries	143		145	387		409
Net loans charged off	2,801		2,864	8,119		8,033
Provision for loan losses	2,080		5,225	7,066		14,190
Balance at end of period	43,426		43,605	43,426		43,605
Collateral deficiency charge-offs for TDR reclassifications	804			804
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0			0
Collectively evaluated for impairment	43,426			43,426			44,479
Total ending allowance balance	43,426		43,605	43,426		43,605
Loans [Abstract]
Individually evaluated for impairment	16,068			16,068			3,730
Collectively evaluated for impairment	2,367,987			2,367,987			2,265,259
Total ending loans balance	2,384,055			2,384,055			2,268,989
Installment [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	79		153	98		236
Loans charged off [Abstract]
Total loan chargeoffs	18		23	48		72
Recoveries of loans previously charged off [Abstract]
Total recoveries	10		5	41		37
Net loans charged off	8		18	7		35
Provision for loan losses	7		(9)	(13)		(75)
Balance at end of period	78		126	78		126
Allowance for loan losses [Abstract]
Individually evaluated for impairment	0			0			0
Collectively evaluated for impairment	78			78			98
Total ending allowance balance	78		126	78		126
Loans [Abstract]
Individually evaluated for impairment	0			0			0
Collectively evaluated for impairment	4,455			4,455			4,151
Total ending loans balance	4,455			4,455			4,151
New York and other states [Member]
Loans charged off [Abstract]
Total loan chargeoffs	2,248		1,024	6,530		2,956
Recoveries of loans previously charged off [Abstract]
Total recoveries	75		152	344		471
Loans [Abstract]
Total ending loans balance	2,325,507	[1]		2,325,507	[1]		2,289,884	[1]
New York and other states [Member] | Commercial [Member]
Loans charged off [Abstract]
Total loan chargeoffs	34		1	1,073		70
Recoveries of loans previously charged off [Abstract]
Total recoveries	25		4	30		55
Loans [Abstract]
Total ending loans balance	199,037			199,037			222,835
New York and other states [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loans charged off [Abstract]
Total loan chargeoffs	2,197		1,001	5,410		2,816
Recoveries of loans previously charged off [Abstract]
Total recoveries	40		143	273		380
New York and other states [Member] | Installment [Member]
Loans charged off [Abstract]
Total loan chargeoffs	17		22	47		70
Recoveries of loans previously charged off [Abstract]
Total recoveries	10		5	41		36
Loans [Abstract]
Total ending loans balance	4,395	[1]		4,395	[1]		4,078	[1]
Florida [Member]
Loans charged off [Abstract]
Total loan chargeoffs	1,484		2,009	4,289		6,228
Recoveries of loans previously charged off [Abstract]
Total recoveries	103		2	122		34
Loans [Abstract]
Total ending loans balance	280,434			280,434			231,419
Florida [Member] | Commercial [Member]
Loans charged off [Abstract]
Total loan chargeoffs	736		0	1,192		600
Recoveries of loans previously charged off [Abstract]
Total recoveries	0		0	8		4
Loans [Abstract]
Total ending loans balance	18,394			18,394			25,328
Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loans charged off [Abstract]
Total loan chargeoffs	747		2,008	3,096		5,626
Recoveries of loans previously charged off [Abstract]
Total recoveries	103		2	114		29
Florida [Member] | Installment [Member]
Loans charged off [Abstract]
Total loan chargeoffs	1		1	1		2
Recoveries of loans previously charged off [Abstract]
Total recoveries	0		0	0		1
Loans [Abstract]
Total ending loans balance	$ 60			$ 60			$ 73

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