Loans Receivable and Credit Quality Impaired Loans With and Without Related Allowance (Details) (USD $)	3 Months Ended				6 Months Ended				12 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 88,130,000	[1]	$ 94,878,000	[2]	$ 88,130,000	[1]	$ 94,878,000	[2]	$ 89,793,000	[3]
Impaired Financing Receivable, Unpaid Principal Balance	116,254,000		117,831,000		116,254,000		117,831,000		111,492,000
Impaired Financing Receivable, Related Allowance	5,869,000		5,674,000		5,869,000		5,674,000		4,208,000
Impaired Financing Receivable, Average Recorded Investment	93,959,000		116,103,000		92,785,000		111,796,000		106,264,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	460,000		244,000		981,000		384,000		1,213,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	43,075,000	[1]	38,501,000	[2]	43,075,000	[1]	38,501,000	[2]	31,965,000	[3]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	46,344,000		41,207,000		46,344,000		41,207,000		33,198,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	43,968,000		36,747,000		39,657,000		35,238,000		34,023,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	285,000		144,000		523,000		179,000		583,000
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	45,055,000	[1]	56,377,000	[2]	45,055,000	[1]	56,377,000	[2]	57,828,000	[3]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	69,910,000		76,624,000		69,910,000		76,624,000		78,294,000
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	49,991,000		79,356,000		53,128,000		76,558,000		72,241,000
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	175,000		100,000		458,000		205,000		630,000
Charge offs to date on impaired loans receivable	24,500,000		20,500,000		24,500,000		20,500,000		18,200,000
Nonaccrual Interest Payments to Date Applied to Principal	3,600,000		2,500,000		3,600,000		2,500,000		3,500,000
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	6,573,000	[1]	2,894,000	[2]	6,573,000	[1]	2,894,000	[2]	6,718,000	[3]
Impaired Financing Receivable, Unpaid Principal Balance	9,311,000		3,485,000		9,311,000		3,485,000		7,376,000
Impaired Financing Receivable, Related Allowance	1,013,000		22,000		1,013,000		22,000		149,000
Impaired Financing Receivable, Average Recorded Investment	7,055,000		8,115,000		7,005,000		8,443,000		7,185,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	0		0		0		16,000		59,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	3,242,000	[1]	129,000	[2]	3,242,000	[1]	129,000	[2]	1,123,000	[3]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	4,115,000		131,000		4,115,000		131,000		1,137,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,118,000		1,358,000		1,609,000		936,000		748,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0		0		0		0		0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	3,331,000	[1]	2,765,000	[2]	3,331,000	[1]	2,765,000	[2]	5,595,000	[3]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	5,196,000		3,354,000		5,196,000		3,354,000		6,239,000
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	4,937,000		6,757,000		5,396,000		7,507,000		6,437,000
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0		0		0		16,000		59,000
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	49,782,000	[1]	72,323,000	[2]	49,782,000	[1]	72,323,000	[2]	58,165,000	[3]
Impaired Financing Receivable, Unpaid Principal Balance	68,715,000		90,975,000		68,715,000		90,975,000		74,088,000
Impaired Financing Receivable, Related Allowance	2,412,000		4,867,000		2,412,000		4,867,000		3,307,000
Impaired Financing Receivable, Average Recorded Investment	55,212,000		85,460,000		56,671,000		79,406,000		76,039,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	272,000		201,000		549,000		286,000		813,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	23,924,000	[1]	32,676,000	[2]	23,924,000	[1]	32,676,000	[2]	23,202,000	[3]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	25,203,000		35,371,000		25,203,000		35,371,000		24,398,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	26,524,000		27,942,000		25,555,000		26,625,000		26,274,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	189,000		121,000		362,000		121,000		440,000
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	25,858,000	[1]	39,647,000	[2]	25,858,000	[1]	39,647,000	[2]	34,963,000	[3]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	43,512,000		55,604,000		43,512,000		55,604,000		49,690,000
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	28,688,000		57,518,000		31,116,000		52,781,000		49,765,000
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	83,000		80,000		187,000		165,000		373,000
Construction and land [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	8,633,000	[1]	6,808,000	[2]	8,633,000	[1]	6,808,000	[2]	7,772,000	[3]
Impaired Financing Receivable, Unpaid Principal Balance	13,011,000		9,963,000		13,011,000		9,963,000		12,085,000
Impaired Financing Receivable, Related Allowance	1,177,000		308,000		1,177,000		308,000		219,000
Impaired Financing Receivable, Average Recorded Investment	7,958,000		9,234,000		7,743,000		11,037,000		9,064,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	0		0		97,000		0		0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	2,614,000	[1]	1,563,000	[2]	2,614,000	[1]	1,563,000	[2]	1,279,000	[3]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	2,651,000		1,572,000		2,651,000		1,572,000		1,302,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,566,000		3,309,000		1,400,000		3,601,000		2,591,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0		0		0		0		0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	6,019,000	[1]	5,245,000	[2]	6,019,000	[1]	5,245,000	[2]	6,493,000	[3]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	10,360,000		8,391,000		10,360,000		8,391,000		10,783,000
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	6,392,000		5,925,000		6,343,000		7,436,000		6,473,000
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0		0		97,000		0		0
Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	22,553,000	[1]	11,514,000	[2]	22,553,000	[1]	11,514,000	[2]	16,681,000	[3]
Impaired Financing Receivable, Unpaid Principal Balance	24,602,000		12,027,000		24,602,000		12,027,000		17,452,000
Impaired Financing Receivable, Related Allowance	1,136,000		346,000		1,136,000		346,000		402,000
Impaired Financing Receivable, Average Recorded Investment	23,156,000		12,093,000		20,841,000		11,881,000		13,089,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	186,000		41,000		330,000		79,000		335,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	13,164,000	[1]	4,002,000	[2]	13,164,000	[1]	4,002,000	[2]	6,230,000	[3]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	14,244,000		4,002,000		14,244,000		4,002,000		6,230,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	13,629,000		4,007,000		10,962,000		3,945,000		4,279,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	95,000		21,000		158,000		55,000		137,000
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,389,000	[1]	7,512,000	[2]	9,389,000	[1]	7,512,000	[2]	10,451,000	[3]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	10,358,000		8,025,000		10,358,000		8,025,000		11,222,000
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9,527,000		8,086,000		9,879,000		7,936,000		8,810,000
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	91,000		20,000		172,000		24,000		198,000
Home equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	491,000	[1]	1,339,000	[2]	491,000	[1]	1,339,000	[2]	457,000	[3]
Impaired Financing Receivable, Unpaid Principal Balance	491,000		1,381,000		491,000		1,381,000		491,000
Impaired Financing Receivable, Related Allowance	131,000		131,000		131,000		131,000		131,000
Impaired Financing Receivable, Average Recorded Investment	491,000		1,201,000		482,000		1,008,000		876,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	2,000		2,000		5,000		3,000		6,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	131,000	[1]	131,000	[2]	131,000	[1]	131,000	[2]	131,000	[3]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	131,000		131,000		131,000		131,000		131,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	131,000		131,000		131,000		131,000		131,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	1,000		2,000		3,000		3,000		6,000
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	360,000	[1]	1,208,000	[2]	360,000	[1]	1,208,000	[2]	326,000	[3]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	360,000		1,250,000		360,000		1,250,000		360,000
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	360,000		1,070,000		351,000		877,000		745,000
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	1,000		0		2,000		0		0
Consumer and other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	98,000	[1]	0	[2]	98,000	[1]	0	[2]	0	[3]
Impaired Financing Receivable, Unpaid Principal Balance	124,000		0		124,000		0		0
Impaired Financing Receivable, Related Allowance	0		0		0		0		0
Impaired Financing Receivable, Average Recorded Investment	87,000		0		43,000		21,000		11,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	0		0		0		0		0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[1]	0	[2]	0	[1]	0	[2]	0	[3]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0		0		0		0		0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0		0		0		0		0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0		0		0		0		0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	98,000	[1]	0	[2]	98,000	[1]	0	[2]	0	[3]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	124,000		0		124,000		0		0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	87,000		0		43,000		21,000		11,000
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	$ 0		$ 0		$ 0		$ 0		$ 0

[1] (1)Recorded investment represents the client loan balance net of historical charge-offs of $24.5 million and historical nonaccrual interest paid, which was applied to principal, of $3.6 million.

[2] (1)Recorded investment represents the client loan balance net of historical charge-offs of $20.5 million and historical nonaccrual interest paid, which was applied to principal, of $2.5 million.

[3] (1)Recorded investment represents the client loan balance net of historical charge-offs of $18.2 million and historical nonaccrual interest paid, which was applied to principal, of $3.5 million.