Allowance For Credit Losses (Summary Of Activity In The Allowance For Loan Losses) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 133,802,000	$ 124,704,000
Loans charged-off	(8,546,000)	(10,036,000)	[1]
Charged-off loans recovered	2,240,000	1,092,000
Net charge-offs	(6,306,000)	(8,944,000)
Provision for loan losses	5,374,000	24,087,000	[2]
Ending balance	132,870,000	139,847,000
Covered loans charge-offs		5,100,000
Provision for covered loan losses		18,882,000
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	73,649,000	61,967,000
Loans charged-off	(4,807,000)	(6,672,000)	[1]
Charged-off loans recovered	1,005,000	448,000
Net charge-offs	(3,802,000)	(6,224,000)
Provision for loan losses	3,464,000	20,128,000	[2]
Ending balance	73,311,000	75,871,000
Total Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	34,637,000	30,409,000
Loans charged-off	(1,080,000)	(823,000)	[1]
Charged-off loans recovered	120,000	21,000
Net charge-offs	(960,000)	(802,000)
Provision for loan losses	738,000	2,610,000	[2]
Ending balance	34,415,000	32,217,000
Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	9,120,000	9,476,000
Loans charged-off	(1,176,000)	(783,000)	[1]
Charged-off loans recovered	514,000	21,000
Net charge-offs	(662,000)	(762,000)
Provision for loan losses	1,379,000	2,589,000	[2]
Ending balance	9,837,000	11,303,000
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	8,677,000	14,499,000
Loans charged-off	(1,483,000)	(1,758,000)	[1]
Charged-off loans recovered	601,000	602,000
Net charge-offs	(882,000)	(1,156,000)
Provision for loan losses	145,000	(1,043,000)	[2]
Ending balance	7,940,000	12,300,000
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	7,719,000	8,353,000
Provision for loan losses	(352,000)	(197,000)	[2]
Ending balance	$ 7,367,000	$ 8,156,000

[1] The allowance for covered loans was reduced by loan charge-offs totaling $5.1 million during the first quarter of 2011.

[2] Includes an $18.9 million provision for covered loans during the quarter ended March 31, 2011 due to declines in the expected cash flows caused by credit impairment in certain loan pools, primarily consisting of commercial and industrial loans.