Loans (Schedule Of Allowance For Loan Losses By Portfolio Segment And Based On Impairment) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment, Allowance	$ 7,403	$ 13,116
Loans individually evaluated for impairment, Balance	320,260	366,740
Loans collectively evaluated for impairment, Allowance	201,713	232,115
Loans collectively evaluated for impairment, Balance	6,696,882	6,501,881
Total allowance	209,116	245,231
Total balance	7,017,142	6,868,621
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment, Allowance	2,270	2,540
Loans individually evaluated for impairment, Balance	44,989	33,555
Loans collectively evaluated for impairment, Allowance	61,518	61,379
Loans collectively evaluated for impairment, Balance	1,776,070	1,407,612
Total allowance	63,788	63,919
Total balance	1,821,059	1,441,167
Real Estate Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment, Allowance		7,470
Loans individually evaluated for impairment, Balance	82,818	77,691
Loans collectively evaluated for impairment, Allowance	23,876	35,791
Loans collectively evaluated for impairment, Balance	166,185	332,295
Total allowance	23,876	43,261
Total balance	249,003	409,986
Commercial Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment, Allowance	3,930	3,106
Loans individually evaluated for impairment, Balance	173,563	248,059
Loans collectively evaluated for impairment, Allowance	109,144	125,241
Loans collectively evaluated for impairment, Balance	3,574,961	3,692,002
Total allowance	113,074	128,347
Total balance	3,748,524	3,940,061
Residential Mortgage And Equity Lines [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment, Allowance	1,203
Loans individually evaluated for impairment, Balance	18,890	7,435
Loans collectively evaluated for impairment, Allowance	7,140	9,668
Loans collectively evaluated for impairment, Balance	1,163,821	1,053,895
Total allowance	8,343	9,668
Total balance	1,182,711	1,061,330
Consumer And Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans collectively evaluated for impairment, Allowance	35	36
Loans collectively evaluated for impairment, Balance	15,845	16,077
Total allowance	35	36
Total balance	$ 15,845	$ 16,077