Loans (Schedule Of Allowance For Loan Losses By Portfolio Segment) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	$ 229,900	$ 255,650	$ 245,231	$ 211,889
Provision for possible credit losses	8,684	20,066	25,474	149,443
Charge-offs	(30,840)	(21,347)	(70,736)	(113,211)
Recoveries	1,372	3,337	9,147	9,585
Net charge-offs	(29,468)	(18,010)	(61,589)	(103,626)
Ending Balance	209,116	257,706	209,116	257,706
Reserve for impaired loans	7,403	23,458	7,403	23,458
Reserve for non-impaired loans	201,713	234,248	201,713	234,248
Reserve for off-balance sheet credit commitments	1,863	2,664	1,863	2,664
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	65,860	60,738	63,919	57,815
Provision for possible credit losses	(1,366)	7,266	9,516	19,733
Charge-offs	(1,219)	(5,588)	(11,215)	(17,501)
Recoveries	513	963	1,568	3,332
Net charge-offs	(706)	(4,625)	(9,647)	(14,169)
Ending Balance	63,788	63,379	63,788	63,379
Reserve for impaired loans	2,270	3,126	2,270	3,126
Reserve for non-impaired loans	61,518	60,253	61,518	60,253
Reserve for off-balance sheet credit commitments	757	575	757	575
Real Estate Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	37,683	42,442	43,261	45,086
Provision for possible credit losses	9,324	14,255	10,713	37,897
Charge-offs	(23,539)	(9,014)	(34,394)	(38,213)
Recoveries	408	1,945	4,296	4,858
Net charge-offs	(23,131)	(7,069)	(30,098)	(33,355)
Ending Balance	23,876	49,628	23,876	49,628
Reserve for impaired loans		11,263		11,263
Reserve for non-impaired loans	23,876	38,365	23,876	38,365
Reserve for off-balance sheet credit commitments	967	1,933	967	1,933
Commercial Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	117,014	144,000	128,347	100,494
Provision for possible credit losses	951	(1,920)	5,704	89,981
Charge-offs	(5,264)	(6,605)	(24,083)	(55,892)
Recoveries	373	428	3,106	1,320
Net charge-offs	(4,891)	(6,177)	(20,977)	(54,572)
Ending Balance	113,074	135,903	113,074	135,903
Reserve for impaired loans	3,930	8,089	3,930	8,089
Reserve for non-impaired loans	109,144	127,814	109,144	127,814
Reserve for off-balance sheet credit commitments	103	116	103	116
Residential Mortgage And Equity Lines [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	9,307	8,430	9,668	8,480
Provision for possible credit losses	(224)	464	(458)	1,807
Charge-offs	(818)	(140)	(1,044)	(1,605)
Recoveries	78	1	177	73
Net charge-offs	(740)	(139)	(867)	(1,532)
Ending Balance	8,343	8,755	8,343	8,755
Reserve for impaired loans	1,203	980	1,203	980
Reserve for non-impaired loans	7,140	7,775	7,140	7,775
Reserve for off-balance sheet credit commitments	34	37	34	37
Installment And Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	36	40	36	14
Provision for possible credit losses	(1)	1	(1)	25
Recoveries				2
Net charge-offs				2
Ending Balance	35	41	35	41
Reserve for non-impaired loans	35	41	35	41
Reserve for off-balance sheet credit commitments	$ 2	$ 3	$ 2	$ 3