Loans (Schedule Of Allowance For Loan Losses By Portfolio Segment) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	$ 245,231	$ 211,889	$ 122,093
Provision for possible credit losses	27,268	159,770
Charge-offs	(77,626)	(138,755)	(222,547)
Recoveries	11,407	12,327	3,218
Net charge-offs	(66,219)	(126,428)
Balance at end of year	206,280	245,231	211,889
Reserve to impaired loans	7,552	15,186
Reserve to non-impaired loans	198,728	230,045
Reserve for off-balance sheet credit commitments	2,069	2,337
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	63,918	57,814
Provision for possible credit losses	11,711	23,001
Charge-offs	(11,745)	(21,609)
Recoveries	1,774	4,712
Net charge-offs	(9,971)	(16,897)
Balance at end of year	65,658	63,918
Reserve to impaired loans	3,336	2,925
Reserve to non-impaired loans	62,322	60,994
Reserve for off-balance sheet credit commitments	816	691
Real Estate Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	43,262	45,087
Provision for possible credit losses	11,514	37,495
Charge-offs	(37,500)	(45,321)
Recoveries	4,473	6,001
Net charge-offs	(33,027)	(39,320)
Balance at end of year	21,749	43,262
Reserve to impaired loans		7,470
Reserve to non-impaired loans	21,749	35,791
Reserve for off-balance sheet credit commitments	1,103	1,505
Commercial Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	128,348	100,495
Provision for possible credit losses	1,454	96,217
Charge-offs	(26,750)	(69,891)
Recoveries	4,969	1,527
Net charge-offs	(21,781)	(68,364)
Balance at end of year	108,021	128,348
Reserve to impaired loans	2,969	3,812
Reserve to non-impaired loans	105,052	124,535
Reserve for off-balance sheet credit commitments	113	103
Residential Mortgage And Equity Lines [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	9,668	8,480
Provision for possible credit losses	2,392	3,048
Charge-offs	(1,456)	(1,934)
Recoveries	191	74
Net charge-offs	(1,265)	(1,860)
Balance at end of year	10,795	9,668
Reserve to impaired loans	1,247	979
Reserve to non-impaired loans	9,548	8,690
Reserve for off-balance sheet credit commitments	34	36
Installment And Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	35	13
Provision for possible credit losses	197	9
Charge-offs	(175)
Recoveries		13
Net charge-offs	(175)	13
Balance at end of year	57	35
Reserve to non-impaired loans	57	35
Reserve for off-balance sheet credit commitments	$ 3	$ 2