Loans And Allowance For Loan Losses (Summary Of Activity In The Allowance For Loan Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 178,533	$ 191,538	$ 184,532	$ 197,538
Provision	5,581	11,395	18,961	39,372
Loans charged off	14,275	18,878	47,212	61,869
Less recoveries on loans	5,193	3,983	18,751	12,997
Net loans charged off	9,082	14,895	28,461	48,872
Balance at end of period	175,032	188,038	175,032	188,038
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	114,671	127,263	122,497	119,946
Provision	(2,479)	1,503	(10,125)	16,783
Loans charged off	1,795	4,047	7,502	14,357
Less recoveries on loans	1,720	514	7,247	2,861
Net loans charged off	75	3,533	255	11,496
Balance at end of period	112,117	125,233	112,117	125,233
Personal Banking [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	63,862	64,275	62,035	77,592
Provision	8,060	9,892	29,086	22,589
Loans charged off	12,480	14,831	39,710	47,512
Less recoveries on loans	3,473	3,469	11,504	10,136
Net loans charged off	9,007	11,362	28,206	37,376
Balance at end of period	$ 62,915	$ 62,805	$ 62,915	$ 62,805