Loans And Leases (Impaired Loans) (Details) (USD $) In Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2011	Dec. 31, 2010
Recorded Investment	$ 299	$ 299	$ 463
Unpaid Principal Balance	499	499	619
Related Allowance			(69)
Average Recorded Investment	338	377
Interest Revenue Recognized	4	14
Additional allowance for loan losses		22	31
With No Related Allowance Recorded [Member] | CRE - Property Development [Member]
Recorded Investment	251	251	209
Unpaid Principal Balance	347	347	240
Average Recorded Investment	274	280
Interest Revenue Recognized	4	12
With No Related Allowance Recorded [Member] | CRE - Property Development - Acquired Credit-Impaired [Member]
Unpaid Principal Balance	34	34	34
Average Recorded Investment		6
With No Related Allowance Recorded [Member] | CRE - Other - Acquired Credit-Impaired [Member]
Recorded Investment	8	8	16
Unpaid Principal Balance	69	69	47
Average Recorded Investment	23	46
With No Related Allowance Recorded [Member] | CRE - Other [Member]
Recorded Investment	2	2	27
Unpaid Principal Balance	3	3	29
Average Recorded Investment	3	7
Interest Revenue Recognized		1
With An Allowance Recorded [Member] | CRE - Property Development [Member]
Recorded Investment			79
Unpaid Principal Balance			113
Related Allowance			(24)
With An Allowance Recorded [Member] | CRE - Property Development - Acquired Credit-Impaired [Member]
Recorded Investment			42
Unpaid Principal Balance			47
Related Allowance			(19)
With An Allowance Recorded [Member] | CRE - Other - Acquired Credit-Impaired [Member]
Recorded Investment	31	31	83
Unpaid Principal Balance	37	37	100
Related Allowance			(26)
Average Recorded Investment	31	31
Interest Revenue Recognized		1
With An Allowance Recorded [Member] | CRE - Other [Member]
Recorded Investment	7	7	7
Unpaid Principal Balance	9	9	9
Average Recorded Investment	$ 7	$ 7