Loans (Commercial Banking: Risk Profile By Geographic Region And Internal Risk Rating) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	$ 15,702	[1],[2],[3]	$ 15,736	[1],[2],[3]
Percent of Total Commercial and Multifamily Real Estate	100.00%	[2],[3],[4]	100.00%	[2],[3],[4]
Commercial and Industrial	17,761	[1],[2],[3]	17,088	[1],[2],[3]
Percentage of Total Commercial and Industrial	100.00%	[2],[3],[4]	100.00%	[2],[3],[4]
Small-ticket Commercial Real Estate	1,443	[1],[2],[3]	1,503	[1],[2],[3]
Percent of Total Small-ticket Commercial Real Estate	100.00%	[2],[3],[4]	100.00%	[2],[3],[4]
Total Commercial	34,906	[1],[2],[3]	34,327	[1],[2],[3]
Percent of Total Commercial	100.00%	[2],[3],[4]	100.00%	[2],[3],[4]
Loans [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	15,490	[3],[5]	15,573	[3],[5]
Percent of Total Commercial and Multifamily Real Estate	98.60%	[3],[4],[5]	99.00%	[3],[4],[5]
Commercial and Industrial	17,503	[3],[5]	16,770	[3],[5]
Percentage of Total Commercial and Industrial	98.50%	[3],[4],[5]	98.10%	[3],[4],[5]
Small-ticket Commercial Real Estate	1,443	[3],[5]	1,503	[3],[5]
Percent of Total Small-ticket Commercial Real Estate	100.00%	[3],[4],[5]	100.00%	[3],[4],[5]
Total Commercial	34,436	[3],[5]	33,846	[3],[5]
Percent of Total Commercial	98.70%	[3],[4],[5]	98.60%	[3],[4],[5]
Loans [Member] | Noncriticized [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	14,234	[5]	14,256	[5]
Percent of Total Commercial and Multifamily Real Estate	90.60%	[4],[5]	90.60%	[4],[5]
Commercial and Industrial	16,771	[5]	16,002	[5]
Percentage of Total Commercial and Industrial	94.40%	[4],[5]	93.60%	[4],[5]
Small-ticket Commercial Real Estate	1,334	[5]	1,359	[5]
Percent of Total Small-ticket Commercial Real Estate	92.50%	[4],[5]	90.40%	[4],[5]
Total Commercial	32,339	[5]	31,617	[5]
Percent of Total Commercial	92.60%	[4],[5]	92.10%	[4],[5]
Loans [Member] | Criticized Performing [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	1,028	[5]	1,110	[5]
Percent of Total Commercial and Multifamily Real Estate	6.50%	[4],[5]	7.10%	[4],[5]
Commercial and Industrial	619	[5]	642	[5]
Percentage of Total Commercial and Industrial	3.50%	[4],[5]	3.80%	[4],[5]
Small-ticket Commercial Real Estate	48	[5]	105	[5]
Percent of Total Small-ticket Commercial Real Estate	3.30%	[4],[5]	7.00%	[4],[5]
Total Commercial	1,695	[5]	1,857	[5]
Percent of Total Commercial	4.90%	[4],[5]	5.40%	[4],[5]
Loans [Member] | Criticized Nonperforming [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	228	[5]	207	[5]
Percent of Total Commercial and Multifamily Real Estate	1.50%	[4],[5]	1.30%	[4],[5]
Commercial and Industrial	113	[5]	126	[5]
Percentage of Total Commercial and Industrial	0.60%	[4],[5]	0.70%	[4],[5]
Small-ticket Commercial Real Estate	61	[5]	39	[5]
Percent of Total Small-ticket Commercial Real Estate	4.20%	[4],[5]	2.60%	[4],[5]
Total Commercial	402	[5]	372	[5]
Percent of Total Commercial	1.20%	[4],[5]	1.10%	[4],[5]
Loans [Member] | Northeast [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	11,577	[3]	11,470	[3]
Percent of Total Commercial and Multifamily Real Estate	73.70%	[3],[4]	72.90%	[3],[4]
Commercial and Industrial	4,973	[3]	4,987	[3]
Percentage of Total Commercial and Industrial	28.00%	[3],[4]	29.10%	[3],[4]
Small-ticket Commercial Real Estate	757	[3]	790	[3]
Percent of Total Small-ticket Commercial Real Estate	52.50%	[3],[4]	52.60%	[3],[4]
Total Commercial	17,307	[3]	17,247	[3]
Percent of Total Commercial	49.60%	[3],[4]	50.20%	[3],[4]
Loans [Member] | Mid-Atlantic [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	1,038	[3]	1,305	[3]
Percent of Total Commercial and Multifamily Real Estate	6.60%	[3],[4]	8.30%	[3],[4]
Commercial and Industrial	1,111	[3]	763	[3]
Percentage of Total Commercial and Industrial	6.20%	[3],[4]	4.50%	[3],[4]
Small-ticket Commercial Real Estate	55	[3]	56	[3]
Percent of Total Small-ticket Commercial Real Estate	3.80%	[3],[4]	3.70%	[3],[4]
Total Commercial	2,204	[3]	2,124	[3]
Percent of Total Commercial	6.30%	[3],[4]	6.20%	[3],[4]
Loans [Member] | South [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	1,838	[3]	1,743	[3]
Percent of Total Commercial and Multifamily Real Estate	11.70%	[3],[4]	11.10%	[3],[4]
Commercial and Industrial	7,670	[3]	8,324	[3]
Percentage of Total Commercial and Industrial	43.20%	[3],[4]	48.70%	[3],[4]
Small-ticket Commercial Real Estate	91	[3]	93	[3]
Percent of Total Small-ticket Commercial Real Estate	6.30%	[3],[4]	6.20%	[3],[4]
Total Commercial	9,599	[3]	10,160	[3]
Percent of Total Commercial	27.50%	[3],[4]	29.60%	[3],[4]
Loans [Member] | Other States [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	1,037	[3]	1,055	[3]
Percent of Total Commercial and Multifamily Real Estate	6.60%	[3],[4]	6.70%	[3],[4]
Commercial and Industrial	3,749	[3]	2,696	[3]
Percentage of Total Commercial and Industrial	21.10%	[3],[4]	15.80%	[3],[4]
Small-ticket Commercial Real Estate	540	[3]	564	[3]
Percent of Total Small-ticket Commercial Real Estate	37.40%	[3],[4]	37.50%	[3],[4]
Total Commercial	5,326	[3]	4,315	[3]
Percent of Total Commercial	15.30%	[3],[4]	12.60%	[3],[4]
Acquired Loans [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	212	[3]	163	[3]
Percent of Total Commercial and Multifamily Real Estate	1.40%	[3],[4]	1.00%	[3],[4]
Commercial and Industrial	258	[3]	318	[3]
Percentage of Total Commercial and Industrial	1.50%	[3],[4]	1.90%	[3],[4]
Small-ticket Commercial Real Estate	0	[3]	0	[3]
Percent of Total Small-ticket Commercial Real Estate	0.00%	[3],[4]	0.00%	[3],[4]
Total Commercial	470	[3]	481	[3]
Percent of Total Commercial	1.30%	[3],[4]	1.40%	[3],[4]
Acquired Loans [Member] | Noncriticized [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	148		127
Percent of Total Commercial and Multifamily Real Estate	1.00%	[4]	0.80%	[4]
Commercial and Industrial	241		303
Percentage of Total Commercial and Industrial	1.40%	[4]	1.80%	[4]
Small-ticket Commercial Real Estate	0		0
Percent of Total Small-ticket Commercial Real Estate	0.00%	[4]	0.00%	[4]
Total Commercial	389		430
Percent of Total Commercial	1.10%	[4]	1.30%	[4]
Acquired Loans [Member] | Criticized Performing [Member]
Commercial Banking Risk Profile [Line Items]
Commercial & Multifamily Real Estate	64		36
Percent of Total Commercial and Multifamily Real Estate	0.40%	[4]	0.20%	[4]
Commercial and Industrial	17		15
Percentage of Total Commercial and Industrial	0.10%	[4]	0.10%	[4]
Small-ticket Commercial Real Estate	0		0
Percent of Total Small-ticket Commercial Real Estate	0.00%	[4]	0.00%	[4]
Total Commercial	$ 81		$ 51
Percent of Total Commercial	0.20%	[4]	0.10%	[4]

[1] Includes construction loans and land development loans totaling $2.1 billion and $2.2 billion as of March 31, 2012 and December 31, 2011, respectively.

[2] Amounts based on total loans as of March 31, 2012 and December 31, 2011.

[3] Northeast consists of CT, ME, MA, NH, NJ, NY, PA and VT. Mid-Atlantic consists of DE, DC, MD, VA and WV. South consists of AL, AR, FL, GA, KY, LA, MS, MO, NC, SC, TN and TX.

[4] Percentages calculated based on total held-for-investment commercial loans in each respective loan category as of the end of the reported period.

[5] Criticized exposures correspond to the "Special Mention," "Substandard" and "Doubtful" asset categories defined by banking regulatory authorities.