Loans - Consumer, Excluding Credit Card Loans, Loan Modifications, Nature and Extent of Modifications (Details) - Consumer, excluding credit card - loans	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Residential real estate – excluding PCI
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	74.00%	75.00%	73.00%	72.00%
Concession granted - Term of payment extension	84.00%	79.00%	84.00%	80.00%
Concession granted - Principal and/or interest deferred	26.00%	20.00%	28.00%	22.00%
Concession granted - principal forgiveness	14.00%	29.00%	16.00%	31.00%
Concession granted - other	4.00%	6.00%	5.00%	7.00%
Percentage, sum of items by type, may exceed			100.00%
Home equity - senior lien
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	75.00%	64.00%	75.00%	65.00%
Concession granted - Term of payment extension	85.00%	86.00%	83.00%	83.00%
Concession granted - Principal and/or interest deferred	32.00%	12.00%	32.00%	14.00%
Concession granted - principal forgiveness	4.00%	30.00%	6.00%	30.00%
Concession granted - other	0.00%	0.00%	0.00%	0.00%
Home equity - junior lien
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	75.00%	88.00%	76.00%	86.00%
Concession granted - Term of payment extension	88.00%	83.00%	87.00%	83.00%
Concession granted - Principal and/or interest deferred	23.00%	22.00%	25.00%	22.00%
Concession granted - principal forgiveness	4.00%	29.00%	4.00%	28.00%
Concession granted - other	1.00%	0.00%	0.00%	0.00%
Mortgages - prime, including option ARMS
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	76.00%	65.00%	69.00%	62.00%
Concession granted - Term of payment extension	84.00%	79.00%	84.00%	84.00%
Concession granted - Principal and/or interest deferred	36.00%	30.00%	36.00%	32.00%
Concession granted - principal forgiveness	23.00%	22.00%	26.00%	27.00%
Concession granted - other	8.00%	18.00%	8.00%	17.00%
Mortgages - subprime
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	71.00%	68.00%	71.00%	63.00%
Concession granted - Term of payment extension	78.00%	71.00%	80.00%	72.00%
Concession granted - Principal and/or interest deferred	18.00%	15.00%	22.00%	18.00%
Concession granted - principal forgiveness	30.00%	35.00%	31.00%	38.00%
Concession granted - other	10.00%	9.00%	11.00%	12.00%
Trial Modification | Residential real estate – excluding PCI
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,048	1,165	2,225	2,304
Trial Modification | Home equity - senior lien
Financing Receivable, Impaired [Line Items]
Number of contract modifications	294	218	650	419
Trial Modification | Home equity - junior lien
Financing Receivable, Impaired [Line Items]
Number of contract modifications	93	157	247	341
Trial Modification | Mortgages - prime, including option ARMS
Financing Receivable, Impaired [Line Items]
Number of contract modifications	294	261	539	516
Trial Modification | Mortgages - subprime
Financing Receivable, Impaired [Line Items]
Number of contract modifications	367	529	789	1,028
Permanent Modification | Residential real estate – excluding PCI
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,698	1,804	3,318	4,355
Permanent Modification | Home equity - senior lien
Financing Receivable, Impaired [Line Items]
Number of contract modifications	314	226	576	521
Permanent Modification | Home equity - junior lien
Financing Receivable, Impaired [Line Items]
Number of contract modifications	642	699	1,150	1,657
Permanent Modification | Mortgages - prime, including option ARMS
Financing Receivable, Impaired [Line Items]
Number of contract modifications	347	386	708	917
Permanent Modification | Mortgages - subprime
Financing Receivable, Impaired [Line Items]
Number of contract modifications	395	493	884	1,260