Loans - Consumer, Excluding Credit Card Loan Portfolio, Loan Modifications, Nature and Extent of Modifications (Details) - Consumer, excluding credit card - loan	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	72.00%	36.00%	73.00%	56.00%
Concession granted - Term of payment extension	84.00%	36.00%	84.00%	60.00%
Concession granted - Principal and/or interest deferred	24.00%	9.00%	26.00%	16.00%
Concession granted - principal forgiveness	15.00%	62.00%	16.00%	45.00%
Concession granted - other	6.00%	4.00%	5.00%	6.00%
Percentage, sum of items by type, may exceed			100.00%
Trial Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	2,499	1,172	4,724	3,476
Permanent Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,758	3,601	5,076	7,956
Prime, including option ARMs | Mortgages
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	76.00%	23.00%	72.00%	40.00%
Concession granted - Term of payment extension	77.00%	18.00%	82.00%	46.00%
Concession granted - Principal and/or interest deferred	28.00%	7.00%	33.00%	17.00%
Concession granted - principal forgiveness	25.00%	73.00%	25.00%	54.00%
Concession granted - other	10.00%	4.00%	9.00%	9.00%
Prime, including option ARMs | Trial Modification | Mortgages
Financing Receivable, Impaired [Line Items]
Number of contract modifications	283	274	822	790
Prime, including option ARMs | Permanent Modification | Mortgages
Financing Receivable, Impaired [Line Items]
Number of contract modifications	414	1,267	1,122	2,184
Subprime | Mortgages
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	70.00%	26.00%	70.00%	43.00%
Concession granted - Term of payment extension	82.00%	29.00%	80.00%	49.00%
Concession granted - Principal and/or interest deferred	17.00%	6.00%	21.00%	11.00%
Concession granted - principal forgiveness	34.00%	72.00%	32.00%	57.00%
Concession granted - other	15.00%	7.00%	12.00%	9.00%
Subprime | Trial Modification | Mortgages
Financing Receivable, Impaired [Line Items]
Number of contract modifications	381	502	1,170	1,530
Subprime | Permanent Modification | Mortgages
Financing Receivable, Impaired [Line Items]
Number of contract modifications	391	1,420	1,275	2,680
Senior lien | Home equity
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	77.00%	43.00%	75.00%	56.00%
Concession granted - Term of payment extension	90.00%	53.00%	85.00%	71.00%
Concession granted - Principal and/or interest deferred	34.00%	10.00%	32.00%	12.00%
Concession granted - principal forgiveness	3.00%	50.00%	5.00%	38.00%
Concession granted - other	0.00%	0.00%	0.00%	0.00%
Senior lien | Trial Modification | Home equity
Financing Receivable, Impaired [Line Items]
Number of contract modifications	333	232	983	651
Senior lien | Permanent Modification | Home equity
Financing Receivable, Impaired [Line Items]
Number of contract modifications	273	333	849	854
Junior lien | Home equity
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	68.00%	84.00%	73.00%	85.00%
Concession granted - Term of payment extension	87.00%	84.00%	87.00%	83.00%
Concession granted - Principal and/or interest deferred	21.00%	22.00%	24.00%	22.00%
Concession granted - principal forgiveness	5.00%	20.00%	4.00%	26.00%
Concession granted - other	0.00%	0.00%	0.00%	0.00%
Junior lien | Trial Modification | Home equity
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,502	164	1,749	505
Junior lien | Permanent Modification | Home equity
Financing Receivable, Impaired [Line Items]
Number of contract modifications	680	581	1,830	2,238