Loans - Consumer, Excluding Credit Card Loans, Loan Modifications, Nature and Extent of Modifications (Details) - Consumer, excluding credit card - loan	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	68.00%	58.00%	77.00%
Concession granted - Term of payment extension	86.00%	63.00%	70.00%
Concession granted - Principal and/or interest deferred	24.00%	18.00%	21.00%
Concession granted - principal forgiveness	16.00%	41.00%	39.00%
Concession granted - other	5.00%	6.00%	11.00%
Percentage, sum of items by type, may exceed	100.00%
Trial Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	6,644	4,673	9,682
Permanent Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	7,441	9,632	16,525
Home equity | Senior lien
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	75.00%	53.00%	70.00%
Concession granted - Term of payment extension	86.00%	67.00%	76.00%
Concession granted - Principal and/or interest deferred	32.00%	16.00%	12.00%
Concession granted - principal forgiveness	4.00%	36.00%	38.00%
Concession granted - other	0.00%	0.00%	0.00%
Home equity | Senior lien | Trial Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,345	939	1,719
Home equity | Senior lien | Permanent Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,096	1,171	1,765
Home equity | Junior lien
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	63.00%	84.00%	88.00%
Concession granted - Term of payment extension	90.00%	83.00%	80.00%
Concession granted - Principal and/or interest deferred	19.00%	23.00%	24.00%
Concession granted - principal forgiveness	8.00%	22.00%	32.00%
Concession granted - other	0.00%	0.00%	0.00%
Home equity | Junior lien | Trial Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	2,588	626	884
Home equity | Junior lien | Permanent Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	3,200	2,813	5,040
Mortgages | Prime, including option ARMs
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	72.00%	43.00%	73.00%
Concession granted - Term of payment extension	80.00%	51.00%	73.00%
Concession granted - Principal and/or interest deferred	34.00%	19.00%	30.00%
Concession granted - principal forgiveness	24.00%	51.00%	38.00%
Concession granted - other	9.00%	10.00%	23.00%
Mortgages | Prime, including option ARMs | Trial Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,103	1,052	2,846
Mortgages | Prime, including option ARMs | Permanent Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,495	2,507	4,356
Mortgages | Subprime
Financing Receivable, Impaired [Line Items]
Concession granted - Interest rate reduction	71.00%	47.00%	72.00%
Concession granted - Term of payment extension	82.00%	53.00%	56.00%
Concession granted - Principal and/or interest deferred	21.00%	12.00%	13.00%
Concession granted - principal forgiveness	31.00%	53.00%	48.00%
Concession granted - other	13.00%	10.00%	14.00%
Mortgages | Subprime | Trial Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,608	2,056	4,233
Mortgages | Subprime | Permanent Modification
Financing Receivable, Impaired [Line Items]
Number of contract modifications	1,650	3,141	5,364