Credit Quality And Allowance For Credit Losses Credit Quality And Allowance For Credit Losses (Troubled Debt Restructuring Subsequent Default) (Details) - Principal Deferrals - USD ($)
$ in Millions |
Mar. 31, 2018 |
Mar. 31, 2017 |
| Financing Receivable, Modifications [Line Items] |
|
|
|
| Balance |
|
$ 131
|
$ 152
|
| Business loans | Commercial borrower |
|
|
|
| Financing Receivable, Modifications [Line Items] |
|
|
|
| Balance |
|
129
|
150
|
| Business loans | Commercial borrower | Domestic loans |
|
|
|
| Financing Receivable, Modifications [Line Items] |
|
|
|
| Balance |
|
90
|
141
|
| Business loans | Real estate mortgage | Commercial borrower | Domestic loans |
|
|
|
| Financing Receivable, Modifications [Line Items] |
|
|
|
| Balance |
|
39
|
9
|
| Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line |
|
|
|
| Financing Receivable, Modifications [Line Items] |
|
|
|
| Balance |
[1] |
37
|
0
|
| Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines |
|
|
|
| Financing Receivable, Modifications [Line Items] |
|
|
|
| Balance |
|
2
|
9
|
| Retail loans | Home equity | Consumer borrower |
|
|
|
| Financing Receivable, Modifications [Line Items] |
|
|
|
| Balance |
|
$ 2
|
$ 2
|
|
|