Securities - Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
|
| Schedule of Available-for-sale Securities [Line Items] | |||
| Fair Value | $ 290,360 | $ 302,631 | |
| Equity securities, fair value | 988 | ||
| Equity securities, cost | 247 | ||
| Debt securities | |||
| Schedule of Available-for-sale Securities [Line Items] | |||
| Shareholders’ equity | (5,500) | ||
| Accumulated other comprehensive income tax expense (benefit) | (1,800) | ||
| Nonperforming Financing Receivable | |||
| Schedule of Available-for-sale Securities [Line Items] | |||
| Fair Value | 128 | $ 99 | |
| Other income | |||
| Schedule of Available-for-sale Securities [Line Items] | |||
| Unrealized mark-to-market net gains (losses) | 41 | $ 117 | |
| Realized net gains (losses) | $ (6) | $ (103) | |
| X | ||||||||||
- Definition Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Tax No definition available.
|
| X | ||||||||||
- Definition Other Debt Securities Carried at Fair Value, Realized Gains (Losses) No definition available.
|
| X | ||||||||||
- Definition Other Debt Securities Carried at Fair Value, Unrealized Gains (Losses) No definition available.
|
| X | ||||||||||
- Definition Accumulated appreciation or loss, net of tax, in value of the total of available-for-sale securities at the end of an accounting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. No definition available.
|
| X | ||||||||||
- Definition Amount of debt securities categorized neither as held-to-maturity nor trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of equity securities categorized neither as held-to-maturity nor as trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|