Total Equity (Preferred Stock General Disclosure) (Details) - USD ($) shares in Millions, $ in Millions |
1 Months Ended | 3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|---|
Jan. 31, 2017 |
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Preferred Stock | |||||
| Issuance of preferred stock, net of issuance costs | $ 994 | $ 0 | |||
| Preferred Stock | |||||
| Preferred Stock | |||||
| Preferred stock dividends declared | $ 170 | $ 156 | $ 260 | $ 234 | |
| Dividend declared date | Jun. 15, 2017 | ||||
| Date of shareholders on record | Jun. 30, 2017 | ||||
| Dividend payable date | Jul. 17, 2017 | ||||
| Preferred stock shares authorized | 30 | 30 | |||
| Series K Preferred Stock | |||||
| Preferred Stock | |||||
| Issuance of preferred stock, net of issuance costs | $ 994 | ||||