New Accounting Standards (Details) - USD ($) $ in Millions |
3 Months Ended | |||
|---|---|---|---|---|
Jan. 01, 2019 |
Dec. 31, 2018 |
Dec. 31, 2019 |
Jan. 01, 2018 |
|
| Recently Adopted Accounting Standards | ||||
| Lease, Practical Expedients, Package [true false] | true | |||
| Operating Lease - ROU Asset | $ 934 | |||
| Lease liabilities | 960 | |||
| Retained earnings | $ 24,560 | $ 25,847 | ||
| ASU 2018-02 | ||||
| Recently Adopted Accounting Standards | ||||
| Accumulated other comprehensive income (loss) to retained earnings stranded tax effects | $ 337 | |||
| ASU 2014-09 | Cumulative Effect | ||||
| Recently Adopted Accounting Standards | ||||
| Retained earnings | $ 23 | |||
| ASU 2016-02 | Restatement Adjustment | ||||
| Recently Adopted Accounting Standards | ||||
| Operating Lease - ROU Asset | $ 850 | |||
| Lease liabilities | $ 850 |