| **Significant Accounting Policies and Recent Accounting Standards - Adoption of New Accounting Standards (Details) - USD ($) $ / shares in Units, $ in Millions** | 3 Months Ended | 6 Months Ended |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
||
| **New Accounting Pronouncements or Change in Accounting Principle [Line Items]**                                                                                  |           |           |   |   |
| Income tax benefits                                                                                                                                               | $ (76)         | $ (85)         | $ (139) | $ (152) |
| Earnings per diluted share (in usd per share)                                                                                                                     | $ 1.40         | $ (1.22)       | $ 2.68 | $ (0.03) |
| New Accounting Pronouncement, Early Adoption, Effect | Adjustments for New Accounting Pronouncements                                                              |           |           |   |   |
| **New Accounting Pronouncements or Change in Accounting Principle [Line Items]**                                                                                  |           |           |   |   |
| Income tax benefits                                                                                                                                               | $ 3            |           | $ 13 |   |
| Earnings per diluted share (in usd per share)                                                                                                                     | $ 0.02         |           | $ 0.10 |   |
| Net cash provided by operating activities                                                                                                                         |           |           | $ 13 |   |

| X                                                                                                                                                                                                                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount
+ References
No definition available.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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.
+ References
No definition available.
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| X                                                                                                                                                                                      |
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