v3.19.3.a.u2

Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Valuation Allowance [Line Items] |  |  |
Income Tax Expense (Benefit), Intraperiod Tax Allocation | $ 0 | $ 1 | $ 6
NOL and credit carryforwards | 1,731 | 1,595 |
Taxes related to risk management activities and derivatives | 18 | 7 |
Reorganization items and impairments | 73 | 166 |
Deferred Tax Assets, Other | 62 | 101 |
Deferred tax assets before valuation allowance | 1,884 | 1,869 |
Valuation allowance | (873) | (1,000) |
Valuation Allowance, Deferred Tax Asset, Change in Amount | 127 |  |
Total deferred tax assets | 1,011 | 869 |
Deferred tax liabilities: property, plant and equipment | (1,125) | (890) |
Deferred Tax Liabilities, Gross | (1,125) | (890) |
Deferred Tax Liabilities, Net | 114 |  |
Deferred Tax Assets, Net |  | 21 |
Deferred Tax Liabilities, Gross, Noncurrent | (116) | (22) |
Deferred Tax Assets, Gross, Noncurrent | $ 2 | 1 |
Change in Valuation due to Merger [Member] |  |  |
Valuation Allowance [Line Items] |  |  |
Valuation Allowance, Deferred Tax Asset, Change in Amount |  | $ (58) |

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