Derivative Instruments (Details 4) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
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| Summary of Derivative Instruments by Risk Exposure [Abstract] | ||||||||||||||||||
| Gain (Loss) on Derivative Instruments, Net, Pretax | [1] | $ 39 | $ 244 | $ 213 | $ 400 | |||||||||||||
| Gain (Loss) on Sale of Derivatives | [2],[3] | 18 | 58 | 15 | 169 | |||||||||||||
| Mark-to-market gain (loss) | [4] | 21 | 186 | 198 | 231 | |||||||||||||
| Sales [Member] | ||||||||||||||||||
| Summary of Derivative Instruments by Risk Exposure [Abstract] | ||||||||||||||||||
| Gain (Loss) on Derivative Instruments, Net, Pretax | [1],[5],[6] | 34 | 541 | 541 | 578 | |||||||||||||
| Cost of Sales [Member] | ||||||||||||||||||
| Summary of Derivative Instruments by Risk Exposure [Abstract] | ||||||||||||||||||
| Gain (Loss) on Derivative Instruments, Net, Pretax | [1],[5],[6] | 37 | (296) | (272) | (176) | |||||||||||||
| Interest Expense [Member] | ||||||||||||||||||
| Summary of Derivative Instruments by Risk Exposure [Abstract] | ||||||||||||||||||
| Gain (Loss) on Derivative Instruments, Net, Pretax | [1] | (32) | (1) | (56) | (2) | |||||||||||||
| Interest rate hedging instruments | ||||||||||||||||||
| Summary of Derivative Instruments by Risk Exposure [Abstract] | ||||||||||||||||||
| Gain (Loss) on Sale of Derivatives | [2],[3],[7] | (18) | 0 | (18) | 0 | |||||||||||||
| Mark-to-market gain (loss) | [4] | (14) | (1) | (38) | (2) | |||||||||||||
| Energy Related Derivative | ||||||||||||||||||
| Summary of Derivative Instruments by Risk Exposure [Abstract] | ||||||||||||||||||
| Gain (Loss) on Sale of Derivatives | [2],[3] | 36 | 58 | 33 | 169 | |||||||||||||
| Mark-to-market gain (loss) | [4] | $ 35 | $ 187 | $ 236 | $ 233 | |||||||||||||
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