The following tables present assets and liabilities accounted for at fair value on a recurring basis as of March 31, 2018 and December 31, 2017 by fair value hierarchy level. We have elected to offset the fair value amounts recognized for multiple derivative contracts executed with the same counterparty, including any related cash collateral as shown below; however, fair value amounts by hierarchy level are presented on a gross basis in the following tables. | | | | | | | | | | | | | | | | | | | | | | | | | | March 31, 2018 | | Fair Value Hierarchy | | | | | | | (In millions) | Level 1 | | Level 2 | | Level 3 | | Netting and Collateral(a) | | Net Carrying Value on Balance Sheet(b) | | Collateral Pledged Not Offset | Commodity derivative instruments, assets | $ | 21 |
| | $ | — |
| | $ | — |
| | $ | (21 | ) | | $ | — |
| | $ | 22 |
| Other assets | 3 |
| | — |
| | — |
| | N/A |
| | 3 |
| | — |
| Total assets at fair value | $ | 24 |
| | $ | — |
| | $ | — |
| | $ | (21 | ) | | $ | 3 |
| | $ | 22 |
| | | | | | | | | | | | | Commodity derivative instruments, liabilities(c) | $ | 60 |
| | $ | — |
| | $ | 1 |
| | $ | (60 | ) | | $ | 1 |
| | $ | — |
| Embedded derivatives in commodity contracts(c) | — |
| | — |
| | 59 |
| | — |
| | 59 |
| | — |
| Total liabilities at fair value | $ | 60 |
| | $ | — |
| | $ | 60 |
| | $ | (60 | ) | | $ | 60 |
| | $ | — |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | December 31, 2017 | | Fair Value Hierarchy | | | | | | | (In millions) | Level 1 | | Level 2 | | Level 3 | | Netting and Collateral(a) | | Net Carrying Value on Balance Sheet(b) | | Collateral Pledged Not Offset | Commodity derivative instruments, assets | $ | 127 |
| | $ | — |
| | $ | — |
| | $ | (118 | ) | | $ | 9 |
| | $ | 8 |
| Other assets | 3 |
| | — |
| | — |
| | N/A |
| | 3 |
| | — |
| Total assets at fair value | $ | 130 |
| | $ | — |
| | $ | — |
| | $ | (118 | ) | | $ | 12 |
| | $ | 8 |
| | | | | | | | | | | | | Commodity derivative instruments, liabilities | $ | 126 |
| | $ | — |
| | $ | 2 |
| | $ | (126 | ) | | $ | 2 |
| | $ | — |
| Embedded derivatives in commodity contracts(c) | — |
| | — |
| | 64 |
| | — |
| | 64 |
| | — |
| Total liabilities at fair value | $ | 126 |
| | $ | — |
| | $ | 66 |
| | $ | (126 | ) | | $ | 66 |
| | $ | — |
|
| | (a) | Represents the impact of netting assets, liabilities and cash collateral when a legal right of offset exists. As of March 31, 2018, cash collateral of $39 million was netted with the mark-to-market derivative liabilities. As of December 31, 2017, $8 million was netted with mark-to-market derivative liabilities. |
| | (b) | We have no derivative contracts that are subject to master netting arrangements reflected gross on the balance sheet. |
| | (c) | Level 3 includes $11 million and $12 million classified as current at March 31, 2018 and December 31, 2017, respectively. |
|