Segment Information We assess our business on a regional basis due to the effect on our financial performance of the differing characteristics of these regions, particularly with respect to competition, regulation and other factors affecting supply and demand. At March 31, 2019, our geographic reportable segments for our wholesale business are West (including geothermal), Texas and East (including Canada) and we have a separate reportable segment for our retail business. We continue to evaluate the optimal manner in which we assess our performance including our segments and future changes may result in changes to the composition of our geographic segments. Commodity Margin is a key operational measure of profit reviewed by our chief operating decision maker to assess the performance of our segments. The tables below show financial data for our segments (including a reconciliation of our Commodity Margin to income (loss) from operations by segment) for the periods indicated (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended March 31, 2019 | | Wholesale | | | | Consolidation | | | | West | | Texas | | East | | Retail | | Elimination | | Total | Total operating revenues(1) | $ | 682 |
| | $ | 743 |
| | $ | 689 |
| | $ | 998 |
| | $ | (513 | ) | | $ | 2,599 |
| | | | | | | | | | | | | Commodity Margin | $ | 264 |
| | $ | 162 |
| | $ | 265 |
| | $ | 88 |
| | $ | — |
| | $ | 779 |
| Add: Mark-to-market commodity activity, net and other(2) | 56 |
| | 44 |
| | 13 |
| | (53 | ) | | (8 | ) | | 52 |
| Less: | | | | | | | | | | |
|
| Operating and maintenance expense | 81 |
| | 65 |
| | 67 |
| | 34 |
| | (8 | ) | | 239 |
| Depreciation and amortization expense | 73 |
| | 45 |
| | 43 |
| | 13 |
| | — |
| | 174 |
| General and other administrative expense | 7 |
| | 12 |
| | 9 |
| | 4 |
| | — |
| | 32 |
| Other operating expenses | 9 |
| | 2 |
| | 23 |
| | — |
| | — |
| | 34 |
| (Income) from unconsolidated subsidiaries | — |
| | — |
| | (6 | ) | | — |
| | — |
| | (6 | ) | Income (loss) from operations | 150 |
| | 82 |
| | 142 |
| | (16 | ) | | — |
| | 358 |
| Interest expense | | | | | | | | | | | 149 |
| Gain on extinguishment of debt and other (income) expense, net | | | | | | | | | | | 19 |
| Income before income taxes | | | | | | | | | | | $ | 190 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended March 31, 2018 | | Wholesale | | | | Consolidation | | | | West | | Texas | | East | | Retail | | Elimination | | Total | Total operating revenues(1) | $ | 480 |
| | $ | 140 |
| | $ | 614 |
| | $ | 938 |
| | $ | (163 | ) | | $ | 2,009 |
| | | | | | | | | | | | | Commodity Margin | $ | 185 |
| | $ | 166 |
| | $ | 184 |
| | $ | 77 |
| | $ | — |
| | $ | 612 |
| Add: Mark-to-market commodity activity, net and other(2) | 13 |
| | (547 | ) | | 40 |
| | 128 |
| | (7 | ) | | (373 | ) | Less: | | | | | | | | | | | | Operating and maintenance expense | 90 |
| | 80 |
| | 71 |
| | 40 |
| | (6 | ) | | 275 |
| Depreciation and amortization expense | 67 |
| | 76 |
| | 45 |
| | 13 |
| | — |
| | 201 |
| General and other administrative expense | 16 |
| | 25 |
| | 15 |
| | 4 |
| | — |
| | 60 |
| Other operating expenses | 14 |
| | 16 |
| | 7 |
| | — |
| | — |
| | 37 |
| (Income) from unconsolidated subsidiaries | — |
| | — |
| | (6 | ) | | — |
| | — |
| | (6 | ) | Income (loss) from operations | 11 |
|
| (578 | ) | | 92 |
| | 148 |
| | (1 | ) | | (328 | ) | Interest expense | | | | | | | | | | | 151 |
| Other (income) expense, net | | | | | | | | | | | 7 |
| Loss before income taxes | | | | | | | | | | | $ | (486 | ) |
_________ | | (1) | Includes intersegment revenues of $162 million and $114 million in the West, $211 million and $(67) million in Texas, $137 million and $115 million in the East and $3 million and $1 million in Retail for the three months ended March 31, 2019 and 2018, respectively. |
| | (2) | Includes $(16) million and $(16) million of lease levelization and $21 million and $28 million of amortization expense for the three months ended March 31, 2019 and 2018, respectively. |
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