| Segment and Significant Customer Information |
Segment Information We assess our business on a regional basis due to the impact on our financial performance of the differing characteristics of these regions, particularly with respect to competition, regulation and other factors impacting supply and demand. At September 30, 2013, our reportable segments were West (including geothermal), Texas, North (including Canada) and Southeast. We continue to evaluate the optimal manner in which we assess our performance including our segments and future changes may result. Commodity Margin is a key operational measure reviewed by our chief operating decision maker to assess the performance of our segments. The tables below show our financial data for our segments for the periods indicated (in millions). | | | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended September 30, 2013 | | West | | Texas | | North | | Southeast | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 620 |
| | $ | 842 |
| | $ | 401 |
| | $ | 187 |
| | $ | — |
| | $ | 2,050 |
| Intersegment revenues | 1 |
| | (6 | ) | | 12 |
| | 57 |
| | (64 | ) | | — |
| Total operating revenues | $ | 621 |
| | $ | 836 |
| | $ | 413 |
| | $ | 244 |
| | $ | (64 | ) | | $ | 2,050 |
| Commodity Margin | $ | 337 |
| | $ | 328 |
| | $ | 242 |
| | $ | 78 |
| | $ | — |
| | $ | 985 |
| Add: Unrealized mark-to-market commodity activity, net and other(1) | 16 |
| | (5 | ) | | (3 | ) | | 6 |
| | (8 | ) | | 6 |
| Less: | | | | | | | | | | | | Plant operating expense | 80 |
| | 60 |
| | 40 |
| | 27 |
| | (7 | ) | | 200 |
| Depreciation and amortization expense | 57 |
| | 42 |
| | 33 |
| | 18 |
| | — |
| | 150 |
| Sales, general and other administrative expense | 4 |
| | 17 |
| | 6 |
| | 5 |
| | 1 |
| | 33 |
| Other operating expenses | 11 |
| | 2 |
| | 9 |
| | 1 |
| | (3 | ) | | 20 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (9 | ) | | — |
| | — |
| | (9 | ) | Income from operations | 201 |
| | 202 |
| | 160 |
| | 33 |
| | 1 |
| | 597 |
| Interest expense, net of interest income |
| | | | | | | | | | 174 |
| Other (income) expense, net | | | | | | | | | | | 7 |
| Income before income taxes | | | | | | | | | | | $ | 416 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended September 30, 2012 | | West | | Texas | | North | | Southeast | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 509 |
| | $ | 886 |
| | $ | 407 |
| | $ | 194 |
| | $ | — |
| | $ | 1,996 |
| Intersegment revenues | 2 |
| | (34 | ) | | 4 |
| | 68 |
| | (40 | ) | | — |
| Total operating revenues | $ | 511 |
| | $ | 852 |
| | $ | 411 |
| | $ | 262 |
| | $ | (40 | ) | | $ | 1,996 |
| Commodity Margin(2)(3) | $ | 330 |
| | $ | 218 |
| | $ | 266 |
| | $ | 83 |
| | $ | — |
| | $ | 897 |
| Add: Unrealized mark-to-market commodity activity, net and other(1) | (40 | ) | | 249 |
| | (26 | ) | | 27 |
| | (8 | ) | | 202 |
| Less: | | | | | | | | | | | | Plant operating expense | 88 |
| | 49 |
| | 51 |
| | 29 |
| | (10 | ) | | 207 |
| Depreciation and amortization expense | 52 |
| | 35 |
| | 33 |
| | 21 |
| | (1 | ) | | 140 |
| Sales, general and other administrative expense | 9 |
| | 12 |
| | 8 |
| | 8 |
| | (1 | ) | | 36 |
| Other operating expenses | 10 |
| | 1 |
| | 6 |
| | (1 | ) | | 2 |
| | 18 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (7 | ) | | — |
| | — |
| | (7 | ) | Income from operations | 131 |
| | 370 |
| | 149 |
| | 53 |
| | 2 |
| | 705 |
| Interest expense, net of interest income | | | | | | | | | | | 181 |
| Other (income) expense, net | | | | | | | | | | | 6 |
| Income before income taxes | | | | | | | | | | | $ | 518 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | Nine Months Ended September 30, 2013 | | West | | Texas | | North | | Southeast | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 1,482 |
| | $ | 1,820 |
| | $ | 1,055 |
| | $ | 506 |
| | $ | — |
| | $ | 4,863 |
| Intersegment revenues | 2 |
| | (24 | ) | | 27 |
| | 161 |
| | (166 | ) | | — |
| Total operating revenues | $ | 1,484 |
| | $ | 1,796 |
| | $ | 1,082 |
| | $ | 667 |
| | $ | (166 | ) | | $ | 4,863 |
| Commodity Margin | $ | 737 |
| | $ | 537 |
| | $ | 543 |
| | $ | 162 |
| | $ | — |
| | $ | 1,979 |
| Add: Unrealized mark-to-market commodity activity, net and other(4) | (2 | ) | | 18 |
| | (8 | ) | | 20 |
| | (24 | ) | | 4 |
| Less: | | | | | | | | | | | | Plant operating expense | 261 |
| | 224 |
| | 130 |
| | 92 |
| | (23 | ) | | 684 |
| Depreciation and amortization expense | 160 |
| | 129 |
| | 98 |
| | 55 |
| | (1 | ) | | 441 |
| Sales, general and other administrative expense | 11 |
| | 55 |
| | 18 |
| | 17 |
| | 1 |
| | 102 |
| Other operating expenses | 31 |
| | 4 |
| | 23 |
| | 2 |
| | (2 | ) | | 58 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (25 | ) | | — |
| | — |
| | (25 | ) | Income from operations | 272 |
| | 143 |
| | 291 |
| | 16 |
| | 1 |
| | 723 |
| Interest expense, net of interest income | | | | | | | | | | | 517 |
| Debt extinguishment costs and other (income) expense, net | | | | | | | | | | | 83 |
| Income before income taxes | | | | | | | | | | | $ | 123 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | Nine Months Ended September 30, 2012 | | West | | Texas | | North | | Southeast | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 1,183 |
| | $ | 1,430 |
| | $ | 974 |
| | $ | 524 |
| | $ | — |
| | $ | 4,111 |
| Intersegment revenues | 7 |
| | 27 |
| | 9 |
| | 84 |
| | (127 | ) | | — |
| Total operating revenues | $ | 1,190 |
| | $ | 1,457 |
| | $ | 983 |
| | $ | 608 |
| | $ | (127 | ) | | $ | 4,111 |
| Commodity Margin(2)(3) | $ | 748 |
| | $ | 472 |
| | $ | 591 |
| | $ | 212 |
| | $ | — |
| | $ | 2,023 |
| Add: Unrealized mark-to-market commodity activity, net and other(4) | (80 | ) | | 66 |
| | (17 | ) | | (5 | ) | | (22 | ) | | (58 | ) | Less: | | | | | | | | | | | | Plant operating expense | 281 |
| | 189 |
| | 154 |
| | 98 |
| | (23 | ) | | 699 |
| Depreciation and amortization expense | 151 |
| | 104 |
| | 100 |
| | 66 |
| | (3 | ) | | 418 |
| Sales, general and other administrative expense | 23 |
| | 36 |
| | 22 |
| | 23 |
| | — |
| | 104 |
| Other operating expenses | 30 |
| | 4 |
| | 21 |
| | 2 |
| | 1 |
| | 58 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (21 | ) | | — |
| | — |
| | (21 | ) | Income from operations | 183 |
|
| 205 |
|
| 298 |
|
| 18 |
|
| 3 |
| | 707 |
| Interest expense, net of interest income | | | | | | | | | | | 545 |
| Loss on interest rate derivatives | | | | | | | | | | | 14 |
| Debt extinguishment costs and other (income) expense, net | | | | | | | | | | | 26 |
| Income before income taxes | | | | | | | | | | | $ | 122 |
|
_________ | | (1) | Includes $44 million and $16 million of lease levelization and $4 million and $4 million of amortization expense for the three months ended September 30, 2013 and 2012, respectively. |
| | (2) | Our North segment includes Commodity Margin of $32 million and $64 million for the three and nine months ended September 30, 2012 related to Riverside Energy Center, LLC, which was sold in December 2012. |
| | (3) | Our Southeast segment includes Commodity Margin of $20 million and $44 million for the three and nine months ended September 30, 2012 related to Broad River, which was sold in December 2012. |
| | (4) | Includes $17 million and $7 million of lease levelization and $11 million and $11 million of amortization expense for the nine months ended September 30, 2013 and 2012, respectively. |
|