v3.3.1.900

Segment and Significant Customer Information (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Sep. 30, 2014 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  | $ 1,436 | $ 1,948 | $ 1,442 | $ 1,646 | $ 1,939 | $ 2,187 | $ 1,939 | $ 1,965 |  | $ 6,472 | $ 8,030 |  | $ 6,301 |
Commodity Margin |  |  |  |  |  |  |  |  |  |  | 2,786 | 2,759 | [1] | 2,568 | [1]
Mark-to-Market Commodity Activity, Net and Other Revenue | [2] |  |  |  |  |  |  |  |  |  | (81) | 379 |  | (3) |
Plant operating expense |  |  |  |  |  |  |  |  |  |  | 1,018 | 969 |  | 895 |
Depreciation and amortization expense |  |  |  |  |  |  |  |  |  |  | 638 | 603 |  | 593 |
Sales, general and other administrative expense |  |  |  |  |  |  |  |  |  |  | 138 | 144 |  | 136 |
Other Cost and Expense, Operating |  |  |  |  |  |  |  |  |  |  | 80 | 88 |  | 81 |
Impairment losses |  |  |  |  |  |  |  |  |  |  | 0 | 123 |  | 16 |
Gain (Loss) on Disposition of Assets |  |  |  |  |  |  |  |  |  |  | 0 | 753 |  | 0 |
(Income) from unconsolidated investments in power plants |  |  |  |  |  |  |  |  |  |  | (24) | (25) |  | (30) |
Income from operations |  | $ 22 | $ 466 | $ 201 | $ 166 | $ 390 | $ 1,126 | $ 329 | $ 144 |  | 855 | 1,989 |  | 874 |
Interest expense, net of interest income |  |  |  |  |  |  |  |  |  |  | 624 | 639 |  | 690 |
Debt Extinguishment Costs and Other (Income) Expense, Net |  |  |  |  |  |  |  |  |  |  | 58 | 367 |  | 164 |
Income before income taxes |  |  |  |  |  |  |  |  |  |  | 173 | 983 |  | 20 |
Lease levelization |  |  |  |  |  |  |  |  |  |  | (2) | (5) |  | 6 |
Contract amortization |  |  |  |  |  |  |  |  |  |  | $ 20 | $ 14 |  | $ 14 |
Number of significant customers |  |  |  |  |  |  |  |  |  |  | two | one |  | two |
West [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | $ 2,094 | $ 2,358 |  | $ 1,942 |
Commodity Margin |  |  |  |  |  |  |  |  |  |  | 1,106 | 1,050 | [1] | 1,020 | [1]
Mark-to-Market Commodity Activity, Net and Other Revenue | [2] |  |  |  |  |  |  |  |  |  | 160 | 220 |  | (50) |
Plant operating expense |  |  |  |  |  |  |  |  |  |  | 416 | 385 |  | 365 |
Depreciation and amortization expense |  |  |  |  |  |  |  |  |  |  | 250 | 245 |  | 227 |
Sales, general and other administrative expense |  |  |  |  |  |  |  |  |  |  | 35 | 41 |  | 37 |
Other Cost and Expense, Operating |  |  |  |  |  |  |  |  |  |  | 37 | 50 |  | 45 |
Impairment losses |  |  |  |  |  |  |  |  |  |  |  | 0 |  | 16 |
Gain (Loss) on Disposition of Assets |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |
(Income) from unconsolidated investments in power plants |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  | 0 |
Income from operations |  |  |  |  |  |  |  |  |  |  | 528 | 549 |  | 280 |
Texas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 2,359 | 3,252 |  | 2,343 |
Commodity Margin |  |  |  |  |  |  |  |  |  |  | 736 | 760 | [1] | 632 | [1]
Mark-to-Market Commodity Activity, Net and Other Revenue | [2] |  |  |  |  |  |  |  |  |  | (120) | 142 |  | 51 |
Plant operating expense |  |  |  |  |  |  |  |  |  |  | 338 | 313 |  | 269 |
Depreciation and amortization expense |  |  |  |  |  |  |  |  |  |  | 204 | 191 |  | 165 |
Sales, general and other administrative expense |  |  |  |  |  |  |  |  |  |  | 63 | 64 |  | 56 |
Other Cost and Expense, Operating |  |  |  |  |  |  |  |  |  |  | 9 | 5 |  | 3 |
Impairment losses |  |  |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Gain (Loss) on Disposition of Assets |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |
(Income) from unconsolidated investments in power plants |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  | 0 |
Income from operations |  |  |  |  |  |  |  |  |  |  | 2 | 329 |  | 190 |
East [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 2,047 | 2,496 |  | 2,134 |
Commodity Margin |  |  |  |  |  |  |  |  |  |  | 944 | 949 | [1] | 916 | [1]
Mark-to-Market Commodity Activity, Net and Other Revenue | [2] |  |  |  |  |  |  |  |  |  | (92) | 48 |  | 27 |
Plant operating expense |  |  |  |  |  |  |  |  |  |  | 292 | 302 |  | 292 |
Depreciation and amortization expense |  |  |  |  |  |  |  |  |  |  | 184 | 168 |  | 203 |
Sales, general and other administrative expense |  |  |  |  |  |  |  |  |  |  | 40 | 39 |  | 42 |
Other Cost and Expense, Operating |  |  |  |  |  |  |  |  |  |  | 36 | 32 |  | 33 |
Impairment losses |  |  |  |  |  |  |  |  |  |  |  | 123 |  | 0 |
Gain (Loss) on Disposition of Assets |  |  |  |  |  |  |  |  |  |  |  | 753 |  |  |
(Income) from unconsolidated investments in power plants |  |  |  |  |  |  |  |  |  |  | (24) | (25) |  | (30) |
Income from operations |  |  |  |  |  |  |  |  |  |  | 324 | 1,111 |  | 403 |
Commodity Margin for Six Southeast Power Plants Sold |  |  |  |  |  |  |  |  |  |  |  | 81 |  | 152 |
Number of power plants disposed of |  |  |  |  |  |  |  |  |  | 6 |  |  |  |  |
Geography Consolidation and Elimination [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | (28) | (76) |  | (118) |
Commodity Margin |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  | 0 |
Mark-to-Market Commodity Activity, Net and Other Revenue |  |  |  |  |  |  |  |  |  |  | (29) | (31) |  | (31) |
Plant operating expense |  |  |  |  |  |  |  |  |  |  | (28) | (31) |  | (31) |
Depreciation and amortization expense |  |  |  |  |  |  |  |  |  |  | 0 | (1) |  | (2) |
Sales, general and other administrative expense |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  | 1 |
Other Cost and Expense, Operating |  |  |  |  |  |  |  |  |  |  | (2) | 1 |  | 0 |
Impairment losses |  |  |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Gain (Loss) on Disposition of Assets |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |
(Income) from unconsolidated investments in power plants |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  | 0 |
Income from operations |  |  |  |  |  |  |  |  |  |  | 1 | 0 |  | 1 |
PJM Settlement, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 724 | 1,000 |  | 820 |
Pacific Gas & Electric Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 642 |  |  | 694 |
Operating Segments [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 6,472 | 8,030 |  | 6,301 |
Operating Segments [Member] | West [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 2,089 | 2,352 |  | 1,937 |
Operating Segments [Member] | Texas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 2,344 | 3,229 |  | 2,347 |
Operating Segments [Member] | East [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 2,039 | 2,449 |  | 2,017 |
Operating Segments [Member] | Geography Consolidation and Elimination [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  | 0 |
Intersegment Eliminations [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  | 0 |
Intersegment Eliminations [Member] | West [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 5 | 6 |  | 5 |
Intersegment Eliminations [Member] | Texas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 15 | 23 |  | (4) |
Intersegment Eliminations [Member] | East [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | 8 | 47 |  | 117 |
Intersegment Eliminations [Member] | Geography Consolidation and Elimination [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues from External Customers and Long-Lived Assets [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  |  |  | $ (28) | $ (76) |  | $ (118) |
[1] | Our East segment includes Commodity Margin of $81 million and $152 million for the years ended December 31, 2014 and 2013, respectively, related to the six power plants in our East segment that were sold in July 2014.
[2] | Includes $(2) million, $(5) million and $6 million of lease levelization and $20 million, $14 million and $14 million of amortization expense for the years ended December 31, 2015, 2014 and 2013, respectively.

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- Definition The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.4) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=51677171&loc=d3e3636-108311 + Details
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