v3.19.3.a.u2

Summary of Significant Accounting Policies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2019
Accounting Policies [Abstract] |
Schedule of Jointly Owned Utility Plants | The following table summarizes our proportionate ownership interest in jointly-owned power plants:
As of December 31, 2019 |  | Ownership Interest |  | Property, Plant & Equipment |  | Accumulated Depreciation |  | Construction in Progress
(in millions, except percentages)
Freestone Energy Center |  | 75.0 | % |  | $ | 379 |  |  | $ | (177 | ) |  | $ | — |
Hidalgo Energy Center |  | 78.5 | % |  | $ | 250 |  |  | $ | (113 | ) |  | $ | — |
Schedule of Components of Restricted Cash | The table below represents the components of our restricted cash as of December 31, 2019 and 2018 (in millions):
| 2019 |  | 2018
| Current |  | Non-Current |  | Total |  | Current |  | Non-Current |  | Total
Debt service | $ | 58 |  |  | $ | 8 |  |  | $ | 66 |  |  | $ | 13 |  |  | $ | 8 |  |  | $ | 21 |
Construction/major maintenance | 28 |  |  | 6 |  |  | 34 |  |  | 23 |  |  | 24 |  |  | 47 |
Security/project/insurance | 209 |  |  | 31 |  |  | 240 |  |  | 120 |  |  | — |  |  | 120 |
Other | 4 |  |  | 1 |  |  | 5 |  |  | 11 |  |  | 2 |  |  | 13 |
Total | $ | 299 |  |  | $ | 46 |  |  | $ | 345 |  |  | $ | 167 |  |  | $ | 34 |  |  | $ | 201 |
Schedule of Intangible Assets and Goodwill [Table Text Block] | As of December 31, 2019 and 2018, the components of our intangible assets were as follows (in millions):
| 2019 |  | 2018 |  | Lives
Acquired contracts | $ | 444 |  |  | $ | 458 |  |  | 0 – 9 Years
Customer relationships | 445 |  |  | 445 |  |  | 7 – 14 Years
Trademark and trade name | 40 |  |  | 40 |  |  | 15 Years
Other | 4 |  |  | 88 |  |  | 39 – 44 Years
| 933 |  |  | 1,031 |  |  |
Less: Accumulated amortization | 593 |  |  | 619 |  |  |
Intangible assets, net | $ | 340 |  |  | $ | 412 |  |  |
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] | The estimated aggregate amortization expense of our intangible assets for the next five years is as follows (in millions):
2020 | $ | 44 |
2021 | $ | 39 |
2022 | $ | 36 |
2023 | $ | 28 |
2024 | $ | 28 |

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of goodwill and intangible assets, which may be broken down by segment or major class. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
Name: | us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of proportionate interests in jointly owned utility plants. Includes the amount of plants in service, the accumulated provision for depreciation (if available), the amount of plants under construction, and the proportionate share. The amounts presented may be further subdivided to show amounts applicable to plant subcategories (for example, production, transmission, distribution). Includes statements that the amounts represent the utility's share in each joint plant and that it must provide its own financing. Information concerning two or more generating plants on the same site may be combined. States that the utility's share of direct expenses of the joint plants is included in the corresponding operating expenses on its income statement (for example, fuel, maintenance of plant, other operating expense). If the share of direct expenses is charged to purchased power, then disclose the amount so charged and the proportionate amounts charged to specific operating expenses on the records maintained for the joint plants. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -URI http://asc.fasb.org/extlink&oid=115995737&loc=d3e659983-123033 + Details
Name: | us-gaap_ScheduleOfJointlyOwnedUtilityPlantsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of cash and cash equivalents restricted as to withdrawal or usage. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(1)(a)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(2)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
Name: | us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration