v3.7.0.1

Oncor-Related Transactions (Details) - USD ($) | Jul. 07, 2017 | Oct. 31, 2016 | Jul. 29, 2016
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Energy Future Holdings Corp. [Member] |  |  |
Business Acquisition [Line Items] |  |  |
Percentage of interests to be acquired in pending merger |  |  | 100.00%
Energy Future Holdings Corp., Texas Transmission Holdings Corporation, and Oncor Management Investment LLC [Member] | Oncor Electric Delivery Company LLC [Member] |  |  |
Business Acquisition [Line Items] |  |  |
Percentage of interests to be acquired in pending merger |  | 100.00% | 80.00%
Subsequent Event [Member] | Energy Future Holdings Corp., Texas Transmission Holdings Corporation, and Oncor Management Investment LLC [Member] |  |  |
Business Acquisition [Line Items] |  |  |
Termination fee sought | $ 275,000,000 |  |

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