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Commitments and Contingencies (Narrative) (Detail) $ in Millions |  | 3 Months Ended
--- | --- | ---
Feb. 10, 2021 USD ($) | Mar. 31, 2021 USD ($) Lawsuits
Commitments And Contingencies [Line Items] |  |
Other material lawsuits pending | Lawsuits |  | 0
Credit Suisse [Member] |  |
Commitments And Contingencies [Line Items] |  |
Damages Sought Value |  | $ 604
Damages Paid Value | $ 600 |
Fuel Line Lenders [Member] |  |
Commitments And Contingencies [Line Items] |  |
PREPA working capital |  | $ 700

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