Commitments and Contingencies (Narrative) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($) Lawsuits
Commitments And Contingencies [Line Items]
Other material lawsuits pending | Lawsuits	0
Fuel Line Lenders [Member]
Commitments And Contingencies [Line Items]
PREPA working capital | $	$ 700