Amount of damages awarded to the plaintiff in the legal matter.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

Name:	us-gaap_LossContingencyDamagesAwardedValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Commitments and Contingencies (Narrative) (Detail) $ in Millions			1 Months Ended	12 Months Ended
	Feb. 10, 2021 USD ($)	Jan. 31, 2021 USD ($)	Jan. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) Lawsuits
Commitments And Contingencies [Line Items]
Other material lawsuits pending \| Lawsuits				0
Subsequent Event [Member] \| Credit Suisse [Member]
Commitments And Contingencies [Line Items]
Damages Sought Value		$ 604	$ 604
Damages Paid Value	$ 600
Fuel Line Lenders [Member]
Commitments And Contingencies [Line Items]
PREPA working capital				$ 700