Liquidity And Financial Condition (Schedule Of Reorganization Items) (Details) $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($)
Liquidity And Financial Condition [Abstract]
Professional fees and other bankruptcy related costs	$ 25
Reorganization items, net	$ 25

Amount of reorganization items related to legal and advisory professional fees related to entities in bankruptcy.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=116635682&loc=d3e55730-112764

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56145-112766

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