Receivables (Receivables Sold Under The Agreement) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable [Line Items]
Fair value of deferred proceeds	$ 188	$ 188
IPL [Member]
Accounts Receivable [Line Items]
Fair value of deferred proceeds	188	188
Financing Receivable [Member] \| IPL [Member]
Accounts Receivable [Line Items]
Customer accounts receivable	114	125
Unbilled utility revenues	92	95
Other receivables	0	1
Receivables sold to third party	206	221
Less: cash proceeds	1	27
Deferred proceeds	205	194
Less: allowance for expected credit losses	17	6
Fair value of deferred proceeds	188	188
Outstanding receivables past due	$ 27	$ 26

Amount of financing receivable past due.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 80
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922355-210448

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919253-210447

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953401-111524

Name:	us-gaap_FinancingReceivableRecordedInvestmentPastDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant