Subsequent Events (MEC) Subsequent Events - MEC (Details) $ in Millions	Dec. 31, 2020 USD ($)
Subsequent Event [Line Items]
Par value	$ 49,759
MidAmerican Energy Company [Member]
Subsequent Event [Line Items]
Par value	7,276
MidAmerican Energy Company [Member] \| MEC First Mortgage Bonds, 3.95%, Due 2047 [Member]
Subsequent Event [Line Items]
Par value	$ 475
Debt Instrument, Interest Rate, Stated Percentage	3.95%

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant