Document and Entity Information	9 Months Ended
Sep. 30, 2011	Oct. 31, 2011
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Entity Registrant Name	MIDAMERICAN ENERGY HOLDINGS CO /NEW/
Entity Central Index Key	0001081316
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		74,609,001

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