Subsidiary Debt - Summary (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Debt Instrument [Line Items]
Par value	$ 20,735
Other Long-term Debt, Noncurrent	14,977		13,253
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	16,110
Other Long-term Debt, Current	1,137		434
Other Long-term Debt, Noncurrent	14,977		13,253
Other Long-term Debt	16,114		13,687
Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value	6,948
Other Long-term Debt	6,934		6,300
Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value	3,616
Other Long-term Debt	3,546		3,401
Subsidiary Debt [Member] | MidAmerican Energy Pipeline Group [Member]
Debt Instrument [Line Items]
Par value	1,528
Other Long-term Debt	1,528		1,665
Subsidiary Debt [Member] | Northern Powergrid Holdings [Member]
Debt Instrument [Line Items]
Par value	2,362	[1]
Other Long-term Debt	2,451		2,128
Subsidiary Debt [Member] | MidAmerican Renewables [Member]
Debt Instrument [Line Items]
Par value	1,656
Other Long-term Debt	$ 1,655		$ 193

[1] The par values for these debt instruments are denominated in sterling and have been converted to United States dollars at the applicable exchange rate.