Recent Financing Transactions (MEC) Recent Financing Transactions - Long-term Debt (Details) (MidAmerican Energy Company [Member], MidAmerican Energy Company [Member], USD $) In Millions, unless otherwise specified	Apr. 30, 2014 First Mortgage Bonds, 2.40%, Due March 2019 [Member]	Apr. 30, 2014 First Mortgage Bonds, 3.50%, Due October 2024 [Member]	Apr. 30, 2014 First Mortgage Bonds, 4.40%, Due October 2044 [Member]	May 31, 2014 Notes, 4.65% Series, due 2014 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 150	$ 300	$ 400
Debt Instrument, Interest Rate, Stated Percentage	2.40%	3.50%	4.40%	4.65%
Debt Instrument, Repurchased Face Amount				$ 350