Consolidated Statements of Capitalization (MEC) Consolidated Statements of Capitalization (MEC) (Parenthetical) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Tax-exempt bond obligations, variable rate, due 2016-2038 [Member]
Weighted average interest rate at period end	0.18%	0.15%
Notes, 5.125% Series, due 2013 [Member]
Stated interest rate	5.125%	5.125%
Notes, 4.65% Series, due 2014 [Member]
Stated interest rate	4.65%	4.65%
Notes, 5.95% Series, due 2017 [Member]
Stated interest rate	5.95%	5.95%
Notes, 5.3% Series, due 2018 [Member]
Stated interest rate	5.30%	5.30%
Notes, 6.75% Series, due 2031 [Member]
Stated interest rate	6.75%	6.75%
Notes, 5.75% Series, due 2035 [Member]
Stated interest rate	5.75%	5.75%
Notes, 5.8% Series, due 2036 [Member]
Stated interest rate	5.80%	5.80%
Turbine purchase obligation, 1.46%, due 2013 [Member]
Vendor financing, discount rate applied	1.46%	1.46%
Turbine purchase obligation, 1.43%, due 2015 [Member]
Vendor financing, discount rate applied	1.43%
Common Stock [Member]
Common Stock, Par or Stated Value Per Share	$ 0.00	$ 0.00
Common Stock, Shares Authorized	350,000,000	350,000,000
Common Stock, Shares, Outstanding	70,980,203	70,980,203
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated other comprehensive income (loss), available-for-sale adjustment, tax	$ (4)	$ (6)
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from cash flow hedges, tax	$ (13)	$ (17)
Preferred Securities [Member]
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred securities, $3.30 Series, 49,451 shares [Member]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 3.30	$ 3.30
Preferred Stock, Shares Outstanding	49,451	49,451
Preferred securities, $3.75 Series, 38,305 shares [Member]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 3.75	$ 3.75
Preferred Stock, Shares Outstanding	38,305	38,305
Preferred securities, $3.90 Series, 32,630 shares [Member]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 3.90	$ 3.90
Preferred Stock, Shares Outstanding	32,630	32,630
Preferred securities, $4.20 Series, 22,461 shares [Member]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 4.20	$ 4.20
Preferred Stock, Shares Outstanding	22,461	22,461
Preferred securities, $4.35 Series, 39,775 shares [Member]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 4.35	$ 4.35
Preferred Stock, Shares Outstanding	39,775	39,775
Preferred securities, $4.40 Series, 35,697 shares [Member]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 4.40	$ 4.40
Preferred Stock, Shares Outstanding	35,697	35,697
Preferred securities, $4.80 Series, 49,898 shares [Member]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 4.80	$ 4.80
Preferred Stock, Shares Outstanding	49,898	49,898