Consolidated Statements of Capitalization (MEC) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
MidAmerican Energy common shareholder's equity	$ 3,244	$ 2,931
Obligations under capital leases	1	1
Unamortized debt discount	(25)	(6)
Long-term debt	3,115	2,865
Percent of total capitalization	48.80%	49.20%
MidAmerican Energy preferred securities	27	27
Noncontrolling interests	1	1
Total capitalization	6,387	5,824
Total capitalization (percent)	100.00%	100.00%
Variable-rate tax-exempt obligation series, due 2016 [Member]
Unsecured long-term debt, noncurrent	34	34
Variable-rate tax-exempt obligation series, due 2017 [Member]
Unsecured long-term debt, noncurrent	4	4
Variable-rate tax-exempt obligation series, due 2023, issued in 1993 [Member]
Unsecured long-term debt, noncurrent	7	7
Variable-rate tax-exempt obligation series, due 2023, issued in 2008 [Member]
Unsecured long-term debt, noncurrent	57	57
Variable-rate tax-exempt obligation series, due 2024 [Member]
Unsecured long-term debt, noncurrent	35	35
Variable-rate tax-exempt obligation series, due 2025 [Member]
Unsecured long-term debt, noncurrent	13	13
Variable-rate tax-exempt obligation series, due 2038 [Member]
Unsecured long-term debt, noncurrent	45	45
Notes, 5.65% Series, due 2012 [Member]
Unsecured long-term debt, noncurrent	0	400
Notes, 5.125% Series, due 2013 [Member]
Unsecured long-term debt, noncurrent	275	275
Notes, 4.65% Series, due 2014 [Member]
Unsecured long-term debt, noncurrent	350	350
Notes, 5.95% Series, due 2017 [Member]
Unsecured long-term debt, noncurrent	250	250
Notes, 5.3% Series, due 2018 [Member]
Unsecured long-term debt, noncurrent	350	350
Notes, 6.75% Series, due 2031 [Member]
Unsecured long-term debt, noncurrent	400	400
Notes, 5.75% Series, due 2035 [Member]
Unsecured long-term debt, noncurrent	300	300
Notes, 5.8% Series, due 2036 [Member]
Unsecured long-term debt, noncurrent	350	350
Turbine purchase obligation, 1.46%, due 2013 [Member]
Vendor financing, noncurrent	669	0
MidAmerican Energy common shareholder's equity [Member]
MidAmerican Energy common shareholder's equity	3,244	2,931
Percent of total capitalization	50.80%	50.30%
Common Stock [Member]
Common shares, no par; 350,000,000 authorized; 70,980,203 outstanding	562	562
Retained Earnings [Member]
Retained earnings	2,716	2,398
Accumulated Other Comprehensive Income (Loss) [Member]
Unrealized losses on available-for-sale securities, net of tax of $(6) and $(6)	(8)	(9)
Unrealized losses on cash flow hedges, net of tax of $(17) and $(14)	(26)	(20)
Total preferred securities; (100,000,000 shares authorized); not subject to mandatory redemption: [Member]
Percent of total capitalization	0.40%	0.50%
MidAmerican Energy preferred securities	27	27
$3.30 Series, 49,451 shares [Member]
MidAmerican Energy preferred securities	5	5
$3.75 Series, 38,305 shares [Member]
MidAmerican Energy preferred securities	4	4
$3.90 Series, 32,630 shares [Member]
MidAmerican Energy preferred securities	3	3
$4.20 Series, 22,461 shares [Member]
MidAmerican Energy preferred securities	2	2
$4.35 Series, 39,775 shares [Member]
MidAmerican Energy preferred securities	4	4
$4.40 Series, 35,697 shares [Member]
MidAmerican Energy preferred securities	4	4
$4.80 Series, 49,898 shares [Member]
MidAmerican Energy preferred securities	5	5
Noncontrolling Interest [Member]
Percent of total capitalization	0.00%	0.00%
Noncontrolling interests	$ 1	$ 1