Consolidated Statements of Capitalization (MEC) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
MidAmerican Energy common shareholder's equity	$ 3,608	$ 3,244
MidAmerican Energy preferred securities	27	27
Noncontrolling interests	0	1
Long-term debt, excluding current portion	2,590	3,115
Total capitalization	6,225	6,387
MidAmerican Energy Company [Member]
Long-term debt, excluding current portion	2,590	3,115
Obligations under capital leases	1	1
Unamortized debt discount	(32)	(25)
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2016 [Member]
Noncurrent debt, face amount	34	34
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2017 [Member]
Noncurrent debt, face amount	4	4
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2023, issued in 1993 [Member]
Noncurrent debt, face amount	7	7
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2023, issued in 2008 [Member]
Noncurrent debt, face amount	57	57
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2024 [Member]
Noncurrent debt, face amount	35	35
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2025 [Member]
Noncurrent debt, face amount	13	13
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2038 [Member]
Noncurrent debt, face amount	45	45
MidAmerican Energy Company [Member] | Notes, 5.125% Series, due 2013 [Member]
Noncurrent debt, face amount	0	275
MidAmerican Energy Company [Member] | Notes, 4.65% Series, due 2014 [Member]
Noncurrent debt, face amount	350	350
MidAmerican Energy Company [Member] | Notes, 5.95% Series, due 2017 [Member]
Noncurrent debt, face amount	250	250
MidAmerican Energy Company [Member] | Notes, 5.3% Series, due 2018 [Member]
Noncurrent debt, face amount	350	350
MidAmerican Energy Company [Member] | Notes, 6.75% Series, due 2031 [Member]
Noncurrent debt, face amount	400	400
MidAmerican Energy Company [Member] | Notes, 5.75% Series, due 2035 [Member]
Noncurrent debt, face amount	300	300
MidAmerican Energy Company [Member] | Notes, 5.8% Series, due 2036 [Member]
Noncurrent debt, face amount	350	350
MidAmerican Energy Company [Member] | Turbine purchase obligation, 1.46%, due 2013 [Member]
Noncurrent debt, face amount	0	669
MidAmerican Energy Company [Member] | Turbine purchase obligation, 1.43%, due 2015 [Member]
Noncurrent debt, face amount	426	0
MidAmerican Energy common shareholder's equity [Member]
MidAmerican Energy common shareholder's equity	3,608	3,244
Common Stock [Member]
Common shares, no par; 350,000,000 authorized; 70,980,203 outstanding	562	562
Retained Earnings [Member]
Retained earnings	3,070	2,716
Accumulated Other Comprehensive Income (Loss) [Member]
Unrealized losses on available-for-sale securities, net of tax of $(4) and $(6)	(5)	(8)
Unrealized losses on cash flow hedges, net of tax of $(13) and $(17)	(19)	(26)
Total preferred securities; (100,000,000 shares authorized); not subject to mandatory redemption: [Member]
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]
Noncontrolling interests	$ 0	$ 1