Consolidated Statements of Capitalization (LLC) (MidAmerican Funding, LLC and Subsidiaries [Domain], USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
MidAmerican Funding member's equity	$ 4,324	$ 3,972
Noncontrolling interests	27	28
Long-term debt, excluding current portion	2,915	3,440
Total capitalization	7,266	7,440
MidAmerican Energy Company [Member]
Obligations under capital leases	1	1
Unamortized debt discount	(32)	(25)
Total MidAmerican Energy long-term debt	2,590	3,115
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 Funding LLC [Member] | Senior secured notes, 6.927%, due 2029 [Member]
MidAmerican Funding secured long-term debt, noncurrent	325	325
MidAmerican Funding member's equity [Member]
MidAmerican Funding member's equity	4,324	3,972
Additional Paid-in Capital [Member]
Paid-in capital	1,679	1,679
Retained Earnings [Member]
Retained earnings	2,669	2,327
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)
Noncontrolling Interest [Member]
Noncontrolling interests	27	28
Noncontrolling interests in MidAmerican Energy subsidiary [Member]
Noncontrolling interests in MidAmerican Energy subsidiary	0	1
MidAmerican Energy Company [Member] | $3.30 Series, 49,451 shares [Member]
MidAmerican Energy preferred securities	5	5
MidAmerican Energy Company [Member] | $3.75 Series, 38,305 shares [Member]
MidAmerican Energy preferred securities	4	4
MidAmerican Energy Company [Member] | $3.90 Series, 32,630 shares [Member]
MidAmerican Energy preferred securities	3	3
MidAmerican Energy Company [Member] | $4.20 Series, 22,461 shares [Member]
MidAmerican Energy preferred securities	2	2
MidAmerican Energy Company [Member] | $4.35 Series, 39,775 shares [Member]
MidAmerican Energy preferred securities	4	4
MidAmerican Energy Company [Member] | $4.40 Series, 35,697 shares [Member]
MidAmerican Energy preferred securities	4	4
MidAmerican Energy Company [Member] | $4.80 Series, 49,898 shares [Member]
MidAmerican Energy preferred securities	$ 5	$ 5