Regulatory Matters (MEC) Liabilities (Details) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Regulatory Liabilities [Line Items]
Regulatory Liability, Noncurrent	$ 750		$ 719
Cost of removal accrual [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Noncurrent	629	[1]	603	[1]
Average Remaining Life	21 years
Asset retirement obligations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Noncurrent	94	[2]	76	[2]
Average Remaining Life	25 years
Unrealized gain on regulated derivative contracts [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Noncurrent	5		21
Average Remaining Life	1 year
Other [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Noncurrent	$ 22		$ 19
Regulatory liability amortization period years	Various

[1] Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing utility plant in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

[2] Amount predominately represents the excess of nuclear decommission trust assets over the related asset retirement obligation. Refer to Note 12 for a discussion of asset retirement obligations.