Regulatory Matters - MEC - Regulatory Liabilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Regulatory Liabilities [Line Items]
Regulatory liabilities		$ 2,631	$ 2,669
Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[1]	28 years
Asset Retirement Obligation Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		22 years
MidAmerican Energy Company [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities		$ 831	837
MidAmerican Energy Company [Member] | Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[2]	25 years
Regulatory liabilities	[2]	$ 653	642
MidAmerican Energy Company [Member] | Asset Retirement Obligation Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[3]	22 years
Regulatory liabilities	[3]	$ 140	159
MidAmerican Energy Company [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		Various
Regulatory liabilities		$ 38	$ 36

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

[2] (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.

[3] (2)Amount predominantly represents the excess of nuclear decommission trust assets over the related asset retirement obligation. Refer to Note 11for a discussion of asset retirement obligations.