Employee Benefit Plans - MEC - Level 3 Rollforward (Details) - United States Pension Plan of US Entity [Member] - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 2,525	$ 2,489	$ 2,718
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	0	0
MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		684	678	$ 730
MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 0	$ 0

[1] Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.