Asset Retirement Obligation Asset Retirement Obligations - MEC - Asset Retirement Obligations By Type (Details) - MidAmerican Energy Company [Member] - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation	$ 802	$ 562
Quad Cities Unit Nos 1 and 2 [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation	348	345
Fossil Fuel Plant [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation	328	93
Wind Generating Facility [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation	125	123
Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation	$ 1	$ 1