XML 321 R244.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Employee Benefit Plans - MEC - Defined Contribution Plans (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
MidAmerican Energy Company [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Contribution Plan, Cost $ 23 $ 22 $ 20