XML 155 R99.htm IDEA: XBRL DOCUMENT v3.5.0.2
Risk Management and Hedging Activities - MEC - Collateral and Contingent Features (Details) - Commodity derivative [Member] - USD ($)
$ in Millions
Jun. 30, 2016
Dec. 31, 2015
Derivative [Line Items]    
Collateral already posted, aggregate fair value $ 68 $ 75
Derivative, net liability position, aggregate fair value 219 288
Additional collateral, aggregate fair value 131 198
MidAmerican Energy Company [Member]    
Derivative [Line Items]    
Collateral already posted, aggregate fair value 0 0
Derivative, net liability position, aggregate fair value 5 66
Additional collateral, aggregate fair value $ 4 $ 55