Components of Accumulated Other Comprehensive Loss, Net (MEC) (Details) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive loss	$ 0	$ 0	$ 0	$ 1
Other comprehensive loss	7	10	(7)	12
Other comprehensive income (loss)	7	10	(7)	13
Accumulated Other Comprehensive Loss, Net [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			(8)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax			(26)
Accumulated Other Comprehensive Income (Loss), Net of Tax			(34)
Other comprehensive loss			0
Other comprehensive loss			(7)
Other comprehensive income (loss)			(7)	13
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(8)		(8)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(33)		(33)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (41)		$ (41)