Fair Value Measurements (MEC) Level 3 (Details) (MidAmerican Energy Company [Member], USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Commodity Derivative [Member]
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ (2)		$ 8		$ 0		$ 22
Changes included in earnings	1	[1]	(2)	[1]	6	[1]	7	[1]
Changes in fair value recognized in other comprehensive income	0		1		(5)		(3)
Changes in fair value recognized in net regulatory assets	(1)		(3)		1		(1)
Settlements	0		1		(4)		(20)
Ending balance	(2)		5		(2)		5
Net unrealized gains (losses) included in earnings	1		(2)		0		3
Auction rate securities [Member]
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	22		17		21		16
Changes included in earnings	0	[1]	0	[1]	0	[1]	0	[1]
Changes in fair value recognized in other comprehensive income	1		1		2		2
Changes in fair value recognized in net regulatory assets	0		0		0		0
Settlements	0		0		0		0
Ending balance	$ 23		$ 18		$ 23		$ 18

[1] Changes included in earnings are reported as nonregulated operating revenue on the Statements of Operations. For commodity derivatives held as of September 30, 2013 and 2012, net unrealized gains (losses) included in earnings for the three-month periods ended September 30, 2013 and 2012, totaled $1 million and $(2) million, respectively, and for the nine-month periods ended September 30, 2013 and 2012, totaled $- million and $3 million, respectively.