Components of Accumulated Other Comprehensive Loss, Net Components of Accumulated Other Comprehensive Loss, Net - MEC (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance - Accumulated other comprehensive loss, net	$ (908)
Unrealized gains on available-for-sale securities, net of tax of $22 and $113	33	$ 166
Unrealized (losses) gains on cash flow hedges, net of tax of $(14) and $1	(23)	1
Other comprehensive income (loss)	99	(235)
Ending balance - Accumulated other comprehensive loss, net	(809)
Accumulated Other Comprehensive (Loss) Income, Net [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance - unrealized gains on available-for-sale securities	615	390
Beginning balance - unrealized gains on cash flow hedges	7	18
Beginning balance - Accumulated other comprehensive loss, net	(908)	(494)
Unrealized gains on available-for-sale securities, net of tax of $22 and $113	33	166
Unrealized (losses) gains on cash flow hedges, net of tax of $(14) and $1	(23)	1
Other comprehensive income (loss)	99	(235)
Ending balance - unrealized gains on available-for-sale securities	648	556
Ending balance - unrealized gains on cash flow hedges	(16)	19
Ending balance - Accumulated other comprehensive loss, net	(809)	(729)
MidAmerican Energy Company [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance - Accumulated other comprehensive loss, net	(30)
Unrealized gains on available-for-sale securities, net of tax of $22 and $113	1	0
Unrealized (losses) gains on cash flow hedges, net of tax of $(14) and $1	0	2
Other comprehensive income (loss)	1	2
Dividend, Noncash, Transfer Of Operations	90
Ending balance - Accumulated other comprehensive loss, net	(2)
MidAmerican Energy Company [Member] | Accumulated Other Comprehensive (Loss) Income, Net [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance - unrealized gains on available-for-sale securities	(3)	(3)
Beginning balance - unrealized gains on cash flow hedges	(27)	(20)
Beginning balance - Accumulated other comprehensive loss, net	(30)	(23)
Unrealized gains on available-for-sale securities, net of tax of $22 and $113	1	0
Unrealized (losses) gains on cash flow hedges, net of tax of $(14) and $1	0	2
Other comprehensive income (loss)	1	2
Dividend, Noncash, Transfer Of Operations	27
Ending balance - unrealized gains on available-for-sale securities	(2)	(3)
Ending balance - unrealized gains on cash flow hedges	0	(18)
Ending balance - Accumulated other comprehensive loss, net	$ (2)	$ (21)