Income Taxes Income Taxes - MEC - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	$ (929)	$ (1,872)	$ (985)
Current State and Local Tax Expense (Benefit)	29	(3)	(2)
Current Income Tax Expense (Benefit)	(816)	(1,746)	(866)
Deferred Federal Income Tax Expense (Benefit)	1,310	2,296	1,306
Deferred State and Local Income Tax Expense (Benefit)	(53)	37	(247)
Deferred Income Tax Expense (Benefit)	1,274	2,344	1,000
Other Tax Expense (Benefit)	(8)	(9)	(4)
Income tax (benefit) expense	450	589	130
MidAmerican Energy Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	(405)	(401)	(196)
Current State and Local Tax Expense (Benefit)	(10)	(3)	(10)
Current Income Tax Expense (Benefit)	(415)	(404)	(206)
Deferred Federal Income Tax Expense (Benefit)	281	299	101
Deferred State and Local Income Tax Expense (Benefit)	(6)	2	3
Deferred Income Tax Expense (Benefit)	275	301	104
Other Tax Expense (Benefit)	(1)	(1)	(1)
Income tax (benefit) expense	$ (141)	$ (104)	$ (103)