Fair Value Measurements - MEC (Details) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash collateral, net receivable, offset against derivative positions		$ 85	$ 74
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash collateral, net receivable, offset against derivative positions		85	74
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset		(19)	(22)
Assets, fair value disclosure		4,284	2,878
Derivative liability, fair value, gross asset and right to reclaim cash, offset		104	96
Recurring [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		855	586
Recurring [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		168	161
Recurring [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		5	3
Recurring [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		37	36
Recurring [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		2	2
Recurring [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		1	2
Recurring [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		270	250
Recurring [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		2,094	1,190
Recurring [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		182	147
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure		3,570	2,339
Recurring [Member] | Level 1 [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		855	586
Recurring [Member] | Level 1 [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		168	161
Recurring [Member] | Level 1 [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 1 [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 1 [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 1 [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 1 [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		270	250
Recurring [Member] | Level 1 [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		2,094	1,190
Recurring [Member] | Level 1 [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		182	147
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure		617	467
Recurring [Member] | Level 2 [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 2 [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 2 [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		5	3
Recurring [Member] | Level 2 [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		37	36
Recurring [Member] | Level 2 [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		2	2
Recurring [Member] | Level 2 [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		1	2
Recurring [Member] | Level 2 [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 2 [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 2 [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Trading Securities			0
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure		116	94
Recurring [Member] | Level 3 [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Recurring [Member] | Level 3 [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
Trading Securities			0
Commodity derivative [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset		(19)	(22)
Derivative liability, fair value, gross asset and right to reclaim cash, offset		104	96
Commodity derivative [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		1	5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(1)	(2)
Commodity derivative [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		24	49
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(207)	(199)
Commodity derivative [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		102	87
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(16)	(27)
MidAmerican Energy Company [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash collateral, net receivable, offset against derivative positions		0	1
Assets, fair value disclosure		1,027	477
MidAmerican Energy Company [Member] | Recurring [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	[1]	520	1
MidAmerican Energy Company [Member] | Recurring [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		168	161
MidAmerican Energy Company [Member] | Recurring [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		5	3
MidAmerican Energy Company [Member] | Recurring [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		37	36
MidAmerican Energy Company [Member] | Recurring [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		2	2
MidAmerican Energy Company [Member] | Recurring [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		1	2
MidAmerican Energy Company [Member] | Recurring [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		270	250
MidAmerican Energy Company [Member] | Recurring [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		7	5
MidAmerican Energy Company [Member] | Recurring [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities		15	9
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure		980	426
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	[1]	520	1
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		168	161
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		270	250
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		7	5
MidAmerican Energy Company [Member] | Recurring [Member] | Level 1 [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities		15	9
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure		47	52
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	[1]	0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		5	3
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		37	36
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		2	2
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		1	2
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 2 [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities		0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure		2	1
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	[1]	0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | United States government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | International government obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | Corporate obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | Municipal obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | Agency, asset and mortgage-backed obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | United States companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | International companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities		0	0
MidAmerican Energy Company [Member] | Recurring [Member] | Level 3 [Member] | Investment funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities		0
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		2	8
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[2]	(2)	(2)
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(8)	(3)
Derivative liability, fair value, gross asset and right to reclaim cash, offset	[2]	2	3
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		2	9
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(6)	(3)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		2	1
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		$ (4)	$ (3)

[1] Amounts are included in cash and cash equivalents and investments and restricted cash and investments on the Balance Sheets. The fair value of these money market mutual funds approximates cost.

[2] Represents netting under master netting arrangements and a net cash collateral receivable of $- million and $1 million as of September 30, 2017 and December 31, 2016, respectively.