Subsidiary Debt - MidAmerican Funding (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2019	Dec. 31, 2018	Dec. 31, 2017	Feb. 01, 2019	Jan. 31, 2019
Debt Instrument [Line Items]
Par value		$ 37,014
Equity Restrictions		16,500
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,263
Other long-term debt		28,097	$ 28,641
MidAmerican Funding [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		5,668
Other long-term debt		5,599	5,259
MidAmerican Energy Company [Member]
Debt Instrument [Line Items]
Par value		5,428
Other long-term debt		5,381	5,042
Eligible Property Subject To Lien Of Mortgages		18,000
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 2.40%, Due March 2019 [Member]
Debt Instrument [Line Items]
Par value		500
Other long-term debt		$ 500	$ 499
Debt Instrument, Interest Rate, Stated Percentage		2.40%	2.40%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.70%, Due September 2023 [Member]
Debt Instrument [Line Items]
Par value		$ 250
Other long-term debt		$ 249	$ 248
Debt Instrument, Interest Rate, Stated Percentage		3.70%	3.70%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.50%, Due October 2024 [Member]
Debt Instrument [Line Items]
Par value		$ 500
Other long-term debt		$ 500	$ 501
Debt Instrument, Interest Rate, Stated Percentage		3.50%	3.50%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.10%, Due May 2027 [Member]
Debt Instrument [Line Items]
Par value		$ 375
Other long-term debt		372	$ 372
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 4.80%, Due September 2043 [Member]
Debt Instrument [Line Items]
Par value		350
Other long-term debt		$ 346	$ 346
Debt Instrument, Interest Rate, Stated Percentage		4.80%	4.80%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 4.40%, Due October 2044 [Member]
Debt Instrument [Line Items]
Par value		$ 400
Other long-term debt		$ 395	$ 394
Debt Instrument, Interest Rate, Stated Percentage		4.40%	4.40%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 4.25%, Due May 2046 [Member]
Debt Instrument [Line Items]
Par value		$ 450
Other long-term debt		$ 445	$ 445
Debt Instrument, Interest Rate, Stated Percentage		4.25%	4.25%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.95%, Due 2047 [Member]
Debt Instrument [Line Items]
Par value		$ 475
Other long-term debt		470	$ 470
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.65, Due 2048 [Member]
Debt Instrument [Line Items]
Par value		700
Other long-term debt		688	0
MidAmerican Energy Company [Member] | MEC Notes, 5.3% Series, due 2018 [Member]
Debt Instrument [Line Items]
Par value		0
Other long-term debt		0	$ 350
Debt Instrument, Interest Rate, Stated Percentage			5.30%
MidAmerican Energy Company [Member] | MEC Notes, 6.75% Series, due 2031 [Member]
Debt Instrument [Line Items]
Par value		400
Other long-term debt		$ 396	$ 396
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
MidAmerican Energy Company [Member] | MEC Notes, 5.75% Series, due 2035 [Member]
Debt Instrument [Line Items]
Par value		$ 300
Other long-term debt		$ 298	$ 298
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
MidAmerican Energy Company [Member] | MEC Notes, 5.8% Series, due 2036 [Member]
Debt Instrument [Line Items]
Par value		$ 350
Other long-term debt		$ 347	$ 347
Debt Instrument, Interest Rate, Stated Percentage		5.80%	5.80%
MidAmerican Energy Company [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Par value		$ 6
Other long-term debt		5	$ 6
MidAmerican Energy Company [Member] | Capital Lease Obligations, 4.16%, Due Through 2020 [Member]
Debt Instrument [Line Items]
Par value		2
Other long-term debt		$ 2	$ 2
Debt Instrument, Interest Rate, Stated Percentage		4.16%	4.16%
MidAmerican Funding, LLC and Subsidiaries [Domain]
Debt Instrument [Line Items]
Equity Restrictions		$ 3,900
MidAmerican Funding LLC [Member] | Senior Notes, 6.927%, due 2029 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Gain (Loss), Net of Tax			$ 29
MidAmerican Funding LLC [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | Senior Notes, 6.927%, due 2029 [Member]
Debt Instrument [Line Items]
Par value		240
Other long-term debt		$ 217	$ 216
Debt Instrument, Interest Rate, Stated Percentage		6.927%	6.927%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 5,428
Other long-term debt		5,382	$ 5,043
Eligible Property Subject To Lien Of Mortgages		18,000
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | Tax-exempt bond obligations, variable rate, due 2023-2047 [Member]
Debt Instrument [Line Items]
Par value		370
Other long-term debt		$ 368	$ 368
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.74%	1.91%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 2.40%, Due March 2019 [Member]
Debt Instrument [Line Items]
Par value		$ 500
Other long-term debt		$ 500	$ 499
Debt Instrument, Interest Rate, Stated Percentage		2.40%	2.40%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.70%, Due September 2023 [Member]
Debt Instrument [Line Items]
Par value		$ 250
Other long-term debt		$ 249	$ 248
Debt Instrument, Interest Rate, Stated Percentage		3.70%	3.70%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.50%, Due October 2024 [Member]
Debt Instrument [Line Items]
Par value		$ 500
Other long-term debt		$ 501	$ 501
Debt Instrument, Interest Rate, Stated Percentage		3.50%	3.50%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.10%, Due May 2027 [Member]
Debt Instrument [Line Items]
Par value		$ 375
Other long-term debt		$ 372	$ 372
Debt Instrument, Interest Rate, Stated Percentage		3.10%	3.10%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 4.80%, Due September 2043 [Member]
Debt Instrument [Line Items]
Par value		$ 350
Other long-term debt		$ 346	$ 346
Debt Instrument, Interest Rate, Stated Percentage		4.80%	4.80%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 4.40%, Due October 2044 [Member]
Debt Instrument [Line Items]
Par value		$ 400
Other long-term debt		$ 394	$ 394
Debt Instrument, Interest Rate, Stated Percentage		4.40%	4.40%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 4.25%, Due May 2046 [Member]
Debt Instrument [Line Items]
Par value		$ 450
Other long-term debt		$ 445	$ 445
Debt Instrument, Interest Rate, Stated Percentage		4.25%	4.25%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.95%, Due 2047 [Member]
Debt Instrument [Line Items]
Par value		$ 475
Other long-term debt		$ 470	$ 470
Debt Instrument, Interest Rate, Stated Percentage		3.95%	3.95%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.65, Due 2048 [Member]
Debt Instrument [Line Items]
Par value		$ 700
Other long-term debt		$ 688	$ 0
Debt Instrument, Interest Rate, Stated Percentage		3.65%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 5.3% Series, due 2018 [Member]
Debt Instrument [Line Items]
Par value		$ 0
Other long-term debt		$ 0	$ 350
Debt Instrument, Interest Rate, Stated Percentage		5.30%	5.30%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 6.75% Series, due 2031 [Member]
Debt Instrument [Line Items]
Par value		$ 400
Other long-term debt		$ 396	$ 396
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 5.75% Series, due 2035 [Member]
Debt Instrument [Line Items]
Par value		$ 300
Other long-term debt		$ 298	$ 298
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 5.8% Series, due 2036 [Member]
Debt Instrument [Line Items]
Par value		$ 350
Other long-term debt		$ 348	$ 348
Debt Instrument, Interest Rate, Stated Percentage		5.80%	5.80%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Par value		$ 7
Other long-term debt		5	$ 6
Vendor Financing, Discount Rate Applied			4.45%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Capital Lease Obligations, 4.16%, Due Through 2020 [Member]
Debt Instrument [Line Items]
Par value		1
Other long-term debt		2	$ 2
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Par value		$ 180
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | Capital Lease Obligations, 4.16%, Due Through 2020 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		4.16%	4.16%
MidAmerican Funding LLC [Member] | MidAmerican Funding LLC [Member] | Senior Notes, 6.927%, due 2029 [Member]
Debt Instrument [Line Items]
Par value		$ 239
Other long-term debt		$ 240
Debt Instrument, Interest Rate, Stated Percentage		6.927%
Minimum [Member] | MidAmerican Energy Company [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		3.42%
Minimum [Member] | MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		3.42%
Maximum [Member] | MidAmerican Energy Company [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		4.45%
Maximum [Member] | MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		4.45%
Subsequent Event [Member] | MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 2.40%, Due March 2019 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 500
Subsequent Event [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.65%, Due April 2029 [Member]
Debt Instrument [Line Items]
Par value					$ 600
Debt Instrument, Interest Rate, Stated Percentage					3.65%
Subsequent Event [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 4.25%, Due July 2049 [Member]
Debt Instrument [Line Items]
Par value					$ 900
Debt Instrument, Interest Rate, Stated Percentage					4.25%
Subsequent Event [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 2.40%, Due March 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.40%			2.40%
Committed Common Equity Percentage To Regulators Beyond Companies Control [Member] | MidAmerican Energy Company [Member]
Debt Instrument [Line Items]
Common equity to total capitalization percentage below which reasonable efforts to maintain agreed to percentage is not required		39.00%