Risk Management and Hedging Activities Risk Management and Hedging Activities - NPC - Balance Sheet Location (Details) - Commodity Contract [Member] - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	$ 292	$ 291
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	113	146
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		46	43
Nevada Power Company [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[2]	8	9
Nevada Power Company [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[2]	14	21
Nevada Power Company [Member] | Fair Value, Measurements, Recurring [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		22	30
Nevada Power Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		$ 22	$ 30

[1] The Company's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of December 31, 2015 and 2014, a net regulatory asset of $250 million and $223 million, respectively, was recorded related to the net derivative liability of $186 million and $156 million, respectively. The difference between the net regulatory asset and the net derivative liability relates primarily to a power purchase agreement derivative at BHE Renewables.

[2] Nevada Power's commodity derivatives not designated as hedging contracts are included in regulated rates and as of December 31, 2015 and 2014, a regulatory asset of $22 million and $30 million, respectively, was recorded related to the derivative liability of $22 million and $30 million, respectively.