Label	Element	Value
Sierra Pacific Power Company [Member] | Distribution only service [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	$ 4,000,000
Sierra Pacific Power Company [Member] | Fully bundled and distribution services only customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	801,000,000
Sierra Pacific Power Company [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	797,000,000
Sierra Pacific Power Company [Member] | Regulated retail gas [Member] | Distribution only service [Member] | Regulated Operation [Member] | Regulated Gas [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	0
Sierra Pacific Power Company [Member] | Regulated retail gas [Member] | Fully bundled and distribution services only customer [Member] | Regulated Operation [Member] | Regulated Gas [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	101,000,000
Sierra Pacific Power Company [Member] | Regulated retail gas [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Gas [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	101,000,000
Sierra Pacific Power Company [Member] | Regulated retail electric [Member] | Distribution only service [Member] | Regulated Operation [Member] | Regulated Electric [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	4,000,000
Sierra Pacific Power Company [Member] | Regulated retail electric [Member] | Fully bundled and distribution services only customer [Member] | Regulated Operation [Member] | Regulated Electric [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	700,000,000
Sierra Pacific Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Electric [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	696,000,000
Nevada Power Company [Member] | Regulated retail electric [Member] | Distribution only service [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	30,000,000
Nevada Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	2,077,000,000
Residential [Member] | Sierra Pacific Power Company [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	334,000,000
Residential [Member] | Sierra Pacific Power Company [Member] | Regulated retail gas [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Gas [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	67,000,000
Residential [Member] | Sierra Pacific Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Electric [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	267,000,000
Residential [Member] | Nevada Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	1,195,000,000
Commercial [Member] | Sierra Pacific Power Company [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	271,000,000
Commercial [Member] | Sierra Pacific Power Company [Member] | Regulated retail gas [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Gas [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	25,000,000
Commercial [Member] | Sierra Pacific Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Electric [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	246,000,000
Commercial [Member] | Nevada Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	433,000,000
Other [Member] | Sierra Pacific Power Company [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	7,000,000
Other [Member] | Sierra Pacific Power Company [Member] | Regulated retail gas [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Gas [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	1,000,000
Other [Member] | Sierra Pacific Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Electric [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	6,000,000
Other [Member] | Nevada Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	24,000,000
Industrial [Member] | Sierra Pacific Power Company [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	185,000,000
Industrial [Member] | Sierra Pacific Power Company [Member] | Regulated retail gas [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Gas [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	8,000,000
Industrial [Member] | Sierra Pacific Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member] | Regulated Electric [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	177,000,000
Industrial [Member] | Nevada Power Company [Member] | Regulated retail electric [Member] | Fully bundled customer [Member] | Regulated Operation [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax	$ 425,000,000