Long-Term Deposits (Details)
$ in Millions

12 Months Ended

Dec. 31, 2018

USD ($)

Dec. 31, 2017

USD ($)

Mar. 10, 2015

facility

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]

In March 2015, NV Energy and Switch, Ltd. entered into a Substation Agreement and related land purchase agreement for land owned by a wholly-owned subsidiary of Switch, Ltd. Pursuant to the Substation Agreement, NV Energy designed, constructed, maintains, and owns a substation and related feeders in connection with service to Switch’s development of three of its data center facilities in Las Vegas. The substation was placed into service in April 2016. Switch has paid the associated costs and associated tax gross-up related to the development of the substation and related feeders as defined in the Substation Agreement. These costs are subject to reimbursement based upon Switch’s future power usage.Costs incurred as of December 31, 2018 totaled $3.3 million, of which $3.2 million is classified as long-term deposits and $0.1 million as property and equipment on the consolidated balance sheets. Costs incurred as of December 31, 2017 totaled $4.8 million, of which $3.8 million are classified as long-term deposits and $1.0 million as property and equipment on the consolidated balance sheets.

Number Of Facilities Under Development | facility

3

Long-Term Deposit - Built for Calculation Relationship [Line Items]

Costs Incurred, Development of Property, Plant And Equipment, In Long-Term Deposits

$ 3.2

$ 3.8

Costs Incurred, Development Of Property, Plant And Equipment

3.3

4.8

Substation Equipment [Member]

Long-Term Deposit - Built for Calculation Relationship [Line Items]

Costs Incurred, Development of Property, Plant And Equipment, In Property, Plant And Equipment

$ 0.1

$ 1.0