Revenue - Narrative (Details) $ in Millions |
12 Months Ended |
---|---|
Dec. 31, 2019
USD ($)
Type
Contract
Customer
| |
Segment Reporting Information [Line Items] | |
Number of customers | Customer | 2,000,000 |
Number of customers party to contracts with rate components subject to negotiation (less than) | Customer | 24 |
Southwest Gas Corporation | |
Segment Reporting Information [Line Items] | |
Number of types of services provided to customers | 2 |
Centuri | |
Segment Reporting Information [Line Items] | |
Number of types of services provided to customers | 3 |
Number of types of agreements with customers | 2 |
Change in contract liability, revenue recognized | $ | $ 4.2 |
Number of contracts with original duration more than one year | Contract | 48 |