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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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- Definition

The number of derivative instruments of a particular group held by the entity.

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- Definition

Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

The carrying amount of capitalized costs of materials, supplies, and other assets, which are not included in inventory but used in production.

+ References

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- Definition

Change in noncontrolling interest during the period as a result of a change in the redemption value of redeemable noncontrolling interest.

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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- Definition

The number of states the entity operates in as of the balance sheet date.

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- Definition

Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.

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- Definition

Threshold period past due for trade accounts receivable to write off as uncollectible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Background, Organization, and Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($) instrument state	Sep. 30, 2020 USD ($) instrument state	Dec. 31, 2019 USD ($)	Nov. 30, 2018
Significant Accounting Policies [Line Items]
Number of states in which entity operates \| state	3	3
Threshold period after inactivation for write-off of accounts receivable		2 months
Goodwill impairment		$ 0
Redemption value adjustments	$ 17,600,000	$ 17,573,000
Interest Rate Swap
Significant Accounting Policies [Line Items]
Derivative, Number of Instruments Held \| instrument	2	2
Linetec
Significant Accounting Policies [Line Items]
Ownership percentage by noncontrolling owners				20.00%
Gas Pipe Materials and Supplies \| Prepaid and other current assets
Significant Accounting Policies [Line Items]
Gas pipe materials and operating supplies	$ 55,000,000	$ 55,000,000	$ 57,000,000
Prepaid and other current assets			33,000,000
Pooled Funds and Mutual Funds
Significant Accounting Policies [Line Items]
Money market fund investments	40,000	40,000	26,700,000
Southwest Gas Corporation
Significant Accounting Policies [Line Items]
Dividends declared but not yet paid	27,000,000	27,000,000	25,200,000
Southwest Gas Corporation \| Pooled Funds and Mutual Funds
Significant Accounting Policies [Line Items]
Money market fund investments	$ 40,000	$ 40,000	$ 23,500,000