Significant Accounting Policies [Line Items]

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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- Definition

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.

+ References

No definition available.

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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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-Publisher FASB
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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.

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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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Background, Organization, and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)		9 Months Ended
	Nov. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Goodwill impairment		$ 0
Gas Pipe Materials and Supplies \| Prepaid and other current assets
Significant Accounting Policies [Line Items]
Gas pipe materials and operating supplies		59,000,000	$ 56,000,000
Prepaid and other current assets		47,000,000	74,000,000
Pooled Funds and Mutual Funds \| Level 2 - Significant Other Observable Inputs
Significant Accounting Policies [Line Items]
Money market fund investments		10,200,000	59,900,000
Centuri \| Linetec
Significant Accounting Policies [Line Items]
Percentage of voting interests acquired	80.00%
Purchase consideration	$ 26,200,000
Southwest Gas Corporation
Significant Accounting Policies [Line Items]
Dividends declared but not yet paid		24,900,000	23,500,000
Southwest Gas Corporation \| Pooled Funds and Mutual Funds \| Level 2 - Significant Other Observable Inputs
Significant Accounting Policies [Line Items]
Money market fund investments		$ 1,500,000	$ 18,000,000