Line Of Credit Facility, Amount Classified As Long-Term Debt

No definition available.

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- Definition

Line Of Credit Facility, Working Capital Purposes

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Amount of assets pledged to secure a debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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-SubTopic 10
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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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Period Type:	instant

- Details

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- Details

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- Details

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Long-Term Debt - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Nov. 30, 2018	Oct. 31, 2018
Debt Instrument [Line Items]
Short term borrowings outstanding	$ 188,000,000	$ 152,000,000
Southwest Gas Corporation
Debt Instrument [Line Items]
Short term borrowings outstanding	188,000,000	$ 152,000,000
Southwest Gas Credit Facility
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity	100,000,000
Southwest Gas Credit Facility \| Southwest Gas Corporation
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity	400,000,000
Line of credit designated as long term debt	150,000,000
Line of credit designated for working capital purposes	250,000,000
Long-term debt	150,000,000
Short term borrowings outstanding	$ 188,000,000
Southwest Gas Credit Facility \| LIBOR \| Southwest Gas Corporation
Debt Instrument [Line Items]
Applicable margin	1.00%
Southwest Gas Credit Facility \| Alternative Base Rate \| Southwest Gas Corporation
Debt Instrument [Line Items]
Applicable margin	0.00%
Commercial Paper Program \| Southwest Gas Corporation
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity	$ 50,000,000
Borrowings outstanding under facility	50,000,000
Secured Revolving Credit Facility and Term Loan \| Centuri
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity			$ 590,000,000	$ 450,000,000
Borrowings outstanding under facility	261,000,000
Debt secured by assets	$ 1,100,000,000
Line of Credit \| Centuri
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity			325,000,000
Centuri term loan facility \| Centuri
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity			$ 265,000,000