Long-Term Debt, Excluding Maturities, Gross

No definition available.

Name:	swn_LongTermDebtExcludingMaturitiesGross
Namespace Prefix:	swn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Secured Term Loan Facility, Amount

+ References

No definition available.

+ Details

Name:	swn_SecuredTermLoanFacilityAmount
Namespace Prefix:	swn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash received from principal payments made on loans related to operating activities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3536-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3291-108585

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
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Period Type:

Debt (Term Loan Credit Agreement - Narrative) (Details) - USD ($) $ in Thousands			1 Months Ended
	Dec. 30, 2022	Dec. 31, 2021	Mar. 31, 2022	Dec. 31, 2022	Dec. 22, 2021
Debt Instrument [Line Items]
Debt repurchased face amount				$ 816,000
Debt instrument, excluding current maturities, gross		$ 5,234,000		4,414,000
Term Loan Due June 2027 \| Term Loan
Debt Instrument [Line Items]
Secured term loan facility, amount					$ 550,000
Proceeds from Loans		542,000
Repayments of term loan	$ 305,000		$ 1,375
Debt repurchased face amount	546,000			550,000
Debt instrument, excluding current maturities, gross		545,000
2022 Revolving Credit Facility \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, excluding current maturities, gross	$ 250,000	$ 460,000		$ 250,000