Line of Credit Facility, Aggregate Revolving Lender Commitments

No definition available.

Name:	sm_LineOfCreditFacilityAggregateRevolvingLenderCommitments
Namespace Prefix:	sm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum Repayment Amount For Outstanding Senior Notes Under Credit Agreement

+ References

No definition available.

+ Details

Name:	sm_MinimumRepaymentAmountForOutstandingSeniorNotesUnderCreditAgreement
Namespace Prefix:	sm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

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+ Details

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

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap_
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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

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

- 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

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
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+ Details

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

- Definition

The carrying value as of the balance sheet date of the noncurrent portion 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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+ Details

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

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

No definition available.

+ Details

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

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Credit Agreement (Details) - USD ($) $ in Thousands	9 Months Ended
Credit Agreement (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Oct. 22, 2025	Oct. 13, 2025	Dec. 31, 2024
Line of Credit Facility [Line Items]
Revolving credit facility	$ 0			$ 68,500
Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving credit facility, maximum loan amount	3,000,000
Revolving credit facility, current borrowing base	3,000,000
Revolving credit facility, aggregate lender commitments	2,000,000			2,000,000
Revolving credit facility	$ 0			68,500
Debt Instrument, Maturity Date	Oct. 01, 2029
Letters of credit	$ 1,500			2,000
Available borrowing capacity	1,998,500			1,929,500
Revolving Credit Facility, unamortized deferred financing costs	$ 15,800			$ 18,700
Revolving Credit Facility \| Subsequent Event
Line of Credit Facility [Line Items]
Revolving credit facility, aggregate lender commitments		$ 2,000,000
Minimum Repayment Amount For Outstanding Senior Notes Under Credit Agreement			$ 50,000
Revolving credit facility		0
Letters of credit		1,500
Available borrowing capacity		$ 1,998,500