Letter of Credit, Dividend Restrictions, Amount

No definition available.

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- Definition

Line of Credit Facility, Aggregate Lender Commitments

+ References

No definition available.

+ Details

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Namespace Prefix:	sm_
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

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

+ References

No definition available.

+ Details

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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

+ Details

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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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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

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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

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Period Type:	duration

- 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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1336-112600

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 45
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1314-112600

+ Details

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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

+ Details

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Period Type:	instant

- Details

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- Details

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Balance Type:
Period Type:

- Details

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- Details

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- Details

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Revolving Credit Facility (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020	Oct. 21, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Revolving credit facility	$ 178,000			$ 122,500
Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, maximum loan amount	2,500,000
Revolving credit facility, current borrowing base	1,100,000
Revolving credit facility, aggregate lender commitments	1,100,000			1,200,000
Revolving credit facility, dividend restrictions, amount	12,000	$ 50,000
Revolving credit facility	178,000			122,500
Letters of credit	42,000			0
Available borrowing capacity	880,000			1,077,500
Revolving Credit Facility, unamortized deferred financing costs	$ 4,700			$ 5,900
Revolving Credit Facility [Member] \| Revolving Credit Facility [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, aggregate lender commitments			$ 1,100,000
Revolving credit facility			129,000
Letters of credit			42,000
Available borrowing capacity			$ 929,000
Borrowing Base Utilization Of Less Than 25 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, unused capacity, commitment fee rate	0.375%
Borrowing Base Utilization Of 25 Percent Or More But Less Than 50 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, unused capacity, commitment fee rate	0.375%
Borrowing Base Utilization Of 50 Percent Or More But Less Than 75 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, unused capacity, commitment fee rate	0.50%
Borrowing Base Utilization Of 75 Percent Or More But Less Than 90 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, unused capacity, commitment fee rate	0.50%
Borrowing Base Utilization Of 90 Percent Or More [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, unused capacity, commitment fee rate	0.50%
Eurodollar [Member] \| Borrowing Base Utilization Of Less Than 25 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	1.75%
Eurodollar [Member] \| Borrowing Base Utilization Of 25 Percent Or More But Less Than 50 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	2.00%
Eurodollar [Member] \| Borrowing Base Utilization Of 50 Percent Or More But Less Than 75 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	2.50%
Eurodollar [Member] \| Borrowing Base Utilization Of 75 Percent Or More But Less Than 90 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	2.75%
Eurodollar [Member] \| Borrowing Base Utilization Of 90 Percent Or More [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	3.00%
Prime Rate [Member] \| Borrowing Base Utilization Of Less Than 25 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	0.75%
Prime Rate [Member] \| Borrowing Base Utilization Of 25 Percent Or More But Less Than 50 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	1.00%
Prime Rate [Member] \| Borrowing Base Utilization Of 50 Percent Or More But Less Than 75 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	1.50%
Prime Rate [Member] \| Borrowing Base Utilization Of 75 Percent Or More But Less Than 90 Percent [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	1.75%
Prime Rate [Member] \| Borrowing Base Utilization Of 90 Percent Or More [Member] \| Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, basis spread on variable rate	2.00%