XML 43 R32.htm IDEA: XBRL DOCUMENT v3.21.1

Senior Unsecured Notes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Senior Notes [Line Items]
Unsecured Long-term Debt, Noncurrent	$ 1,661,429		$ 1,660,663
Gain (Loss) on Extinguishment of Debt	$ 0	$ 12,195
6.125% Senior Unsecured Notes due 2022 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.125%		6.125%
Senior Notes, Principal amount	$ 212,403		$ 212,403
Senior Notes, unamortized deferred financing costs	743		855
Unsecured Long-term Debt, Noncurrent	$ 211,660		$ 211,548
Senior Unsecured Notes, exchanged or repurchased face amount		40,700
Senior Unsecured Notes, repurchased settlement amount		28,300
Gain (Loss) on Extinguishment of Debt		12,200
Discount realized on extinguishment of debt		12,400
Write off of Deferred Debt Issuance Cost		$ 235
5.0% Senior Unsecured Notes due 2024 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	5.00%		5.00%
Senior Notes, Principal amount	$ 277,034		$ 277,034
Senior Notes, unamortized deferred financing costs	1,448		1,576
Unsecured Long-term Debt, Noncurrent	$ 275,586		$ 275,458
5.625% Senior Unsecured Notes due 2025 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	5.625%		5.625%
Senior Notes, Principal amount	$ 349,118		$ 349,118
Senior Notes, unamortized deferred financing costs	2,634		2,792
Unsecured Long-term Debt, Noncurrent	$ 346,484		$ 346,326
6.75% Senior Unsecured Notes due 2026 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.75%		6.75%
Senior Notes, Principal amount	$ 419,235		$ 419,235
Senior Notes, unamortized deferred financing costs	3,795		3,970
Unsecured Long-term Debt, Noncurrent	$ 415,440		$ 415,265
6.625% Senior Unsecured Notes due 2027 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.625%		6.625%
Senior Notes, Principal amount	$ 416,791		$ 416,791
Senior Notes, unamortized deferred financing costs	4,532		4,725
Unsecured Long-term Debt, Noncurrent	412,259		412,066
Senior Unsecured Notes [Member]
Senior Notes [Line Items]
Senior Notes, Principal amount	1,674,581		1,674,581
Senior Notes, unamortized deferred financing costs	$ 13,152		$ 13,918

X

- Definition

Discount realized on debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	sm_DebtInstrumentRepurchaseDiscount
Namespace Prefix:	sm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

X

- Definition

Contractual interest rate for funds borrowed, under the debt 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(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- 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

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

X

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

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

X

- 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

X

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12355-112629

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12317-112629

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

+ Details

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

X

- 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

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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

X

- Definition

Carrying value as of the balance sheet date of uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

+ 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

+ Details

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

X

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

+ Details

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

X

- Details

Name:	us-gaap_DebtInstrumentAxis=sm_A6125SeniorUnsecuredNotesDue2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=sm_A50SeniorUnsecuredNotesDue2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=sm_A5625SeniorUnsecuredNotesDue2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=sm_A675SeniorUnsecuredNotesDue2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=sm_A6625SeniorUnsecuredNotesDue2027Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=sm_SeniorUnsecuredNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: