XML 43 R32.htm IDEA: XBRL DOCUMENT
v3.21.2

Senior Unsecured Notes (Details) - USD ($) $ in Thousands | Jun. 30, 2021 | Jun. 23, 2021 | Dec. 31, 2020
--- | --- | --- | ---
Senior Notes [Line Items] |  |  |
Unsecured Long-term Debt, Noncurrent | $ 1,671,818 |  | $ 1,660,663
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 | $ 0 |  | $ 212,403
Senior Notes, unamortized deferred financing costs | 0 |  | 855
Unsecured Long-term Debt, Noncurrent | $ 0 |  | $ 211,548
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 | $ 104,769 |  | $ 277,034
Senior Notes, unamortized deferred financing costs | 499 |  | 1,576
Unsecured Long-term Debt, Noncurrent | $ 104,270 |  | $ 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 | 2,476 |  | 2,792
Unsecured Long-term Debt, Noncurrent | $ 346,642 |  | $ 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 | 3,620 |  | 3,970
Unsecured Long-term Debt, Noncurrent | $ 415,615 |  | $ 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 | 4,337 |  | 4,725
Unsecured Long-term Debt, Noncurrent | $ 412,454 |  | 412,066
6.5% Senior Unsecured Notes Due 2028 [Member] |  |  |
Senior Notes [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.50% | 6.50% |
Senior Notes, Principal amount | $ 400,000 | $ 400,000 | 0
Senior Notes, unamortized deferred financing costs | 7,163 |  | 0
Unsecured Long-term Debt, Noncurrent | 392,837 |  | 0
Senior Unsecured Notes [Member] |  |  |
Senior Notes [Line Items] |  |  |
Senior Notes, Principal amount | 1,689,913 |  | 1,674,581
Senior Notes, unamortized deferred financing costs | $ 18,095 |  | $ 13,918

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: 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=124435984&loc=d3e28551-108399 Reference 3: 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 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 + 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://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: 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: | dtr-types: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 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
- 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_A65SeniorUnsecuredNotesDue2028Member
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: |