XML 52 R41.htm IDEA: XBRL DOCUMENT
v3.21.2

Derivative Financial Instruments Gains and Losses (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Derivative Instruments, (Gain) Loss [Line Items] |  |  |  |
Derivative settlement (gain) loss | $ 213,555 | $ (70,305) | $ 480,262 | $ (286,270)
Net derivative (gain) loss | 209,146 | 63,871 | 924,183 | (314,269)
Oil Contracts [Member] |  |  |  |
Derivative Instruments, (Gain) Loss [Line Items] |  |  |  |
Derivative settlement (gain) loss | 154,113 | (68,907) | 344,740 | (261,095)
Net derivative (gain) loss | 68,194 | 30,641 | 611,224 | (360,649)
Gas Contracts [Member] |  |  |  |
Derivative Instruments, (Gain) Loss [Line Items] |  |  |  |
Derivative settlement (gain) loss | 35,757 | (896) | 88,437 | (16,575)
Net derivative (gain) loss | 109,802 | 31,548 | 220,088 | 46,537
NGL Contracts [Member] |  |  |  |
Derivative Instruments, (Gain) Loss [Line Items] |  |  |  |
Derivative settlement (gain) loss | 23,685 | (502) | 47,085 | (8,600)
Net derivative (gain) loss | $ 31,150 | $ 1,682 | $ 92,871 | $ (157)

X
- Definition Realized gain or loss recognized in earnings from the settlement of derivative instruments not designated as hedges. + References No definition available. + Details
Name: | sm_Derivativesettlementgainorloss
Namespace Prefix: | sm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959 + Details
Name: | us-gaap_GainLossOnDerivativeInstrumentsNetPretax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_OilContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NGLContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |