XML 38 R25.htm IDEA: XBRL DOCUMENT
v3.25.1

Description of the Business and Significant Accounting Policies - Description of the Business (Details) $ in Thousands |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Apr. 01, 2025 | Mar. 31, 2025 USD ($) segment item | Dec. 31, 2024 USD ($)
Segment Reporting Information |  |  |
Number of reportable segments | segment |  | 4 |
Redeemable noncontrolling interests |  | $ 171,212 | $ 171,212
United Steel Supply, LLC | Subsequent Event |  |  |
Segment Reporting Information |  |  |
Percentage of remaining voting interest to be acquired | 5.00% |  |
Acquisition of interest (as a percent) | 5.00% |  |
United Steel Supply, LLC |  |  |
Segment Reporting Information |  |  |
Noncontrolling interest, ownership percentage |  | 90.00% |
Redeemable noncontrolling interests |  | $ 60,000 | $ 60,000
United Steel Supply, LLC | Subsequent Event |  |  |
Segment Reporting Information |  |  |
Noncontrolling interest, ownership percentage | 95.00% |  |
SDI Biocarbon Solutions |  |  |
Segment Reporting Information |  |  |
Noncontrolling interest, ownership percentage |  | 75.00% |
Mesabi Nugget |  |  |
Segment Reporting Information |  |  |
Noncontrolling interest, ownership percentage |  | 86.00% | 86.00%
Redeemable noncontrolling interests |  | $ 111,200 | $ 111,200
Unity Aluminum, Inc | Aluminum Operations |  |  |
Segment Reporting Information |  |  |
Number Of Satellite Recycled Aluminum Slab Centers | item |  | 2 |
Noncontrolling interest, ownership percentage |  | 94.40% |

X
- Definition The number of satellite recycled aluminum slab centers in aluminum operations. + References No definition available. + Details
Name: | stld_NumberOfSatelliteRecycledAluminumSlabCenters
Namespace Prefix: | stld_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of remaining voting interests to be acquired. + References No definition available. + Details
Name: | stld_PercentageOfRemainingVotingInterestsToBeAcquired
Namespace Prefix: | stld_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479328/805-10-50-2 + Details
Name: | us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 47 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-47 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 54 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-54 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-18 + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Subparagraph (12)(c) -Section S99 -Paragraph 3A -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-3A Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Subparagraph (16)(c) -Paragraph 3A -Section S99 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-3A Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3A -Subparagraph (15) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-3A Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3A -Subparagraph (14) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-3A + Details
Name: | us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationAdditionalInformationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions. + References No definition available. + Details
Name: | us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=stld_UnitedSteelSupplyLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=stld_UnitedSteelSupplyLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=stld_SteelDynamicsInc.BiocarbonSolutionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=stld_MesabiNuggetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=stld_UnityAluminumInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=stld_AluminumOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |