The number of locations under collective bargaining arrangements.

No definition available.

Name:	stld_NumberOfLocationsSubjectToCollectiveBargainingAgreements
Namespace Prefix:	stld_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- 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

- Definition

The percentage of employees covered by a collective bargaining agreement as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	stld_PercentageOfWorkforceSubjectToCollectiveBargainingArrangements
Namespace Prefix:	stld_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of net revenue of the entity's external sales accounted for by the reportable unit.

+ References

No definition available.

+ Details

Name:	stld_SegmentRevenuesFromExternalCustomersNetPercentage
Namespace Prefix:	stld_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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/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

- 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 14
-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
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Subparagraph 15
-Paragraph 3A
-Section S99
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480244/480-10-S99-3A

Reference 4: 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

+ Details

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

- References

No definition available.

+ Details

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

- 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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=stld_SteelOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=stld_MetalsRecyclingOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=stld_SteelFabricationOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=stld_UnitedSteelSupplyLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=stld_MesabiNuggetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=stld_UnityAluminumInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Description of the Business and Summary of Significant Accounting Policies (Description of the Business) (Details) $ in Thousands		12 Months Ended
	Apr. 01, 2023	Dec. 31, 2023 USD ($) segment item	Dec. 31, 2022 USD ($)	Dec. 31, 2021
Segment Reporting Information
Number of reportable segments \| segment		4
Workforce represented by collective bargaining agreements (as a percent)		6.00%
Number of locations under collective bargaining arrangements \| item		5
Redeemable noncontrolling interests \| $		$ 171,212	$ 181,503
Steel Operations
Segment Reporting Information
Percentage of external net sales		67.00%	65.00%	72.00%
Metals Recycling Operations
Segment Reporting Information
Percentage of external net sales		12.00%	10.00%	12.00%
Steel Fabrication Operations
Segment Reporting Information
Percentage of external net sales		15.00%	19.00%	10.00%
United Steel Supply, LLC
Segment Reporting Information
Noncontrolling interest, ownership percentage	90.00%
United Steel Supply, LLC \| Steel Operations
Segment Reporting Information
Noncontrolling interest, ownership percentage	90.00%
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%