Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

No definition available.

Name:	dei_AmendmentFlag
Namespace Prefix:	dei_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

PCAOB issued Audit Firm Identifier

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 10-K
-Number 249
-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 20-F
-Number 249
-Section 220
-Subsection f

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 40-F
-Number 249
-Section 240
-Subsection f

Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2025	Mar. 31, 2026	Jun. 30, 2025
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Amendment Flag	false
Entity Central Index Key	0002032019
Document Period End Date	Dec. 31, 2025
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity Registrant Name	EQT Infrastructure Company LLC
Entity File Number	000-56691
Current Fiscal Year End Date	--12-31
Entity Tax Identification Number	99-3884445
Entity Incorporation, State or Country Code	DE
Entity Emerging Growth Company	true
Entity Address, Address Line One	245 Park Avenue
Entity Address, Address Line Two	34th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10167
City Area Code	917
Local Phone Number	281-0850
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Small Business	false
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Public Float			$ 0
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE None.
Auditor Name	KPMG LLP
Auditor Firm ID	185
Auditor Location	New York, New York
Auditor Opinion [Text Block]	Opinion on the Consolidated Financial Statements We have audited the accompanying consolidated statement of assets and liabilities of EQT Infrastructure Company LLC and subsidiaries (the Company) as of December 31, 2025, the related consolidated statement of operations for the period from January 1, 2025 through December 31, 2025, and the related notes (collectively, the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025, and the results of its operations for the period from January 1, 2025 through December 31, 2025, in conformity with U.S. generally accepted accounting principles.
Common Class I Shares [Member]
Document Information [Line Items]
Title of 12(g) Security	Class I Shares
Entity Common Stock, Shares Outstanding		400
Common Class S Shares [Member]
Document Information [Line Items]
Title of 12(g) Security	Class S Shares
Common Class T Shares [Member]
Document Information [Line Items]
Title of 12(g) Security	Class T Shares
Entity Common Stock, Shares Outstanding		4,327
Common Class H Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		40
Common Class E Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,391,400
Common Class A-I Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		11,873,118
Common Class A-S Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		978,269
Common Class Q [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		40