v3.26.1
Document and Entity Information
Jul. 28, 2026
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0002028686
Document Type 8-K
Document Period End Date Jul. 28, 2026
Entity Registrant Name SL Investment Fund II LLC
Entity Incorporation State Country Code DE
Entity File Number 814-01754
Entity Tax Identification Number 99-4692047
Entity Address, Address Line One 1585 Broadway
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10036
City Area Code 1 (212)
Local Phone Number 761-4000
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Units
Entity Emerging Growth Company true
Entity Ex Transition Period true