v3.25.4
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2025
Mar. 03, 2026
Jun. 30, 2025
Cover [Abstract]      
Entity Central Index Key 0001772704    
Document Period End Date Dec. 31, 2025    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --12-31    
Entity Small Business false    
Entity Shell Company false    
Entity Voluntary Filers No    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Filer Category Non-accelerated Filer    
Entity Interactive Data Current Yes    
Entity Current Reporting Status Yes    
Entity Public Float     $ 0
Entity Common Stock, Shares Outstanding   13,854,750  
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 83-3053002    
Document Annual Report true    
Document Transition Report false    
Amendment Flag false    
Securities Act File Number 814-01307    
Document Type 10-K    
Entity Registrant Name Goldman Sachs Private Middle Market Credit II LLC    
Entity Address, Address Line One 200 West Street    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10282    
City Area Code 312    
Local Phone Number 655-4419    
Title of 12(g) Security Limited Liability Company Common Units    
Entity Well-known Seasoned Issuer No    
Entity Emerging Growth Company true    
Entity Ex Transition Period true    
Auditor Firm ID 238    
Auditor Name PricewaterhouseCoopers LLP    
Auditor Location Boston, Massachusetts    
Auditor Opinion [Text Block]

Opinion on the Financial Statements

We have audited the accompanying consolidated statements of financial condition, including the consolidated schedules of investments, of Goldman Sachs Private Middle Market Credit II LLC and its subsidiaries (the “Company”) as of December 31, 2025 and 2024, and the related consolidated statements of operations, changes in members’ capital and cash flows for each of the three years in the period ended December 31, 2025, including the related notes (collectively referred to as 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 2024, and the results of its operations, changes in its members’ capital and its cash flows for each of the three years in the period ended December 31, 2025 in conformity with accounting principles generally accepted in the United States of America.