v3.26.1
Cover - shares
 6 Months Ended
Jun. 30, 2026
Aug. 11, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Entity Interactive Data Current Yes  
Amendment Flag false  
Document Period End Date Jun. 30, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Entity Registrant Name Mountain Lake Acquisition Corp. II  
Entity Central Index Key 0002094265  
Entity File Number 001-43075  
Entity Tax Identification Number 98-1891915  
Entity Incorporation, State or Country Code E9  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Shell Company true  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Address, Address Line One 930 Tahoe Blvd  
Entity Address, Address Line Two STE 802 PMB 45  
Entity Address, City or Town Incline Village  
Entity Address, State or Province NV  
Entity Address, Postal Zip Code 89451  
City Area Code (775)  
Local Phone Number 204-1489  
Class A Ordinary Shares    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   36,980,000
Class B Ordinary Shares    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   12,000,000
Units, each consisting of one Class A Ordinary Share and one-half of one redeemable Warrant    
Document Information [Line Items]    
Title of 12(b) Security Units, each consisting of one Class A Ordinary Share and one-half of one redeemable Warrant  
Trading Symbol MLAAU  
Security Exchange Name NASDAQ  
Class A Ordinary Shares, par value $0.0001 per share    
Document Information [Line Items]    
Title of 12(b) Security Class A Ordinary Shares, par value $0.0001 per share  
Trading Symbol MLAA  
Security Exchange Name NASDAQ  
Redeemable Warrants, each whole Warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share    
Document Information [Line Items]    
Title of 12(b) Security Redeemable Warrants, each whole Warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share  
Trading Symbol MLAAW  
Security Exchange Name NASDAQ