v3.25.2
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2025
Aug. 13, 2025
Document and Entity Information    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity Registrant Name SPRING VALLEY ACQUISITION CORP. II  
Entity Incorporation, State or Country Code E9  
Entity File Number 001-41529  
Entity Tax Identification Number 98-1579063  
Entity Address, Address Line One 2100 McKinney Ave., Suite 1675  
Entity Address, City or Town Dallas  
Entity Address State Or Province TX  
Entity Address, Postal Zip Code 75201  
City Area Code 214  
Local Phone Number 308-5230  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company true  
Entity Central Index Key 0001843477  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Units, each consisting of one Class A ordinary share, $0.0001 par value, one right and one-half of one redeemable public warrant    
Document and Entity Information    
Title of 12(b) Security Units, each consisting of one Class A ordinary share, $0.0001 par value, one right and one-half of one redeemable public warrant  
Trading Symbol SVIIU  
Security Exchange Name NASDAQ  
Class A ordinary shares    
Document and Entity Information    
Title of 12(b) Security Class A ordinary shares, par value $0.0001 per share  
Trading Symbol SVII  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding   9,880,095
Rights included as part of the units to acquire one-tenth (1/10) of one share of Class A ordinary share    
Document and Entity Information    
Title of 12(b) Security Rights included as part of the units to acquire one-tenth (1/10) of one share of Class A ordinary share  
Trading Symbol SVIIR  
Security Exchange Name NASDAQ  
Redeemable public warrants included as part of the units; each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50    
Document and Entity Information    
Title of 12(b) Security Redeemable public warrants included as part of the units; each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50  
Trading Symbol SVIIW  
Security Exchange Name NASDAQ  
Class B ordinary shares    
Document and Entity Information    
Entity Common Stock, Shares Outstanding   1