v3.26.1
Summary of Significant Accounting Policies - Basic and diluted net income (loss) per ordinary share (Details) - CIK_0001843477_Spring Valley Acquisition Corp. II - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Class A ordinary shares subject to possible redemption    
Summary of Significant Accounting Policies    
Allocation of net (loss) income $ (688,378) $ 4,313,847
Weighted average ordinary shares outstanding - basic (in shares) 2,213,398 13,236,821
Weighted average ordinary shares outstanding - diluted (in shares) 2,213,398 13,236,821
Net (loss) income per ordinary share - basic (in dollars per share) $ (0.31) $ 0.33
Net (loss) income per ordinary share - diluted (in dollars per share) $ (0.31) $ 0.33
Class A ordinary shares subject not to possible redemption    
Summary of Significant Accounting Policies    
Allocation of net (loss) income $ (2,384,372) $ 2,327,882
Weighted average ordinary shares outstanding - basic (in shares) 7,666,666 7,142,987
Weighted average ordinary shares outstanding - diluted (in shares) 7,666,666 7,142,987
Net (loss) income per ordinary share - basic (in dollars per share) $ (0.31) $ 0.33
Net (loss) income per ordinary share - diluted (in dollars per share) $ (0.31) $ 0.33
Class B Ordinary Shares    
Summary of Significant Accounting Policies    
Allocation of net (loss) income   $ 170,666
Weighted average ordinary shares outstanding - basic (in shares) 1 523,680
Weighted average ordinary shares outstanding - diluted (in shares) 1 523,680
Net (loss) income per ordinary share - basic (in dollars per share) $ (0.31) $ 0.33
Net (loss) income per ordinary share - diluted (in dollars per share) $ (0.31) $ 0.33