v3.26.1
Fair Value of ZEN - Summary of changes in quantity of ZEN and respective fair value (Detail)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
USD ($)
Horizen
Mar. 31, 2025
USD ($)
Horizen
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Investment, Type [Extensible Enumeration] Investment in ZEN [Member] Investment in ZEN [Member] Investment in ZEN [Member]
Investment Owned, Balance, Contracts | Horizen 949,408.87165001 889,400.61619664  
ZEN contributed | Horizen 0 70,658.46700949  
ZEN distributed for Sponsor's Fee, related party | Horizen (5,834.71806594) (5,663.3185726)  
Net change in unrealized appreciation/depreciation on investment in ZEN | Horizen 0 0  
Net realized loss on investment in ZEN | Horizen 0 0  
Investment Owned, Balance, Contracts | Horizen 943,574.15358407 954,395.76463353  
Investment Owned, at Fair Value | $ $ 8,673 $ 25,713  
ZEN contributed | $ 0 924  
ZEN distributed for Sponsor's Fee, related party | $ (42) (90)  
Net change in unrealized appreciation/depreciation on investment in ZEN | $ (3,252) (18,118)  
Net realized loss on investment in ZEN | $ (69) (21)  
Investment Owned, at Fair Value | $ $ 5,310 $ 8,408