v3.26.1
Derivative financial instruments and hedging activities - Schedule of Fair Value of Derivative Contracts (Details) - Treasury bond forwards - USD ($)
$ in Thousands
Apr. 30, 2026
Jan. 31, 2026
Location, Statement of Financial Position, Balance [Axis]: us-gaap:AccruedLiabilitiesCurrent    
Derivative Instruments, Gain (Loss) [Line Items]    
Derivative liabilities $ (19,387) $ (6,935)
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent    
Derivative Instruments, Gain (Loss) [Line Items]    
Derivative assets 0 3,285
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivative Instruments, Gain (Loss) [Line Items]    
Derivative liabilities (27,161) (7,997)
Location, Statement of Financial Position, Balance [Axis]: us-gaap:PrepaidExpenseAndOtherAssetsCurrent    
Derivative Instruments, Gain (Loss) [Line Items]    
Derivative assets $ 666 $ 0