v3.26.1
Fair Value Measurements - Marketable Securities (Details) - U.S. government treasury securities - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Apr. 30, 2026
Jan. 31, 2026
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized cost, due withen one year $ 688,576 $ 770,766
Amortized cost, due after one year and withen three years 701,244 527,268
Amortized cost, total 1,389,820 1,298,034
Unrealized loss, due withen one year 587 1,539
Due after one year and within three years 392 4,128
Total short-term investments 979 5,667
Short-term investments 689,163 772,305
Marketable securities, non-current 701,636 531,396
Total short-term investments $ 1,390,799 $ 1,303,701