Annual report [Section 13 and 15(d), not S-K Item 405]

Marketable Securities -Narrative (Details)

v3.25.1
Marketable Securities -Narrative (Details)
12 Months Ended
Jan. 31, 2025
USD ($)
security
Jan. 31, 2024
USD ($)
security
Jan. 31, 2023
USD ($)
Investments, Debt and Equity Securities [Abstract]      
Investment income interest $ 26,000,000 $ 30,200,000 $ 8,500,000
Debt securities, available-for-sale, unrealized loss position, number of positions | security 40 64  
Unleased loss position $ 140,000,000 $ 178,700,000  
Expected credit losses $ 0 $ 0