Investments - Summary of Contractual Maturities of Marketable Securities (Details) - USD ($) $ in Thousands	Jul. 31, 2026	Jan. 31, 2026
Investments, Debt and Equity Securities [Abstract]
Less than one year	$ 1,564,734	$ 3,168,258
Due in one to five years	4,752,995	3,375,773
Total	$ 6,317,729	$ 6,544,031

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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