Cash Equivalents and Investments - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021
Debt Securities, Available-for-sale, Unrealized Loss Position
Contractual maturities of available-for-sale debt securities, maximum	36 months
Gross unrealized losses on available-for-sale debt securities	$ 15,581	$ 637
Prepaid Expenses and Other Current Assets
Debt Securities, Available-for-sale, Unrealized Loss Position
Interest receivable, current	$ 14,100	$ 15,200