Convertible Senior Notes - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2023	Jul. 31, 2022
Debt Instrument
Amortization of debt issuance costs			$ 4,441	$ 5,484
Convertible Senior Notes | 2023 Notes
Debt Instrument
Coupon interest expense	$ 971	$ 971	1,942	1,942
Amortization of debt issuance costs	424	638	801	966
Total interest expense	1,395	1,609	2,743	2,908
Convertible Senior Notes | 2025 Notes
Debt Instrument
Coupon interest expense	2,426	2,426	4,852	4,852
Amortization of debt issuance costs	349	642	603	866
Total interest expense	2,775	3,068	5,455	5,718
Convertible Senior Notes | 2026 Notes
Debt Instrument
Coupon interest expense	1,875	1,875	3,750	3,750
Amortization of debt issuance costs	917	1,417	1,737	1,944
Total interest expense	2,792	3,292	5,487	5,694
Convertible Senior Notes | 2027 Notes
Debt Instrument
Coupon interest expense	3,558	3,558	7,116	7,116
Amortization of debt issuance costs	723	1,274	1,300	1,708
Total interest expense	$ 4,281	$ 4,832	$ 8,416	$ 8,824