Accumulated Other Comprehensive Income - Component of Accumulated Other Comprehensive Income (loss) (Details) - USD ($) $ in Thousands	Jul. 31, 2021	Jan. 31, 2021	Jul. 31, 2020
Accumulated Other Comprehensive Income Loss [Line Items]
Foreign currency translation adjustments	$ 91,058	$ 93,166	$ 86,408
Available-for-sale securities	149	124	92
Total accumulated other comprehensive income	90,486	92,540	86,109
Unrecognized Prior Service Cost
Accumulated Other Comprehensive Income Loss [Line Items]
Defined benefit pension plan	(315)	(344)	(339)
Net Actuarial Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Defined benefit pension plan	$ (406)	$ (406)	$ (52)