Other Income (Expense), Net - Other Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Other Income and Expenses [Abstract]
Interest income	$ 6,770	$ 5,497	$ 20,376	$ 12,151
Interest expense	(7,077)	(6,706)	(20,725)	(14,819)
Foreign currency transactions gains (losses)	97	(1,667)	(2,329)	(6,074)
Other income (expense)	219	(13)	219	822
Total other income (expense), net	$ 9	$ (2,889)	$ (2,459)	$ (7,920)