Other Income (Expense), Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Other Income and Expenses [Abstract]
Interest income	$ 18,013	$ 5,424		$ 4,052
Interest expense	(21,615)	(19)		(44)
Foreign currency transaction gains (losses)	(5,230)	5,976		(2,632)
Other income	816	64		251
Total other income (expense), net	$ (8,016)	$ 11,445	[1]	$ 1,627	[1]

[1] *As adjusted to reflect the impact of the full retrospective adoption of ASC 606 - see Note 2.