Interest and Other Expense, net (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Other Income and Expenses [Abstract]
Interest and investment expense, net	$ (51.1)	$ (54.0)	$ (52.1)
Gain on foreign currency	3.5	3.9	5.1
(Loss) gain on strategic investments	(41.7)	(3.3)	12.5
Other income	6.9	5.2	16.8
Interest and other expense, net	$ (82.4)	$ (48.2)	$ (17.7)