Cloud Computing Arrangements (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Jan. 31, 2020
Capitalized Contract Cost [Line Items]
Capitalized contract cost	$ 89.4		$ 89.4		$ 98.8
Amortization expense	23.8	$ 25.2	70.2	$ 75.4
Cloud-based Software Hosting Arrangements
Capitalized Contract Cost [Line Items]
Capitalized contract cost	56.9		56.9		22.3
Accumulated amortization	3.9		3.9		$ 1.2
Amortization expense	$ 1.0	$ 0.0	$ 2.7	$ 0.0