Basis of Presentation (Details) - USD ($) $ in Millions	Apr. 30, 2021	Jan. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Marketable securities	$ 0.0	$ 4.0
Prepaid and other current assets	256.1	206.2
Long-term other assets		486.6
Total current assets	$ 1,505.4	2,625.5
Total assets		7,279.8
Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Marketable securities		85.0
Prepaid and other current assets		198.9
Long-term other assets		412.9
Total current assets		2,699.2
Total assets		7,279.8
Effect of Changes in Presentation
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Marketable securities		(81.0)
Prepaid and other current assets		7.3
Long-term other assets		73.7
Total current assets		(73.7)
Total assets		$ 0.0