Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,327.8	$ 67.3	$ 965.5	$ (139.1)
Other comprehensive income (loss) before reclassifications			16.2	7.3
Pre-tax losses reclassified from accumulated other comprehensive loss			14.9	(4.7)
Tax effects			(7.6)	1.3
Total other comprehensive income (loss)	11.0	(1.9)	23.5	3.9
Ending balance	1,279.9	69.3	1,279.9	69.3
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(113.4)	(154.5)	(125.9)	(160.3)
Ending balance	(102.4)	(156.4)	(102.4)	(156.4)
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(24.1)	8.4
Other comprehensive income (loss) before reclassifications			30.4	(8.3)
Pre-tax losses reclassified from accumulated other comprehensive loss			14.6	(4.8)
Tax effects			(6.7)	1.5
Total other comprehensive income (loss)			38.3	(11.6)
Ending balance	14.2	(3.2)	14.2	(3.2)
Net Unrealized Gains on Available-for-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			6.4	4.7
Other comprehensive income (loss) before reclassifications			7.1	1.7
Pre-tax losses reclassified from accumulated other comprehensive loss			0.0	0.1
Tax effects			0.0	0.1
Total other comprehensive income (loss)			7.1	1.9
Ending balance	13.5	6.6	13.5	6.6
Defined Benefit Pension Components
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(21.3)	(22.8)
Other comprehensive income (loss) before reclassifications			0.0	0.0
Pre-tax losses reclassified from accumulated other comprehensive loss			0.3	0.0
Tax effects			0.0	0.0
Total other comprehensive income (loss)			0.3	0.0
Ending balance	(21.0)	(22.8)	(21.0)	(22.8)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(86.9)	(150.6)
Other comprehensive income (loss) before reclassifications			(21.3)	13.9
Pre-tax losses reclassified from accumulated other comprehensive loss			0.0	0.0
Tax effects			(0.9)	(0.3)
Total other comprehensive income (loss)			(22.2)	13.6
Ending balance	$ (109.1)	$ (137.0)	$ (109.1)	$ (137.0)