Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ (210.9)	$ (256.0)	$ 733.6
Other comprehensive income (loss) before reclassifications	(7.8)	(22.3)
Pre-tax gains (losses) reclassified from accumulated other comprehensive income	(17.7)	13.7
Tax effects	0.2	(2.6)
Total other comprehensive (loss) income	(25.3)	(11.2)	54.7
Ending Balance	(139.1)	(210.9)	(256.0)
Net Unrealized (Losses) Gains on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	15.0	(16.6)
Other comprehensive income (loss) before reclassifications	4.1	20.6
Pre-tax gains (losses) reclassified from accumulated other comprehensive income	(9.6)	12.1
Tax effects	(1.1)	(1.1)
Total other comprehensive (loss) income	(6.6)	31.6
Ending Balance	8.4	15.0	(16.6)
Net Unrealized Gains (Losses) on Available for Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	3.3	1.3
Other comprehensive income (loss) before reclassifications	1.8	0.7
Pre-tax gains (losses) reclassified from accumulated other comprehensive income	0.0	1.3
Tax effects	(0.4)	0.0
Total other comprehensive (loss) income	1.4	2.0
Ending Balance	4.7	3.3	1.3
Defined Benefit Pension Components
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(16.3)	(29.3)
Other comprehensive income (loss) before reclassifications	0.0	14.7
Pre-tax gains (losses) reclassified from accumulated other comprehensive income	(8.1)	0.3
Tax effects	1.6	(2.0)
Total other comprehensive (loss) income	(6.5)	13.0
Ending Balance	(22.8)	(16.3)	(29.3)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(137.0)	(79.2)
Other comprehensive income (loss) before reclassifications	(13.7)	(58.3)
Pre-tax gains (losses) reclassified from accumulated other comprehensive income	0.0	0.0
Tax effects	0.1	0.5
Total other comprehensive (loss) income	(13.6)	(57.8)
Ending Balance	(150.6)	(137.0)	(79.2)
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(135.0)	(123.8)	(178.5)
Ending Balance	$ (160.3)	$ (135.0)	$ (123.8)

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Amount before tax and reclassification adjustments of other comprehensive income (loss) attributable to parent.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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