Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (256.0)
Other comprehensive income (loss) before reclassifications	(7.5)
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	(0.8)
Tax effects	(1.7)
Total other comprehensive (loss) income	(10.0)	$ 12.2
Ending balance	(128.6)
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(16.6)
Other comprehensive income (loss) before reclassifications	7.6
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	(0.9)
Tax effects	(0.7)
Total other comprehensive (loss) income	6.0
Ending balance	(10.6)
Net Unrealized Gains (Losses) on Available-for-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1.3
Other comprehensive income (loss) before reclassifications	0.5
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	0.0
Tax effects	0.1
Total other comprehensive (loss) income	0.6
Ending balance	1.9
Defined Benefit Pension Components
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(29.3)
Other comprehensive income (loss) before reclassifications	9.0
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	0.1
Tax effects	(1.4)
Total other comprehensive (loss) income	7.7
Ending balance	(21.6)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(79.2)
Other comprehensive income (loss) before reclassifications	(24.6)
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	0.0
Tax effects	0.3
Total other comprehensive (loss) income	(24.3)
Ending balance	(103.5)
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(123.8)
Ending balance	$ (133.8)