Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 733.6
Total other comprehensive income (loss)	12.2	$ (0.4)
Ending balance	508.1
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	14.6
Other comprehensive (loss) income before reclassifications	(2.6)
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	0.7
Tax effects	0.5
Total other comprehensive income (loss)	(1.4)
Ending balance	13.2
Net Unrealized Gains (Losses) on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1.5
Other comprehensive (loss) income before reclassifications	1.0
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	0.0
Tax effects	(0.3)
Total other comprehensive income (loss)	0.7
Ending balance	2.2
Defined Benefit Pension Components
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(33.8)
Other comprehensive (loss) income before reclassifications	(0.1)
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	(0.4)
Tax effects	0.0
Total other comprehensive income (loss)	(0.5)
Ending balance	(34.3)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(160.8)
Other comprehensive (loss) income before reclassifications	13.7
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	0.0
Tax effects	(0.3)
Total other comprehensive income (loss)	13.4
Ending balance	(147.4)
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(178.5)
Other comprehensive (loss) income before reclassifications	12.0
Pre-tax (gains) losses reclassified from accumulated other comprehensive loss	0.3
Tax effects	(0.1)
Total other comprehensive income (loss)	12.2
Ending balance	$ (166.3)