Segments Information Regarding Operations by Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2016	Apr. 30, 2015
Segment Reporting Information [Line Items]
Net revenue	$ 511.9	$ 646.5
Americas
Segment Reporting Information [Line Items]
Net revenue	217.7	244.0
Americas | U.S.
Segment Reporting Information [Line Items]
Net revenue	184.7	199.6
Americas | Other Americas
Segment Reporting Information [Line Items]
Net revenue	33.0	44.4
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Net revenue	202.6	245.4
Asia Pacific
Segment Reporting Information [Line Items]
Net revenue	91.6	157.1
Asia Pacific | Japan
Segment Reporting Information [Line Items]
Net revenue	37.3	65.1
Asia Pacific | Other Asia Pacific
Segment Reporting Information [Line Items]
Net revenue	$ 54.3	$ 92.0