Segments Information Regarding Operations by Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Segment Reporting Information [Line Items]
Net revenue	$ 609.5	$ 637.1	$ 1,256.0	$ 1,229.6
Americas
Segment Reporting Information [Line Items]
Net revenue	235.7	223.3	479.7	429.0
Americas | U.S.
Segment Reporting Information [Line Items]
Net revenue	194.5	184.6	394.1	354.1
Americas | Other Americas
Segment Reporting Information [Line Items]
Net revenue	41.2	38.7	85.6	74.9
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Net revenue	225.7	243.5	471.1	469.0
Asia Pacific
Segment Reporting Information [Line Items]
Net revenue	148.1	170.3	305.2	331.6
Asia Pacific | Japan
Segment Reporting Information [Line Items]
Net revenue	50.7	70.5	115.8	157.1
Asia Pacific | Other Asia Pacific
Segment Reporting Information [Line Items]
Net revenue	$ 97.4	$ 99.8	$ 189.4	$ 174.5