Segments Information Regarding Operations by Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Segment Reporting Information [Line Items]
Net revenue	$ 550.7	$ 609.5	$ 1,062.6	$ 1,256.0
Americas
Segment Reporting Information [Line Items]
Net revenue	230.1	235.7	447.8	479.7
Americas | U.S.
Segment Reporting Information [Line Items]
Net revenue	195.2	194.5	379.9	394.1
Americas | Other Americas
Segment Reporting Information [Line Items]
Net revenue	34.9	41.2	67.9	85.6
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Net revenue	220.5	225.7	423.1	471.1
Asia Pacific
Segment Reporting Information [Line Items]
Net revenue	100.1	148.1	191.7	305.2
Asia Pacific | Japan
Segment Reporting Information [Line Items]
Net revenue	36.8	50.7	74.1	115.8
Asia Pacific | Other Asia Pacific
Segment Reporting Information [Line Items]
Net revenue	$ 63.3	$ 97.4	$ 117.6	$ 189.4