Segments - Operations by geographic area (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										12 Months Ended
	Jan. 31, 2014		Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013		Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2014		Jan. 31, 2013		Jan. 31, 2012
Segment Reporting Information [Line Items]
Net revenue	$ 586.6		$ 555.2	$ 561.7	$ 570.4	$ 606.9		$ 548.0	$ 568.7	$ 588.6	$ 2,273.9		$ 2,312.2		$ 2,215.6
Total long-lived assets	1,351.6	[1]				1,222.1	[1]				1,351.6	[1]	1,222.1	[1]
Americas
Segment Reporting Information [Line Items]
Net revenue											818.9		836.2		798.5
Total long-lived assets	1,079.0	[1]				1,003.6	[1]				1,079.0	[1]	1,003.6	[1]
Americas | U.S.
Segment Reporting Information [Line Items]
Net revenue											672.3		672.1		631.0
Total long-lived assets	1,041.9	[1]				964.0	[1]				1,041.9	[1]	964.0	[1]
Americas | Other Americas
Segment Reporting Information [Line Items]
Net revenue											146.6		164.1		167.5
Total long-lived assets	37.1	[1]				39.6	[1]				37.1	[1]	39.6	[1]
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Net revenue											851.8		868.5		862.2
Total long-lived assets	228.6	[1]				168.4	[1]				228.6	[1]	168.4	[1]
Asia Pacific
Segment Reporting Information [Line Items]
Net revenue											603.2		607.5		554.9
Total long-lived assets	44.0	[1]				50.1	[1]				44.0	[1]	50.1	[1]
Asia Pacific | Japan
Segment Reporting Information [Line Items]
Net revenue											274.5		278.3		240.5
Asia Pacific | Other Asia Pacific
Segment Reporting Information [Line Items]
Net revenue											$ 328.7		$ 329.2		$ 314.4

[1] Long-lived assets exclude deferred tax assets and marketable securities.