Segments Operations by geographic area (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										12 Months Ended
	Jan. 31, 2013		Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012		Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2013		Jan. 31, 2012		Jan. 31, 2011
Revenue, Net	$ 606.9		$ 548.0	$ 568.7	$ 588.6	$ 592.4		$ 548.6	$ 546.3	$ 528.3	$ 2,312.2		$ 2,215.6		$ 1,951.8
Long-Lived Assets	1,222.1	[1]				1,003.3	[1]				1,222.1	[1]	1,003.3	[1]
Total Americas
Revenue, Net											836.2		798.5		701.5
Long-Lived Assets	1,003.6	[1]				831.7	[1]				1,003.6	[1]	831.7	[1]
Total Americas | U.S.
Revenue, Net											672.1		631.0		561.6
Long-Lived Assets	964.0	[1],[2]				747.9	[1],[2]				964.0	[1],[2]	747.9	[1],[2]
Total Americas | Other Americas
Revenue, Net											164.1		167.5		139.9
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	39.6	[1],[2]				83.8	[1],[2]				39.6	[1],[2]	83.8	[1],[2]
Europe Middle East And Africa
Revenue, Net											868.5		862.2		782.8
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	168.4	[1]				121.1	[1]				168.4	[1]	121.1	[1]
Europe Middle East And Africa | SWITZERLAND
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	35.1	[1]				37.7	[1]				35.1	[1]	37.7	[1]
Europe Middle East And Africa | Other Europe, Middle East and Africa [Domain]
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	133.3	[1]				83.4	[1]				133.3	[1]	83.4	[1]
Asia [Member]
Revenue, Net											607.5		554.9		467.5
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	50.1	[1]				50.5	[1]				50.1	[1]	50.5	[1]
Asia [Member] | JAPAN
Revenue, Net											278.3		240.5		200.6
Asia [Member] | Other Asia Pacific
Revenue, Net											$ 329.2		$ 314.4		$ 266.9

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

[2] For comparability, the presentation of the balances at January 31, 2012 was adjusted to align to current year presentation.