Segments Information regarding operations by geographic area (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										12 Months Ended
	Jan. 31, 2012		Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011		Oct. 31, 2010	Jul. 31, 2010	Apr. 30, 2010	Jan. 31, 2012		Jan. 31, 2011		Jan. 31, 2010
Revenue, Net	$ 592.4		$ 548.6	$ 546.3	$ 528.3	$ 527.7		$ 476.7	$ 472.8	$ 474.6	$ 2,215.6		$ 1,951.8		$ 1,713.7
Long-Lived Assets	1,003.3	[1]				790.0	[1]				1,003.3	[1]	790.0	[1]
Total Americas
Revenue, Net											798.5		701.5		654.4
Long-Lived Assets	831.7	[1]				636.8	[1]				831.7	[1]	636.8	[1]
Total Americas | U.S.
Revenue, Net											631.0		561.6		527.5
Long-Lived Assets	792.5	[1]				571.2	[1]				792.5	[1]	571.2	[1]
Total Americas | Other Americas
Revenue, Net											167.5		139.9		126.9
Long-Lived Assets	39.2	[1]				65.6	[1]				39.2	[1]	65.6	[1]
Europe Middle East And Africa
Revenue, Net											862.2		782.8		671.1
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	121.1	[1]				111.3	[1]				121.1	[1]	111.3	[1]
Europe Middle East And Africa | SWITZERLAND
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	37.7	[1]				42.8	[1]				37.7	[1]	42.8	[1]
Europe Middle East And Africa | Other Europe, Middle East and Africa [Domain]
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	83.4	[1]				68.5	[1]				83.4	[1]	68.5	[1]
Asia [Member]
Revenue, Net											554.9		467.5		388.2
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	50.5	[1]				41.9	[1]				50.5	[1]	41.9	[1]
Asia [Member] | JAPAN
Revenue, Net											240.5		200.6		171.1
Asia [Member] | Other Asia Pacific
Revenue, Net											$ 314.4		$ 266.9		$ 217.1

[1] Long-lived assets exclude investments in subsidiaries, deferred tax assets and marketable securities.