Interest And Other Income, net (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2013		Jan. 31, 2012		Jan. 31, 2011
Component of Other Income, Nonoperating [Line Items]
Interest and investment income, net	$ 4.9	[1]	$ 5.4	[1]	$ 8.9	[1]
Gain (Loss) on foreign currency	1.2		(1.1)		(14.0)
Loss on Strategic Investments	(4.0)	[1]	0.3	[1]	2.0	[1]
Other Income	2.0		2.7		3.7
Interest and other income, net	$ 4.1		$ 7.3		$ 0.6

[1] For comparability, the presentation of the balances at January 31, 2012 and January 31, 2011 was adjusted to align to current year presentation.