Income Taxes Provision for income taxes (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
Federal
Current									$ 30.9	$ 54.3	$ 16.0
Deferred									(13.3)	(34.5)	(8.2)
State
Current									7.8	4.9	(1.5)
Deferred									(18.6)	1.3	7.4
Foreign
Current									54.3	55.9	48.4
Deferred									1.5	(4.3)	(2.1)
Income Tax Expense (Benefit)	$ 11.6	$ 4.9	$ 27.5	$ 18.6	$ 20.9	$ 18.5	$ 23.0	$ 15.2	$ 62.6	$ 77.6	$ 60.0