Financial Instruments Effects of Derivative Instruments on Condensed Consolidated Statements of Operations (Details) (USD $) In Millions, unless otherwise specified					3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Jul. 31, 2013	Jan. 31, 2013	Jul. 31, 2013 Foreign Exchange Contract [Member]	Jan. 31, 2013 Foreign Exchange Contract [Member]	Jul. 31, 2013 Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Sales [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Sales [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Sales [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Sales [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Operating Expense [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Operating Expense [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Operating Expense [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Operating Expense [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Interest and other income (expense), net [member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Interest and other income (expense), net [member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Interest and other income (expense), net [member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Interest and other income (expense), net [member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Interest and other income (expense), net [member] Not Designated as Hedging Instrument [Member]	Jul. 31, 2013 Interest and other income (expense), net [member] Not Designated as Hedging Instrument [Member]	Jul. 31, 2012 Interest and other income (expense), net [member] Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Interest and other income (expense), net [member] Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in accumulated other comprehensive income on derivatives (effective portion)					$ (1.0)	$ 10.6	$ 12.6	$ 12.1
Derivative, Notional Amount	353.0	359.8	(23.8)	78.4
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net					3.9	3.7	7.7	8.5	4.4	6.1	8.7	12.4	(0.5)	(2.4)	(1.0)	(3.9)
Interest and other income (expense), net																	(0.1)	0	0	0.1
Interest and other income, net																					$ 0.5	$ 2.0	$ 0	$ 1.0