Financial Instruments Cost and Fair Value of Financial Instuments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Oct. 31, 2013		Jan. 31, 2013		Oct. 31, 2012	Jan. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 1,473.4		$ 1,612.2		$ 827.0	$ 1,156.9
Derivative Instruments and Hedges, Carrying Amount	11.0	[1]	10.2	[1]
Unrealized Gain on Foreign Currency Derivatives, before Tax	6.0	[1]	9.2	[1]
Unrealized Loss on Foreign Currency Derivatives, before Tax	7.1	[1]	5.9	[1]
Derivative, Fair Value, Net	9.9	[1]	13.5	[1]
Derivative Asset, Fair Value, Gross Asset	12.1		17.4
Amortized Cost Securities	1,845.5		2,029.2
Unrealized Gain on Securities	17.0		16.9
Unrealized Loss on Securities	(10.3)		(8.1)
Fair Value, Assets Measured on Recurring Basis	1,852.2		2,038.0
Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, at Carrying Value			1.8	[2]
Available-for-sale Securities, Gross Unrealized Gains			0	[2]
Available-for-sale Securities, Gross Unrealized Losses			0	[2]
Cash and Cash Equivalents, Fair Value Disclosure			1.8	[2]
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, at Carrying Value	289.6	[2]	263.3	[2]
Available-for-sale Securities, Gross Unrealized Gains	0	[2]	0	[2]
Available-for-sale Securities, Gross Unrealized Losses	0	[2]	0	[2]
Cash and Cash Equivalents, Fair Value Disclosure	289.6	[2]	263.3	[2]
Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, at Carrying Value	248.3	[2]	596.3	[2]
Available-for-sale Securities, Gross Unrealized Gains	0	[2]	0	[2]
Available-for-sale Securities, Gross Unrealized Losses	0	[2]	0	[2]
Cash and Cash Equivalents, Fair Value Disclosure	248.3	[2]	596.3	[2]
Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, at Carrying Value	277.2	[2]	392.4	[2]
Available-for-sale Securities, Gross Unrealized Gains	0	[2]	0	[2]
Available-for-sale Securities, Gross Unrealized Losses	0	[2]	0	[2]
Cash and Cash Equivalents, Fair Value Disclosure	277.2	[2]	392.4	[2]
Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	[1]	0	[1]
Fair Value, Assets Measured on Recurring Basis	711.2		678.3
Level 1 [Member] | Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			1.8	[2]
Level 1 [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[2]	0	[2]
Level 1 [Member] | Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[2]	0	[2]
Level 1 [Member] | Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	21.2	[2]	17.2	[2]
Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Derivative Asset, Fair Value, Gross Asset	0.1	[1]	2.8	[1]
Fair Value, Assets Measured on Recurring Basis	1,109.6		1,327.3
Level 2 [Member] | Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			0	[2]
Level 2 [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	289.6	[2]	263.3	[2]
Level 2 [Member] | Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	248.3	[2]	596.3	[2]
Level 2 [Member] | Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	256.0	[2]	375.2	[2]
Level 3 [Member]
Schedule of Available-for-sale Securities [Line Items]
Derivative Asset, Fair Value, Gross Asset	9.8	[1]	10.7	[1]
Fair Value, Assets Measured on Recurring Basis	31.4		32.4
Level 3 [Member] | Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			0	[2]
Level 3 [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[2]	0	[2]
Level 3 [Member] | Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[2]	0	[2]
Level 3 [Member] | Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[2]	0	[2]
Other Long-term Investments [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0.2		0.1
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	123.3		145.2
Available-for-sale Securities, Fair Value Disclosure	123.5		145.3
Other Long-term Investments [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0.1		0.2
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	37.1		50.8
Available-for-sale Securities, Fair Value Disclosure	37.2		51.0
Other Long-term Investments [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0.1		0.1
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	50.8		36.0
Available-for-sale Securities, Fair Value Disclosure	50.9		36.1
Other Long-term Investments [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	1.0		1.0
Available-for-sale Securities, Fair Value Disclosure	1.0		1.0
Other Long-term Investments [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0.9		1.4
Available-for-sale Securities, Gross Unrealized Losses	(0.1)		0
Available-for-sale Securities, Amortized Cost Basis	205.1		172.1
Available-for-sale Securities, Fair Value Disclosure	205.9		173.5
Other Long-term Investments [Member] | Taxable Auction Rate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains			0
Available-for-sale Securities, Gross Unrealized Losses			0
Available-for-sale Securities, Amortized Cost Basis			4.2
Available-for-sale Securities, Fair Value Disclosure			4.2
Other Long-term Investments [Member] | Level 1 [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	123.5		145.3
Other Long-term Investments [Member] | Level 1 [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	37.2		51.0
Other Long-term Investments [Member] | Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	50.9		36.1
Other Long-term Investments [Member] | Level 1 [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 1 [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	205.9		173.5
Other Long-term Investments [Member] | Level 1 [Member] | Taxable Auction Rate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure			0
Other Long-term Investments [Member] | Level 2 [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 2 [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 2 [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	1.0		1.0
Other Long-term Investments [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 2 [Member] | Taxable Auction Rate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure			0
Other Long-term Investments [Member] | Level 3 [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 3 [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 3 [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 3 [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Other Long-term Investments [Member] | Level 3 [Member] | Taxable Auction Rate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure			4.2
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Trading Securities, Short-term Investments, Amortized Cost	35.9		31.1
Trading Securities	42.3		35.3
Trading Securities, Unrealized Holding Gain	6.4		4.2
Trading Securities, Unrealized Holding Loss	0		0
Short-term Investments [Member] | Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	131.7		15.1
Available-for-sale Securities, Fair Value Disclosure	131.7		15.1
Short-term Investments [Member] | Commercial paper and corporate securities [member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0		0.1
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	280.0		122.9
Available-for-sale Securities, Fair Value Disclosure	280.0		123.0
Short-term Investments [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	41.2		83.3
Available-for-sale Securities, Fair Value Disclosure	41.2		83.3
Short-term Investments [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	68.8		79.5
Available-for-sale Securities, Fair Value Disclosure	68.8		79.5
Short-term Investments [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0		0
Available-for-sale Securities, Gross Unrealized Losses	0		0
Available-for-sale Securities, Amortized Cost Basis	21.7		4.6
Available-for-sale Securities, Fair Value Disclosure	21.7		4.6
Short-term Investments [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains			0
Available-for-sale Securities, Gross Unrealized Losses			0
Available-for-sale Securities, Amortized Cost Basis			1.0
Available-for-sale Securities, Fair Value Disclosure			1.0
Short-term Investments [Member] | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Gains	0	[3]	0
Available-for-sale Securities, Gross Unrealized Losses	0	[3]	0
Available-for-sale Securities, Amortized Cost Basis	1.4	[3]	0.3
Available-for-sale Securities, Fair Value Disclosure	1.4	[3]	0.3
Short-term Investments [Member] | Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Trading Securities	42.3		35.3
Short-term Investments [Member] | Level 1 [Member] | Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		10.0
Short-term Investments [Member] | Level 1 [Member] | Commercial paper and corporate securities [member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	98.0		40.4
Short-term Investments [Member] | Level 1 [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	41.2		83.3
Short-term Investments [Member] | Level 1 [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	68.8		79.5
Short-term Investments [Member] | Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	21.7		4.6
Short-term Investments [Member] | Level 1 [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure			0
Short-term Investments [Member] | Level 1 [Member] | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0.5	[3]	0.3
Short-term Investments [Member] | Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Trading Securities	0		0
Short-term Investments [Member] | Level 2 [Member] | Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	131.7		5.1
Short-term Investments [Member] | Level 2 [Member] | Commercial paper and corporate securities [member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	182.0		82.6
Short-term Investments [Member] | Level 2 [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 2 [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 2 [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure			1.0
Short-term Investments [Member] | Level 2 [Member] | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0.9	[3]	0
Short-term Investments [Member] | Level 3 [Member]
Schedule of Available-for-sale Securities [Line Items]
Trading Securities	0		0
Short-term Investments [Member] | Level 3 [Member] | Bank Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 3 [Member] | Commercial paper and corporate securities [member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 3 [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 3 [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Short-term Investments [Member] | Level 3 [Member] | Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure			0
Short-term Investments [Member] | Level 3 [Member] | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[3]	0
Other Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	21.4	[4]	18.1	[4]
Available-for-sale Debt Securities Gross Unrealized Gain	3.3	[4]	1.6	[4]
Available-for-sale Debt Securities, Gross Unrealized Loss	3.1	[4]	2.2	[4]
Convertible Debt Securities, Fair Value Disclosure	21.6	[4]	17.5	[4]
Other Assets [Member] | Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Convertible Debt Securities, Fair Value Disclosure	0	[4]	0	[4]
Other Assets [Member] | Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Convertible Debt Securities, Fair Value Disclosure	0	[4]	0	[4]
Other Assets [Member] | Level 3 [Member]
Schedule of Available-for-sale Securities [Line Items]
Convertible Debt Securities, Fair Value Disclosure	$ 21.6	[4]	$ 17.5	[4]

[1] Included in “Prepaid expenses and other current assets,” “Other assets,” or “Other accrued liabilities” in the accompanying Condensed Consolidated Balance Sheets.

[2] Included in “Cash and cash equivalents” in the accompanying Condensed Consolidated Balance Sheets.

[3] Consists of sovereign debt and other short-term securities.

[4] Considered “available for sale” and included in “Other assets” in the accompanying Condensed Consolidated Balance Sheets.