CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
Apr. 30, 2014	Apr. 30, 2013
Statement of Comprehensive Income [Abstract]
Net (loss) gain on derivative instruments - tax effect	$ (0.7)	$ 0.2
Change in net unrealized (loss) gain on available-for-sale securities, tax effect	(0.4)	0.2
Net change in cumulative foreign currency translation gain (loss), tax effect	$ (1.4)	$ 1.4

Amount of tax expense (benefit), before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 30

-Section 45

-Paragraph 20

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32211-110900

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e640-108580

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Amount of tax expense (benefit), after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount of tax expense (benefit), after reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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