Income Taxes - Income Taxes Unrecognized Tax Benefits Reconciliation, Table (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at the beginning of the fiscal year	$ 245.8	$ 222.1	$ 212.7
Increases for tax positions of prior years	1.4	3.2	1.8
Decreases for tax positions of prior years	(7.0)	(2.5)	(0.3)
Increases for tax positions related to the current year	15.8	33.2	15.3
Decreases relating to settlements with taxing authorities	(0.5)	(5.4)	(4.6)
Reductions as a result of lapse of the statute of limitations	(1.2)	(4.8)	(2.8)
Gross unrecognized tax benefits at the end of the fiscal year	$ 254.3	$ 245.8	$ 222.1

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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