Income Tax (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
Aug. 03, 2019	Aug. 04, 2018	Aug. 03, 2019	Aug. 04, 2018
Income Tax Disclosure [Abstract]
Current income tax expense (benefit)	$ (10.5)		$ (3.3)
Unrecognized tax benefits decrease	9.3		12.5
Tax due on amounts previously considered permanently reinvested	2.1		9.9
Uncertain tax positions, decrease from the lapse of statutes of limitation in various jurisdictions during next 12 months	14.2		14.2
Tax incentives, decrease in foreign taxes	$ 1.6	$ 0.5	$ 1.7	$ 1.2
Tax incentives, effect on net income per share (less than) (in usd per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Income Taxes [Line Items]
Cash, cash equivalents and short-term investments	$ 573.0		$ 573.0
Undistributed earnings of foreign subsidiaries	173.0		173.0
Foreign Subsidiaries
Income Taxes [Line Items]
Cash, cash equivalents and short-term investments	$ 496.0		$ 496.0

Income Taxes [Line Items]

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Taxes Due On Amounts Previously Considered Permanently Reinvested

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Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

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Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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The amount of income taxes from which a reporting entity is exempt or for which it will receive a reduction in income taxes as a result of the income tax holiday granted by the taxing jurisdiction.

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Per share amount effect of the income tax benefit resulting from the income tax holidays granted by taxing jurisdictions.

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Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile.

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Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

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