Fair Value Hierarchy of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Nov. 24, 2017	Feb. 24, 2017
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	$ 244.1	$ 197.1
Restricted Cash and Cash Equivalents	2.5	2.5
Assets, Fair Value Disclosure	251.4	280.0
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	(1.6)	(0.9)
Liabilities, Fair Value Disclosure	(1.6)	(0.9)
Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		33.6
US Government Agencies Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		18.6
Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		3.7
US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		2.4
Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		15.1
Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.9	3.5
Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	3.9	3.5
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	244.1	197.1
Restricted Cash and Cash Equivalents	2.5	2.5
Assets, Fair Value Disclosure	246.6	202.0
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	0.0	0.0
Liabilities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| US Government Agencies Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		2.4
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0.0	0.0
Restricted Cash and Cash Equivalents	0.0	0.0
Assets, Fair Value Disclosure	0.9	74.5
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	(1.6)	(0.9)
Liabilities, Fair Value Disclosure	(1.6)	(0.9)
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		33.6
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| US Government Agencies Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		18.6
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		3.7
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		15.1
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.9	3.5
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0.0	0.0
Restricted Cash and Cash Equivalents	0.0	0.0
Assets, Fair Value Disclosure	3.9	3.5
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	0.0	0.0
Liabilities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| US Government Agencies Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	$ 3.9	$ 3.5

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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No definition available.

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Fair value portion of asset contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward contracts, and swaps.

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Fair value portion of liability contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into.

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Fair value of financial and nonfinancial obligations.

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Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(1)(a))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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