Fair Value Measurements (Details) - USD ($) $ in Thousands	Nov. 26, 2016	Feb. 27, 2016
Cash equivalents
Total cash equivalents	$ 36,565	$ 52,973
Available-for-sale Securities, Current	30,635	30,173
Available-for-sale Securities	41,597	42,692
Total assets at fair value	78,162	95,665
Commercial Paper [Member]
Cash equivalents
Total cash equivalents	25,686	29,774
Money market funds [Member]
Cash equivalents
Total cash equivalents		23,199
Quoted Prices in Active Markets (Level 1) [Member]
Cash equivalents
Total cash equivalents	10,879	23,199
Available-for-sale Securities, Current	30,269
Available-for-sale Securities		30,123
Total assets at fair value	41,148	53,322
Quoted Prices in Active Markets (Level 1) [Member] \| Commercial Paper [Member]
Cash equivalents
Total cash equivalents	0	0
Quoted Prices in Active Markets (Level 1) [Member] \| Money market funds [Member]
Cash equivalents
Total cash equivalents		23,199
Quoted Prices in Active Markets (Level 1) [Member] \| Municipal bonds [Member]
Cash equivalents
Available-for-sale Securities		0
Other Observable Inputs (Level 2) [Member]
Cash equivalents
Total cash equivalents	25,686
Available-for-sale Securities, Current	366
Available-for-sale Securities		50
Total assets at fair value	37,014	42,343
Other Observable Inputs (Level 2) [Member] \| Commercial Paper [Member]
Cash equivalents
Total cash equivalents	25,686	29,774
Other Observable Inputs (Level 2) [Member] \| Money market funds [Member]
Cash equivalents
Total cash equivalents		0
Mutual Fund [Member]
Cash equivalents
Available-for-sale Securities, Current		30,123
Mutual Fund [Member] \| Quoted Prices in Active Markets (Level 1) [Member]
Cash equivalents
Available-for-sale Securities, Current		30,123
Mutual Fund [Member] \| Other Observable Inputs (Level 2) [Member]
Cash equivalents
Available-for-sale Securities, Current		0
Mutual funds [Member]
Cash equivalents
Available-for-sale Securities, Current	30,269
Mutual funds [Member] \| Quoted Prices in Active Markets (Level 1) [Member]
Cash equivalents
Available-for-sale Securities, Current	30,269
Mutual funds [Member] \| Other Observable Inputs (Level 2) [Member]
Cash equivalents
Available-for-sale Securities, Current	0
Money market funds [Member]
Cash equivalents
Total cash equivalents	10,879
Money market funds [Member] \| Quoted Prices in Active Markets (Level 1) [Member]
Cash equivalents
Total cash equivalents	10,879
Money market funds [Member] \| Other Observable Inputs (Level 2) [Member]
Cash equivalents
Total cash equivalents	0
Municipal bonds [Member]
Cash equivalents
Available-for-sale Securities, Current	366	50
Available-for-sale Securities, Noncurrent	10,962	12,519
Municipal bonds [Member] \| Quoted Prices in Active Markets (Level 1) [Member]
Cash equivalents
Available-for-sale Securities, Current	0
Available-for-sale Securities, Noncurrent	0	0
Municipal bonds [Member] \| Other Observable Inputs (Level 2) [Member]
Cash equivalents
Available-for-sale Securities, Current	366	50
Available-for-sale Securities, Noncurrent	$ 10,962	$ 12,519

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
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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
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6505594

Reference 2: 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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