Investment Securities - Narrative (Details) - USD ($)	Nov. 27, 2021	Feb. 27, 2021
Debt Securities, Available-for-sale [Line Items]
Short term held-to-maturity securities	$ 0	$ 0
Auction Rate Securities
Debt Securities, Available-for-sale [Line Items]
Long term available-for-sale investment securities	20,300,000	20,300,000
Valuation adjustments	$ 1,100,000	$ 800,000

Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity), classified as current.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26626-111562

Name:	us-gaap_HeldToMaturitySecuritiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant