Summary of Significant Accounting Policies - Debt (Details) - USD ($) $ in Millions	Feb. 28, 2021	Feb. 29, 2020
Senior Notes \| Unsecured Senior Notes Due March 31, 2018
Debt Instrument [Line Items]
Fair value of notes	$ 144.8	$ 125.3

Fair value portion of notes payable.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19,20,22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_NotesPayableFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant