Stock Plans (Detail Textuals) - USD ($) $ in Millions	Aug. 31, 2019	May 31, 2019
New Stock Repurchase Program \| Common Stock
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount	$ 1.0	$ 8.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_EquityClassOfTreasuryStockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration