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

Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481520/505-30-50-4

Name:	srt_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant