Note 13 - Restricted Cash and Deposits	6 Months Ended
Oct. 31, 2021
Notes to Financial Statements
Restricted Assets Disclosure [Text Block]	Note 13 - Restricted Cash and Deposits: Restricted Money Market Investment in the noncurrent assets on the Consolidated Condensed Balance Sheet at October 31, 2021, includes $469,000, which represents cash invested in a bank money market fund securing a letter of credit ("LOC") in the amount of $469,000 issued to the sublandlord as a security deposit for the Company's New York City leased corporate office facility. The sublease agreement provided for the reduction of the LOC and restricted cash to $305,000 as of November 30, 2021.

Note 13 - Restricted Cash and Deposits

6 Months Ended

Oct. 31, 2021

Restricted Assets Disclosure [Text Block]

Note 13 - Restricted Cash and Deposits:

Restricted Money Market Investment in the noncurrent assets on the Consolidated Condensed Balance Sheet at October 31, 2021, includes $469,000, which represents cash invested in a bank money market fund securing a letter of credit ("LOC") in the amount of $469,000 issued to the sublandlord as a security deposit for the Company's New York City leased corporate office facility. The sublease agreement provided for the reduction of the LOC and restricted cash to $305,000 as of November 30, 2021.