Note 7 - Shareholders' Equity (Details Textual) - USD ($)	Mar. 31, 2023	Mar. 31, 2022
Statement [Line Items]
Common Stock, Shares Authorized (in shares)	75,000,000	75,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares, Outstanding (in shares)	21,042,652	21,042,652
Treasury Stock, Common, Shares (in shares)	31,923,145	31,923,145
Preferred Stock, Shares Issued (in shares)	3,677	3,677
Preferred Stock, Shares Outstanding (in shares)	3,677	3,677
Preferred Stock, Liquidation Preference, Value	$ 3,677,000,000	$ 3,677,000,000
Series A Preferred Stock [Member]
Statement [Line Items]
Preferred Stock, Shares Issued (in shares)	3,677
Preferred Stock, Shares Outstanding (in shares)	3,677
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 1
Preferred Stock, Liquidation Preference, Value	$ 3,677,000