Note 6 - Stockholders' Equity (Details Textual) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2022 USD ($) shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares
Capital Units, Authorized (in shares)	245,000,000	245,000,000
Common Stock, Shares Authorized (in shares)	200,000,000	200,000,000
Preferred Stock, Shares Authorized (in shares)	20,000,000	20,000,000
Common Stock, Voting Rights, Votes Per Share	1	1
Common Stock, Dividends, Per Share, Declared (in dollars per share) | $ / shares		$ 0.32	$ 0.32	$ 0
Dividends, Common Stock, Total | $		$ 30,000	$ 31,000
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	7,200,000	7,200,000
Treasury Stock, Value, Acquired, Cost Method | $	$ 50,000		$ 30,000	$ 75,000
Class A Common Stock (No Par Value) [Member]
Common Stock, Shares Authorized (in shares)	25,000,000	25,000,000	25,000,000
Common Stock, Voting Rights, Votes Per Share	10	10
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	2,800,000	2,800,000
Common Stock and Class A Common Stock [Member]
Dividends, Common Stock, Total | $				$ 0
Stock Repurchased During Period, Shares (in shares)		2,600,000
Treasury Stock, Value, Acquired, Cost Method | $		$ 50,000
Stock Repurchase Program, Authorized Amount | $	$ 124,000	$ 124,000