Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ / shares in Thousands, $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Series A Perpetual Preferred Stock, par value (in dollars per share)	$ 0	$ 0
Temporary Equity, Shares Authorized (in shares)	1,500,000	1,500,000
Temporary Equity, Shares Issued (in shares)	650,000	650,000
Temporary Equity, Shares Outstanding (in shares)	650,000	650,000
Series A Perpetual Preferred Stock, liquidation value	$ 650	$ 650
Common Stock, Shares Authorized (in shares)	200,000,000	200,000,000
Common Stock (No Par Value) [Member]
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares issued (in shares)	115,042,050	113,779,383
Common stock, shares outstanding (in shares)	92,912,582	92,444,984
Treasury stock, shares (in shares)	22,129,468	21,334,399
Class A Common Stock (No Par Value) [Member]
Common stock, par value (in dollars per share)	$ 0	$ 0
Common Stock, Shares Authorized (in shares)	25,000,000	25,000,000
Common stock, shares issued (in shares)	12,978,335	12,198,808
Common stock, shares outstanding (in shares)	9,869,307	9,557,830
Treasury stock, shares (in shares)	3,109,028	2,640,978