CONSOLIDATED BALANCE SHEETS (Unaudited) (Parentheticals) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Cash and cash equivalents, securities carried at fair value		$ 22,000
Accumulated depreciation	$ 340,233	334,101
Accumulated amortization	$ 743,140	$ 775,190
Common stock, par value (per share)	$ 1	$ 1
Common stock, shares authorized	500,000	500,000
Common stock, shares outstanding	44,046	43,743