Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Consolidated Balance Sheets [Abstract]
Properties and equipment, at cost, accumulated depreciation	$ 365,074	$ 354,872
Identifiable intangible assets, accumulated amortization	$ 51,485	$ 48,965
Capital stock - authorized	80,000,000	80,000,000
Capital stock - par value	$ 1	$ 1
Capital stock - issued	37,297,015	37,183,681
Treasury stock	22,212,667	22,148,927