CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	371,353,000	371,353,000
Common stock, shares outstanding (in shares)	272,494,000	293,433,000
Treasury stock, shares at cost (in shares)	98,859,000	77,920,000
Fixed income
Fixed income, amortized cost	$ 5,939,483	$ 5,859,688
Short-Term Investments
Fixed income, amortized cost	121,539	67,097
Equity securities
Cost	$ 16,025	$ 15,924