Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jan. 01, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt securities, available-for-sale, amortized cost (in dollars)		$ 434,119	$ 288,175
Equity securities, available for sale, cost (in dollars)		$ 30,058	$ 42,120
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00	$ 1.00
Common stock, authorized shares	3,333,333	3,333,333	3,333,333
Common stock, issued shares		2,087,283	2,087,283
Treasury stock, shares		268,801	270,036
Senior unsecured notes due 2029 [Member]
Unamortized debt issuance cost (in dollars)		$ 648	$ 746
Subordinated Debt [Member]
Unamortized debt issuance cost (in dollars)		$ 691	$ 744