Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Investment securities held-to-maturity, fair value	$ 343,023	$ 330,626
Common Stock, Par Value	$ 1.00	$ 1.00
Common Stock, Shares Authorized	20,000,000	20,000,000
Common Stock, Shares, Issued	16,059,368	16,056,282
Common Stock, Shares, Outstanding	15,960,917	15,957,830
Treasury Stock, Shares	98,452	98,452