UNAUDITED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Available for sale securities, amortized cost	$ 202,688	$ 201,270
Held-to-maturity securities, fair value	$ 1,043,391	$ 971,092
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares, outstanding	7,000,995	6,968,192