Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Available for sale securities, amortized cost	$ 7,248,525	$ 7,777,950
Held to maturity securities, allowance for credit losses	2,886	2,407
Held to Maturity, Fair value	$ 4,856,466	$ 5,280,659
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	55,056,730	55,056,730
Common stock, shares outstanding	48,529,097	48,319,404
Treasury stock, shares	6,527,633	6,737,326