Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 6,085,309	$ 6,310,214
Securities held to maturity, fair value	2,430,287	2,615,398
Loans held-for-sale, fair value	13,298	10,843
Property and equipment, accumulated depreciation	310,928	303,451
Right of use assets, accumulated amortization	$ 52,572	$ 44,901
Preferred stock, par value per share	$ 20	$ 20
Common stock, par value per share	$ 3.33	$ 3.33