Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 6,238,835	$ 6,310,214
Securities held to maturity, fair value	2,623,760	2,615,398
Loans held-for-sale, fair value	14,923	10,843
Property and equipment, accumulated depreciation	304,305	303,451
Right of use assets, accumulated amortization	$ 46,939	$ 44,901
Preferred stock, par value per share	$ 20.00	$ 20.00
Common stock, par value per share	$ 3.33	$ 3.33