Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 6,984,530	$ 5,766,234
Securities held to maturity, fair value	1,631,482	1,467,581
Loans held-for-sale, fair value	41,022	0
Property and equipment, accumulated depreciation	280,065	271,801
Right of use assets, accumulated amortization	$ 34,425	$ 23,330
Preferred stock, par value per share	$ 20.00	$ 20.00
Common stock, par value per share	$ 3.33	$ 3.33