Goodwill and Other Intangible Assets - Summary of Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill, beginning balance	$ 175,510	$ 175,510
Goodwill, acquired during period	0	0
Goodwill, ending balance	175,510	175,510
Banking [Member]
Goodwill [Line Items]
Goodwill, beginning balance	138,476	138,476
Goodwill, acquired during period	0	0
Goodwill, ending balance	138,476	138,476
Wealth Management [Member]
Goodwill [Line Items]
Goodwill, beginning balance	15,434	15,434
Goodwill, acquired during period	0	0
Goodwill, ending balance	15,434	15,434
Insurance [Member]
Goodwill [Line Items]
Goodwill, beginning balance	21,600	21,600
Goodwill, acquired during period	0	0
Goodwill, ending balance	$ 21,600	$ 21,600