Goodwill and Other Intangibles - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
	Mar. 28, 2022	Jun. 30, 2023	Dec. 31, 2022
Goodwill And Other Intangible Assets [Line Items]
Goodwill		$ 207,385	$ 174,518
Healthcare savings account business acquisition			25,160
Branch acquisition	$ 7,700		7,707
Goodwill		207,385	207,385
Commercial Banking [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill		63,113	59,419
Branch acquisition			3,694
Goodwill		63,113	63,113
Institutional Banking [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill		76,492	51,332
Healthcare savings account business acquisition			25,160
Goodwill		76,492	76,492
Personal Banking [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill		67,780	63,767
Branch acquisition			4,013
Goodwill		$ 67,780	$ 67,780