Business Segments - Financial Information by Business Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Interest and dividend income	$ 195,333	$ 160,555
Interest expense	81,367	36,223
NET INTEREST INCOME	113,966	124,332
Provision for credit losses	4,014	3,577
Net interest income after provision for credit losses	109,952	120,755
Non-interest income	30,629	27,653
Non-interest expense	97,191	96,125
Income before provision for income taxes	43,390	52,283
Provision for income taxes	7,697	9,942
Net income	35,693	42,341
Preferred stock dividends	2,531	2,531
Net income available to common shareholders	33,162	39,810
Community Banking [Member]
Segment Reporting Information [Line Items]
Interest and dividend income	195,333	160,555
Interest expense	81,367	36,223
NET INTEREST INCOME	113,966	124,332
Provision for credit losses	4,014	3,577
Net interest income after provision for credit losses	109,952	120,755
Non-interest income	22,547	20,159
Non-interest expense	91,968	91,617
Income before provision for income taxes	40,531	49,297
Provision for income taxes	7,097	9,315
Net income	33,434	39,982
Preferred stock dividends	2,531	2,531
Net income available to common shareholders	30,903	37,451
Trust and Investment Services [Member]
Segment Reporting Information [Line Items]
Non-interest income	8,082	7,494
Non-interest expense	5,223	4,508
Income before provision for income taxes	2,859	2,986
Provision for income taxes	600	627
Net income	2,259	2,359
Net income available to common shareholders	$ 2,259	$ 2,359