PARENT COMPANY FINANCIAL INFORMATION - Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Flows from Operating Activities:
Net income	$ 122,844	$ 166,299	$ 235,107
Adjustments to reconcile net income to net cash provided by operating activities:
Share based compensation expense	7,631	7,887	5,299
Other-net	1,630	(3,710)	1,894
Net cash provided by operating activities	137,815	216,322	216,398
Cash Flows from Investing Activities:
Proceeds from sales of investment available-for-sale	0	18,087	400,567
Net cash provided by/ (used in) investing activities	178,938	(1,619,196)	308,261
Cash Flows from Financing Activities:
Retirement of subordinated debt	0	0	(53,000)
Proceeds from issuance of subordinated debt	0	200,000	0
Proceeds from issuance of common stock	2,417	2,192	5,758
Stock tendered for payment of withholding taxes	(1,821)	(2,353)	(1,577)
Repurchase of common stock	0	(24,987)	(107,268)
Dividends paid	(61,159)	(61,368)	(60,351)
Net cash provided by/ (used in) financing activities	36,913	1,175,086	(401,642)
Net increase/ (decrease) in cash and cash equivalents	353,666	(227,788)	123,017
Cash and cash equivalents at beginning of year	192,232	420,020	297,003
Cash and cash equivalents at end of year	545,898	192,232	420,020
Parent Company
Cash Flows from Operating Activities:
Net income	122,844	166,299	235,107
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed income-subsidiary	(21,370)	(113,025)	(52,295)
Share based compensation expense	7,631	7,887	5,299
Other-net	(7,300)	(9,760)	4,133
Net cash provided by operating activities	101,805	51,401	192,244
Cash Flows from Investing Activities:
Proceeds from sales of investment available-for-sale	0	0	9,099
Investment in subsidiary	0	(150,000)	0
Net cash provided by/ (used in) investing activities	0	(150,000)	9,099
Cash Flows from Financing Activities:
Retirement of subordinated debt	0	0	(32,810)
Proceeds from issuance of subordinated debt	0	200,000	0
Proceeds from issuance of common stock	2,417	2,192	5,758
Stock tendered for payment of withholding taxes	(1,821)	(2,353)	(1,577)
Repurchase of common stock	0	(24,987)	(107,268)
Dividends paid	(61,159)	(61,368)	(60,351)
Net cash provided by/ (used in) financing activities	(60,563)	113,484	(196,248)
Net increase/ (decrease) in cash and cash equivalents	41,242	14,885	5,095
Cash and cash equivalents at beginning of year	83,923	69,038	63,943
Cash and cash equivalents at end of year	$ 125,165	$ 83,923	$ 69,038