Parent Company Financial Information- Cash flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Income	$ 140,930	$ 176,691	$ 132,217
Adjustments to reconcile net income to net cash provided by operating activities:
Net tax benefits from stock compensation	0	0	118
Securities premium amortization (discount accretion), net	9,011	4,031	8,196
Provision for credit losses	266	(20,821)	45,571
Depreciation and amortization	3,319	5,874	4,696
Increase (decrease) in other assets	(26,162)	1,358	(28,626)
Increase (decrease) in other liabilities	12,581	24,823	9,826
Net cash provided by operating activities	194,902	238,437	133,139
Cash Flows From Investing Activities:
Purchases of available-for-sale investment securities	(425,263)	(2,029,434)	(739,955)
Proceeds from maturities of available-for-sale securities	261,999	313,921	302,471
Purchase of held to maturity investment securities	(290,740)	0	0
Proceeds from maturities from held to maturity securities	115,777	0	0
Net cash used in by investing activities	(927,077)	(857,922)	(557,676)
Cash Flows From Financing Activities:
Repayment of long-term borrowings	0	(200,000)	0
Proceeds from exercise of stock options	97	0	63
Proceeds from employee stock purchase plan	748	496	760
Common stock repurchased	(33,087)	(682)	(61,432)
Cash dividends paid	(55,776)	(44,691)	(28,330)
Net cash used in financing activities	(670,193)	544,652	1,971,619
Net (Decrease) Increase In Cash and Cash Equivalents	(1,402,368)	(74,833)	1,547,082
Cash and Cash Equivalents at Beginning of Period	1,714,222	1,789,055	241,973
Cash and Cash Equivalents at End of Period	311,854	1,714,222	1,789,055
Non-Cash Investing Activities
Transfers of investment securities from available-for-sale to held-to-maturity	922,975	0	0
Parent Company
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Income	140,930	176,691	132,217
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed income of subsidiary	(72,748)	(17,449)	(6,191)
Net tax benefits from stock compensation	9,899	7,811	118
Securities premium amortization (discount accretion), net	(54)	5	6
Provision for credit losses	326	0	0
Depreciation and amortization	0	0	390
Increase (decrease) in other assets	(12,909)	66,598	(48,966)
Increase (decrease) in other liabilities	4,593	(681)	6,823
Net cash provided by operating activities	70,037	232,975	84,397
Cash Flows From Investing Activities:
Purchases of available-for-sale investment securities	0	(40,000)	(10,000)
Proceeds from maturities of available-for-sale securities	0	13,031	613
Purchase of held to maturity investment securities	(3,976)	0	0
Proceeds from maturities from held to maturity securities	1,500	0	0
Net cash used in by investing activities	(2,476)	(26,969)	(9,387)
Cash Flows From Financing Activities:
Repayment of long-term borrowings	0	(148,407)	0
Proceeds from exercise of stock options	97	0	63
Proceeds from employee stock purchase plan	748	496	760
Common stock repurchased	(33,087)	(682)	(61,432)
Cash dividends paid	(55,776)	(44,691)	(28,330)
Net cash used in financing activities	(88,018)	(193,284)	(88,939)
Net (Decrease) Increase In Cash and Cash Equivalents	(20,457)	12,722	(13,929)
Cash and Cash Equivalents at Beginning of Period	41,997	29,275	43,204
Cash and Cash Equivalents at End of Period	21,540	41,997	29,275
Non-Cash Investing Activities
Transfers of investment securities from available-for-sale to held-to-maturity	$ 42,467	$ 0	$ 0