CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 283,743	$ 339,889	$ 60,351
Adjustments to net income:
Depreciation and amortization expense	14,752	15,977	13,349
Provision for credit losses	4,832	(70,876)	191,816
Share-based compensation expense	18,925	13,264	10,859
Loss on sale and disposal of premises and equipment	89	234	255
Loss on sale of or write down of other real estate owned	0	0	112
Net amortization on securities	18,618	24,468	15,971
Net (accretion) of discounts/premiums for acquired loans and deferred loan fees/costs	(27,310)	(41,162)	(40,291)
Gain on sale of investment securities available-for-sale	(1,710)	(16,906)	(13,882)
Loss on debt extinguishment	0	180	0
Originations of loans held for sale	(61,237)	(51,098)	(14,251)
Proceeds from the sales of and principal payments from loans held for sale	73,300	44,734	16,552
Gain on sales of loans	(3,238)	(4,428)	(8,609)
Deferred income tax expense (benefit)	5,899	28,807	(42,622)
Change in accrued expenses and other liabilities, net	6,512	(29,038)	(9,455)
Income from bank owned life insurance, net	(10,658)	(9,000)	(5,538)
Amortization of intangible assets	13,983	15,936	17,072
Change in accrued interest receivable and other assets, net	74,532	59,234	20,609
Net cash provided by operating activities	411,032	320,215	212,298
Cash flows from investing activities:
Net decrease in interest-bearing time deposits with financial institutions	482	629	0
Proceeds from sales of other real estate owned	0	0	534
Loan originations and payments, net	(431,181)	(1,022,505)	53,972
Proceeds from sales of loans previously classified as loans held for investment	5,800	1,530	1,338,325
Purchase of loans held for investment	(797)	0	(66,470)
Purchase of securities held-to-maturity	0	(48,695)	0
Proceeds from prepayments and maturities of securities held-to-maturity	20,115	10,334	13,959
Purchase of securities available-for-sale	(986,997)	(2,231,699)	(2,715,499)
Proceeds from prepayments and maturities of securities available-for-sale	326,980	563,061	268,463
Proceeds from sales of securities available-for-sale	936,413	901,137	766,512
Proceeds from the sales of premises and equipment	0	55	42
Proceeds from surrender of bank owned life insurance	0	1,809	17,799
Purchase of bank owned life insurance	0	(150,000)	0
Purchases of premises and equipment	(7,476)	(9,290)	(11,408)
Change in FHLB, FRB, and other stock	(10,571)	(62)	(22,664)
Funding of CRA investments, net	(12,861)	(24,001)	(10,182)
Change in cash acquired in acquisitions, net	0	0	937,100
Net cash (used in) provided by investing activities	(160,093)	(2,007,697)	570,483
Cash flows from financing activities:
Net increase in deposit accounts	236,812	901,412	399,678
Net change in short-term borrowings	(358,000)	548,000	(691,000)
Proceeds from long-term borrowings	800,000	(21,503)	(5,000)
Redemption of subordinated debentures	0	(171,153)	0
Proceeds from issuance of subordinated debt, net	0	0	147,359
Cash dividends paid	(125,160)	(121,887)	(79,901)
Repurchase and retirement of common stock	0	(18,067)	0
Proceeds from exercise of stock options	873	1,001	1,652
Restricted stock surrendered and canceled	(8,918)	(6,384)	(1,653)
Net cash provided by (used in) financing activities	545,607	1,111,419	(228,865)
Net change in cash and cash equivalents	796,546	(576,063)	553,916
Cash and cash equivalents, beginning of year	304,703	880,766	326,850
Cash and cash equivalents, end of year	1,101,249	304,703	880,766
Supplemental cash flow disclosures:
Interest paid	59,149	38,761	57,020
Income taxes paid	75,294	86,535	36,158
Noncash investing activities during the period:
Transfers from portfolio loans to loans held for sale	6,399	1,006	1,330,946
Transfers from loans to other real estate owned	0	0	208
Transfers of investment securities from available-for-sale to held-to-maturity	1,019,472	319,924	0
Transfer of investment securities from other stock to held-to-maturity	7,000	0	0
Recognition of operating lease right-of-use assets	(1,635)	(5,003)	(12,277)
Recognition of operating lease liabilities	1,635	5,003	12,277
Assets acquired and liabilities assumed in acquisitions:
Fair value of stock and equity award consideration	0	0	749,603
Cash consideration	0	0	2
Fair value of assets acquired	0	0	8,102,281
Liabilities assumed	$ 0	$ 0	$ 7,352,676