Consolidated Statements of Income and Comprehensive Income (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Interest income
Interest and fees on loans	$ 292,012	$ 190,740	$ 563,976	$ 368,306
Interest on taxable securities	15,915	7,064	30,215	11,303
Interest on nontaxable securities	339	269	678	455
Interest on deposits in other banks and federal funds sold	13,686	4,495	22,799	5,878
Total interest income	321,952	202,568	617,668	385,942
Interest expense
Interest on deposits	88,087	4,908	141,269	9,000
Interest on other borrowings	24,325	6,296	55,207	13,034
Total interest expense	112,412	11,204	196,476	22,034
Net interest income	209,540	191,364	421,192	363,908
Provision for loan losses	43,643	13,227	93,019	10,493
Provision for unfunded commitments	1,873	1,779	2,219	10,788
Provision for other credit losses	0	(82)	7	(126)
Provision for credit losses	45,516	14,924	95,245	21,155
Net interest income after provision for credit losses	164,024	176,440	325,947	342,753
Noninterest income
Service charges on deposit accounts	11,295	11,148	22,231	22,206
Mortgage banking activity	40,742	58,761	72,134	121,699
Other service charges, commissions and fees	975	998	1,946	1,937
Net gain (loss) on securities	(6)	248	0	221
Other noninterest income	14,343	12,686	27,088	24,689
Total noninterest income	67,349	83,841	123,399	170,752
Noninterest expense
Salaries and employee benefits	81,336	81,545	162,246	165,826
Occupancy and equipment	12,522	12,746	25,508	25,473
Data processing and communications expenses	13,451	12,155	26,485	24,727
Credit resolution-related expenses	848	496	1,283	(469)
Advertising and marketing	2,627	3,122	6,159	5,110
Amortization of intangible assets	4,688	5,144	9,394	10,325
Merger and conversion charges	0	0	0	977
Loan servicing expense	8,771	9,920	17,102	18,839
Other noninterest expenses	24,160	17,068	39,647	35,208
Total noninterest expense	148,403	142,196	287,824	286,016
Income before income tax expense	82,970	118,085	161,522	227,489
Income tax expense	20,335	28,019	38,466	55,725
Net income	62,635	90,066	123,056	171,764
Other comprehensive loss
Net unrealized holding losses arising during period on debt securities available-for-sale, net of tax benefit of $(5,118), $(2,870), $(1,399) and $(7,503)	(15,037)	(10,794)	(4,111)	(28,225)
Total other comprehensive loss	(15,037)	(10,794)	(4,111)	(28,225)
Comprehensive income	$ 47,598	$ 79,272	$ 118,945	$ 143,539
Basic earnings per common share (in dollars per share)	$ 0.91	$ 1.30	$ 1.78	$ 2.48
Diluted earnings per common share (in dollars per share)	$ 0.91	$ 1.30	$ 1.78	$ 2.47
Weighted average common shares outstanding
Basic (in shares)	68,990	69,136	69,085	69,246
Diluted (in shares)	69,035	69,316	69,192	69,485