Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest income
Interest and fees on loans	$ 834,969	$ 676,089	$ 690,909
Interest on taxable securities	34,656	22,524	33,086
Interest on nontaxable securities	1,176	575	623
Interest on deposits in other banks	23,008	3,882	1,739
Interest on federal funds sold	77	42	146
Total interest income	893,886	703,112	726,503
Interest expense
Interest on deposits	56,105	22,357	59,067
Interest on other borrowings	36,755	25,428	29,683
Total interest expense	92,860	47,785	88,750
Net interest income	801,026	655,327	637,753
Provision for loan losses	52,610	(35,081)	125,488
Provision for unfunded commitments	19,226	332	19,062
Provision for other credit losses	(139)	(616)	830
Provision for credit losses	71,697	(35,365)	145,380
Net interest income after provision for credit losses	729,329	690,692	492,373
Noninterest income
Service charges on deposit accounts	44,499	45,106	44,145
Mortgage banking activity	184,904	285,900	374,077
Other service charges, commissions and fees	3,875	4,188	3,914
Net gain on securities	203	515	5
Gain on sale of SBA loans	5,552	6,623	7,226
Other noninterest income	45,391	23,212	17,133
Total noninterest income	284,424	365,544	446,500
Noninterest expense
Salaries and employee benefits	319,719	337,776	360,278
Occupancy and equipment	51,361	48,066	52,349
Advertising and marketing	12,481	8,434	8,046
Amortization of intangible assets	19,744	14,965	19,612
Data processing and communications expenses	49,228	45,976	46,017
Legal and other professional fees	16,439	11,920	15,972
Credit resolution-related expenses	29	3,538	5,106
Merger and conversion charges	1,212	4,206	1,391
FDIC insurance	8,063	5,614	14,078
Loan servicing expenses	36,835	26,481	20,910
Other noninterest expenses	45,544	53,148	54,870
Total noninterest expense	560,655	560,124	598,629
Income before income tax expense	453,098	496,112	340,244
Income tax expense	106,558	119,199	78,256
Net income	$ 346,540	$ 376,913	$ 261,988
Basic earnings per common share (in dollars per share)	$ 5.01	$ 5.43	$ 3.78
Diluted earnings per common share (in dollars per share)	$ 4.99	$ 5.40	$ 3.77
Weighted average common shares outstanding
Basic (in shares)	69,194	69,432	69,256
Diluted (in shares)	69,420	69,761	69,426