Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest income
Interest and fees on loans	$ 676,089	$ 690,909	$ 586,848
Interest on taxable securities	22,524	33,086	40,138
Interest on nontaxable securities	575	623	593
Interest on deposits in other banks	3,882	1,739	8,139
Interest on federal funds sold	42	146	676
Total interest income	703,112	726,503	636,394
Interest expense
Interest on deposits	22,357	59,067	102,533
Interest on other borrowings	25,428	29,683	28,695
Total interest expense	47,785	88,750	131,228
Net interest income	655,327	637,753	505,166
Provision for loan losses	(35,081)	125,488	19,758
Provision for unfunded commitments	332	19,062	0
Provision for other credit losses	(616)	830	0
Provision for credit losses	(35,365)	145,380	19,758
Net interest income after provision for credit losses	690,692	492,373	485,408
Noninterest income
Service charges on deposit accounts	45,106	44,145	50,792
Mortgage banking activity	285,900	374,077	119,409
Other service charges, commissions and fees	4,188	3,914	3,566
Net gain (loss) on securities	515	5	138
Gain on sale of SBA loans	6,623	7,226	6,058
Other noninterest income	23,212	17,133	18,150
Total noninterest income	365,544	446,500	198,113
Noninterest expense
Salaries and employee benefits	337,776	360,278	223,938
Occupancy and equipment	48,066	52,349	40,596
Advertising and marketing	8,434	8,046	7,927
Amortization of intangible assets	14,965	19,612	17,713
Data processing and communications expenses	45,976	46,017	38,513
Legal and other professional fees	11,920	15,972	10,634
Credit resolution-related expenses	3,538	5,106	4,082
Merger and conversion charges	4,206	1,391	73,105
FDIC insurance	5,614	14,078	1,945
Loan servicing expenses	26,481	20,910	10,817
Other noninterest expenses	53,148	54,870	42,667
Total noninterest expense	560,124	598,629	471,937
Income before income tax expense	496,112	340,244	211,584
Income tax expense	119,199	78,256	50,143
Net income	$ 376,913	$ 261,988	$ 161,441
Basic earnings per common share (in dollars per share)	$ 5.43	$ 3.78	$ 2.76
Diluted earnings per common share (in dollars per share)	$ 5.40	$ 3.77	$ 2.75
Weighted average common shares outstanding
Basic (in shares)	69,432	69,256	58,462
Diluted (in shares)	69,761	69,426	58,614