Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income
Interest and fees on loans	$ 172,351	$ 175,046	$ 518,938	$ 404,457
Interest on taxable securities	7,259	11,354	26,688	29,780
Interest on nontaxable securities	159	168	473	426
Interest on deposits in other banks and federal funds sold	165	1,793	1,621	7,655
Total interest income	179,934	188,361	547,720	442,318
Interest expense
Interest on deposits	11,822	29,425	50,197	74,563
Interest on other borrowings	5,574	10,167	23,226	17,940
Total interest expense	17,396	39,592	73,423	92,503
Net interest income	162,538	148,769	474,297	349,815
Provision for loan losses	26,692	5,989	132,188	14,065
Provision for unfunded commitments	(10,131)	0	13,581	0
Provision for other credit losses	1,121	0	1,121	0
Provision for credit losses	17,682	5,989	146,890	14,065
Net interest income after provision for credit losses	144,856	142,780	327,407	335,750
Noninterest income
Service charges on deposit accounts	10,914	13,411	32,680	37,225
Mortgage banking activity	138,627	53,041	278,885	86,241
Other service charges, commissions and fees	1,151	1,236	3,409	2,828
Net gain on securities	0	4	5	139
Other noninterest income	8,326	9,301	19,378	16,567
Total noninterest income	159,018	76,993	334,357	143,000
Noninterest expense
Salaries and employee benefits	96,698	77,633	267,812	154,296
Occupancy and equipment expense	13,805	12,639	39,640	28,677
Data processing and communications expenses	12,226	10,372	34,694	27,151
Credit resolution-related expenses	802	1,094	3,950	2,984
Advertising and marketing expense	966	1,949	4,779	5,677
Amortization of intangible assets	4,190	5,719	15,422	11,972
Merger and conversion charges	(44)	65,158	1,391	70,690
Other noninterest expenses	25,049	18,133	79,825	47,926
Total noninterest expense	153,692	192,697	447,513	349,373
Income (loss) before income tax expense	150,182	27,076	214,251	129,377
Income tax expense	34,037	5,692	46,548	29,184
Net income	116,145	21,384	167,703	100,193
Other comprehensive income
Net unrealized holding gains (losses) arising during period on investment securities available for sale, net of tax expense (benefit) of $(663), $(244), $5,080 and $5,549	(2,494)	(921)	19,110	20,873
Reclassification adjustment for gains on investment securities included in earnings, $0, $0, $0 and $25	0	0	0	(94)
Unrealized gains (losses) on cash flow hedges arising during period, net of tax expense (benefit) of $35, $(15), $39 and $(125)	133	(59)	147	(471)
Other comprehensive income	(2,361)	(980)	19,257	20,308
Total comprehensive income	$ 113,784	$ 20,404	$ 186,960	$ 120,501
Basic earnings per common share (in dollars per share)	$ 1.68	$ 0.31	$ 2.42	$ 1.83
Diluted earnings per common share (in dollars per share)	$ 1.67	$ 0.31	$ 2.42	$ 1.83
Weighted average common shares outstanding (in thousands)
Basic (in shares)	69,231	69,372	69,243	54,762
Diluted (in shares)	69,346	69,600	69,403	54,883