Consolidated statements of income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest income:
Interest and fees on loans	$ 61,092	$ 66,276	$ 124,846	$ 126,724
Interest on securities
Taxable	2,619	3,548	5,675	7,117
Tax-exempt	1,590	1,160	3,023	2,304
Other	306	735	1,737	1,507
Total interest income	65,607	71,719	135,281	137,652
Interest expense:
Deposits	9,309	13,488	21,477	25,343
Borrowings	961	1,208	2,218	2,270
Total interest expense	10,270	14,696	23,695	27,613
Net interest income	55,337	57,023	111,586	110,039
Provision for credit losses	24,039	881	52,003	2,272
Provision for credit losses on unfunded commitments	1,882	0	3,483	0
Net interest income after provisions for credit losses	29,416	56,142	56,100	107,767
Noninterest income:
(Loss) gain from securities, net	(28)	52	35	95
Gain on sales or write-downs of other real estate owned	86	277	137	238
(Loss) gain from other assets	(54)	(183)	(382)	8
Other income	2,487	1,691	5,262	3,484
Total noninterest income	81,491	32,979	124,191	62,018
Noninterest expenses:
Salaries, commissions and employee benefits	55,258	37,918	98,880	71,615
Occupancy and equipment expense	4,096	4,319	8,274	8,049
Legal and professional fees	1,952	1,694	3,510	3,419
Data processing	2,782	2,643	5,235	5,027
Merger costs	1,586	3,783	4,636	4,404
Amortization of core deposit and other intangibles	1,205	1,254	2,408	1,983
Advertising	2,591	2,434	4,980	5,171
Other expense	11,109	10,074	21,215	19,552
Total noninterest expense	80,579	64,119	149,138	119,220
Income before income taxes	30,328	25,002	31,153	50,565
Income tax expense	7,455	6,314	7,535	12,289
Net income	$ 22,873	$ 18,688	$ 23,618	$ 38,276
Earnings per common share
Basic (in dollars per share)	$ 0.71	$ 0.60	$ 0.75	$ 1.24
Diluted (in dollars per share)	$ 0.70	$ 0.59	$ 0.74	$ 1.21
Mortgage banking income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	$ 72,168	$ 24,526	$ 104,913	$ 45,547
Service charges on deposit accounts
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	1,858	2,327	4,421	4,406
ATM and interchange fees
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	3,606	3,002	6,740	5,658
Investment services and trust income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	$ 1,368	$ 1,287	$ 3,065	$ 2,582