Consolidated statements of income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Interest and fees on loans	$ 260,458	$ 221,001	$ 153,969
Interest on securities
Taxable	13,223	12,397	10,084
Tax-exempt	4,805	4,047	4,006
Other	4,051	2,126	1,554
Total interest income	282,537	239,571	169,613
Interest expense:
Deposits	51,568	29,536	13,031
Borrowings	4,933	5,967	3,311
Total interest expense	56,501	35,503	16,342
Net interest income	226,036	204,068	153,271
Provision for loan losses	7,053	5,398	(950)
Net interest income after provision for loan losses	218,983	198,670	154,221
Noninterest income:
Gain (loss) from securities, net	57	(116)	285
Gain (loss) on sales or write-downs of other real estate owned	545	(99)	774
(Loss) gain from other assets	(104)	328	(664)
Other income	7,099	6,172	4,094
Total noninterest income	135,397	130,642	141,581
Noninterest expenses:
Salaries, commissions and employee benefits	152,084	136,892	130,005
Occupancy and equipment expense	15,641	13,976	13,010
Legal and professional fees	7,486	7,903	5,737
Data processing	10,589	9,100	6,488
Merger costs	5,385	1,594	19,034
Amortization of core deposit and other intangibles	4,339	3,185	1,995
Advertising	9,138	13,139	12,957
Other expense	40,179	37,669	33,091
Total noninterest expense	244,841	223,458	222,317
Income before income taxes	109,539	105,854	73,485
Income tax expense	25,725	25,618	21,087
Net income	$ 83,814	$ 80,236	$ 52,398
Earnings per common share
Basic (in dollars per share)	$ 2.70	$ 2.60	$ 1.90
Fully diluted (in dollars per share)	$ 2.65	$ 2.55	$ 1.86
Mortgage banking income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	$ 100,916	$ 100,661	$ 116,933
Service charges on deposit accounts
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	9,479	8,502	7,426
ATM and interchange fees
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	12,161	10,013	8,784
Investment services and trust income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	$ 5,244	$ 5,181	$ 3,949