Consolidated statements of income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income:
Interest and fees on loans	$ 221,001	$ 153,969	$ 105,865
Interest on securities
Taxable	12,397	10,084	10,646
Tax-exempt	4,047	4,006	3,372
Other	2,126	1,554	611
Total interest income	239,571	169,613	120,494
Interest expense:
Deposits	29,536	13,031	7,342
Borrowings	5,967	3,311	2,202
Total interest expense	35,503	16,342	9,544
Net interest income	204,068	153,271	110,950
Provision for loan losses	5,398	(950)	(1,479)
Net interest income after provision for loan losses	198,670	154,221	112,429
Noninterest income:
(Loss) gain from securities, net	(116)	285	4,407
(Loss) gain on sales or write-downs of other real estate owned	(99)	774	1,282
Gain (loss) from other assets	328	(664)	(103)
Other income	6,172	4,094	2,498
Total noninterest income	130,642	141,581	144,685
Noninterest expenses:
Salaries, commissions and employee benefits	136,892	130,005	113,486
Occupancy and equipment expense	13,976	13,010	12,272
Legal and professional fees	7,903	5,737	3,514
Data processing	9,100	6,488	4,181
Merger and conversion	1,594	19,034	3,268
Amortization of core deposit and other intangibles	3,185	1,995	2,132
Amortization of mortgage servicing rights	0	0	8,321
Impairment of mortgage servicing rights	0	0	4,678
Loss on sale of mortgage servicing rights	0	249	4,447
Regulatory fees and deposit insurance assessments	2,714	2,049	1,952
Advertising	13,139	12,957	10,608
Other expense	32,584	28,035	22,551
Total noninterest expense	223,458	222,317	194,790
Income before income taxes	105,854	73,485	62,324
Income tax expense (Note 13)	25,618	21,087	21,733
Net income	$ 80,236	$ 52,398	$ 40,591
Earnings per share
Basic (in dollars per share)	$ 2.60	$ 1.90	$ 2.12
Fully diluted (in dollars per share)	$ 2.55	$ 1.86	$ 2.10
Pro Forma (C Corporation basis) (unaudited) (Note 13):
Income tax expense	$ 25,618	$ 21,087	$ 22,902
Net income	$ 80,236	$ 52,398	$ 39,422
Pro Forma Earnings per share (unaudited):
Basic (in dollars per share)	$ 2.60	$ 1.90	$ 2.06
Fully diluted (in dollars per share)	$ 2.55	$ 1.86	$ 2.04
Mortgage banking income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	$ 100,661	$ 116,933	$ 117,751
Service charges on deposit accounts
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	8,502	7,426	7,722
ATM and interchange fees
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	10,013	8,784	7,791
Investment services and trust income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	5,181	3,949	3,337
Software license and maintenance fees
Noninterest expenses:
Software license and maintenance fees	$ 2,371	$ 2,758	$ 3,380