Consolidated statements of income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Interest and fees on loans	$ 153,969	$ 105,865	$ 87,723
Interest on securities
Taxable	10,084	10,646	11,783
Tax-exempt	4,006	3,372	2,808
Other	1,554	611	468
Total interest income	169,613	120,494	102,782
Deposits
Demand and savings accounts	9,272	5,413	4,733
Time deposits	3,759	1,929	1,559
Short-term borrowings	42	121	712
Long-term debt	3,269	2,081	1,906
Total interest expense	16,342	9,544	8,910
Net interest income	153,271	110,950	93,872
Provision for loan losses	(950)	(1,479)	(3,064)
Net interest income after provision for loan losses	154,221	112,429	96,936
Noninterest income:
Mortgage banking income	116,933	117,751	70,190
Service charges on deposit accounts	7,787	8,009	7,389
ATM and interchange fees	8,784	7,791	6,536
Investment services and trust income	3,949	3,337	3,260
Bargain purchase gain			2,794
Gain from securities, net	285	4,407	1,844
Gain (loss) on sales or write-downs of other real estate owned	774	1,282	(317)
Loss from other assets	(664)	(103)	(393)
Other income	3,733	2,211	1,077
Total noninterest income	141,581	144,685	92,380
Noninterest expenses:
Salaries, commissions and employee benefits	130,355	113,992	84,214
Occupancy and equipment expense	13,836	12,611	10,777
Legal and professional fees	5,737	3,514	3,355
Data processing	6,488	4,181	2,053
Merger and conversion	19,034	3,268	3,543
Amortization of core deposit and other intangibles	1,995	2,132	1,731
Amortization of mortgage servicing rights		8,321	2,601
Impairment of mortgage servicing rights		4,678	194
Loss on sale of mortgage servicing rights	249	4,447
Regulatory fees and deposit insurance assessments	2,049	1,952	2,190
Software license and maintenance fees	1,873	2,874	1,986
Advertising	12,957	10,608	8,062
Other expense	27,744	22,212	17,786
Total noninterest expense	222,317	194,790	138,492
Income before income taxes	73,485	62,324	50,824
Income tax expense (Note 15)	21,087	21,733	2,968
Net income	$ 52,398	$ 40,591	$ 47,856
Weighted average shares of common stock outstanding
Basic	27,627,228	19,165,182	17,180,000
Fully diluted	28,207,602	19,312,174	17,180,000
Earnings per share
Basic	$ 1.90	$ 2.12	$ 2.79
Fully diluted	$ 1.86	$ 2.10	$ 2.79
Pro Forma (C Corporation basis) (Note 15):
Income tax expense	$ 21,087	$ 22,902	$ 17,829
Net income	$ 52,398	$ 39,422	$ 32,995
Pro Forma Earnings per share
Basic	$ 1.90	$ 2.06	$ 1.92
Fully diluted	$ 1.86	$ 2.04	$ 1.92