Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income:
Loans	$ 249,549	$ 170,588	$ 122,962
Mortgage-backed securities	16,034	11,108	6,697
Investment securities and other	11,071	7,133	3,766
Total interest income	276,654	188,829	133,425
Interest expense:
Deposits	22,578	12,336	7,517
Borrowed funds	13,574	7,275	5,646
Total interest expense	36,152	19,611	13,163
Net interest income	240,502	169,218	120,262
Provision for loan losses	3,490	4,445	2,623
Net interest income after provision for loan losses	237,012	164,773	117,639
Other income:
Bankcard services revenue	9,228	6,965	4,833
Net gain on sales of loans	668	100	986
Net unrealized loss on equity investments	(199)	0	0
Net loss from other real estate operations	(3,812)	(874)	(856)
Income from Bank Owned Life Insurance	5,105	3,299	2,230
Other	2,131	374	137
Total other income	34,827	27,072	20,412
Operating expenses:
Compensation and employee benefits	83,135	60,100	47,105
Occupancy	17,915	10,657	8,332
Equipment	8,319	6,769	5,104
Marketing	3,415	2,678	1,882
Federal deposit insurance	3,713	2,564	2,825
Data processing	13,286	8,849	7,577
Check card processing	4,209	3,561	2,210
Professional fees	4,963	3,995	2,848
Other operating expense	13,509	10,810	7,676
Amortization of core deposit intangible	3,811	2,039	623
Federal Home Loan Bank advance prepayment fee			136
Branch consolidation expenses	3,151	6,205	0
Merger related expenses	26,911	8,293	16,534
Total operating expenses	186,337	126,520	102,852
Income before provision for income taxes	85,502	65,325	35,199
Provision for income taxes	13,570	22,855	12,153
Net income	$ 71,932	$ 42,470	$ 23,046
Basic earnings per share (in dollars per share)	$ 1.54	$ 1.32	$ 1.00
Diluted earnings per share (in dollars per share)	$ 1.51	$ 1.28	$ 0.98
Average basic shares outstanding	46,773	32,113	23,093
Average diluted shares outstanding	47,657	33,125	23,526
Wealth management revenue
Other income:
Other income	$ 2,245	$ 2,150	$ 2,324
Fees and service charges
Other income:
Other income	$ 19,461	$ 15,058	$ 10,758