Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Loans	$ 279,931	$ 249,549	$ 170,588
Mortgage-backed securities	15,300	16,034	11,108
Debt securities, equity investments and other	13,563	11,071	7,133
Total interest income	308,794	276,654	188,829
Interest expense:
Deposits	38,432	22,578	12,336
Borrowed funds	14,391	13,574	7,275
Total interest expense	52,823	36,152	19,611
Net interest income	255,971	240,502	169,218
Provision for loan losses	1,636	3,490	4,445
Net interest income after provision for loan losses	254,335	237,012	164,773
Other income:
Bankcard services revenue	10,263	9,228	6,965
Net gain on sales of loans	16	668	100
Net unrealized gain (loss) on equity investments	267	(199)	0
Net loss from other real estate operations	(330)	(3,812)	(874)
Income from Bank Owned Life Insurance	5,420	5,105	3,299
Other	5,927	2,131	374
Total other income	42,165	34,827	27,072
Operating expenses:
Compensation and employee benefits	89,912	83,135	60,100
Occupancy	17,159	17,915	10,657
Equipment	7,719	8,319	6,769
Marketing	3,469	3,415	2,678
Federal deposit insurance and regulatory assessments	2,227	3,713	2,564
Data processing	14,814	13,286	8,849
Check card processing	5,956	4,209	3,561
Professional fees	9,338	4,963	3,995
Other operating expense	14,968	13,509	10,810
Amortization of core deposit intangible	4,027	3,811	2,039
Branch consolidation expenses	9,050	3,151	6,205
Merger related expenses	10,503	26,911	8,293
Total operating expenses	189,142	186,337	126,520
Income before provision for income taxes	107,358	85,502	65,325
Provision for income taxes	18,784	13,570	22,855
Net income	$ 88,574	$ 71,932	$ 42,470
Basic earnings per share (in dollars per share)	$ 1.77	$ 1.54	$ 1.32
Diluted earnings per share (in dollars per share)	$ 1.75	$ 1.51	$ 1.28
Average basic shares outstanding (shares)	50,166	46,773	32,113
Average diluted shares outstanding (shares)	50,746	47,657	33,125
Trust and asset management revenue
Other income:
Trust and asset management revenue and fees and service charges	$ 2,102	$ 2,245	$ 2,150
Fees and service charges
Other income:
Trust and asset management revenue and fees and service charges	$ 18,500	$ 19,461	$ 15,058