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	$ 201,524		$ 168,824		$ 147,982
Interest and dividends on investment securities:
Taxable	8,482		6,799		7,266
Nontaxable	3,276		3,569		3,827
Dividends	2,012		1,421		1,410
Interest on federal funds sold and other short-term investments	839		711		756
Total interest income	216,133		181,324		161,241
Interest expense:
Deposits	39,936		23,670		18,667
Borrowings	18,982		12,585		12,429
Total interest expense	58,918		36,255		31,096
Net interest income	157,215		145,069		130,145
Provision for loan losses	21,100		6,000		38,700
Net interest income after provision for loan losses	136,115		139,069		91,445
Noninterest income:
Annuity and insurance commissions		[1]	39	[1],[2]	191
Income on bank owned life insurance	3,094	[1]	3,181	[1],[2]	2,559
Net gains on sale of loans held-for-sale	61	[1]	708	[1],[2]	232
Deposit, loan and other income	2,584		2,680		2,704
Net gains on sale of investment securities		[1]	1,596	[1],[2]	4,234
Total noninterest income	5,739		8,204	[2]	9,920
Noninterest expense:
Salaries and employee benefits	39,556		34,878		30,726
Occupancy and equipment	8,312		8,163		8,571
FDIC insurance	3,115		3,485		2,940
Professional and consulting	3,568		2,863		2,979
Marketing and advertising	980		996		1,040
Data processing	4,421		4,543		4,141
Merger expenses	1,335
Amortization of core deposit intangible	627		724		820
Other components of net periodic pension expense	28		250		304
Increase in valuation allowance, loans held-for-sale			15,592
Other expenses	8,778		7,265		6,986
Total noninterest expenses	70,720		78,759		58,507
Income before income tax expense	71,134		68,514		42,858
Income tax expense	10,782		25,294		11,776
Net income	60,352		43,220		31,082
Less: Preferred stock dividends					22
Net income available to common stockholders	$ 60,352		$ 43,220		$ 31,060
Earnings per common share:
Basic	$ 1.87		$ 1.35		$ 1.02
Diluted	1.86		1.34		1.01
Dividends per common share	$ 0.30		$ 0.30		$ 0.30

[1] Not within scope of ASC 606.

[2] The Company elected the modified retrospective approach of adoption; therefore, prior period balances are presented under legacy GAAP and may not be comparable to current year presentation.