CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Loans		$ 170,288	$ 158,691	$ 117,633
Taxable investment securities		167	417	939
Tax-exempt investment securities		16,856	24,960	24,529
Mortgage-backed securities		50,486	41,584	41,361
Federal Home Loan Bank stock and equity investments		1,654	1,595	1,306
Other interest earning assets		1,336	1,918	1,706
Total interest income		240,787	229,165	187,474
Interest expense:
Deposits		44,565	35,864	20,736
Federal Home Loan Bank borrowings		17,719	12,813	15,106
Subordinated notes		5,661	5,659	5,633
Trust preferred subordinated debentures		2,775	2,610	2,013
Other borrowings		262	155	16
Total interest expense		70,982	57,101	43,504
Net interest income		169,805	172,064	143,970
Provision for loan losses	[1]	5,101	8,437	4,675
Net interest income after provision for loan losses		164,704	163,627	139,295
Noninterest income:
Deposit services		26,038	25,082	21,785
Net gain (loss) on sale of securities available for sale		756	(1,839)
Net gain (loss) on sale of securities available for sale				625
Gain on sale of loans		509	692	1,821
Trust fees		6,269	6,832	3,818
Bank owned life insurance		2,307	2,923	2,537
Brokerage services		2,080	1,987	2,422
Other		4,409	5,096	4,465
Total noninterest income		42,368	40,773	37,473
Noninterest expense:
Salaries and employee benefits		73,731	70,643	60,779
Net occupancy		13,128	13,814	12,068
Acquisition expense		0	2,413	4,352
Advertising, travel & entertainment		2,964	2,894	2,219
ATM expense		894	1,090	3,889
Professional fees		4,717	4,035	3,844
Software and data processing		4,537	3,996	3,027
Communications		1,941	1,847	1,905
FDIC insurance		859	1,871	1,769
Amortization of intangibles		4,418	5,213	1,955
Other		12,108	12,283	10,528
Total noninterest expense		119,297	120,099	106,335
Income before income tax expense		87,775	84,301	70,433
Income tax expense		13,221	10,163	16,121
Net income		$ 74,554	$ 74,138	$ 54,312
Earnings per common share - basic (in dollars per share)		$ 2.21	$ 2.12	$ 1.82
Earnings per common share - diluted (in dollars per share)		2.20	2.11	1.81
Dividends paid on common stock (in dollars per share)		$ 1.26	$ 1.20	$ 1.11

[1] Of the $5.1 million in provision for loan losses for the year ended December 31, 2019, $45,000 related to provision expense reversed on PCI loans. Of the $8.4 million in provision for loan losses for the year ended December 31, 2018, $302,000 related to provision expense on PCI loans. Of the $4.7 million recorded in provision for loan losses for the year ended December 31, 2017, none was related to provision expense on PCI loans.