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	$ 175,466	$ 129,213	$ 122,147
Taxable interest on investment securities	17,602	12,688	11,215
Nontaxable interest on investment securities	4,649	5,269	4,870
Interest on other interest earning assets	1,642	539	280
Total interest income	199,359	147,709	138,512
INTEREST EXPENSE:
Deposits	10,397	6,049	5,010
Junior subordinated debentures	1,263	1,014	880
Other borrowings	753	1,283	116
Total interest expense	12,413	8,346	6,006
Net interest income	186,946	139,363	132,506
Provision for loan losses	5,129	4,220	4,931
Net interest income after provision for loan losses	181,817	135,143	127,575
NONINTEREST INCOME:
Service charges and other fees	18,914	18,004	14,354
Gain on sale of investment securities, net	137	6	1,315
Gain on sale of loans, net	2,759	7,696	6,994
Interest rate swap fees	564	1,045	1,854
Other income	9,291	8,828	7,102
Total noninterest income	31,665	35,579	31,619
NONINTEREST EXPENSE:
Compensation and employee benefits	86,830	64,268	61,405
Occupancy and equipment	19,779	15,396	15,763
Data processing	9,888	8,176	7,312
Marketing	3,228	2,943	2,835
Professional services	9,670	4,777	3,606
State and local taxes	3,210	2,461	2,616
Federal deposit insurance premium	1,480	1,435	1,620
Other real estate owned, net	106	(70)	334
Amortization of intangible assets	3,819	1,286	1,415
Other expense	11,385	9,903	9,567
Total noninterest expense	149,395	110,575	106,473
Income before income taxes	64,087	60,147	52,721
Income tax expense	11,030	18,356	13,803
Net income	$ 53,057	$ 41,791	$ 38,918
Basic earnings per common share (in usd per share)	$ 1.49	$ 1.39	$ 1.30
Diluted earnings per common share (in usd per share)	1.49	1.39	1.30
Dividends declared per common share (in usd per share)	$ 0.72	$ 0.61	$ 0.72