Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest income:
Interest and fees on loans	$ 64,478	$ 69,628	$ 131,647	$ 130,653
Interest on debt securities:
Taxable	6,587	7,757	14,144	13,232
Nontaxable	1,812	861	3,301	1,308
Interest on interest-earning deposits	87	703	387	1,150
Dividends on equity securities	227	252	400	475
Total interest income	73,191	79,201	149,879	146,818
Interest expense:
Interest Expense, Deposits	4,383	13,119	14,271	24,939
Subordinated debentures and notes	2,316	1,958	4,235	3,606
FHLB advances	455	1,696	1,350	3,094
Notes payable and other borrowings	204	713	822	1,121
Total interest expense	7,358	17,486	20,678	32,760
Net interest income	65,833	61,715	129,201	114,058
Provision for credit losses	19,591	1,722	41,855	3,198
Net interest income after provision for credit losses	46,242	59,993	87,346	110,860
Noninterest income:
Total noninterest income	9,960	11,964	23,368	21,194
Noninterest expense:
Employee compensation and benefits	22,389	20,687	44,074	40,039
Occupancy	3,185	3,188	6,532	5,825
Data processing	2,144	2,458	4,226	4,364
Professional fees	1,287	1,037	2,149	1,783
Merger-related expenses	0	10,306	0	17,576
Other	8,907	11,378	19,604	19,305
Total noninterest expense	37,912	49,054	76,585	88,892
Income before income tax expense	18,290	22,903	34,129	43,162
Income tax expense	3,656	4,479	6,627	8,582
Net income	$ 14,634	$ 18,424	$ 27,502	$ 34,580
Earnings per common share
Basic (usd per share)	$ 0.56	$ 0.69	$ 1.04	$ 1.36
Diluted (usd per share)	$ 0.56	$ 0.68	$ 1.04	$ 1.36
Deposit Account [Member]
Noninterest income:
Total noninterest income	$ 2,616	$ 3,366	$ 5,759	$ 6,301
Fiduciary and Trust [Member]
Noninterest income:
Total noninterest income	2,326	2,661	4,827	4,653
Card Services Revenue [Member]
Noninterest income:
Total noninterest income	2,225	2,461	4,472	4,251
Tax credit activity, net [Member]
Noninterest income:
Total noninterest income	(221)	572	1,815	730
Financial Service, Other [Member]
Noninterest income:
Total noninterest income	$ 3,014	$ 2,904	$ 6,495	$ 5,259