Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest revenue:
Loans, including fees	$ 420,383	$ 315,050	$ 268,382
Investment securities:
Taxable	73,496	70,172	63,413
Tax exempt	4,189	2,216	614
Deposits in banks and short-term investments	2,012	2,282	2,611
Total interest revenue	500,080	389,720	335,020
Deposits:
NOW and interest-bearing demand	7,390	3,365	1,903
Money market	12,097	7,033	4,982
Savings	150	135	135
Time	19,906	6,529	3,136
Total deposit interest expense	39,543	17,062	10,156
Short-term borrowings	1,112	352	399
Federal Home Loan Bank advances	6,345	6,095	3,676
Long-term debt	14,330	10,226	11,005
Total interest expense	61,330	33,735	25,236
Net interest revenue	438,750	355,985	309,784
Provision for (release of) credit losses	9,500	3,800	(800)
Net interest revenue after provision for credit losses	429,250	352,185	310,584
Noninterest income:
Service charges and fees	35,997	38,295	42,113
Mortgage loan and other related fees	19,010	18,320	20,292
Brokerage fees	5,191	4,633	4,280
Gains from sales of SBA/USDA loans	9,277	10,493	9,545
Securities (losses) gains, net	(656)	42	982
Other	24,142	16,477	16,485
Total noninterest income	92,961	88,260	93,697
Total revenue	522,211	440,445	404,281
Noninterest expenses:
Salaries and employee benefits	181,015	153,098	138,789
Occupancy	22,781	20,344	19,603
Communications and equipment	21,277	19,660	18,355
FDIC assessments and other regulatory charges	8,491	6,534	5,866
Professional fees	15,540	12,074	11,822
Postage, printing and supplies	6,416	5,952	5,382
Advertising and public relations	5,991	4,242	4,426
Amortization of intangibles	6,846	4,845	4,182
Merger-related and other charges	5,414	13,901	8,122
Other	32,514	26,961	24,742
Total noninterest expenses	306,285	267,611	241,289
Income before income taxes	215,926	172,834	162,992
Income tax expense	49,815	105,013	62,336
Net income	166,111	67,821	100,656
Net income available to common shareholders	$ 164,927	$ 67,250	$ 100,635
Income per common share:
Basic (in dollars per share)	$ 2.07	$ 0.92	$ 1.40
Diluted (in dollars per share)	$ 2.07	$ 0.92	$ 1.40
Weighted average common shares outstanding:
Basic (in shares)	79,662	73,247	71,910
Diluted (in shares)	79,671	73,259	71,915