Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest income
Loans	$ 466,432	$ 501,336	$ 428,374
Securities
Taxable	24,224	29,875	23,948
Tax-exempt	6,287	5,477	6,456
Other	1,189	5,892	3,076
Total interest income	498,132	542,580	461,854
Interest expense
Deposits	54,016	81,995	49,760
Borrowings	17,319	16,928	15,569
Total interest expense	71,335	98,923	65,329
Net interest income	426,797	443,657	396,525
Provision for loan losses	85,350	7,050	6,810
Provision for other credit losses	1,500	0	0
Provision for credit losses	86,850	7,050	6,810
Net interest income after provision for credit losses	339,947	436,607	389,715
Noninterest income
Service charges on deposit accounts	31,326	35,972	34,660
Fees and commissions	13,043	19,430	23,868
Insurance commissions	8,990	8,919	8,590
Wealth management revenue	16,504	14,433	13,540
Mortgage banking income	150,499	57,896	50,142
Net gains (losses) on sales of securities	46	348	(16)
BOLI income	5,627	6,109	4,644
Other	9,497	10,147	8,533
Total noninterest income	235,532	153,254	143,961
Noninterest expense
Salaries and employee benefits	302,388	250,784	214,294
Data processing	20,685	19,679	18,627
Net occupancy and equipment	54,080	49,553	42,111
Other real estate owned	2,754	2,013	1,892
Professional fees	11,293	10,166	8,753
Advertising and public relations	10,322	11,607	9,464
Intangible amortization	7,121	8,105	7,179
Communications	8,866	8,858	8,318
Merger and conversion related expenses	0	279	14,246
Restructuring charges	7,365	0	0
Swap termination fees	2,040	0	0
Debt prepayment penalty	121	54	0
Other	44,953	13,076	20,145
Total noninterest expense	471,988	374,174	345,029
Income before income taxes	103,491	215,687	188,647
Income taxes	19,840	48,091	41,727
Net income	$ 83,651	$ 167,596	$ 146,920
Basic earnings per share (usd per share)	$ 1.49	$ 2.89	$ 2.80
Diluted earnings per share (usd per share)	1.48	2.88	2.79
Cash dividends per common share (usd per share)	$ 0.88	$ 0.87	$ 0.80