CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest income:
Loans and leases	$ 242,772	$ 258,348	$ 234,455
Investment securities, taxable	18,080	20,946	19,356
Investment securities, tax-exempt	895	1,351	1,857
Other	1,284	2,232	1,648
Total interest income	263,031	282,877	257,316
Interest expense:
Deposits	30,459	50,495	34,631
Short-term borrowings	517	1,934	2,838
Subordinated notes	3,367	3,677	3,625
Long-term debt and mandatorily redeemable securities	2,868	2,905	2,316
Total interest expense	37,211	59,011	43,410
Net interest income	225,820	223,866	213,906
Provision for credit losses	36,001	15,833	19,462
Net interest income after provision for credit losses	189,819	208,033	194,444
Noninterest income:
Mortgage banking	15,674	4,698	3,844
Insurance commissions	7,025	6,761	6,502
Income related to lease payments	23,380	30,741	31,793
Gains (losses) on investment securities available-for-sale	279	0	(345)
Other	11,949	13,019	10,362
Total noninterest income	103,889	101,130	97,050
Noninterest expense:
Salaries and employee benefits	101,556	97,098	93,857
Net occupancy	10,276	10,528	10,041
Furniture and equipment	25,688	24,815	23,433
Professional fees	6,317	6,952	7,680
Supplies and communication	5,563	6,454	6,320
FDIC and other insurance	2,606	1,795	2,923
Business development and marketing	4,157	6,303	6,112
Loan and lease collection and repossession	3,099	3,402	3,375
Other	7,902	6,534	6,478
Total noninterest expense	187,367	189,009	186,467
Income before income taxes	106,341	120,154	105,027
Income tax expense	24,880	28,139	22,613
Net income	81,461	92,015	82,414
Net (income) loss attributable to noncontrolling interests	(24)	(55)	0
Net income available to common shareholders	$ 81,437	$ 91,960	$ 82,414
Basic net income per common share, in dollars per share	$ 3.17	$ 3.57	$ 3.16
Diluted net income per common share, in dollars per share	$ 3.17	$ 3.57	$ 3.16
Trust and wealth advisory
Noninterest income:
Trust and wealth advisory, service charges on deposit accounts, and debit card income	$ 21,114	$ 20,692	$ 21,071
Service charges on deposit accounts
Noninterest income:
Trust and wealth advisory, service charges on deposit accounts, and debit card income	9,485	11,010	10,454
Debit card
Noninterest income:
Trust and wealth advisory, service charges on deposit accounts, and debit card income	14,983	14,209	13,369
Leased equipment
Noninterest expense:
Depreciation	$ 20,203	$ 25,128	$ 26,248