Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest Income
Loans	$ 415,770	$ 426,003	$ 448,041
Taxable securities	107,594	81,578	69,864
Tax-exempt securities	11,746	9,567	10,735
Deposits in banks	955	661	1,312
Total interest income	536,065	517,809	529,952
Interest Expense
Deposits	6,186	9,367	22,146
FHLB advances and FRB borrowings	291	6,264	11,861
Subordinated debentures	1,932	1,871	1,871
Other borrowings	137	196	669
Total interest expense	8,546	17,698	36,547
Net Interest Income	527,519	500,111	493,405
Provision for credit losses	4,800	77,700	3,493
Net interest income after provision for credit losses	522,719	422,411	489,912
Noninterest Income
Deposit account and treasury management fees	27,107	27,019	35,695
Card revenue	18,503	13,928	15,198
Financial services and trust revenue	15,753	12,830	12,799
Loan revenue	22,044	24,802	13,465
Bank owned life insurance	6,533	6,418	6,294
Investment securities gains (losses), net	314	16,710	2,132
Other	3,840	2,793	11,598
Total noninterest income	94,094	104,500	97,181
Noninterest Expense
Compensation and employee benefits	224,034	209,722	212,867
Occupancy	37,815	36,013	35,176
Data processing and software	33,498	29,449	27,095
Legal and professional fees	18,910	12,158	21,645
Amortization of intangibles	7,987	8,724	10,479
Business and Occupation taxes	5,903	4,970	5,846
Advertising and promotion	3,383	4,466	4,925
Regulatory premiums	4,912	2,956	1,920
Net cost (benefit) of operation of OREO	66	(315)	(692)
Other	23,796	26,376	26,221
Total noninterest expense	360,304	334,519	345,482
Income before income taxes	256,509	192,392	241,611
Income tax provision	53,689	38,148	47,160
Net Income	$ 202,820	$ 154,244	$ 194,451
Per Common Share
Basic earnings per common share	$ 2.79	$ 2.17	$ 2.68
Diluted earnings per common share	$ 2.78	$ 2.17	$ 2.68
Weighted average number of common shares outstanding	72,683	70,835	71,999
Weighted average number of diluted common shares outstanding	72,873	70,880	72,032