Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest Income
Investment securities	$ 122,099	$ 99,616	$ 85,504
Residential real estate loans	43,300	46,392	46,899
Commercial loans	471,061	436,497	369,107
Consumer and other loans	44,614	44,559	44,667
Total interest income	681,074	627,064	546,177
Interest Expense
Deposits	12,135	17,620	23,280
Securities sold under agreements to repurchase	2,303	3,601	3,694
Federal Home Loan Bank advances	0	733	9,023
Other borrowed funds	713	646	215
Subordinated debentures	3,407	4,715	6,561
Total interest expense	18,558	27,315	42,773
Net Interest Income	662,516	599,749	503,404
Provision for credit losses	23,076	39,765	57
Net interest income after provision for credit losses	639,440	559,984	503,347
Non-Interest Income
Service charges and other fees	59,317	52,503	67,934
Miscellaneous loan fees and charges	12,038	7,344	5,313
Gain on sale of loans	63,063	99,450	34,064
(Loss) gain on sale of debt securities	(638)	1,139	14,415
Other income	11,040	12,431	9,048
Total non-interest income	144,820	172,867	130,774
Non-Interest Expense
Compensation and employee benefits	270,644	253,047	222,753
Occupancy and equipment	39,394	37,673	34,497
Advertising and promotions	11,949	10,201	10,621
Data processing	23,470	21,132	17,392
Other real estate owned and foreclosed assets	236	923	1,105
Regulatory assessments and insurance	8,249	4,656	3,771
Loss on termination of hedging activities	0	0	13,528
Aggregate amortization expense	10,271	10,370	8,485
Other expenses	70,609	66,809	62,775
Total non-interest expense	434,822	404,811	374,927
Income Before Income Taxes	349,438	328,040	259,194
Federal and state income tax expense	64,681	61,640	48,650
Net Income	$ 284,757	$ 266,400	$ 210,544
Basic earnings per share (in dollars per share)	$ 2.87	$ 2.81	$ 2.39
Diluted earnings per share (in dollars per share)	2.86	2.81	2.38
Dividends declared per share (in dollars per share)	$ 1.37	$ 1.33	$ 1.31
Average outstanding shares - basic (in shares)	99,313,255	94,883,864	88,255,290
Average outstanding shares - diluted (in shares)	99,398,250	94,932,353	88,385,775