Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest Income
Investment securities	$ 99,616	$ 85,504	$ 86,499
Residential real estate loans	46,392	46,899	40,041
Commercial loans	436,497	369,107	304,164
Consumer and other loans	44,559	44,667	38,292
Total interest income	627,064	546,177	468,996
Interest Expense
Deposits	17,620	23,280	18,359
Securities sold under agreements to repurchase	3,601	3,694	2,248
Federal Home Loan Bank advances	733	9,023	8,880
Other borrowed funds	646	215	95
Subordinated debentures	4,715	6,561	5,949
Total interest expense	27,315	42,773	35,531
Net Interest Income	599,749	503,404	433,465
Provision for credit losses	39,765	57	9,953
Net interest income after provision for credit losses	559,984	503,347	423,512
Non-Interest Income
Service charges and other fees	52,503	67,934	74,887
Miscellaneous loan fees and charges	7,344	5,313	6,805
Gain on sale of loans	99,450	34,064	27,134
Gain (loss) on sale of debt securities	1,139	14,415	(1,113)
Other income	12,431	9,048	11,111
Total non-interest income	172,867	130,774	118,824
Non-Interest Expense
Compensation and employee benefits	253,047	222,753	195,056
Occupancy and equipment	37,673	34,497	30,734
Advertising and promotions	10,201	10,621	9,566
Data processing	21,132	17,392	15,911
Other real estate owned	923	1,105	3,221
Regulatory assessments and insurance	4,656	3,771	5,075
Loss on termination of hedging activities	0	13,528	0
Core deposit intangible amortization	10,370	8,485	6,270
Other expenses	66,809	62,775	54,294
Total non-interest expense	404,811	374,927	320,127
Income Before Income Taxes	328,040	259,194	222,209
Federal and state income tax expense	61,640	48,650	40,331
Net Income	$ 266,400	$ 210,544	$ 181,878
Basic earnings per share (in dollars per share)	$ 2.81	$ 2.39	$ 2.18
Diluted earnings per share (in dollars per share)	2.81	2.38	2.17
Dividends declared per share (in dollars per share)	$ 1.33	$ 1.31	$ 1.31
Average outstanding shares - basic (in shares)	94,883,864	88,255,290	83,603,515
Average outstanding shares - diluted (in shares)	94,932,353	88,385,775	83,677,185