Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest income:
Loans, including fees	$ 171,305	$ 189,848	$ 343,442	$ 375,120
Securities:
Taxable	23,360	30,324	49,390	55,003
Tax-exempt	59,009	58,596	117,895	117,739
Interest-bearing deposits	1,257	7,828	9,382	18,467
Federal funds sold and resell agreements	63	1,541	865	3,129
Total interest income	254,994	288,137	520,974	569,458
Interest expense:
Deposits	6,227	26,844	22,280	54,018
Federal funds purchased and repurchase agreements	486	5,220	3,523	10,236
Junior subordinated deferrable interest debentures	988	1,478	2,193	2,976
Subordinated notes	1,164	1,164	2,328	2,328
Federal Home Loan Bank advances	318	0	318	0
Total interest expense	9,183	34,706	30,642	69,558
Net interest income	245,811	253,431	490,332	499,900
Credit loss expense	31,975	6,400	207,172	17,403
Net interest income after credit loss expense	213,836	247,031	283,160	482,497
Non-interest income:
Trust and investment management fees	31,060	30,448	65,533	62,145
Service charges on deposit accounts	17,580	21,798	40,231	42,588
Insurance commissions and fees	10,668	10,118	27,153	28,524
Interchange and debit card transaction fees	2,966	3,868	6,221	7,148
Other charges, commissions and fees	7,663	8,933	17,028	17,995
Net gain (loss) on securities transactions	0	169	108,989	169
Other	7,664	7,304	25,361	20,854
Total non-interest income	77,601	82,638	290,516	179,423
Non-interest expense:
Salaries and wages	90,350	90,790	189,162	183,266
Employee benefits	18,861	20,051	43,750	43,577
Net occupancy	25,266	21,133	50,650	40,400
Technology, furniture and equipment	26,046	22,157	51,286	43,821
Deposit insurance	2,800	2,453	5,424	5,261
Intangible amortization	241	305	498	630
Other	36,115	46,320	83,072	88,054
Total non-interest expense	199,679	203,209	423,842	405,009
Income before income taxes	91,758	126,460	149,834	256,911
Income taxes \ (benefits)	(1,314)	14,874	2,009	28,829
Net income	93,072	111,586	147,825	228,082
Preferred stock dividends	0	2,015	2,016	4,031
Redemption of preferred stock	0	0	5,514	0
Net income available to common shareholders	$ 93,072	$ 109,571	$ 140,295	$ 224,051
Earnings per common share:
Basic	$ 1.47	$ 1.73	$ 2.22	$ 3.53
Diluted	$ 1.47	$ 1.72	$ 2.21	$ 3.51