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	$ 97,764	$ 105,564	$ 196,994	$ 208,369
Investment securities:
Taxable	15,092	19,602	31,580	38,902
Tax-exempt	653	1,377	1,419	3,026
Other interest income	141	317	269	626
Total interest income	113,650	126,860	230,262	250,923
Interest expense:
Savings deposits	1,161	4,249	4,396	8,492
Time deposits	5,319	5,044	11,289	9,422
Securities sold under repurchase agreements	148	591	613	1,180
Other borrowings	2,088	3,513	4,914	7,007
Junior subordinated deferrable interest debentures	1,080	1,681	2,353	3,631
Total interest expense	9,796	15,078	23,565	29,732
Net interest income	103,854	111,782	206,697	221,191
Provision for credit loss expenses	10,989	2,665	27,825	10,085
Net interest income after provision for probable loan losses	92,865	109,117	178,872	211,106
Non-interest income:
Investment securities transactions, net		(6)	(5)	(10)
Other investments, net	617	(1,703)	386	2,245
Other income	6,840	4,513	11,649	7,053
Total non-interest income	33,596	34,416	68,726	70,545
Non-interest expense:
Employee compensation and benefits	32,319	37,246	68,649	73,655
Occupancy	5,770	6,580	12,669	12,957
Depreciation of bank premises and equipment	7,190	7,032	14,299	14,013
Professional fees	3,913	3,745	7,883	7,337
Deposit insurance assessments	202	859	202	1,642
Net expense, other real estate owned	2,835	1,203	5,837	2,198
Advertising	1,892	2,081	3,876	4,163
Software and software maintenance	5,257	5,003	9,748	9,500
Other	14,530	15,864	27,726	27,099
Total non-interest expense	73,908	79,613	150,889	152,564
Income before income taxes	52,553	63,920	96,709	129,087
Provision for income taxes	11,044	13,900	20,361	27,161
Net income	$ 41,509	$ 50,020	$ 76,348	$ 101,926
Basic earnings per common share:
Weighted average number of shares outstanding (in shares)	63,295,597	65,648,090	64,183,093	65,633,117
Net income (in dollars per share)	$ 0.66	$ 0.76	$ 1.19	$ 1.55
Fully diluted earnings per common share:
Weighted average number of shares outstanding (in shares)	63,397,199	65,867,234	64,313,011	65,849,281
Net income (in dollars per share)	$ 0.65	$ 0.76	$ 1.19	$ 1.55
Services charges on deposit accounts
Non-interest income:
Service charges	$ 12,880	$ 17,610	$ 30,517	$ 34,870
Other service charges, commissions and fees, Banking
Non-interest income:
Service charges	11,229	11,764	22,395	22,640
Other service charges, commissions and fees, Non-banking
Non-interest income:
Service charges	$ 2,030	$ 2,238	$ 3,784	$ 3,747