Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest income:
Loans, including fees	$ 104,688	$ 95,828	$ 313,057	$ 275,744
Investment securities:
Taxable	18,040	20,213	56,942	62,121
Tax-exempt	1,019	1,981	4,045	6,263
Other interest income	372	352	998	719
Total interest income	124,119	118,374	375,042	344,847
Interest expense:
Savings deposits	4,023	3,353	12,515	8,872
Time deposits	5,680	3,493	15,102	9,172
Securities sold under repurchase agreements	640	468	1,820	1,839
Other borrowings	3,144	4,358	10,151	13,426
Junior subordinated deferrable interest debentures	1,414	1,828	5,045	5,119
Total interest expense	14,901	13,500	44,633	38,428
Net interest income	109,218	104,874	330,409	306,419
Provision for probable loan losses	5,278	4,280	15,363	3,212
Net interest income after provision for probable loan losses	103,940	100,594	315,046	303,207
Non-interest income:
Investment securities transactions, net	(2)	(141)	(12)	(141)
Other investments, net	2,440	5,625	4,685	16,192
Other income	4,813	3,643	11,866	13,425
Total non-interest income	42,697	42,503	113,242	123,781
Non-interest expense:
Employee compensation and benefits	37,038	35,360	110,693	104,670
Occupancy	7,294	6,839	20,251	20,077
Depreciation of bank premises and equipment	7,127	6,460	21,140	19,097
Professional fees	4,744	4,063	12,081	10,010
Deposit insurance assessments	829	928	2,471	2,902
Net expense, other real estate owned	1,578	911	3,776	3,289
Advertising	1,987	2,020	6,150	5,667
Software and software maintenance	4,691	4,481	14,191	12,943
Other	15,778	17,005	42,877	48,922
Total non-interest expense	81,066	78,067	233,630	227,577
Income before income taxes	65,571	65,030	194,658	199,411
Provision for income taxes	14,127	13,935	41,288	42,009
Net income	$ 51,444	$ 51,095	$ 153,370	$ 157,402
Basic earnings per common share:
Weighted average number of shares outstanding (in shares)	65,449,159	66,136,091	65,571,124	66,114,482
Net income (in dollars per share)	$ 0.79	$ 0.77	$ 2.34	$ 2.38
Fully diluted earnings per common share:
Weighted average number of shares outstanding (in shares)	65,636,116	66,423,209	65,777,552	66,739,899
Net income (in dollars per share)	$ 0.78	$ 0.77	$ 2.33	$ 2.36
Services charges on deposit accounts
Non-interest income:
Service charges	$ 18,723	$ 18,391	$ 53,593	$ 53,658
Other service charges, commissions and fees, Banking
Non-interest income:
Service charges	14,708	13,100	37,348	35,374
Other service charges, commissions and fees, Non-banking
Non-interest income:
Service charges	$ 2,015	$ 1,885	$ 5,762	$ 5,273