Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
INTEREST INCOME
Loans, including fees	$ 146,424	$ 187,566
Interest bearing balances due from banks and federal funds sold	798	2,441
Investment securities	21,573	18,943
Mortgage loans held for sale	639	281
TOTAL INTEREST INCOME	169,434	209,231
INTEREST EXPENSE
Deposits	13,179	31,277
Federal funds purchased and securities sold under agreements to repurchase	245	759
Other borrowings	4,802	4,877
Subordinated notes and debentures	4,527	4,835
TOTAL INTEREST EXPENSE	22,753	41,748
NET INTEREST INCOME	146,681	167,483
Provision for credit loss expense	1,445	23,134
NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES	145,236	144,349
NON-INTEREST INCOME
Investment banking income	695	877
Bank owned life insurance income	1,523	1,298
Gain on sale of securities, net	5,471	32,095
Other income	10,260	12,801
TOTAL NON-INTEREST INCOME	51,903	82,394
NON-INTEREST EXPENSE
Salaries and employee benefits	60,340	67,924
Occupancy expense, net	9,300	9,510
Furniture and equipment expense	5,415	5,723
Other real estate and foreclosure expense	343	325
Deposit insurance	1,308	2,475
Merger related costs	233	1,068
Other operating expenses	38,417	41,788
TOTAL NON-INTEREST EXPENSE	115,356	128,813
INCOME BEFORE INCOME TAXES	81,783	97,930
Provision for income taxes	14,363	20,694
NET INCOME	67,420	77,236
Preferred stock dividends	13	13
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 67,407	$ 77,223
BASIC EARNINGS PER SHARE (in dollars per share)	$ 0.62	$ 0.68
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 0.62	$ 0.68
Trust income
NON-INTEREST INCOME
Non-interest income	$ 6,666	$ 7,151
Service charges on deposit accounts
NON-INTEREST INCOME
Non-interest income	9,715	13,328
Other service charges and fees
NON-INTEREST INCOME
Non-interest income	1,922	1,588
Mortgage lending income
NON-INTEREST INCOME
Non-interest income	6,447	5,046
SBA lending income
NON-INTEREST INCOME
Non-interest income	240	296
Debit and credit card fees
NON-INTEREST INCOME
Non-interest income	$ 8,964	$ 7,914