Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
INTEREST INCOME
Loans	$ 710,935	$ 616,037	$ 352,351
Interest bearing balances due from banks and federal funds sold	7,486	5,996	1,933
Investment securities	66,898	57,318	40,115
Mortgage loans held for sale	1,326	1,336	605
TOTAL INTEREST INCOME	786,645	680,687	395,004
INTEREST EXPENSE
Deposits	139,011	87,210	27,756
Federal funds purchased and securities sold under agreements to repurchase	1,010	423	347
Other borrowings	23,008	23,654	8,621
Subordinated notes and debentures	18,341	16,848	3,350
TOTAL INTEREST EXPENSE	181,370	128,135	40,074
NET INTEREST INCOME	605,275	552,552	354,930
Provision for loan losses	43,240	38,148	26,393
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	562,035	514,404	328,537
NON-INTEREST INCOME
Investment banking income	2,313	3,141	2,793
Bank owned life insurance income	4,768	4,415	3,503
Gain on sale of securities, net	13,314	61	1,059
Other income	58,493	19,863	19,268
TOTAL NON-INTEREST INCOME	201,509	143,896	138,765
NON-INTEREST EXPENSE
Salaries and employee benefits	227,795	216,743	154,314
Occupancy expense, net	32,008	29,610	21,159
Furniture and equipment expense	18,220	16,323	19,366
Other real estate and foreclosure expense	3,442	4,480	3,042
Deposit insurance	4,416	8,721	3,696
Merger related costs	36,379	4,777	21,923
Other operating expenses	138,852	111,575	88,879
TOTAL NON-INTEREST EXPENSE	461,112	392,229	312,379
INCOME BEFORE INCOME TAXES	302,432	266,071	154,923
Provision for income taxes	64,265	50,358	61,983
NET INCOME	238,167	215,713	92,940
Preferred stock dividends	339	0	0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 237,828	$ 215,713	$ 92,940
Basic earnings per share (in dollars per share)	$ 2.42	$ 2.34	$ 1.34	[1]
Diluted earnings per share (in dollars per share)	$ 2.41	$ 2.32	$ 1.33	[1]
Trust income
NON-INTEREST INCOME
NON-INTEREST INCOME	$ 25,040	$ 23,128	$ 18,570
Service charges on deposit accounts
NON-INTEREST INCOME
NON-INTEREST INCOME	44,782	42,508	36,079
Other service charges and fees
NON-INTEREST INCOME
NON-INTEREST INCOME	5,824	7,469	9,919
Mortgage lending income
NON-INTEREST INCOME
NON-INTEREST INCOME	15,017	9,230	9,708
SBA lending income
NON-INTEREST INCOME
NON-INTEREST INCOME	2,669	1,813	3,608
Debit and credit card fees
NON-INTEREST INCOME
NON-INTEREST INCOME	$ 29,289	$ 32,268	$ 34,258

[1] Per share amounts for the year ended 2017 have been restated to reflect the effect of the two-for-one stock split on February 8, 2018.