CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest income:
Interest and fees on loans	$ 423,152	$ 393,477	$ 316,550
Interest on loans held for sale	1,736	1,686	1,607
Interest on deposits with banks	725	446	2,129
Interest and dividends on investment securities:
Taxable for federal income taxes	16,118	22,136	21,739
Exempt from federal income taxes	8,552	5,814	5,834
Interest on federal funds sold	1	1	10
Total interest income	450,284	423,560	347,869
Interest expense:
Interest on deposits	15,022	41,651	61,681
Interest on retail repurchase agreements and federal funds purchased	182	1,965	1,161
Interest on advances from FHLB	2,649	6,593	16,578
Interest on subordinated debt	7,913	10,192	3,141
Total interest expense	25,766	60,401	82,561
Net interest income	424,518	363,159	265,308
Provision/ (credit)	(45,556)	85,669	4,684
Net interest income after provision/ (credit) for credit losses	470,074	277,490	260,624
Non-interest income:
Investment securities gains	212	467	77
Insurance agency commissions	7,017	6,795	6,612
Income from bank owned life insurance	3,022	2,867	3,165
Other income	15,317	9,221	8,780
Total non-interest income	102,055	102,716	71,322
Non-interest expense:
Salaries and employee benefits	155,830	134,471	103,950
Occupancy expense of premises	22,405	21,383	19,470
Equipment expenses	12,883	12,224	10,720
Marketing	4,730	4,281	4,456
Outside data services	8,983	8,759	7,567
FDIC insurance	4,294	4,727	2,260
Amortization of intangible assets	6,600	6,221	1,946
Merger and acquisition expense	45	25,174	1,312
Professional fees and services	10,308	7,939	6,978
Other expenses	34,392	30,603	20,426
Total non-interest expense	260,470	255,782	179,085
Income before income tax expense	311,659	124,424	152,861
Income tax expense	76,552	27,471	36,428
Net income	$ 235,107	$ 96,953	$ 116,433
Earnings Per Share [Abstract]
Basic net income per common share (in dollars per share)	$ 5.00	$ 2.19	$ 3.25
Diluted net income per common share (in dollars per share)	4.98	2.18	3.25
Dividends declared per share (in dollars per share)	$ 1.28	$ 1.20	$ 1.18
Service charges on deposit accounts
Non-interest income:
Fees and commissions, mortgage banking and servicing	$ 8,241	$ 7,066	$ 9,692
Mortgage banking activities
Non-interest income:
Fees and commissions, mortgage banking and servicing	24,509	40,058	14,711
Wealth management income
Non-interest income:
Fees and commissions, mortgage banking and servicing	36,841	30,570	22,669
Bank card fees
Non-interest income:
Fees and commissions, mortgage banking and servicing	$ 6,896	$ 5,672	$ 5,616