CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Interest and fees on loans
Taxable		$ 181,451	$ 150,295		$ 124,830
Tax exempt		814	729		462
Interest and dividends on securities
Taxable		9,717	9,218		9,421
Tax exempt		6,079	5,102		3,885
Interest on short-term investments		909	354		353
Total interest income		198,970	165,698		138,951
Interest on deposits		44,913	27,026		18,944
Interest on borrowings
Short-term		1,143	1,446		352
Long-term		1,643	1,334		1,174
Total interest expense		47,699	29,806		20,470
NET INTEREST INCOME		151,271	135,892		118,481
Provision for loan losses		6,400	3,000		1,150
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES		144,871	132,892		117,331
NONINTEREST INCOME
Wealth advisory fees		6,344	5,481	[1]	4,805	[1]
Investment brokerage fees		1,458	1,273	[1]	1,010	[1]
Service charges on deposit accounts		15,831	13,696		12,013
Loan and service fees		9,291	7,900		7,681
Merchant and interchange fee income		2,461	2,279	[1]	2,098	[1]
Bank owned life insurance income	[2]	1,244	1,768	[1]	1,392	[1]
Other income		2,381	2,598	[1]	2,213	[1]
Mortgage banking income	[2]	1,150	982	[1]	1,586	[1]
Net securities gains (losses)	[2]	(50)	32	[1]	66	[1]
Total noninterest income		40,110	36,009	[1]	32,864	[1]
NONINTEREST EXPENSE
Salaries and employee benefits		48,353	45,306		41,656
Net occupancy expense		5,149	4,595		4,266
Equipment costs		5,243	4,629		3,850
Data processing fees and supplies		9,685	8,233		8,148
Corporate and business development		5,066	4,744		3,328
FDIC insurance and other regulatory fees		1,701	1,798		2,001
Professional fees		3,798	3,574		3,208
Other expense		7,042	6,388		6,521
Total noninterest expense		86,037	79,267		72,978
INCOME BEFORE INCOME TAX EXPENSE		98,944	89,634		77,217
Income tax expense		18,533	32,304		25,133
NET INCOME		$ 80,411	$ 57,330		$ 52,084
BASIC WEIGHTED AVERAGE COMMON SHARES		25,288,533	25,181,208		25,056,095
BASIC EARNINGS PER COMMON SHARE		$ 3.18	$ 2.28		$ 2.08
DILUTED WEIGHTED AVERAGE COMMON SHARES		25,727,831	25,663,381		25,460,727
DILUTED EARNINGS PER COMMON SHARE		$ 3.13	$ 2.23		$ 2.05

[1] The Company elected the modified retrospective approach of adoption; therefore, prior period balances are presented under legacy GAAP and may not be comparable to current year presentation. As a result of this new standard, the only revenue streams with changes in reporting in the current periods compared to the prior year comparable periods are loan and service fees and other income.

[2] Not within scope of ASC 606