Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest and dividend income
Loans, including fees	$ 223,750	$ 186,117	$ 146,794
Investments
Taxable securities	39,810	33,997	27,772
Tax exempt securities	4,002	4,345	4,165
Dividends	1,285	1,705	1,324
Interest bearing cash at Federal Reserve and other banks	3,597	2,054	1,347
Total interest and dividend income	272,444	228,218	181,402
Interest expense
Deposits	11,716	6,996	3,958
Other borrowings	387	2,745	305
Junior subordinated debt	3,272	3,131	2,535
Total interest expense	15,375	12,872	6,798
Net interest income	257,069	215,346	174,604
Provision for (benefit from) loan losses	(1,690)	2,583	89
Net interest income after provision for (benefit from) loan losses	258,759	212,763	174,515
Noninterest income
Service charges and fees	40,417	38,460	37,423
Commissions on sale of non-deposit investment products	2,877	3,151	2,729
Increase in cash value of life insurance	3,029	2,718	2,685
Gain on sale of loans	3,282	2,371	3,109
Gain on sale of investment securities	110	207	961
Other	3,805	2,154	2,545
Total noninterest income	53,520	49,061	49,452
Noninterest expense
Salaries and related benefits	106,065	93,942	82,930
Other	79,392	74,530	63,525
Total noninterest expense	185,457	168,472	146,455
Income before income taxes	126,822	93,352	77,512
Provision for income taxes	34,750	25,032	36,958
Net income	$ 92,072	$ 68,320	$ 40,554
Earnings per share
Basic	$ 3.02	$ 2.57	$ 1.77
Diluted	$ 3.00	$ 2.54	$ 1.74