Consolidated Condensed Statements Of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest and dividend income:
Interest and fees on loans	$ 84,213	$ 69,905	$ 238,687	$ 198,803
Interest and dividends on:
Obligations of U.S. Government, its agencies and other securities	6,326	7,691	20,240	22,204
Interest Income, Securities, State and Municipal	2,225	2,205	6,750	6,557
Other interest income	1,825	428	2,994	1,070
Total interest and dividend income	94,589	80,229	268,671	228,634
Interest on deposits:
Demand and savings deposits	9,649	6,412	25,553	13,809
Time deposits	4,694	3,328	12,828	8,765
Interest on borrowings:
Short-term borrowings	478	288	1,977	1,283
Long-term debt	2,667	2,525	7,585	7,509
Total interest expense	17,488	12,553	47,943	31,366
Net interest income	77,101	67,676	220,728	197,268
Provision for loan losses	1,967	2,940	6,384	4,586
Net interest income after provision for loan losses	75,134	64,736	214,344	192,682
Noninterest Income [Abstract]
Debit card fee income	5,313	4,352	14,909	12,736
Bank owned life insurance income	1,107	2,585	3,399	4,625
ATM Fees	482	500	1,382	1,534
OREO valuation adjustments	(41)	(77)	(123)	(398)
Gain on sale of OREO, net	(53)	(81)	(224)	4,093
Gain (Loss) on Sale of Investments	186	0	(421)	(2,271)
Gain on equity securities, net	3,335	89	5,309	4,633
Other components of net periodic benefit income	1,183	1,705	3,549	5,115
Other	2,658	2,466	5,493	5,164
Total other income	28,136	24,064	72,969	74,209
Other expense:
Salaries and employee benefits	30,713	27,229	88,611	76,652
Employee Benefits and Share-based Compensation	10,389	7,653	27,833	22,312
Occupancy expense	3,226	2,976	9,460	8,482
Furniture and equipment expense	4,177	3,807	12,713	11,969
Data processing fees	2,935	2,580	7,973	6,255
Professional fees and services	6,702	8,065	22,814	20,378
Marketing	1,604	1,364	4,285	3,767
Insurance	276	1,388	2,813	4,012
Communication	1,387	1,207	4,095	3,646
Excise and Sales Taxes	746	1,000	2,805	3,063
Amortization of Intangible Assets	741	289	1,732	289
Other expense	2,842	1,758	7,623	5,333
Total other expense	65,738	59,316	192,757	166,158
Income before income taxes	37,532	29,484	94,556	100,733
Income taxes	6,386	4,722	15,792	16,607
Net income	31,146	24,762	78,764	84,126
Net income available to common shareholders	$ 31,146	$ 24,762	$ 78,764	$ 84,126
Net income available to common shareholders
Basic	$ 1.90	$ 1.58	$ 4.86	$ 5.46
Diluted	$ 1.89	$ 1.56	$ 4.84	$ 5.41
Weighted average common shares outstanding
Basic	16,382,798	15,686,542	16,198,294	15,420,135
Diluted	16,475,741	15,832,734	16,287,695	15,560,666
Cash dividends declared	$ 1.01	$ 0.96	$ 3.23	$ 3.11
Fiduciary and Trust [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 6,842	$ 6,418	$ 20,500	$ 19,479
Deposit Account [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	2,864	2,861	8,078	8,609
Bank Servicing [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 4,260	$ 3,246	$ 11,118	$ 10,890