Consolidated Condensed Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Amortized Cost	$ 980,047,000	$ 1,187,499,000
Preferred Stock, Shares Authorized	200,000	200,000
Preferred Stock, Shares Issued	0	0
Common Stock, Shares Authorized	20,000,000
Common Stock, Shares, Issued	17,623,179	17,623,199
Treasury Stock, Shares	1,322,416	1,276,757
Assets:
Cash and due from banks	$ 110,774,000	$ 135,567,000
Money market instruments	135,935,000	24,389,000
Cash and cash equivalents	246,709,000	159,956,000
Marketable Securities [Abstract]
Debt Securities, Available-for-sale, Current	1,032,814,000	1,209,701,000
Other Investments and Securities, at Cost	64,784,000	69,806,000
Total investment securities	1,097,598,000	1,279,507,000
Loan balance	7,278,546,000	6,501,404,000
Allowance for loan losses	(87,038,000)	(56,679,000)
Net loans	7,191,508,000	6,444,725,000
Bank owned life insurance	215,214,000	212,529,000
Prepaid assets	114,548,000	101,990,000
Goodwill	159,595,000	159,595,000
Other intangible assets	9,785,000	11,523,000
Premises and equipment, net	85,287,000	73,322,000
Affordable housing tax credit investments	57,583,000	53,070,000
Other real estate owned	836,000	4,029,000
Interest Receivable	26,492,000	24,217,000
Operating Lease, Right-of-Use Asset	18,011,000	13,714,000
Mortgage loan servicing rights	11,040,000	10,070,000
Other	5,800,000	10,130,000
Total assets	9,240,006,000	8,558,377,000
Liabilities and Shareholders' Equity:
Noninterest bearing	2,579,335,000	1,959,935,000
Interest bearing	4,896,494,000	5,092,677,000
Total deposits	7,475,829,000	7,052,612,000
Short-term borrowings	320,435,000	230,657,000
Long-term debt	135,000,000	192,500,000
Subordinated debentures and notes	187,668,000	15,000,000
Unfunded commitments in affordable housing tax credit investments	31,593,000	25,894,000
Operating Lease, Liability	19,127,000	14,482,000
Accrued interest payable	2,938,000	2,927,000
Other	50,420,000	55,291,000
Total liabilities	8,223,010,000	7,589,363,000
Shareholders' equity:
Preferred shares (200,000 shares authorized; 0 shares issued)	0	0
Common shares (No par value; 20,000,000 shares authorized; 17,623,179 shares issued at September 30, 2020 and 17,623,199 shares issued at December 31, 2019)	458,440,000	459,389,000
Retained earnings	676,465,000	646,847,000
Treasury shares (1,322,416 shares at September 30, 2020 and 1,276,757 shares at December 31, 2019)	(132,109,000)	(127,633,000)
Accumulated other comprehensive income (loss), net of taxes	14,200,000	(9,589,000)
Total shareholders' equity	1,016,996,000	969,014,000
Total liabilities and shareholders' equity	$ 9,240,006,000	$ 8,558,377,000