Parent Only Financial Information Parent Only Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Interest and Dividends on Investments	$ 109,759	$ 96,503	$ 84,657
Other Operating Income	1,477	1,324	927
Interest Expense	21,710	12,485	7,006
Other Operating Expense	10,430	9,076	8,752
Provision for Income Taxes	9,600	9,026	10,529
Net Income	37,475	36,279	29,326
Parent Company
Condensed Financial Statements, Captions [Line Items]
Dividends from Bank Subsidiaries	14,100	13,300	12,800
Interest and Dividends on Investments	49	48	53
Other Operating Income	1,006	907	677
Total Income	15,155	14,255	13,530
Interest Expense	1,024	976	781
Other Operating Expense	875	1,175	958
Total Expense	1,899	2,151	1,739
Income Before Income Tax Benefit and Equity in Undistributed Net Income of Subsidiaries	13,256	12,104	11,791
Provision for Income Taxes	466	686	225
Equity in Undistributed Net Income of Subsidiaries	23,753	23,489	17,310
Net Income	$ 37,475	$ 36,279	$ 29,326