Fair Value of Financial Instruments (Fair Values of Financial Assets and Liabilities on Balance Sheets) (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Financial assets:
Cash and cash equivalents	$ 66,344,000	$ 71,115,000
Investment securities	857,163,000	868,955,000
Loans (1)	2,083,649,000	2,018,482,000
Financial liabilities:
Deposits	2,537,078,000	2,540,131,000
Short-term borrowings	173,512,000	160,386,000
Long-term borrowings	152,610,000	117,299,000
Cash flow hedges (2)	288,000	0
Carrying Amount
Financial assets:
Cash and cash equivalents	66,344,000	71,115,000
Investment securities	855,326,000	868,830,000
Loans (1)	2,115,175,000	2,057,614,000
Financial liabilities:
Deposits	2,532,971,000	2,535,944,000
Short-term borrowings	173,512,000	160,386,000
Long-term borrowings	147,980,000	113,670,000
Cash flow hedges (2)	$ 288	$ 0