Short-Term Borrowings and Long-Term Debt (Schedule of Debt) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Long-term debt
Long-term debt outstanding at end of period	$ 40,370	$ 20,436
Weighted average rate on outstanding long-term debt	2.31%	2.84%
Maximum outstanding long-term debt of any month end	$ 55,392	$ 55,493
Average outstanding long-term debt	$ 32,702	$ 35,684
Approximate average rate paid on long-term debt	2.27%	2.39%
Short-term borrowings
Short-term borrowings outstanding at end of period	$ 5,000	$ 35,000
Weighted average rate on short-term borrowings	1.81%	2.51%
Maximum outstanding short-term borrowings at any month end	$ 59,500	$ 74,000
Average outstanding short-term borrowings	$ 30,965	$ 42,286
Approximate average rate paid on short-term borrowings	2.50%	1.81%