Short-Term Borrowings and Long-Term Debt (Schedule of Debt) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Long-term debt | |||
| Long-term debt outstanding at end of period | $ 55,617 | $ 74,672 | $ 70,476 |
| Weighted average rate on outstanding long-term debt | 2.47% | 2.35% | 2.49% |
| Maximum outstanding long-term debt of any month end | $ 74,668 | $ 75,471 | $ 70,519 |
| Average outstanding long-term debt | $ 68,924 | $ 74,714 | $ 68,996 |
| Approximate average rate paid on long-term debt | 2.26% | 2.39% | 2.53% |
| Short-term borrowings | |||
| Short-term borrowings outstanding at end of period | $ 36,000 | $ 2,000 | |
| Weighted average rate on short-term borrowings | 0.38% | 0.31% | 0.00% |
| Maximum outstanding short-term borrowings at any month end | $ 36,000 | $ 15,000 | $ 24,000 |
| Average outstanding short-term borrowings | $ 13,463 | $ 4,344 | $ 4,278 |
| Approximate average rate paid on short-term borrowings | 0.27% | 0.28% | 0.33% |