Earnings Per Share (Calculation of Basic and Diluted EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Earnings Per Share [Abstract] | ||||
| Net income | $ 13,236 | $ 14,756 | $ 32,457 | $ 31,825 |
| Average Common Shares: | ||||
| Basic (weighted-average outstanding shares) | 11,460 | 11,380 | 11,424 | 11,337 |
| Dilutive potential common shares from stock options, shares | 135 | 116 | 127 | 140 |
| Diluted (weighted-average outstanding shares) | 11,595 | 11,496 | 11,551 | 11,477 |
| Basic earnings per share (in dollars per share) | $ 1.15 | $ 1.30 | $ 2.84 | $ 2.81 |
| Diluted earnings per share (in dollars per share) | $ 1.14 | $ 1.28 | $ 2.81 | $ 2.77 |