Consolidated Balance Sheets (Parenthetical) (USD $) | Sep. 30, 2011 | Dec. 31, 2010 |
|---|---|---|
| Consolidated Balance Sheets [Abstract] | ||
| Common stock, par value | $ 1.25 | $ 1.25 |
| Common stock, shares authorized | 36,000,000 | 36,000,000 |
| Common stock, shares issued | 18,496,680 | 18,496,680 |
| Treasury stock, shares at cost | 7,151,153 | 7,029,575 |