Unaudited Condensed Consolidated Balance Sheet (Parenthetical) Statement (USD $) | Sep. 30, 2011 | Dec. 31, 2010 |
|---|---|---|
| Common stock, par value | $ 1 | $ 1 |
| Common stock, shares authorized | 500,000,000 | 500,000,000 |
| Common stock, shares issued | 243,767,641 | 242,019,650 |
| Common stock, shares outstanding | 227,998,397 | 241,035,250 |