UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.2	$ 0.2
Preferred stock, shares authorized	20,000,000	20,000,000
Common stock, par value (in dollars per share)	$ 0.2	$ 0.2
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	256,518,000	258,760,000