Earnings (Losses) Per Share (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Debt, Disclosure
0.94% senior exchangeable notes due 2011, par value outstanding	$ 389,000		$ 389,000		$ 275,326,000
Average number of options and warrants excluded from diluted earnings (losses) per share (in shares)	15,010,906	10,271,673	13,934,259	7,678,536
0.94% Senior Exchangeable Notes Due May 2011
Debt, Disclosure
Principal redeemed senior exchangeable notes			1,400,000,000
Interest rate on senior note due (as a percent)	0.94%		0.94%
0.94% senior exchangeable notes due 2011, par value outstanding	1,400,000,000		1,400,000,000
Purchase amount of 0.94% senior exchangeable notes due 2011			$ 1,200,000,000