Organization (Schedule Of Effect Of Restatement On Income And Shareholders' Equity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Market value reserve			$ (571,784)
Net income (loss)	234,419	2,739	(31,561)
Shareholders' equity (deficit) - beginning of period	(975,307)	571,784	(387,329)
Net income (loss) per share	$ 0.75	$ 0.01	$ (0.16)
Shareholders' equity (deficit) - end of period	(5,105,181)	(975,307)	571,784
As Originally Reported [Member]
Market value reserve			(571,784)
Market value recovery		(571,784)	571,784
Net income (loss)		574,523	(603,345)
Shareholders' equity (deficit) - beginning of period			(387,329)
Net income (loss) per share		$ 2.07	$ (3.07)
Shareholders' equity (deficit) - end of period		(975,307)
As Restated [Member]
Net income (loss)		2,739	(31,561)
Shareholders' equity (deficit) - beginning of period		571,784	(387,329)
Net income (loss) per share		$ 0.01	$ (0.16)
Shareholders' equity (deficit) - end of period		$ (975,307)	$ 571,784