Investment In Unconsolidated Affiliates (Summarized Statements Of Operations For Unconsolidated Investments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Investment In Unconsolidated Affiliates [Line Items]
Total revenues	$ 19,820	$ 26,745	$ 25,284	$ 73,436	$ 37,100	$ 27,105	$ 22,035	$ 13,300	$ 145,285	$ 99,540	$ 138,257
Total expenses									532,092	151,094	347,612
Net loss									(330,308)	(35,905)	(130,848)
Statements Of Operations [Member]
Investment In Unconsolidated Affiliates [Line Items]
Total revenues									11	14	514
Total expenses									1,042	2,847	2,122
Net loss									$ (1,031)	$ (2,833)	$ (1,608)