Investments In Associated Companies (Schedule Of Income (Losses) Related To Associated Companies) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	$ 420,008	$ (612,362)	$ 375,021
Income tax (expense) benefit	(143,729)	218,321	5,745
Income (losses) related to associated companies, net of taxes	276,279	(394,041)	380,766
Jefferies Group Inc [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	301,341	(668,282)	157,873
Mueller [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	30,018	(6,093)
ACF [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes			183,572
Berkadia [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	38,026	29,033	16,166
Garcadia [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	31,738	19,996	14,424
JHYH [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	33,938	11,211	20,053
Linkem
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	(18,890)	(2,243)
HomeFed Corporation [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	1,891	1,410	1,108
Las Cruces [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes			(16,159)
Other [Member]
Investments In Associated Companies [Line Items]
Income (losses) related to associated companies before income taxes	$ 1,946	$ 2,606	$ (2,016)