Investments In Associated Companies (Schedule Of Investments In Associated Companies) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Investments In Associated Companies [Line Items]
Equity method investments	$ 807,474	[1]	$ 793,766	[1]
Investments in associated companies carried at fair value	1,077,172		1,198,029
Investments in associated companies	1,884,646		1,991,795
JHYH [Member]
Investments In Associated Companies [Line Items]
Equity method investments	351,835	[1]	323,262	[1]
Berkadia [Member]
Investments In Associated Companies [Line Items]
Equity method investments	172,942	[1]	193,496	[1]
Garcadia [Member]
Investments In Associated Companies [Line Items]
Equity method investments	82,425	[1]	72,303	[1]
HomeFed Corporation [Member]
Investments In Associated Companies [Line Items]
Equity method investments	49,384	[1]	47,493	[1]
Brooklyn Renaissance Plaza [Member]
Investments In Associated Companies [Line Items]
Equity method investments	30,332	[1]	31,931	[1]
Linkem
Investments In Associated Companies [Line Items]
Equity method investments	86,424	[1]	86,332	[1]
Associated Companies Other [Member]
Investments In Associated Companies [Line Items]
Equity method investments	34,132	[1]	38,949	[1]
Jefferies Group Inc [Member]
Investments In Associated Companies [Line Items]
Investments in associated companies carried at fair value	1,077,172		797,583
Mueller [Member]
Investments In Associated Companies [Line Items]
Investments in associated companies carried at fair value			$ 400,446

[1] Investments accounted for under the equity method of accounting are initially recorded at their original cost and subsequently increased for the Company's share of the investees' earnings, decreased for the Company's share of the investees' losses, reduced for dividends received and impairment charges recorded, if any, and increased for any additional investment of capital.