Consolidated Statements Of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 58,536	$ (187,768)	$ 358,825	$ 299,467
Other comprehensive income (loss):
Net unrealized holding gains (losses) on investments arising during the period, net of income tax provision (benefit) of $(28,124), $(71,081), $(23,788) and $(80,282)	(50,653)	(128,028)	(42,844)	(144,599)
Less: reclassification adjustment for net (gains) losses included in net income (loss), net of income tax provision (benefit) of $3,027, $21, $117,170 and $123,812	(5,453)	(36)	(211,037)	(223,000)
Net change in unrealized holding gains (losses) on investments, net of income tax provision (benefit) of $(31,151), $(71,102), $(140,958) and $(204,094)	(56,106)	(128,064)	(253,881)	(367,599)
Net unrealized foreign exchange gains (losses) arising during the period, net of income tax provision (benefit) of $258, $(1,431), $(680) and $(2,501)	(11,003)	(2,579)	(12,692)	(4,506)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income (loss), net of income tax provision (benefit) of $0, $0, $0 and $0
Net change in unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $258, $(1,431), $(680) and $(2,501)	(11,003)	(2,579)	(12,692)	(4,506)
Net unrealized gains (losses) on derivatives arising during the period, net of income tax provision (benefit) of $(6), $4, $(4) and $(85)	(11)	7	(6)	(153)
Less: reclassification adjustment for derivative (gains) losses included in net income (loss), net of income tax provision (benefit) of $0, $0, $0 and $0
Net change in unrealized derivative gains (losses), net of income tax provision (benefit) of $(6), $4, $(4) and $(85)	(11)	7	(6)	(153)
Net pension and postretirement gains (losses) arising during the period, net of income tax provision (benefit) of $0, $0, $0 and $0
Less: reclassification adjustment for pension and postretirement (gains) losses included in net income (loss), net of income tax provision (benefit) of $(666), $(433), $(1,332) and $(866)	1,200	778	2,400	1,558
Net change in pension liability and postretirement benefits, net of income tax provision (benefit) of $666, $433, $1,332 and $866	1,200	778	2,400	1,558
Other comprehensive loss, net of income taxes	(65,920)	(129,858)	(264,179)	(370,700)
Comprehensive income (loss)	(7,384)	(317,626)	94,646	(71,233)
Comprehensive loss attributable to the noncontrolling interest	729	297	1,351	95
Comprehensive income attributable to the redeemable noncontrolling interests	(5,638)	(9,780)	(1,107)	(5,936)
Preferred stock dividends	(1,015)		(1,354)
Comprehensive income (loss) attributable to Leucadia National Corporation common shareholders	$ (13,308)	$ (327,109)	$ 93,536	$ (77,074)