Earnings (Loss) Per Common Share (Earnings Per Share Computation) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net income (loss) attributable to Leucadia National Corporation common shareholders for basic earnings (loss) per share	$ (291,022)	$ 287,755	$ (94,206)	$ 244,090
Interest on 3 3/4% Convertible Notes		846		2,750
Net income (loss) attributable to Leucadia National Corporation common shareholders for diluted earnings (loss) per share	$ (291,022)	$ 288,601	$ (94,206)	$ 246,840
Denominator for basic earnings (loss) per share - weighted average shares	244,580	243,317	244,378	243,307
Stock options		6		33
Warrants
3 3/4 % Convertible Notes		4,249		4,249
Denominator for diluted earnings (loss) per share	244,580	247,572	244,378	247,589
Convertible Notes [Member]
Interest rate	3.75%	3.75%	3.75%	3.75%

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method.

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Other Comprehensive Income

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-Publisher AICPA

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Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Net Income

-URI http://asc.fasb.org/extlink&oid=6518256

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-Publisher FASB

-Name Accounting Standards Codification

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-Publisher SEC

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-Number 210

-Article 5

-Section 03

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+ Details

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References+ Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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+ Details