Variable Interest Entities (Non-Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	$ 566.9	$ 389.2
Financial statement carrying amount, liabilities	4.8	0.2
Maximum Exposure to Loss	1,410.8	1,461.1
VIE Assets	10,229.3	12,516.0
Collateralized Loan Obligations [Member]
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	264.7	73.6
Financial statement carrying amount, liabilities	4.8	0.2
Maximum Exposure to Loss	930.0	458.1
VIE Assets	4,472.9	6,368.7
Consumer Loan Financing Vehicles [Member]
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	90.3	188.3
Financial statement carrying amount, liabilities	0.0	0.0
Maximum Exposure to Loss	219.6	845.8
VIE Assets	985.5	1,133.0
Related Party Private Equity Vehicles [Member]
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	37.6	39.3
Financial statement carrying amount, liabilities	0.0	0.0
Maximum Exposure to Loss	63.6	65.8
VIE Assets	155.6	168.2
Real Estate Investment Vehicles [Member]
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	90.3
Financial statement carrying amount, liabilities	0.0
Maximum Exposure to Loss	101.8
VIE Assets	85.6
Other Private Investment Vehicles [Member]
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	84.0	88.0
Financial statement carrying amount, liabilities	0.0	0.0
Maximum Exposure to Loss	95.8	91.4
VIE Assets	$ 4,529.7	$ 4,846.1

Variable Interest Entity Carrying Amount Of Assets Non Consolidated Vie

No definition available.

Name:	luk_VariableInterestEntityCarryingAmountOfAssetsNonConsolidatedVie
Namespace Prefix:	luk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph b
-URI http://asc.fasb.org/extlink&oid=64801991&loc=d3e5728-111685

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64801991&loc=d3e5747-111685

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

+ Details

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Period Type:	instant

- Definition

Carrying amount of the liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

+ Details

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- Details

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- Details

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