Value of input used to measure contingent consideration liability from business combination.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_MeasurementInputTypeAxis=lcii_WeightedAverageCostOfCapitalMember
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Commitments And Contingencies (Narrative) (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2015	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Long-term Purchase Commitment [Line Items]
Rent expense		$ 24.2	$ 15.2	$ 11.5
Furrion Limited
Long-term Purchase Commitment [Line Items]
Long-term purchase commitment, time period	6 years
Weighted Average Cost of Capital
Long-term Purchase Commitment [Line Items]
Percentage of weighted average cost of capital		0.121	0.136