v2.4.0.8

Marketable Securities (Additional Information) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013		Dec. 29, 2012
Available-for-sale Securities, Gross Unrealized Loss, Total	$ 4,377	[1]	$ 6,884	[1]
Change In Treasury Bond Yield Description	The decline was due to increases in the 10 Year Treasury Bond Yield during 2013, which caused market valuations of securities in our investment portfolios to decline.
Held To Maturity Securities Continuous Unrealized Loss Position Percentage	50.00%
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	1,153,765
Available For Sale Securities Continuous Unrealized Loss Position Amortization Cost	$ 1,215,498
[1] Represents unrealized losses on investment securities that have not been determined to be other-than-temporarily impaired.

X

- Definition

This item represents the aggregate amortization cost of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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X

- Definition

Represent the total details of The majority of the decline due to an unusually change and causing market valuations of many securities.

+ References

No definition available.

+ Details

Name:	grmn_ChangeInTreasuryBondYieldDescription
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Data Type:	xbrli:stringItemType
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X

- Definition

This item represents the percentage of securities categorized as held-to-maturity which are in an unrealized loss position.

+ References

No definition available.

+ Details

Name:	grmn_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionPercentage
Namespace Prefix:	grmn_
Data Type:	num:percentItemType
Balance Type:	na
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X

- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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Period Type:	instant

X

- Definition

Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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