v2.4.0.8

Share-Based Compensation - Market Stock Units - Additional Information (Detail) (Market Stock Units [Member], USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended	6 Months Ended	12 Months Ended
	Nov. 30, 2012	Dec. 31, 2012	Jun. 29, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period, tranche one	1 year
Vesting period, tranche two	2 years
Vesting period, tranche three	3 years
Potential payout range			100.00%
Potential payout adjustment ratio		2
Weighted average grant date fair value for the MSUs granted			$ 25.82
Unrecognized share-based compensation cost			$ 1.5
Unrecognized share-based compensation, period for recognition			1 year 3 months
Aggregate intrinsic value of stock option outstanding calculated using the closing price of common stock			$ 38.56
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential payout range	0.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential payout range	200.00%

X

- Definition

Percentage of potential payout.

+ References

No definition available.

+ Details

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X

- Definition

Potential payout adjustment ratio.

+ References

No definition available.

+ Details

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X

- Definition

Share based compensation arrangement by share based payment award, award vesting period tranche one.

+ References

No definition available.

+ Details

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X

- Definition

Share based compensation arrangement share based payment award, award vesting period tranche three.

+ References

No definition available.

+ Details

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X

- Definition

Share based compensation arrangement by share based payment award award vesting period tranche two.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
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X

- Definition

Share based compensation arrangement by share based payment award intrinsic value closing price.

+ References

No definition available.

+ Details

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Namespace Prefix:	syna_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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X

- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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X

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Details

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