Delivery of targeted shares in percentage delivered by entity.

No definition available.

Name:	syna_DeliveryOfTargetedSharesInPercentageDeliveredByEntity
Namespace Prefix:	syna_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of potential payout.

+ References

No definition available.

+ Details

Name:	syna_PercentageOfPotentialPayout
Namespace Prefix:	syna_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	syna_ShareBasedCompensationArrangementByShareBasedPaymentAwardIntrinsicValueClosingPrice
Namespace Prefix:	syna_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

TSR decrease in percentage points.

+ References

No definition available.

+ Details

Name:	syna_TsrDecreaseInPercentagePoints
Namespace Prefix:	syna_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Tsr Percentile relative to Russell 2000 index.

+ References

No definition available.

+ Details

Name:	syna_TsrPercentileRelativeToRussellTwoThousandIndex
Namespace Prefix:	syna_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of decrease to equity for grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

No definition available.

+ Details

Name:	us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
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

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=syna_MarketStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=syna_FiscalTwoThousandTwentyMSUGrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=syna_FiscalTwoThousandNineteenMSUGrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=syna_FiscalTwoThousandTwentyOneMSUGrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=syna_October2020MSUGrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=syna_ThreeYearPerformanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=syna_FourYearPerformanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=syna_ShareBasedCompensationAwardTrancheFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=syna_TSRPercentileBelow25Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=syna_TSRPercentileAbove75Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=syna_TSRPercentile50Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Share-Based Compensation - Market Stock Units - Additional Information (Detail) - Market stock units outstanding [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jun. 25, 2022	Jun. 26, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of the underlying awards	3 years
Earlier Options vesting period	3 years
Percentage Of Potential Payout	100.00%
Shares withheld to meet statutory minimum tax withholding requirements	105,719
Shares valued withheld to meet statutory minimum tax withholding requirements	$ 18.3
Closing price of common stock used to calculate Aggregate intrinsic value of stock option outstanding	$ 128.78
Unrecognized share-based compensation cost	$ 14.9
Unrecognized share-based compensation, period for recognition	8 months 19 days
Fiscal 2020 MSU Grants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
SOX Index TSR percentage points	226.12%
Percentage of targeted shares, MSU grants	100.00%
Fiscal 2019 MSU Grants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
SOX Index TSR percentage points	185.21%
Percentage of targeted shares, MSU grants	200.00%
Fiscal 2021 MSU Grants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
TSR percentile relative to Russell two thousand index	76
October2020 M S U Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of targeted shares, MSU grants	200.00%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	0.00%
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	200.00%
Share-based Compensation Award, First Tranche [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of the underlying awards	1 year
Earlier Options vesting period	1 year
Share-based Compensation Award, First Tranche [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	200.00%
Share-based Compensation Award, First Tranche [Member] \| Maximum [Member] \| Three-Year Performance Period [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout		100.00%
Share-based Compensation Award, First Tranche [Member] \| Maximum [Member] \| Four-Year Performance Period [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	100.00%
Share-based Compensation Award, Second Tranche [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of the underlying awards	2 years
Earlier Options vesting period	2 years
Share-based Compensation Award, Second Tranche [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	200.00%
Share-based Compensation Award, Second Tranche [Member] \| Maximum [Member] \| Three-Year Performance Period [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	100.00%
Share-based Compensation Award, Second Tranche [Member] \| Maximum [Member] \| Four-Year Performance Period [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	100.00%
Share-based Compensation Award, Third Tranche [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of the underlying awards	3 years
Earlier Options vesting period	3 years
Share-based Compensation Award, Third Tranche [Member] \| Maximum [Member] \| Four-Year Performance Period [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	100.00%
Share-based Compensation Award, Fourth Tranche [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of the underlying awards	4 years
Earlier Options vesting period	4 years
TSR Percentile Below 25 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	0.00%
TSR Percentile Above 75 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	200.00%
TSR Percentile 50 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage Of Potential Payout	100.00%