XML 63 R45.htm IDEA: XBRL DOCUMENT v3.7.0.1

Auction Rate Securities - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Jun. 24, 2017	Jun. 25, 2016	Jun. 27, 2015
Schedule of Available-for-sale Securities [Line Items]
Auction Rate Securities with fair value having no stated maturity	$ 1.5
Auction Rate Securities Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
ARS investments redeemed at par value	7.5	$ 6.6	$ 4.9
Original Cost Basis		$ 12.5
Auction Rate Securities Investments [Member] | Below Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Original Cost Basis	$ 5.0

X

- Definition

Auction rate securities with fair value having no stated maturity.

+ References

No definition available.

+ Details

Name:	syna_AuctionRateSecuritiesWithFairValueHavingNoStatedMaturity
Namespace Prefix:	syna_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Investment securities at original cost basis.

+ References

No definition available.

+ Details

Name:	syna_InvestmentSecuritiesAtOriginalCostBasis
Namespace Prefix:	syna_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The aggregate value of securities held, which were categorized neither as trading nor held-to-maturity, for which the interest rate reset through an auction process, that failed to be liquidated through auction, and which were sold at par value during the period.

+ References

No definition available.

+ Details

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

X

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

X

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_AuctionRateSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=syna_BelowInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: