Revenue from Contracts with Customers - Additional Information (Detail)	3 Months Ended
Mar. 31, 2019
Disaggregation Of Revenue [Line Items]
Revenue, performance obligation, payment terms description	The Company usually expects payment within 30 to 90 days from the invoice date (fulfillment of performance obligations or per contract terms).
Practical expedient, remaining performance obligation original expected length	true
Minimum [Member]
Disaggregation Of Revenue [Line Items]
Revenue, performance obligation, payment terms	30 days
Maximum [Member]
Disaggregation Of Revenue [Line Items]
Revenue, performance obligation, payment terms	90 days

Revenue, performance obligation, payment terms.

No definition available.

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Namespace Prefix:	sync_
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

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

- Definition

Description of payment terms in contract with customer. Includes, but is not limited to, timing of payment, existence of financing component, variability of consideration and constraint on variable consideration.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130554-203045

+ Details

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

- Definition

Indicates (true false) whether optional exemption was applied not to disclose amount of transaction price allocated to and explanation of expected timing of revenue recognition for remaining performance obligation, when contract has expected duration of one year or less or right to consideration corresponds directly to performance completed.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130558-203045

+ Details

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Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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