Represents the maximum useful life of capitalized software development costs.

No definition available.

Name:	sncr_CapitalizedComputerSoftwareUsefulLifeMaximum
Namespace Prefix:	sncr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the minimum useful life of capitalized software development costs.

+ References

No definition available.

+ Details

Name:	sncr_CapitalizedComputerSoftwareUsefulLifeMinimum
Namespace Prefix:	sncr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum original maturity period of investments classified as cash equivalents.

+ References

No definition available.

+ Details

Name:	sncr_CashEquivalentsOriginalMaturityPeriodMaximum
Namespace Prefix:	sncr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of excess cash in high-quality financial instruments that may be deposited at any given time with one financial institution.

+ References

No definition available.

+ Details

Name:	sncr_ConcentrationRiskCreditRiskFinancialInstrumentDenominationsForExcessCashDeposits
Namespace Prefix:	sncr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the maturity period of fixed income investments under marketable securities.

+ References

No definition available.

+ Details

Name:	sncr_MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod
Namespace Prefix:	sncr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maturity period of marketable securities to be classified as long-term.

+ References

No definition available.

+ Details

Name:	sncr_MarketableSecuritiesMaturityPeriod
Namespace Prefix:	sncr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of top customers of the reporting entity.

+ References

No definition available.

+ Details

Name:	sncr_NumberOfTopCustomers
Namespace Prefix:	sncr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

For each income statement presented, the amount charged to expense for amortization of capitalized computer software costs.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 86

-Paragraph 11

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Implementation Guide (Q and A)

-Number FAS86

-Paragraph 18

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

+ Details

Name:	us-gaap_CapitalizedComputerSoftwareAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The gross amount of capitalized computer software costs as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

+ Details

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

- Details

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

- Details

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

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13537-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13531-108611

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

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

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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

- Details

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

Summary of Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash and Cash Equivalents
Maximum time period for which an investment is considered a cash equivalent	3 months
Research and Development
Unamortized software development costs	2,000,000	3,100,000
Amortization expenses of capital software development costs	1,300,000	567,000
Software Development
Research and Development
Estimated minimum useful life of software development costs	3 years
Estimated maximum useful life of software development costs	5 years
Minimum
Concentration of Credit Risk
Interest bearing accounts	250,000
Marketable Securities
Maturity period of fixed income investments	3 months
Maturity period of marketable securities to be classified as long-term	12 months
Property and Equipment
Estimated useful life of property and equipment and leasehold improvements	3 years
Maximum
Property and Equipment
Estimated useful life of property and equipment and leasehold improvements	5 years
Customer concentration
Concentration of Credit Risk
Number of top customers	5
Net Revenues \| Customer concentration \| Top five customers
Concentration of Credit Risk
Percentage of concentration risk	76.00%	86.00%	83.00%
Net Revenues \| Customer concentration \| AT&T Inc.
Concentration of Credit Risk
Percentage of concentration risk	46.00%	51.00%
Net Revenues \| Customer concentration \| Verizon Wireless \| Minimum
Concentration of Credit Risk
Percentage of concentration risk	10.00%
Accounts receivable \| Customer concentration \| Top five customers
Concentration of Credit Risk
Percentage of concentration risk	67.00%	80.00%