XML 285 R90.htm IDEA: XBRL DOCUMENT v3.10.0.1

Stock Plans - Option Vesting (Details) - Stock options	12 Months Ended
	Dec. 31, 2017
2000 Plan | First Anniversary
Stockholder's Equity
Percentage of awards vesting	25.00%
2000 Plan | Monthly vesting after first anniversary
Stockholder's Equity
Percentage of awards vesting	2.10%
2006 Plan | First Anniversary
Stockholder's Equity
Percentage of awards vesting	25.00%
2006 Plan | Monthly vesting after first anniversary
Stockholder's Equity
Percentage of awards vesting	2.10%
2015 Plan | First Anniversary
Stockholder's Equity
Percentage of awards vesting	25.00%
2015 Plan | Monthly vesting after first anniversary
Stockholder's Equity
Percentage of awards vesting	2.10%
2010 Plan | Second Anniversary
Stockholder's Equity
Percentage of awards vesting	50.00%
2010 Plan | Monthly vesting after second anniversary
Stockholder's Equity
Percentage of awards vesting	2.10%
2000 and 2006 Stock incentive plans | First Anniversary
Stockholder's Equity
Percentage of awards vesting	25.00%
2000 and 2006 Stock incentive plans | Monthly vesting after first anniversary
Stockholder's Equity
Percentage of awards vesting	2.10%

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

X

- Definition

Percentage of vesting of share-based compensation awards.

+ 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 (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

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

X

- Details

Name:	us-gaap_PlanNameAxis=sncr_StockIncentive2000PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

Name:	us-gaap_PlanNameAxis=sncr_StockIncentive2006PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PlanNameAxis=sncr_EquityIncentivePlan2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PlanNameAxis=sncr_StockIncentive2010PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

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

X

- Details

Name:	us-gaap_PlanNameAxis=sncr_StockIncentive2000And2006PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: