Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Schedule Of Financial Assets And Liabilities Measured At Fair Value) (Details)

v2.4.1.9
Fair Value Measurements (Schedule Of Financial Assets And Liabilities Measured At Fair Value) (Details) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents $ 1,073,000us-gaap_CashAndCashEquivalentsFairValueDisclosure $ 5,992,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
Current Liabilities, fair value   (559,000)us-gaap_AccruedLiabilitiesFairValueDisclosure
Assets (Liabilities) Net, fair value 17,216,000us-gaap_FairValueNetAssetLiability 15,096,000us-gaap_FairValueNetAssetLiability
Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 1,073,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
5,752,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Assets (Liabilities) Net, fair value 1,073,000us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
5,752,000us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   240,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Assets (Liabilities) Net, fair value 16,143,000us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
9,903,000us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Current Liabilities, fair value   (559,000)us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
Assets (Liabilities) Net, fair value   (559,000)us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
Money Market Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 1,073,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_MoneyMarketFundsMember
5,752,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_MoneyMarketFundsMember
Money Market Funds [Member] | Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 1,073,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
5,752,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Certificates Of Deposit [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   240,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
Certificates Of Deposit [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   240,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Accrued Consideration [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Current Liabilities, fair value   (559,000)us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_AccruedConsiderationMember
Accrued Consideration [Member] | Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Current Liabilities, fair value   (558,801)us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_AccruedConsiderationMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
Short-Term Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 4,603,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
5,742,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
Short-Term Investments [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 4,603,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
5,742,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Short-Term Investments [Member] | Certificates Of Deposit [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 1,920,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
2,583,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
Short-Term Investments [Member] | Certificates Of Deposit [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 1,920,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
2,583,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Short-Term Investments [Member] | Corporate Notes/Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 2,683,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
3,159,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
Short-Term Investments [Member] | Corporate Notes/Bonds [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 2,683,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
3,159,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Long Term Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 11,540,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
3,921,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
Long Term Investments [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 11,540,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
3,921,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Long Term Investments [Member] | Certificates Of Deposit [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 5,463,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
1,197,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
Long Term Investments [Member] | Certificates Of Deposit [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 5,463,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
1,197,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= us-gaap_CertificatesOfDepositMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Long Term Investments [Member] | Corporate Notes/Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 6,077,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
2,724,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
Long Term Investments [Member] | Corporate Notes/Bonds [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments $ 6,077,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
$ 2,724,000us-gaap_InvestmentsFairValueDisclosure
/ jcs_AdditionalInvestmentInformationAxis
= jcs_LongTermInvestmentsMember
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= jcs_CorporateNotesAndBondsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member